14.0.0-1

Remove broken link to terminated cattaz website

.bowerrc

@@ -1,3 +0,0 @@
-{
- "directory": "../"
-}

.circleci/config.yml

@@ -0,0 +1,7 @@
+version: 2.1
+orbs:
+  node: circleci/node@3.0.0
+workflows:
+  node-tests:
+    jobs:
+      - node/test

.github/workflows/node.js.yml

@@ -0,0 +1,29 @@
+# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: Node.js CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x, 14.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm ci
+    - run: npm run build --if-present
+    - run: npm test

.github/workflows/nodejs.yml

@@ -0,0 +1,31 @@
+# This workflow will do a clean install of node dependencies, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: Node.js CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 12.x, 13.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm ci
+    - run: npm run lint
+    - run: npm run test-extensive
+      env:
+        CI: true

.gitignore

@@ -1,6 +1,4 @@
-/node_modules/
-bower_components
-.directory
-.c9
-.codio
-.settings
+node_modules
+dist
+.vscode
+docs

.jsdoc.json

@@ -0,0 +1,52 @@
+{
+  "sourceType": "module",
+  "tags": {
+    "allowUnknownTags": true,
+    "dictionaries": ["jsdoc"]
+  },
+  "source": {
+    "include": ["./src"],
+    "includePattern": ".js$"
+  },
+  "plugins": [
+    "plugins/markdown"
+  ],
+  "templates": {
+    "referenceTitle": "Yjs",
+    "disableSort": false,
+    "useCollapsibles": true,
+    "collapse": true,
+    "resources": {
+      "yjs.dev": "Website",
+      "docs.yjs.dev": "Docs",
+      "discuss.yjs.dev": "Forum",
+      "https://gitter.im/Yjs/community": "Chat"
+    },
+    "logo": {
+      "url": "https://yjs.dev/images/logo/yjs-512x512.png",
+      "width": "162px",
+      "height": "162px",
+      "link": "/"
+    },
+    "tabNames": {
+      "api": "API",
+      "tutorials": "Examples"
+    },
+    "footerText": "Shared Editing",
+    "css": [
+      "./style.css"
+    ],
+    "default": {
+      "staticFiles": {
+          "include": []
+      }
+    }
+  },
+  "opts": {
+    "destination": "./docs/",
+    "encoding": "utf8",
+    "private": false,
+    "recurse": true,
+    "template": "./node_modules/tui-jsdoc-template"
+  }
+}

.markdownlint.json

@@ -0,0 +1,4 @@
+{
+  "default": true,
+  "no-inline-html": false
+}

.travis.yml

@@ -1,11 +0,0 @@
-language: node_js
-before_install:
-  - "npm install -g bower coffee-script"
-  - "bower install"
-node_js:
-  - "0.12"
-  - "0.11"
-  - "0.10"
-branches:
-  only:
-    - master

INTERNALS.md

@@ -0,0 +1,179 @@
+# Yjs Internals
+
+This document roughly explains how Yjs works internally. There is a complete
+walkthrough of the Yjs codebase available as a recording:
+https://youtu.be/0l5XgnQ6rB4
+
+The Yjs CRDT algorithm is described in the [YATA
+paper](https://www.researchgate.net/publication/310212186_Near_Real-Time_Peer-to-Peer_Shared_Editing_on_Extensible_Data_Types)
+from 2016. For an algorithmic view of how it works, the paper is a reasonable
+place to start. There are a handful of small improvements implemented in Yjs
+which aren't described in the paper. The most notable is that items have an
+`originRight` as well as an `origin` property, which improves performance when
+many concurrent inserts happen after the same character.
+
+At its heart, Yjs is a list CRDT. Everything is squeezed into a list in order to
+reuse the CRDT resolution algorithm:
+
+- Arrays are easy - they're lists of arbitrary items.
+- Text is a list of characters, optionally punctuated by formatting markers and
+  embeds for rich text support. Several characters can be wrapped in a single
+linked list `Item` (this is also known as the compound representation of
+CRDTs). More information about this in [this blog
+article](https://blog.kevinjahns.de/are-crdts-suitable-for-shared-editing/).
+- Maps are lists of entries. The last inserted entry for each key is used, and
+  all other duplicates for each key are flagged as deleted.
+
+Each client is assigned a unique *clientID* property on first insert. This is a
+random 53-bit integer (53 bits because that fits in the javascript safe integer
+range).
+
+## List items
+
+Each item in a Yjs list is made up of two objects:
+
+- An `Item` (*src/structs/Item.js*). This is used to relate the item to other
+  adjacent items.
+- An object in the `AbstractType` hierarchy (subclasses of
+  *src/types/AbstractType.js* - eg `YText`). This stores the actual content in
+the Yjs document.
+
+The item and type object pair have a 1-1 mapping. The item's `content` field
+references the AbstractType object and the AbstractType object's `_item` field
+references the item.
+
+Everything inserted in a Yjs document is given a unique ID, formed from a
+*ID(clientID, clock)* pair (also known as a [Lamport
+Timestamp](https://en.wikipedia.org/wiki/Lamport_timestamp)). The clock counts
+up from 0 with the first inserted character or item a client makes. This is
+similar to automerge's operation IDs, but note that the clock is only
+incremented by inserts. Deletes are handled in a very different way (see
+below).
+
+If a run of characters is inserted into a document (eg `"abc"`), the clock will
+be incremented for each character (eg 3 times here). But Yjs will only add a
+single `Item` into the list. This has no effect on the core CRDT algorithm, but
+the optimization dramatically decreases the number of javascript objects
+created during normal text editing. This optimization only applies if the
+characters share the same clientID, they're inserted in order, and all
+characters have either been deleted or all characters are not deleted. The item
+will be split if the run is interrupted for any reason (eg a character in the
+middle of the run is deleted).
+
+When an item is created, it stores a reference to the IDs of the preceeding and
+succeeding item. These are stored in the item's `origin` and `originRight`
+fields, respectively. These are used when peers concurrently insert at the same
+location in a document. Though quite rare in practice, Yjs needs to make sure
+the list items always resolve to the same order on all peers. The actual logic
+is relatively simple - its only a couple dozen lines of code and it lives in
+the `Item#integrate()` method. The YATA paper has much more detail on the this
+algorithm.
+
+### Item Storage
+
+The items themselves are stored in two data structures and a cache:
+
+- The items are stored in a tree of doubly-linked lists in *document order*.
+  Each item has `left` and `right` properties linking to its siblings in the
+document. Items also have a `parent` property to reference their parent in the
+document tree (null at the root). (And you can access an item's children, if
+any, through `item.content`).
+- All items are referenced in *insertion order* inside the struct store
+  (*src/utils/StructStore.js*). This references the list of items inserted by
+for each client, in chronological order. This is used to find an item in the
+tree with a given ID (using a binary search). It is also used to efficiently
+gather the operations a peer is missing during sync (more on this below).
+
+When a local insert happens, Yjs needs to map the insert position in the
+document (eg position 1000) to an ID. With just the linked list, this would
+require a slow O(n) linear scan of the list. But when editing a document, most
+inserts are either at the same position as the last insert, or nearby. To
+improve performance, Yjs stores a cache of the 10 most recently looked up
+insert positions in the document. This is consulted and updated when a position
+is looked up to improve performance in the average case. The cache is updated
+using a heuristic that is still changing (currently, it is updated when a new
+position significantly diverges from existing markers in the cache). Internally
+this is referred to as the skip list / fast search marker.
+
+### Deletions
+
+Deletions in Yjs are treated very differently from insertions. Insertions are
+implemented as a sequential operation based CRDT, but deletions are treated as
+a simpler state based CRDT.
+
+When an item has been deleted by any peer, at any point in history, it is
+flagged as deleted on the item. (Internally Yjs uses the `info` bitfield.) Yjs
+does not record metadata about a deletion:
+
+- No data is kept on *when* an item was deleted, or which user deleted it.
+- The struct store does not contain deletion records
+- The clientID's clock is not incremented
+
+If garbage collection is enabled in Yjs, when an object is deleted its content
+is discarded. If a deleted object contains children (eg a field is deleted in
+an object), the content is replaced with a `GC` object (*src/structs/GC.js*).
+This is a very lightweight structure - it only stores the length of the removed
+content.
+
+Yjs has some special logic to share which content in a document has been
+deleted:
+
+- When a delete happens, as well as marking the item, the deleted IDs are
+  listed locally within the transaction. (See below for more information about
+transactions.) When a transaction has been committed locally, the set of
+deleted items is appended to a transaction's update message.
+- A snapshot (a marked point in time in the Yjs history) is specified using
+  both the set of (clientID, clock) pairs *and* the set of all deleted item
+IDs. The deleted set is O(n), but because deletions usually happen in runs,
+this data set is usually tiny in practice. (The real world editing trace from
+the B4 benchmark document contains 182k inserts and 77k deleted characters. The
+deleted set size in a snapshot is only 4.5Kb).
+
+## Transactions
+
+All updates in Yjs happen within a *transaction*. (Defined in
+*src/utils/Transaction.js*.)
+
+The transaction collects a set of updates to the Yjs document to be applied on
+remote peers atomically. Once a transaction has been committed locally, it
+generates a compressed *update message* which is broadcast to synchronized
+remote peers to notify them of the local change. The update message contains:
+
+- The set of newly inserted items
+- The set of items deleted within the transaction.
+
+## Network protocol
+
+The network protocol is not really a part of Yjs. There are a few relevant
+concepts that can be used to create a custom network protocol:
+
+* `update`: The Yjs document can be encoded to an *update* object that can be
+  parsed to reconstruct the document. Also every change on the document fires
+an incremental document updates that allows clients to sync with each other.
+The update object is an Uint8Array that efficiently encodes `Item` objects and
+the delete set.
+* `state vector`: A state vector defines the know state of each user (a set of
+  tubles `(client, clock)`). This object is also efficiently encoded as a
+Uint8Array.
+
+The client can ask a remote client for missing document updates by sending
+their state vector (often referred to as *sync step 1*). The remote peer can
+compute the missing `Item` objects using the `clocks` of the respective clients
+and compute a minimal update message that reflects all missing updates (sync
+step 2).
+
+An implementation of the syncing process is in
+[y-protocols](https://github.com/yjs/y-protocols).
+
+## Snapshots
+
+A snapshot can be used to restore an old document state. It is a `state vector`
+\+ `delete set`. I client can restore an old document state by iterating through
+the sequence CRDT and ignoring all Items that have an `id.clock >
+stateVector[id.client].clock`. Instead of using `item.deleted` the client will
+use the delete set to find out if an item was deleted or not.
+
+It is not recommended to restore an old document state using snapshots,
+although that would certainly be possible. Instead, the old state should be
+computed by iterating through the newest state and using the additional
+information from the state vector.

LICENSE

@@ -1,6 +1,8 @@
 The MIT License (MIT)
 
-Copyright (c) 2014 Kevin Jahns <kevin.jahns@rwth-aachen.de>.
+Copyright (c) 2014
+  - Kevin Jahns <kevin.jahns@rwth-aachen.de>.
+  - Chair of Computer Science 5 (Databases & Information Systems), RWTH Aachen University, Germany
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

bower.json

@@ -1,33 +0,0 @@
-{
-  "name": "yjs",
-  "version": "0.5.2",
-  "homepage": "https://github.com/DadaMonad/yjs",
-  "authors": [
-    "Kevin Jahns <kevin.jahns@rwth-aachen.de>"
-  ],
-  "description": "A Framework that enables Real-Time collaboration on arbitrary data structures.",
-  "main": [
-    "./y.js",
-    "./y-object.html",
-    "./build/node/y.js"
-  ],
-  "keywords": [
-    "OT",
-    "collaboration",
-    "synchronization",
-    "ShareJS",
-    "Coweb",
-    "concurrency"
-  ],
-  "license": "MIT",
-  "ignore": [
-    "node_modules",
-    "bower_components",
-    "test",
-    "extras",
-    "test"
-  ],
-  "devDependencies": {
-    "y-test" : "y-test#~0.4.0"
-  }
-}

build/README.md

@@ -1,11 +0,0 @@
-
-# Directories
-
-### build/browser
-You find the browserified (not minified) version of yjs here. This is nice for debugging, since it also includes sourcemaps. For production, however, you should use the version that you find in the main directory.
-
-### build/node
-Yjs for nodejs is located here. You can only use the submodules, or require 'y' in your node project. Also works with browserify.
-
-### build/test
-Start build/test/index.html' in your browser, to perform testing Yjs.

build/browser/y-object.html

@@ -1,7 +0,0 @@
-
-<polymer-element name="y-object" hidden attributes="val connector y">
-</polymer-element>
-<polymer-element name="y-property" hidden attributes="val name y">
-</polymer-element>
-
-<script src="./y-object.js"></script>

build/node/ConnectorAdapter.js

@@ -1,71 +0,0 @@
-var ConnectorClass, adaptConnector;
-
-ConnectorClass = require("./ConnectorClass");
-
-adaptConnector = function(connector, engine, HB, execution_listener) {
-  var applyHB, encode_state_vector, f, getHB, getStateVector, name, parse_state_vector, send_;
-  for (name in ConnectorClass) {
-    f = ConnectorClass[name];
-    connector[name] = f;
-  }
-  connector.setIsBoundToY();
-  send_ = function(o) {
-    if ((o.uid.creator === HB.getUserId()) && (typeof o.uid.op_number !== "string") && (HB.getUserId() !== "_temp")) {
-      return connector.broadcast(o);
-    }
-  };
-  if (connector.invokeSync != null) {
-    HB.setInvokeSyncHandler(connector.invokeSync);
-  }
-  execution_listener.push(send_);
-  encode_state_vector = function(v) {
-    var results, value;
-    results = [];
-    for (name in v) {
-      value = v[name];
-      results.push({
-        user: name,
-        state: value
-      });
-    }
-    return results;
-  };
-  parse_state_vector = function(v) {
-    var i, len, s, state_vector;
-    state_vector = {};
-    for (i = 0, len = v.length; i < len; i++) {
-      s = v[i];
-      state_vector[s.user] = s.state;
-    }
-    return state_vector;
-  };
-  getStateVector = function() {
-    return encode_state_vector(HB.getOperationCounter());
-  };
-  getHB = function(v) {
-    var hb, json, state_vector;
-    state_vector = parse_state_vector(v);
-    hb = HB._encode(state_vector);
-    json = {
-      hb: hb,
-      state_vector: encode_state_vector(HB.getOperationCounter())
-    };
-    return json;
-  };
-  applyHB = function(hb, fromHB) {
-    return engine.applyOp(hb, fromHB);
-  };
-  connector.getStateVector = getStateVector;
-  connector.getHB = getHB;
-  connector.applyHB = applyHB;
-  if (connector.receive_handlers == null) {
-    connector.receive_handlers = [];
-  }
-  return connector.receive_handlers.push(function(sender, op) {
-    if (op.uid.creator !== HB.getUserId()) {
-      return engine.applyOp(op);
-    }
-  });
-};
-
-module.exports = adaptConnector;

build/node/ConnectorClass.js

@@ -1,415 +0,0 @@
-module.exports = {
-  init: function(options) {
-    var req;
-    req = (function(_this) {
-      return function(name, choices) {
-        if (options[name] != null) {
-          if ((choices == null) || choices.some(function(c) {
-            return c === options[name];
-          })) {
-            return _this[name] = options[name];
-          } else {
-            throw new Error("You can set the '" + name + "' option to one of the following choices: " + JSON.encode(choices));
-          }
-        } else {
-          throw new Error("You must specify " + name + ", when initializing the Connector!");
-        }
-      };
-    })(this);
-    req("syncMethod", ["syncAll", "master-slave"]);
-    req("role", ["master", "slave"]);
-    req("user_id");
-    if (typeof this.on_user_id_set === "function") {
-      this.on_user_id_set(this.user_id);
-    }
-    if (options.perform_send_again != null) {
-      this.perform_send_again = options.perform_send_again;
-    } else {
-      this.perform_send_again = true;
-    }
-    if (this.role === "master") {
-      this.syncMethod = "syncAll";
-    }
-    this.is_synced = false;
-    this.connections = {};
-    if (this.receive_handlers == null) {
-      this.receive_handlers = [];
-    }
-    this.connections = {};
-    this.current_sync_target = null;
-    this.sent_hb_to_all_users = false;
-    return this.is_initialized = true;
-  },
-  onUserEvent: function(f) {
-    if (this.connections_listeners == null) {
-      this.connections_listeners = [];
-    }
-    return this.connections_listeners.push(f);
-  },
-  isRoleMaster: function() {
-    return this.role === "master";
-  },
-  isRoleSlave: function() {
-    return this.role === "slave";
-  },
-  findNewSyncTarget: function() {
-    var c, ref, user;
-    this.current_sync_target = null;
-    if (this.syncMethod === "syncAll") {
-      ref = this.connections;
-      for (user in ref) {
-        c = ref[user];
-        if (!c.is_synced) {
-          this.performSync(user);
-          break;
-        }
-      }
-    }
-    if (this.current_sync_target == null) {
-      this.setStateSynced();
-    }
-    return null;
-  },
-  userLeft: function(user) {
-    var f, i, len, ref, results;
-    delete this.connections[user];
-    this.findNewSyncTarget();
-    if (this.connections_listeners != null) {
-      ref = this.connections_listeners;
-      results = [];
-      for (i = 0, len = ref.length; i < len; i++) {
-        f = ref[i];
-        results.push(f({
-          action: "userLeft",
-          user: user
-        }));
-      }
-      return results;
-    }
-  },
-  userJoined: function(user, role) {
-    var base, f, i, len, ref, results;
-    if (role == null) {
-      throw new Error("Internal: You must specify the role of the joined user! E.g. userJoined('uid:3939','slave')");
-    }
-    if ((base = this.connections)[user] == null) {
-      base[user] = {};
-    }
-    this.connections[user].is_synced = false;
-    if ((!this.is_synced) || this.syncMethod === "syncAll") {
-      if (this.syncMethod === "syncAll") {
-        this.performSync(user);
-      } else if (role === "master") {
-        this.performSyncWithMaster(user);
-      }
-    }
-    if (this.connections_listeners != null) {
-      ref = this.connections_listeners;
-      results = [];
-      for (i = 0, len = ref.length; i < len; i++) {
-        f = ref[i];
-        results.push(f({
-          action: "userJoined",
-          user: user,
-          role: role
-        }));
-      }
-      return results;
-    }
-  },
-  whenSynced: function(args) {
-    if (args.constructor === Function) {
-      args = [args];
-    }
-    if (this.is_synced) {
-      return args[0].apply(this, args.slice(1));
-    } else {
-      if (this.compute_when_synced == null) {
-        this.compute_when_synced = [];
-      }
-      return this.compute_when_synced.push(args);
-    }
-  },
-  onReceive: function(f) {
-    return this.receive_handlers.push(f);
-  },
-
-  /*
-   * Broadcast a message to all connected peers.
-   * @param message {Object} The message to broadcast.
-  #
-  broadcast: (message)->
-    throw new Error "You must implement broadcast!"
-  
-  #
-   * Send a message to a peer, or set of peers
-  #
-  send: (peer_s, message)->
-    throw new Error "You must implement send!"
-   */
-  performSync: function(user) {
-    var _hb, hb, i, len, o;
-    if (this.current_sync_target == null) {
-      this.current_sync_target = user;
-      this.send(user, {
-        sync_step: "getHB",
-        send_again: "true",
-        data: this.getStateVector()
-      });
-      if (!this.sent_hb_to_all_users) {
-        this.sent_hb_to_all_users = true;
-        hb = this.getHB([]).hb;
-        _hb = [];
-        for (i = 0, len = hb.length; i < len; i++) {
-          o = hb[i];
-          _hb.push(o);
-          if (_hb.length > 10) {
-            this.broadcast({
-              sync_step: "applyHB_",
-              data: _hb
-            });
-            _hb = [];
-          }
-        }
-        return this.broadcast({
-          sync_step: "applyHB",
-          data: _hb
-        });
-      }
-    }
-  },
-  performSyncWithMaster: function(user) {
-    var _hb, hb, i, len, o;
-    this.current_sync_target = user;
-    this.send(user, {
-      sync_step: "getHB",
-      send_again: "true",
-      data: this.getStateVector()
-    });
-    hb = this.getHB([]).hb;
-    _hb = [];
-    for (i = 0, len = hb.length; i < len; i++) {
-      o = hb[i];
-      _hb.push(o);
-      if (_hb.length > 10) {
-        this.broadcast({
-          sync_step: "applyHB_",
-          data: _hb
-        });
-        _hb = [];
-      }
-    }
-    return this.broadcast({
-      sync_step: "applyHB",
-      data: _hb
-    });
-  },
-  setStateSynced: function() {
-    var args, el, f, i, len, ref;
-    if (!this.is_synced) {
-      this.is_synced = true;
-      if (this.compute_when_synced != null) {
-        ref = this.compute_when_synced;
-        for (i = 0, len = ref.length; i < len; i++) {
-          el = ref[i];
-          f = el[0];
-          args = el.slice(1);
-          f.apply(args);
-        }
-        delete this.compute_when_synced;
-      }
-      return null;
-    }
-  },
-  whenReceivedStateVector: function(f) {
-    if (this.when_received_state_vector_listeners == null) {
-      this.when_received_state_vector_listeners = [];
-    }
-    return this.when_received_state_vector_listeners.push(f);
-  },
-  receiveMessage: function(sender, res) {
-    var _hb, data, f, hb, i, j, k, len, len1, len2, o, ref, ref1, results, sendApplyHB, send_again;
-    if (res.sync_step == null) {
-      ref = this.receive_handlers;
-      results = [];
-      for (i = 0, len = ref.length; i < len; i++) {
-        f = ref[i];
-        results.push(f(sender, res));
-      }
-      return results;
-    } else {
-      if (sender === this.user_id) {
-        return;
-      }
-      if (res.sync_step === "getHB") {
-        if (this.when_received_state_vector_listeners != null) {
-          ref1 = this.when_received_state_vector_listeners;
-          for (j = 0, len1 = ref1.length; j < len1; j++) {
-            f = ref1[j];
-            f.call(this, res.data);
-          }
-        }
-        delete this.when_received_state_vector_listeners;
-        data = this.getHB(res.data);
-        hb = data.hb;
-        _hb = [];
-        if (this.is_synced) {
-          sendApplyHB = (function(_this) {
-            return function(m) {
-              return _this.send(sender, m);
-            };
-          })(this);
-        } else {
-          sendApplyHB = (function(_this) {
-            return function(m) {
-              return _this.broadcast(m);
-            };
-          })(this);
-        }
-        for (k = 0, len2 = hb.length; k < len2; k++) {
-          o = hb[k];
-          _hb.push(o);
-          if (_hb.length > 10) {
-            sendApplyHB({
-              sync_step: "applyHB_",
-              data: _hb
-            });
-            _hb = [];
-          }
-        }
-        sendApplyHB({
-          sync_step: "applyHB",
-          data: _hb
-        });
-        if ((res.send_again != null) && this.perform_send_again) {
-          send_again = (function(_this) {
-            return function(sv) {
-              return function() {
-                var l, len3;
-                hb = _this.getHB(sv).hb;
-                for (l = 0, len3 = hb.length; l < len3; l++) {
-                  o = hb[l];
-                  _hb.push(o);
-                  if (_hb.length > 10) {
-                    _this.send(sender, {
-                      sync_step: "applyHB_",
-                      data: _hb
-                    });
-                    _hb = [];
-                  }
-                }
-                return _this.send(sender, {
-                  sync_step: "applyHB",
-                  data: _hb,
-                  sent_again: "true"
-                });
-              };
-            };
-          })(this)(data.state_vector);
-          return setTimeout(send_again, 3000);
-        }
-      } else if (res.sync_step === "applyHB") {
-        this.applyHB(res.data, sender === this.current_sync_target);
-        if ((this.syncMethod === "syncAll" || (res.sent_again != null)) && (!this.is_synced) && ((this.current_sync_target === sender) || (this.current_sync_target == null))) {
-          this.connections[sender].is_synced = true;
-          return this.findNewSyncTarget();
-        }
-      } else if (res.sync_step === "applyHB_") {
-        return this.applyHB(res.data, sender === this.current_sync_target);
-      }
-    }
-  },
-  parseMessageFromXml: function(m) {
-    var parse_array, parse_object;
-    parse_array = function(node) {
-      var i, len, n, ref, results;
-      ref = node.children;
-      results = [];
-      for (i = 0, len = ref.length; i < len; i++) {
-        n = ref[i];
-        if (n.getAttribute("isArray") === "true") {
-          results.push(parse_array(n));
-        } else {
-          results.push(parse_object(n));
-        }
-      }
-      return results;
-    };
-    parse_object = function(node) {
-      var i, int, json, len, n, name, ref, ref1, value;
-      json = {};
-      ref = node.attrs;
-      for (name in ref) {
-        value = ref[name];
-        int = parseInt(value);
-        if (isNaN(int) || ("" + int) !== value) {
-          json[name] = value;
-        } else {
-          json[name] = int;
-        }
-      }
-      ref1 = node.children;
-      for (i = 0, len = ref1.length; i < len; i++) {
-        n = ref1[i];
-        name = n.name;
-        if (n.getAttribute("isArray") === "true") {
-          json[name] = parse_array(n);
-        } else {
-          json[name] = parse_object(n);
-        }
-      }
-      return json;
-    };
-    return parse_object(m);
-  },
-  encodeMessageToXml: function(m, json) {
-    var encode_array, encode_object;
-    encode_object = function(m, json) {
-      var name, value;
-      for (name in json) {
-        value = json[name];
-        if (value == null) {
-
-        } else if (value.constructor === Object) {
-          encode_object(m.c(name), value);
-        } else if (value.constructor === Array) {
-          encode_array(m.c(name), value);
-        } else {
-          m.setAttribute(name, value);
-        }
-      }
-      return m;
-    };
-    encode_array = function(m, array) {
-      var e, i, len;
-      m.setAttribute("isArray", "true");
-      for (i = 0, len = array.length; i < len; i++) {
-        e = array[i];
-        if (e.constructor === Object) {
-          encode_object(m.c("array-element"), e);
-        } else {
-          encode_array(m.c("array-element"), e);
-        }
-      }
-      return m;
-    };
-    if (json.constructor === Object) {
-      return encode_object(m.c("y", {
-        xmlns: "http://y.ninja/connector-stanza"
-      }), json);
-    } else if (json.constructor === Array) {
-      return encode_array(m.c("y", {
-        xmlns: "http://y.ninja/connector-stanza"
-      }), json);
-    } else {
-      throw new Error("I can't encode this json!");
-    }
-  },
-  setIsBoundToY: function() {
-    if (typeof this.on_bound_to_y === "function") {
-      this.on_bound_to_y();
-    }
-    delete this.when_bound_to_y;
-    return this.is_bound_to_y = true;
-  }
-};

build/node/Engine.js

@@ -1,120 +0,0 @@
-var Engine;
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_counter = 0;
-}
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_exec_counter = 0;
-}
-
-if (typeof window !== "undefined" && window !== null) {
-  window.unprocessed_types = [];
-}
-
-Engine = (function() {
-  function Engine(HB, types) {
-    this.HB = HB;
-    this.types = types;
-    this.unprocessed_ops = [];
-  }
-
-  Engine.prototype.parseOperation = function(json) {
-    var type;
-    type = this.types[json.type];
-    if ((type != null ? type.parse : void 0) != null) {
-      return type.parse(json);
-    } else {
-      throw new Error("You forgot to specify a parser for type " + json.type + ". The message is " + (JSON.stringify(json)) + ".");
-    }
-  };
-
-
-  /*
-  applyOpsBundle: (ops_json)->
-    ops = []
-    for o in ops_json
-      ops.push @parseOperation o
-    for o in ops
-      if not o.execute()
-        @unprocessed_ops.push o
-    @tryUnprocessed()
-   */
-
-  Engine.prototype.applyOpsCheckDouble = function(ops_json) {
-    var i, len, o, results;
-    results = [];
-    for (i = 0, len = ops_json.length; i < len; i++) {
-      o = ops_json[i];
-      if (this.HB.getOperation(o.uid) == null) {
-        results.push(this.applyOp(o));
-      } else {
-        results.push(void 0);
-      }
-    }
-    return results;
-  };
-
-  Engine.prototype.applyOps = function(ops_json) {
-    return this.applyOp(ops_json);
-  };
-
-  Engine.prototype.applyOp = function(op_json_array, fromHB) {
-    var i, len, o, op_json;
-    if (fromHB == null) {
-      fromHB = false;
-    }
-    if (op_json_array.constructor !== Array) {
-      op_json_array = [op_json_array];
-    }
-    for (i = 0, len = op_json_array.length; i < len; i++) {
-      op_json = op_json_array[i];
-      if (fromHB) {
-        op_json.fromHB = "true";
-      }
-      o = this.parseOperation(op_json);
-      o.parsed_from_json = op_json;
-      if (op_json.fromHB != null) {
-        o.fromHB = op_json.fromHB;
-      }
-      if (this.HB.getOperation(o) != null) {
-
-      } else if (((!this.HB.isExpectedOperation(o)) && (o.fromHB == null)) || (!o.execute())) {
-        this.unprocessed_ops.push(o);
-        if (typeof window !== "undefined" && window !== null) {
-          window.unprocessed_types.push(o.type);
-        }
-      }
-    }
-    return this.tryUnprocessed();
-  };
-
-  Engine.prototype.tryUnprocessed = function() {
-    var i, len, old_length, op, ref, unprocessed;
-    while (true) {
-      old_length = this.unprocessed_ops.length;
-      unprocessed = [];
-      ref = this.unprocessed_ops;
-      for (i = 0, len = ref.length; i < len; i++) {
-        op = ref[i];
-        if (this.HB.getOperation(op) != null) {
-
-        } else if ((!this.HB.isExpectedOperation(op) && (op.fromHB == null)) || (!op.execute())) {
-          unprocessed.push(op);
-        }
-      }
-      this.unprocessed_ops = unprocessed;
-      if (this.unprocessed_ops.length === old_length) {
-        break;
-      }
-    }
-    if (this.unprocessed_ops.length !== 0) {
-      return this.HB.invokeSync();
-    }
-  };
-
-  return Engine;
-
-})();
-
-module.exports = Engine;

build/node/HistoryBuffer.js

@@ -1,255 +0,0 @@
-var HistoryBuffer,
-  bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };
-
-HistoryBuffer = (function() {
-  function HistoryBuffer(user_id1) {
-    this.user_id = user_id1;
-    this.emptyGarbage = bind(this.emptyGarbage, this);
-    this.operation_counter = {};
-    this.buffer = {};
-    this.change_listeners = [];
-    this.garbage = [];
-    this.trash = [];
-    this.performGarbageCollection = true;
-    this.garbageCollectTimeout = 30000;
-    this.reserved_identifier_counter = 0;
-    setTimeout(this.emptyGarbage, this.garbageCollectTimeout);
-  }
-
-  HistoryBuffer.prototype.setUserId = function(user_id1, state_vector) {
-    var base, buff, counter_diff, name, o, o_name, ref;
-    this.user_id = user_id1;
-    if ((base = this.buffer)[name = this.user_id] == null) {
-      base[name] = [];
-    }
-    buff = this.buffer[this.user_id];
-    counter_diff = state_vector[this.user_id] || 0;
-    if (this.buffer._temp != null) {
-      ref = this.buffer._temp;
-      for (o_name in ref) {
-        o = ref[o_name];
-        o.uid.creator = this.user_id;
-        o.uid.op_number += counter_diff;
-        buff[o.uid.op_number] = o;
-      }
-    }
-    this.operation_counter[this.user_id] = (this.operation_counter._temp || 0) + counter_diff;
-    delete this.operation_counter._temp;
-    return delete this.buffer._temp;
-  };
-
-  HistoryBuffer.prototype.emptyGarbage = function() {
-    var i, len, o, ref;
-    ref = this.garbage;
-    for (i = 0, len = ref.length; i < len; i++) {
-      o = ref[i];
-      if (typeof o.cleanup === "function") {
-        o.cleanup();
-      }
-    }
-    this.garbage = this.trash;
-    this.trash = [];
-    if (this.garbageCollectTimeout !== -1) {
-      this.garbageCollectTimeoutId = setTimeout(this.emptyGarbage, this.garbageCollectTimeout);
-    }
-    return void 0;
-  };
-
-  HistoryBuffer.prototype.getUserId = function() {
-    return this.user_id;
-  };
-
-  HistoryBuffer.prototype.addToGarbageCollector = function() {
-    var i, len, o, results;
-    if (this.performGarbageCollection) {
-      results = [];
-      for (i = 0, len = arguments.length; i < len; i++) {
-        o = arguments[i];
-        if (o != null) {
-          results.push(this.garbage.push(o));
-        } else {
-          results.push(void 0);
-        }
-      }
-      return results;
-    }
-  };
-
-  HistoryBuffer.prototype.stopGarbageCollection = function() {
-    this.performGarbageCollection = false;
-    this.setManualGarbageCollect();
-    this.garbage = [];
-    return this.trash = [];
-  };
-
-  HistoryBuffer.prototype.setManualGarbageCollect = function() {
-    this.garbageCollectTimeout = -1;
-    clearTimeout(this.garbageCollectTimeoutId);
-    return this.garbageCollectTimeoutId = void 0;
-  };
-
-  HistoryBuffer.prototype.setGarbageCollectTimeout = function(garbageCollectTimeout) {
-    this.garbageCollectTimeout = garbageCollectTimeout;
-  };
-
-  HistoryBuffer.prototype.getReservedUniqueIdentifier = function() {
-    return {
-      creator: '_',
-      op_number: "_" + (this.reserved_identifier_counter++)
-    };
-  };
-
-  HistoryBuffer.prototype.getOperationCounter = function(user_id) {
-    var ctn, ref, res, user;
-    if (user_id == null) {
-      res = {};
-      ref = this.operation_counter;
-      for (user in ref) {
-        ctn = ref[user];
-        res[user] = ctn;
-      }
-      return res;
-    } else {
-      return this.operation_counter[user_id];
-    }
-  };
-
-  HistoryBuffer.prototype.isExpectedOperation = function(o) {
-    var base, name;
-    if ((base = this.operation_counter)[name = o.uid.creator] == null) {
-      base[name] = 0;
-    }
-    o.uid.op_number <= this.operation_counter[o.uid.creator];
-    return true;
-  };
-
-  HistoryBuffer.prototype._encode = function(state_vector) {
-    var json, o, o_json, o_next, o_number, o_prev, ref, u_name, unknown, user;
-    if (state_vector == null) {
-      state_vector = {};
-    }
-    json = [];
-    unknown = function(user, o_number) {
-      if ((user == null) || (o_number == null)) {
-        throw new Error("dah!");
-      }
-      return (state_vector[user] == null) || state_vector[user] <= o_number;
-    };
-    ref = this.buffer;
-    for (u_name in ref) {
-      user = ref[u_name];
-      if (u_name === "_") {
-        continue;
-      }
-      for (o_number in user) {
-        o = user[o_number];
-        if ((o.uid.noOperation == null) && unknown(u_name, o_number)) {
-          o_json = o._encode();
-          if (o.next_cl != null) {
-            o_next = o.next_cl;
-            while ((o_next.next_cl != null) && unknown(o_next.uid.creator, o_next.uid.op_number)) {
-              o_next = o_next.next_cl;
-            }
-            o_json.next = o_next.getUid();
-          } else if (o.prev_cl != null) {
-            o_prev = o.prev_cl;
-            while ((o_prev.prev_cl != null) && unknown(o_prev.uid.creator, o_prev.uid.op_number)) {
-              o_prev = o_prev.prev_cl;
-            }
-            o_json.prev = o_prev.getUid();
-          }
-          json.push(o_json);
-        }
-      }
-    }
-    return json;
-  };
-
-  HistoryBuffer.prototype.getNextOperationIdentifier = function(user_id) {
-    var uid;
-    if (user_id == null) {
-      user_id = this.user_id;
-    }
-    if (this.operation_counter[user_id] == null) {
-      this.operation_counter[user_id] = 0;
-    }
-    uid = {
-      'creator': user_id,
-      'op_number': this.operation_counter[user_id]
-    };
-    this.operation_counter[user_id]++;
-    return uid;
-  };
-
-  HistoryBuffer.prototype.getOperation = function(uid) {
-    var o, ref;
-    if (uid.uid != null) {
-      uid = uid.uid;
-    }
-    o = (ref = this.buffer[uid.creator]) != null ? ref[uid.op_number] : void 0;
-    if ((uid.sub != null) && (o != null)) {
-      return o.retrieveSub(uid.sub);
-    } else {
-      return o;
-    }
-  };
-
-  HistoryBuffer.prototype.addOperation = function(o) {
-    if (this.buffer[o.uid.creator] == null) {
-      this.buffer[o.uid.creator] = {};
-    }
-    if (this.buffer[o.uid.creator][o.uid.op_number] != null) {
-      throw new Error("You must not overwrite operations!");
-    }
-    if ((o.uid.op_number.constructor !== String) && (!this.isExpectedOperation(o)) && (o.fromHB == null)) {
-      throw new Error("this operation was not expected!");
-    }
-    this.addToCounter(o);
-    this.buffer[o.uid.creator][o.uid.op_number] = o;
-    return o;
-  };
-
-  HistoryBuffer.prototype.removeOperation = function(o) {
-    var ref;
-    return (ref = this.buffer[o.uid.creator]) != null ? delete ref[o.uid.op_number] : void 0;
-  };
-
-  HistoryBuffer.prototype.setInvokeSyncHandler = function(f) {
-    return this.invokeSync = f;
-  };
-
-  HistoryBuffer.prototype.invokeSync = function() {};
-
-  HistoryBuffer.prototype.renewStateVector = function(state_vector) {
-    var results, state, user;
-    results = [];
-    for (user in state_vector) {
-      state = state_vector[user];
-      if (((this.operation_counter[user] == null) || (this.operation_counter[user] < state_vector[user])) && (state_vector[user] != null)) {
-        results.push(this.operation_counter[user] = state_vector[user]);
-      } else {
-        results.push(void 0);
-      }
-    }
-    return results;
-  };
-
-  HistoryBuffer.prototype.addToCounter = function(o) {
-    var base, name;
-    if ((base = this.operation_counter)[name = o.uid.creator] == null) {
-      base[name] = 0;
-    }
-    if (o.uid.op_number === this.operation_counter[o.uid.creator]) {
-      this.operation_counter[o.uid.creator]++;
-    }
-    while (this.buffer[o.uid.creator][this.operation_counter[o.uid.creator]] != null) {
-      this.operation_counter[o.uid.creator]++;
-    }
-    return void 0;
-  };
-
-  return HistoryBuffer;
-
-})();
-
-module.exports = HistoryBuffer;

build/node/ObjectType.js

@@ -1,91 +0,0 @@
-var YObject;
-
-YObject = (function() {
-  function YObject(_object) {
-    var name, ref, val;
-    this._object = _object != null ? _object : {};
-    if (this._object.constructor === Object) {
-      ref = this._object;
-      for (name in ref) {
-        val = ref[name];
-        if (val.constructor === Object) {
-          this._object[name] = new YObject(val);
-        }
-      }
-    } else {
-      throw new Error("Y.Object accepts Json Objects only");
-    }
-  }
-
-  YObject.prototype._name = "Object";
-
-  YObject.prototype._getModel = function(types, ops) {
-    var n, o, ref;
-    if (this._model == null) {
-      this._model = new ops.MapManager(this).execute();
-      ref = this._object;
-      for (n in ref) {
-        o = ref[n];
-        this._model.val(n, o);
-      }
-    }
-    delete this._object;
-    return this._model;
-  };
-
-  YObject.prototype._setModel = function(_model) {
-    this._model = _model;
-    return delete this._object;
-  };
-
-  YObject.prototype.observe = function(f) {
-    this._model.observe(f);
-    return this;
-  };
-
-  YObject.prototype.unobserve = function(f) {
-    this._model.unobserve(f);
-    return this;
-  };
-
-  YObject.prototype.val = function(name, content) {
-    var n, ref, res, v;
-    if (this._model != null) {
-      return this._model.val.apply(this._model, arguments);
-    } else {
-      if (content != null) {
-        return this._object[name] = content;
-      } else if (name != null) {
-        return this._object[name];
-      } else {
-        res = {};
-        ref = this._object;
-        for (n in ref) {
-          v = ref[n];
-          res[n] = v;
-        }
-        return res;
-      }
-    }
-  };
-
-  YObject.prototype["delete"] = function(name) {
-    this._model["delete"](name);
-    return this;
-  };
-
-  return YObject;
-
-})();
-
-if (typeof window !== "undefined" && window !== null) {
-  if (window.Y != null) {
-    window.Y.Object = YObject;
-  } else {
-    throw new Error("You must first import Y!");
-  }
-}
-
-if (typeof module !== "undefined" && module !== null) {
-  module.exports = YObject;
-}

build/node/Operations/Basic.js

@@ -1,670 +0,0 @@
-var slice = [].slice,
-  extend = function(child, parent) { for (var key in parent) { if (hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; },
-  hasProp = {}.hasOwnProperty;
-
-module.exports = function() {
-  var execution_listener, ops;
-  ops = {};
-  execution_listener = [];
-  ops.Operation = (function() {
-    function Operation(custom_type, uid, content, content_operations) {
-      var name, op;
-      if (custom_type != null) {
-        this.custom_type = custom_type;
-      }
-      this.is_deleted = false;
-      this.garbage_collected = false;
-      this.event_listeners = [];
-      if (uid != null) {
-        this.uid = uid;
-      }
-      if (content === void 0) {
-
-      } else if ((content != null) && (content.creator != null)) {
-        this.saveOperation('content', content);
-      } else {
-        this.content = content;
-      }
-      if (content_operations != null) {
-        this.content_operations = {};
-        for (name in content_operations) {
-          op = content_operations[name];
-          this.saveOperation(name, op, 'content_operations');
-        }
-      }
-    }
-
-    Operation.prototype.type = "Operation";
-
-    Operation.prototype.getContent = function(name) {
-      var content, n, ref, ref1, v;
-      if (this.content != null) {
-        if (this.content.getCustomType != null) {
-          return this.content.getCustomType();
-        } else if (this.content.constructor === Object) {
-          if (name != null) {
-            if (this.content[name] != null) {
-              return this.content[name];
-            } else {
-              return this.content_operations[name].getCustomType();
-            }
-          } else {
-            content = {};
-            ref = this.content;
-            for (n in ref) {
-              v = ref[n];
-              content[n] = v;
-            }
-            if (this.content_operations != null) {
-              ref1 = this.content_operations;
-              for (n in ref1) {
-                v = ref1[n];
-                v = v.getCustomType();
-                content[n] = v;
-              }
-            }
-            return content;
-          }
-        } else {
-          return this.content;
-        }
-      } else {
-        return this.content;
-      }
-    };
-
-    Operation.prototype.retrieveSub = function() {
-      throw new Error("sub properties are not enable on this operation type!");
-    };
-
-    Operation.prototype.observe = function(f) {
-      return this.event_listeners.push(f);
-    };
-
-    Operation.prototype.unobserve = function(f) {
-      return this.event_listeners = this.event_listeners.filter(function(g) {
-        return f !== g;
-      });
-    };
-
-    Operation.prototype.deleteAllObservers = function() {
-      return this.event_listeners = [];
-    };
-
-    Operation.prototype["delete"] = function() {
-      (new ops.Delete(void 0, this)).execute();
-      return null;
-    };
-
-    Operation.prototype.callEvent = function() {
-      var callon;
-      if (this.custom_type != null) {
-        callon = this.getCustomType();
-      } else {
-        callon = this;
-      }
-      return this.forwardEvent.apply(this, [callon].concat(slice.call(arguments)));
-    };
-
-    Operation.prototype.forwardEvent = function() {
-      var args, f, j, len, op, ref, results;
-      op = arguments[0], args = 2 <= arguments.length ? slice.call(arguments, 1) : [];
-      ref = this.event_listeners;
-      results = [];
-      for (j = 0, len = ref.length; j < len; j++) {
-        f = ref[j];
-        results.push(f.call.apply(f, [op].concat(slice.call(args))));
-      }
-      return results;
-    };
-
-    Operation.prototype.isDeleted = function() {
-      return this.is_deleted;
-    };
-
-    Operation.prototype.applyDelete = function(garbagecollect) {
-      if (garbagecollect == null) {
-        garbagecollect = true;
-      }
-      if (!this.garbage_collected) {
-        this.is_deleted = true;
-        if (garbagecollect) {
-          this.garbage_collected = true;
-          return this.HB.addToGarbageCollector(this);
-        }
-      }
-    };
-
-    Operation.prototype.cleanup = function() {
-      this.HB.removeOperation(this);
-      return this.deleteAllObservers();
-    };
-
-    Operation.prototype.setParent = function(parent1) {
-      this.parent = parent1;
-    };
-
-    Operation.prototype.getParent = function() {
-      return this.parent;
-    };
-
-    Operation.prototype.getUid = function() {
-      var map_uid;
-      if (this.uid.noOperation == null) {
-        return this.uid;
-      } else {
-        if (this.uid.alt != null) {
-          map_uid = this.uid.alt.cloneUid();
-          map_uid.sub = this.uid.sub;
-          return map_uid;
-        } else {
-          return void 0;
-        }
-      }
-    };
-
-    Operation.prototype.cloneUid = function() {
-      var n, ref, uid, v;
-      uid = {};
-      ref = this.getUid();
-      for (n in ref) {
-        v = ref[n];
-        uid[n] = v;
-      }
-      return uid;
-    };
-
-    Operation.prototype.execute = function() {
-      var j, l, len;
-      if (this.validateSavedOperations()) {
-        this.is_executed = true;
-        if (this.uid == null) {
-          this.uid = this.HB.getNextOperationIdentifier();
-        }
-        if (this.uid.noOperation == null) {
-          this.HB.addOperation(this);
-          for (j = 0, len = execution_listener.length; j < len; j++) {
-            l = execution_listener[j];
-            l(this._encode());
-          }
-        }
-        return this;
-      } else {
-        return false;
-      }
-    };
-
-    Operation.prototype.saveOperation = function(name, op, base) {
-      var base1, dest, j, last_path, len, path, paths;
-      if (base == null) {
-        base = "this";
-      }
-      if ((op != null) && (op._getModel != null)) {
-        op = op._getModel(this.custom_types, this.operations);
-      }
-      if (op == null) {
-
-      } else if ((op.execute != null) || !((op.op_number != null) && (op.creator != null))) {
-        if (base === "this") {
-          return this[name] = op;
-        } else {
-          dest = this[base];
-          paths = name.split("/");
-          last_path = paths.pop();
-          for (j = 0, len = paths.length; j < len; j++) {
-            path = paths[j];
-            dest = dest[path];
-          }
-          return dest[last_path] = op;
-        }
-      } else {
-        if (this.unchecked == null) {
-          this.unchecked = {};
-        }
-        if ((base1 = this.unchecked)[base] == null) {
-          base1[base] = {};
-        }
-        return this.unchecked[base][name] = op;
-      }
-    };
-
-    Operation.prototype.validateSavedOperations = function() {
-      var base, base_name, dest, j, last_path, len, name, op, op_uid, path, paths, ref, success, uninstantiated;
-      uninstantiated = {};
-      success = true;
-      ref = this.unchecked;
-      for (base_name in ref) {
-        base = ref[base_name];
-        for (name in base) {
-          op_uid = base[name];
-          op = this.HB.getOperation(op_uid);
-          if (op) {
-            if (base_name === "this") {
-              this[name] = op;
-            } else {
-              dest = this[base_name];
-              paths = name.split("/");
-              last_path = paths.pop();
-              for (j = 0, len = paths.length; j < len; j++) {
-                path = paths[j];
-                dest = dest[path];
-              }
-              dest[last_path] = op;
-            }
-          } else {
-            if (uninstantiated[base_name] == null) {
-              uninstantiated[base_name] = {};
-            }
-            uninstantiated[base_name][name] = op_uid;
-            success = false;
-          }
-        }
-      }
-      if (!success) {
-        this.unchecked = uninstantiated;
-        return false;
-      } else {
-        delete this.unchecked;
-        return this;
-      }
-    };
-
-    Operation.prototype.getCustomType = function() {
-      var Type, j, len, ref, t;
-      if (this.custom_type == null) {
-        return this;
-      } else {
-        if (this.custom_type.constructor === String) {
-          Type = this.custom_types;
-          ref = this.custom_type.split(".");
-          for (j = 0, len = ref.length; j < len; j++) {
-            t = ref[j];
-            Type = Type[t];
-          }
-          this.custom_type = new Type();
-          this.custom_type._setModel(this);
-        }
-        return this.custom_type;
-      }
-    };
-
-    Operation.prototype._encode = function(json) {
-      var n, o, operations, ref, ref1;
-      if (json == null) {
-        json = {};
-      }
-      json.type = this.type;
-      json.uid = this.getUid();
-      if (this.custom_type != null) {
-        if (this.custom_type.constructor === String) {
-          json.custom_type = this.custom_type;
-        } else {
-          json.custom_type = this.custom_type._name;
-        }
-      }
-      if (((ref = this.content) != null ? ref.getUid : void 0) != null) {
-        json.content = this.content.getUid();
-      } else {
-        json.content = this.content;
-      }
-      if (this.content_operations != null) {
-        operations = {};
-        ref1 = this.content_operations;
-        for (n in ref1) {
-          o = ref1[n];
-          if (o._getModel != null) {
-            o = o._getModel(this.custom_types, this.operations);
-          }
-          operations[n] = o.getUid();
-        }
-        json.content_operations = operations;
-      }
-      return json;
-    };
-
-    return Operation;
-
-  })();
-  ops.Delete = (function(superClass) {
-    extend(Delete, superClass);
-
-    function Delete(custom_type, uid, deletes) {
-      this.saveOperation('deletes', deletes);
-      Delete.__super__.constructor.call(this, custom_type, uid);
-    }
-
-    Delete.prototype.type = "Delete";
-
-    Delete.prototype._encode = function() {
-      return {
-        'type': "Delete",
-        'uid': this.getUid(),
-        'deletes': this.deletes.getUid()
-      };
-    };
-
-    Delete.prototype.execute = function() {
-      var res;
-      if (this.validateSavedOperations()) {
-        res = Delete.__super__.execute.apply(this, arguments);
-        if (res) {
-          this.deletes.applyDelete(this);
-        }
-        return res;
-      } else {
-        return false;
-      }
-    };
-
-    return Delete;
-
-  })(ops.Operation);
-  ops.Delete.parse = function(o) {
-    var deletes_uid, uid;
-    uid = o['uid'], deletes_uid = o['deletes'];
-    return new this(null, uid, deletes_uid);
-  };
-  ops.Insert = (function(superClass) {
-    extend(Insert, superClass);
-
-    function Insert(custom_type, content, content_operations, parent, uid, prev_cl, next_cl, origin) {
-      this.saveOperation('parent', parent);
-      this.saveOperation('prev_cl', prev_cl);
-      this.saveOperation('next_cl', next_cl);
-      if (origin != null) {
-        this.saveOperation('origin', origin);
-      } else {
-        this.saveOperation('origin', prev_cl);
-      }
-      Insert.__super__.constructor.call(this, custom_type, uid, content, content_operations);
-    }
-
-    Insert.prototype.type = "Insert";
-
-    Insert.prototype.val = function() {
-      return this.getContent();
-    };
-
-    Insert.prototype.getNext = function(i) {
-      var n;
-      if (i == null) {
-        i = 1;
-      }
-      n = this;
-      while (i > 0 && (n.next_cl != null)) {
-        n = n.next_cl;
-        if (!n.is_deleted) {
-          i--;
-        }
-      }
-      if (n.is_deleted) {
-        null;
-      }
-      return n;
-    };
-
-    Insert.prototype.getPrev = function(i) {
-      var n;
-      if (i == null) {
-        i = 1;
-      }
-      n = this;
-      while (i > 0 && (n.prev_cl != null)) {
-        n = n.prev_cl;
-        if (!n.is_deleted) {
-          i--;
-        }
-      }
-      if (n.is_deleted) {
-        return null;
-      } else {
-        return n;
-      }
-    };
-
-    Insert.prototype.applyDelete = function(o) {
-      var callLater, garbagecollect;
-      if (this.deleted_by == null) {
-        this.deleted_by = [];
-      }
-      callLater = false;
-      if ((this.parent != null) && !this.is_deleted && (o != null)) {
-        callLater = true;
-      }
-      if (o != null) {
-        this.deleted_by.push(o);
-      }
-      garbagecollect = false;
-      if (this.next_cl.isDeleted()) {
-        garbagecollect = true;
-      }
-      Insert.__super__.applyDelete.call(this, garbagecollect);
-      if (callLater) {
-        this.parent.callOperationSpecificDeleteEvents(this, o);
-      }
-      if ((this.prev_cl != null) && this.prev_cl.isDeleted()) {
-        return this.prev_cl.applyDelete();
-      }
-    };
-
-    Insert.prototype.cleanup = function() {
-      var d, j, len, o, ref;
-      if (this.next_cl.isDeleted()) {
-        ref = this.deleted_by;
-        for (j = 0, len = ref.length; j < len; j++) {
-          d = ref[j];
-          d.cleanup();
-        }
-        o = this.next_cl;
-        while (o.type !== "Delimiter") {
-          if (o.origin === this) {
-            o.origin = this.prev_cl;
-          }
-          o = o.next_cl;
-        }
-        this.prev_cl.next_cl = this.next_cl;
-        this.next_cl.prev_cl = this.prev_cl;
-        if (this.content instanceof ops.Operation && !(this.content instanceof ops.Insert)) {
-          this.content.referenced_by--;
-          if (this.content.referenced_by <= 0 && !this.content.is_deleted) {
-            this.content.applyDelete();
-          }
-        }
-        delete this.content;
-        return Insert.__super__.cleanup.apply(this, arguments);
-      }
-    };
-
-    Insert.prototype.getDistanceToOrigin = function() {
-      var d, o;
-      d = 0;
-      o = this.prev_cl;
-      while (true) {
-        if (this.origin === o) {
-          break;
-        }
-        d++;
-        o = o.prev_cl;
-      }
-      return d;
-    };
-
-    Insert.prototype.execute = function() {
-      var base1, distance_to_origin, i, o;
-      if (!this.validateSavedOperations()) {
-        return false;
-      } else {
-        if (this.content instanceof ops.Operation) {
-          this.content.insert_parent = this;
-          if ((base1 = this.content).referenced_by == null) {
-            base1.referenced_by = 0;
-          }
-          this.content.referenced_by++;
-        }
-        if (this.parent != null) {
-          if (this.prev_cl == null) {
-            this.prev_cl = this.parent.beginning;
-          }
-          if (this.origin == null) {
-            this.origin = this.prev_cl;
-          } else if (this.origin === "Delimiter") {
-            this.origin = this.parent.beginning;
-          }
-          if (this.next_cl == null) {
-            this.next_cl = this.parent.end;
-          }
-        }
-        if (this.prev_cl != null) {
-          distance_to_origin = this.getDistanceToOrigin();
-          o = this.prev_cl.next_cl;
-          i = distance_to_origin;
-          while (true) {
-            if (o !== this.next_cl) {
-              if (o.getDistanceToOrigin() === i) {
-                if (o.uid.creator < this.uid.creator) {
-                  this.prev_cl = o;
-                  distance_to_origin = i + 1;
-                } else {
-
-                }
-              } else if (o.getDistanceToOrigin() < i) {
-                if (i - distance_to_origin <= o.getDistanceToOrigin()) {
-                  this.prev_cl = o;
-                  distance_to_origin = i + 1;
-                } else {
-
-                }
-              } else {
-                break;
-              }
-              i++;
-              o = o.next_cl;
-            } else {
-              break;
-            }
-          }
-          this.next_cl = this.prev_cl.next_cl;
-          this.prev_cl.next_cl = this;
-          this.next_cl.prev_cl = this;
-        }
-        this.setParent(this.prev_cl.getParent());
-        Insert.__super__.execute.apply(this, arguments);
-        this.parent.callOperationSpecificInsertEvents(this);
-        return this;
-      }
-    };
-
-    Insert.prototype.getPosition = function() {
-      var position, prev;
-      position = 0;
-      prev = this.prev_cl;
-      while (true) {
-        if (prev instanceof ops.Delimiter) {
-          break;
-        }
-        if (!prev.isDeleted()) {
-          position++;
-        }
-        prev = prev.prev_cl;
-      }
-      return position;
-    };
-
-    Insert.prototype._encode = function(json) {
-      if (json == null) {
-        json = {};
-      }
-      json.prev = this.prev_cl.getUid();
-      json.next = this.next_cl.getUid();
-      if (this.origin.type === "Delimiter") {
-        json.origin = "Delimiter";
-      } else if (this.origin !== this.prev_cl) {
-        json.origin = this.origin.getUid();
-      }
-      json.parent = this.parent.getUid();
-      return Insert.__super__._encode.call(this, json);
-    };
-
-    return Insert;
-
-  })(ops.Operation);
-  ops.Insert.parse = function(json) {
-    var content, content_operations, next, origin, parent, prev, uid;
-    content = json['content'], content_operations = json['content_operations'], uid = json['uid'], prev = json['prev'], next = json['next'], origin = json['origin'], parent = json['parent'];
-    return new this(null, content, content_operations, parent, uid, prev, next, origin);
-  };
-  ops.Delimiter = (function(superClass) {
-    extend(Delimiter, superClass);
-
-    function Delimiter(prev_cl, next_cl, origin) {
-      this.saveOperation('prev_cl', prev_cl);
-      this.saveOperation('next_cl', next_cl);
-      this.saveOperation('origin', prev_cl);
-      Delimiter.__super__.constructor.call(this, null, {
-        noOperation: true
-      });
-    }
-
-    Delimiter.prototype.type = "Delimiter";
-
-    Delimiter.prototype.applyDelete = function() {
-      var o;
-      Delimiter.__super__.applyDelete.call(this);
-      o = this.prev_cl;
-      while (o != null) {
-        o.applyDelete();
-        o = o.prev_cl;
-      }
-      return void 0;
-    };
-
-    Delimiter.prototype.cleanup = function() {
-      return Delimiter.__super__.cleanup.call(this);
-    };
-
-    Delimiter.prototype.execute = function() {
-      var ref, ref1;
-      if (((ref = this.unchecked) != null ? ref['next_cl'] : void 0) != null) {
-        return Delimiter.__super__.execute.apply(this, arguments);
-      } else if ((ref1 = this.unchecked) != null ? ref1['prev_cl'] : void 0) {
-        if (this.validateSavedOperations()) {
-          if (this.prev_cl.next_cl != null) {
-            throw new Error("Probably duplicated operations");
-          }
-          this.prev_cl.next_cl = this;
-          return Delimiter.__super__.execute.apply(this, arguments);
-        } else {
-          return false;
-        }
-      } else if ((this.prev_cl != null) && (this.prev_cl.next_cl == null)) {
-        delete this.prev_cl.unchecked.next_cl;
-        this.prev_cl.next_cl = this;
-        return Delimiter.__super__.execute.apply(this, arguments);
-      } else if ((this.prev_cl != null) || (this.next_cl != null) || true) {
-        return Delimiter.__super__.execute.apply(this, arguments);
-      }
-    };
-
-    Delimiter.prototype._encode = function() {
-      var ref, ref1;
-      return {
-        'type': this.type,
-        'uid': this.getUid(),
-        'prev': (ref = this.prev_cl) != null ? ref.getUid() : void 0,
-        'next': (ref1 = this.next_cl) != null ? ref1.getUid() : void 0
-      };
-    };
-
-    return Delimiter;
-
-  })(ops.Operation);
-  ops.Delimiter.parse = function(json) {
-    var next, prev, uid;
-    uid = json['uid'], prev = json['prev'], next = json['next'];
-    return new this(uid, prev, next);
-  };
-  return {
-    'operations': ops,
-    'execution_listener': execution_listener
-  };
-};

build/node/Operations/Structured.js

@@ -1,579 +0,0 @@
-var basic_ops_uninitialized,
-  extend = function(child, parent) { for (var key in parent) { if (hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; },
-  hasProp = {}.hasOwnProperty;
-
-basic_ops_uninitialized = require("./Basic");
-
-module.exports = function() {
-  var basic_ops, ops;
-  basic_ops = basic_ops_uninitialized();
-  ops = basic_ops.operations;
-  ops.MapManager = (function(superClass) {
-    extend(MapManager, superClass);
-
-    function MapManager(custom_type, uid, content, content_operations) {
-      this._map = {};
-      MapManager.__super__.constructor.call(this, custom_type, uid, content, content_operations);
-    }
-
-    MapManager.prototype.type = "MapManager";
-
-    MapManager.prototype.applyDelete = function() {
-      var name, p, ref;
-      ref = this._map;
-      for (name in ref) {
-        p = ref[name];
-        p.applyDelete();
-      }
-      return MapManager.__super__.applyDelete.call(this);
-    };
-
-    MapManager.prototype.cleanup = function() {
-      return MapManager.__super__.cleanup.call(this);
-    };
-
-    MapManager.prototype.map = function(f) {
-      var n, ref, v;
-      ref = this._map;
-      for (n in ref) {
-        v = ref[n];
-        f(n, v);
-      }
-      return void 0;
-    };
-
-    MapManager.prototype.val = function(name, content) {
-      var o, prop, ref, rep, res, result;
-      if (arguments.length > 1) {
-        if ((content != null) && (content._getModel != null)) {
-          rep = content._getModel(this.custom_types, this.operations);
-        } else {
-          rep = content;
-        }
-        this.retrieveSub(name).replace(rep);
-        return this.getCustomType();
-      } else if (name != null) {
-        prop = this._map[name];
-        if ((prop != null) && !prop.isContentDeleted()) {
-          res = prop.val();
-          if (res instanceof ops.Operation) {
-            return res.getCustomType();
-          } else {
-            return res;
-          }
-        } else {
-          return void 0;
-        }
-      } else {
-        result = {};
-        ref = this._map;
-        for (name in ref) {
-          o = ref[name];
-          if (!o.isContentDeleted()) {
-            result[name] = o.val();
-          }
-        }
-        return result;
-      }
-    };
-
-    MapManager.prototype["delete"] = function(name) {
-      var ref;
-      if ((ref = this._map[name]) != null) {
-        ref.deleteContent();
-      }
-      return this;
-    };
-
-    MapManager.prototype.retrieveSub = function(property_name) {
-      var event_properties, event_this, rm, rm_uid;
-      if (this._map[property_name] == null) {
-        event_properties = {
-          name: property_name
-        };
-        event_this = this;
-        rm_uid = {
-          noOperation: true,
-          sub: property_name,
-          alt: this
-        };
-        rm = new ops.ReplaceManager(null, event_properties, event_this, rm_uid);
-        this._map[property_name] = rm;
-        rm.setParent(this, property_name);
-        rm.execute();
-      }
-      return this._map[property_name];
-    };
-
-    return MapManager;
-
-  })(ops.Operation);
-  ops.MapManager.parse = function(json) {
-    var content, content_operations, custom_type, uid;
-    uid = json['uid'], custom_type = json['custom_type'], content = json['content'], content_operations = json['content_operations'];
-    return new this(custom_type, uid, content, content_operations);
-  };
-  ops.ListManager = (function(superClass) {
-    extend(ListManager, superClass);
-
-    function ListManager(custom_type, uid, content, content_operations) {
-      this.beginning = new ops.Delimiter(void 0, void 0);
-      this.end = new ops.Delimiter(this.beginning, void 0);
-      this.beginning.next_cl = this.end;
-      this.beginning.execute();
-      this.end.execute();
-      ListManager.__super__.constructor.call(this, custom_type, uid, content, content_operations);
-    }
-
-    ListManager.prototype.type = "ListManager";
-
-    ListManager.prototype.applyDelete = function() {
-      var o;
-      o = this.beginning;
-      while (o != null) {
-        o.applyDelete();
-        o = o.next_cl;
-      }
-      return ListManager.__super__.applyDelete.call(this);
-    };
-
-    ListManager.prototype.cleanup = function() {
-      return ListManager.__super__.cleanup.call(this);
-    };
-
-    ListManager.prototype.toJson = function(transform_to_value) {
-      var i, j, len, o, results, val;
-      if (transform_to_value == null) {
-        transform_to_value = false;
-      }
-      val = this.val();
-      results = [];
-      for (o = j = 0, len = val.length; j < len; o = ++j) {
-        i = val[o];
-        if (o instanceof ops.Object) {
-          results.push(o.toJson(transform_to_value));
-        } else if (o instanceof ops.ListManager) {
-          results.push(o.toJson(transform_to_value));
-        } else if (transform_to_value && o instanceof ops.Operation) {
-          results.push(o.val());
-        } else {
-          results.push(o);
-        }
-      }
-      return results;
-    };
-
-    ListManager.prototype.execute = function() {
-      if (this.validateSavedOperations()) {
-        this.beginning.setParent(this);
-        this.end.setParent(this);
-        return ListManager.__super__.execute.apply(this, arguments);
-      } else {
-        return false;
-      }
-    };
-
-    ListManager.prototype.getLastOperation = function() {
-      return this.end.prev_cl;
-    };
-
-    ListManager.prototype.getFirstOperation = function() {
-      return this.beginning.next_cl;
-    };
-
-    ListManager.prototype.toArray = function() {
-      var o, result;
-      o = this.beginning.next_cl;
-      result = [];
-      while (o !== this.end) {
-        if (!o.is_deleted) {
-          result.push(o.val());
-        }
-        o = o.next_cl;
-      }
-      return result;
-    };
-
-    ListManager.prototype.map = function(f) {
-      var o, result;
-      o = this.beginning.next_cl;
-      result = [];
-      while (o !== this.end) {
-        if (!o.is_deleted) {
-          result.push(f(o));
-        }
-        o = o.next_cl;
-      }
-      return result;
-    };
-
-    ListManager.prototype.fold = function(init, f) {
-      var o;
-      o = this.beginning.next_cl;
-      while (o !== this.end) {
-        if (!o.is_deleted) {
-          init = f(init, o);
-        }
-        o = o.next_cl;
-      }
-      return init;
-    };
-
-    ListManager.prototype.val = function(pos) {
-      var o;
-      if (pos != null) {
-        o = this.getOperationByPosition(pos + 1);
-        if (!(o instanceof ops.Delimiter)) {
-          return o.val();
-        } else {
-          throw new Error("this position does not exist");
-        }
-      } else {
-        return this.toArray();
-      }
-    };
-
-    ListManager.prototype.ref = function(pos) {
-      var o;
-      if (pos != null) {
-        o = this.getOperationByPosition(pos + 1);
-        if (!(o instanceof ops.Delimiter)) {
-          return o;
-        } else {
-          return null;
-        }
-      } else {
-        throw new Error("you must specify a position parameter");
-      }
-    };
-
-    ListManager.prototype.getOperationByPosition = function(position) {
-      var o;
-      o = this.beginning;
-      while (true) {
-        if (o instanceof ops.Delimiter && (o.prev_cl != null)) {
-          o = o.prev_cl;
-          while (o.isDeleted() && (o.prev_cl != null)) {
-            o = o.prev_cl;
-          }
-          break;
-        }
-        if (position <= 0 && !o.isDeleted()) {
-          break;
-        }
-        o = o.next_cl;
-        if (!o.isDeleted()) {
-          position -= 1;
-        }
-      }
-      return o;
-    };
-
-    ListManager.prototype.push = function(content) {
-      return this.insertAfter(this.end.prev_cl, [content]);
-    };
-
-    ListManager.prototype.insertAfter = function(left, contents) {
-      var c, j, len, right, tmp;
-      right = left.next_cl;
-      while (right.isDeleted()) {
-        right = right.next_cl;
-      }
-      left = right.prev_cl;
-      if (contents instanceof ops.Operation) {
-        (new ops.Insert(null, content, null, void 0, void 0, left, right)).execute();
-      } else {
-        for (j = 0, len = contents.length; j < len; j++) {
-          c = contents[j];
-          if ((c != null) && (c._name != null) && (c._getModel != null)) {
-            c = c._getModel(this.custom_types, this.operations);
-          }
-          tmp = (new ops.Insert(null, c, null, void 0, void 0, left, right)).execute();
-          left = tmp;
-        }
-      }
-      return this;
-    };
-
-    ListManager.prototype.insert = function(position, contents) {
-      var ith;
-      ith = this.getOperationByPosition(position);
-      return this.insertAfter(ith, contents);
-    };
-
-    ListManager.prototype["delete"] = function(position, length) {
-      var d, delete_ops, i, j, o, ref;
-      if (length == null) {
-        length = 1;
-      }
-      o = this.getOperationByPosition(position + 1);
-      delete_ops = [];
-      for (i = j = 0, ref = length; 0 <= ref ? j < ref : j > ref; i = 0 <= ref ? ++j : --j) {
-        if (o instanceof ops.Delimiter) {
-          break;
-        }
-        d = (new ops.Delete(null, void 0, o)).execute();
-        o = o.next_cl;
-        while ((!(o instanceof ops.Delimiter)) && o.isDeleted()) {
-          o = o.next_cl;
-        }
-        delete_ops.push(d._encode());
-      }
-      return this;
-    };
-
-    ListManager.prototype.callOperationSpecificInsertEvents = function(op) {
-      var getContentType;
-      getContentType = function(content) {
-        if (content instanceof ops.Operation) {
-          return content.getCustomType();
-        } else {
-          return content;
-        }
-      };
-      return this.callEvent([
-        {
-          type: "insert",
-          reference: op,
-          position: op.getPosition(),
-          object: this.getCustomType(),
-          changedBy: op.uid.creator,
-          value: getContentType(op.val())
-        }
-      ]);
-    };
-
-    ListManager.prototype.callOperationSpecificDeleteEvents = function(op, del_op) {
-      return this.callEvent([
-        {
-          type: "delete",
-          reference: op,
-          position: op.getPosition(),
-          object: this.getCustomType(),
-          length: 1,
-          changedBy: del_op.uid.creator,
-          oldValue: op.val()
-        }
-      ]);
-    };
-
-    return ListManager;
-
-  })(ops.Operation);
-  ops.ListManager.parse = function(json) {
-    var content, content_operations, custom_type, uid;
-    uid = json['uid'], custom_type = json['custom_type'], content = json['content'], content_operations = json['content_operations'];
-    return new this(custom_type, uid, content, content_operations);
-  };
-  ops.Composition = (function(superClass) {
-    extend(Composition, superClass);
-
-    function Composition(custom_type, _composition_value, composition_value_operations, uid, tmp_composition_ref) {
-      var n, o;
-      this._composition_value = _composition_value;
-      Composition.__super__.constructor.call(this, custom_type, uid);
-      if (tmp_composition_ref != null) {
-        this.tmp_composition_ref = tmp_composition_ref;
-      } else {
-        this.composition_ref = this.end.prev_cl;
-      }
-      if (composition_value_operations != null) {
-        this.composition_value_operations = {};
-        for (n in composition_value_operations) {
-          o = composition_value_operations[n];
-          this.saveOperation(n, o, '_composition_value');
-        }
-      }
-    }
-
-    Composition.prototype.type = "Composition";
-
-    Composition.prototype.execute = function() {
-      var composition_ref;
-      if (this.validateSavedOperations()) {
-        this.getCustomType()._setCompositionValue(this._composition_value);
-        delete this._composition_value;
-        if (this.tmp_composition_ref) {
-          composition_ref = this.HB.getOperation(this.tmp_composition_ref);
-          if (composition_ref != null) {
-            delete this.tmp_composition_ref;
-            this.composition_ref = composition_ref;
-          }
-        }
-        return Composition.__super__.execute.apply(this, arguments);
-      } else {
-        return false;
-      }
-    };
-
-    Composition.prototype.callOperationSpecificInsertEvents = function(op) {
-      var o;
-      if (this.tmp_composition_ref != null) {
-        if (op.uid.creator === this.tmp_composition_ref.creator && op.uid.op_number === this.tmp_composition_ref.op_number) {
-          this.composition_ref = op;
-          delete this.tmp_composition_ref;
-          op = op.next_cl;
-          if (op === this.end) {
-            return;
-          }
-        } else {
-          return;
-        }
-      }
-      o = this.end.prev_cl;
-      while (o !== op) {
-        this.getCustomType()._unapply(o.undo_delta);
-        o = o.prev_cl;
-      }
-      while (o !== this.end) {
-        o.undo_delta = this.getCustomType()._apply(o.val());
-        o = o.next_cl;
-      }
-      this.composition_ref = this.end.prev_cl;
-      return this.callEvent([
-        {
-          type: "update",
-          changedBy: op.uid.creator,
-          newValue: this.val()
-        }
-      ]);
-    };
-
-    Composition.prototype.callOperationSpecificDeleteEvents = function(op, del_op) {};
-
-    Composition.prototype.applyDelta = function(delta, operations) {
-      (new ops.Insert(null, delta, operations, this, null, this.end.prev_cl, this.end)).execute();
-      return void 0;
-    };
-
-    Composition.prototype._encode = function(json) {
-      var custom, n, o, ref;
-      if (json == null) {
-        json = {};
-      }
-      custom = this.getCustomType()._getCompositionValue();
-      json.composition_value = custom.composition_value;
-      if (custom.composition_value_operations != null) {
-        json.composition_value_operations = {};
-        ref = custom.composition_value_operations;
-        for (n in ref) {
-          o = ref[n];
-          json.composition_value_operations[n] = o.getUid();
-        }
-      }
-      if (this.composition_ref != null) {
-        json.composition_ref = this.composition_ref.getUid();
-      } else {
-        json.composition_ref = this.tmp_composition_ref;
-      }
-      return Composition.__super__._encode.call(this, json);
-    };
-
-    return Composition;
-
-  })(ops.ListManager);
-  ops.Composition.parse = function(json) {
-    var composition_ref, composition_value, composition_value_operations, custom_type, uid;
-    uid = json['uid'], custom_type = json['custom_type'], composition_value = json['composition_value'], composition_value_operations = json['composition_value_operations'], composition_ref = json['composition_ref'];
-    return new this(custom_type, composition_value, composition_value_operations, uid, composition_ref);
-  };
-  ops.ReplaceManager = (function(superClass) {
-    extend(ReplaceManager, superClass);
-
-    function ReplaceManager(custom_type, event_properties1, event_this1, uid) {
-      this.event_properties = event_properties1;
-      this.event_this = event_this1;
-      if (this.event_properties['object'] == null) {
-        this.event_properties['object'] = this.event_this.getCustomType();
-      }
-      ReplaceManager.__super__.constructor.call(this, custom_type, uid);
-    }
-
-    ReplaceManager.prototype.type = "ReplaceManager";
-
-    ReplaceManager.prototype.callEventDecorator = function(events) {
-      var event, j, len, name, prop, ref;
-      if (!this.isDeleted()) {
-        for (j = 0, len = events.length; j < len; j++) {
-          event = events[j];
-          ref = this.event_properties;
-          for (name in ref) {
-            prop = ref[name];
-            event[name] = prop;
-          }
-        }
-        this.event_this.callEvent(events);
-      }
-      return void 0;
-    };
-
-    ReplaceManager.prototype.callOperationSpecificInsertEvents = function(op) {
-      var old_value;
-      if (op.next_cl.type === "Delimiter" && op.prev_cl.type !== "Delimiter") {
-        if (!op.is_deleted) {
-          old_value = op.prev_cl.val();
-          this.callEventDecorator([
-            {
-              type: "update",
-              changedBy: op.uid.creator,
-              oldValue: old_value
-            }
-          ]);
-        }
-        op.prev_cl.applyDelete();
-      } else if (op.next_cl.type !== "Delimiter") {
-        op.applyDelete();
-      } else {
-        this.callEventDecorator([
-          {
-            type: "add",
-            changedBy: op.uid.creator
-          }
-        ]);
-      }
-      return void 0;
-    };
-
-    ReplaceManager.prototype.callOperationSpecificDeleteEvents = function(op, del_op) {
-      if (op.next_cl.type === "Delimiter") {
-        return this.callEventDecorator([
-          {
-            type: "delete",
-            changedBy: del_op.uid.creator,
-            oldValue: op.val()
-          }
-        ]);
-      }
-    };
-
-    ReplaceManager.prototype.replace = function(content, replaceable_uid) {
-      var o, relp;
-      o = this.getLastOperation();
-      relp = (new ops.Insert(null, content, null, this, replaceable_uid, o, o.next_cl)).execute();
-      return void 0;
-    };
-
-    ReplaceManager.prototype.isContentDeleted = function() {
-      return this.getLastOperation().isDeleted();
-    };
-
-    ReplaceManager.prototype.deleteContent = function() {
-      var last_op;
-      last_op = this.getLastOperation();
-      if ((!last_op.isDeleted()) && last_op.type !== "Delimiter") {
-        (new ops.Delete(null, void 0, this.getLastOperation().uid)).execute();
-      }
-      return void 0;
-    };
-
-    ReplaceManager.prototype.val = function() {
-      var o;
-      o = this.getLastOperation();
-      return typeof o.val === "function" ? o.val() : void 0;
-    };
-
-    return ReplaceManager;
-
-  })(ops.ListManager);
-  return basic_ops;
-};

build/node/y-object.js

@@ -1,90 +0,0 @@
-var bindToChildren;
-
-bindToChildren = function(that) {
-  var attr, i, j, ref;
-  for (i = j = 0, ref = that.children.length; 0 <= ref ? j < ref : j > ref; i = 0 <= ref ? ++j : --j) {
-    attr = that.children.item(i);
-    if (attr.name != null) {
-      attr.val = that.val.val(attr.name);
-    }
-  }
-  return that.val.observe(function(events) {
-    var event, k, len, newVal, results;
-    results = [];
-    for (k = 0, len = events.length; k < len; k++) {
-      event = events[k];
-      if (event.name != null) {
-        results.push((function() {
-          var l, ref1, results1;
-          results1 = [];
-          for (i = l = 0, ref1 = that.children.length; 0 <= ref1 ? l < ref1 : l > ref1; i = 0 <= ref1 ? ++l : --l) {
-            attr = that.children.item(i);
-            if ((attr.name != null) && attr.name === event.name) {
-              newVal = that.val.val(attr.name);
-              if (attr.val !== newVal) {
-                results1.push(attr.val = newVal);
-              } else {
-                results1.push(void 0);
-              }
-            } else {
-              results1.push(void 0);
-            }
-          }
-          return results1;
-        })());
-      } else {
-        results.push(void 0);
-      }
-    }
-    return results;
-  });
-};
-
-Polymer("y-object", {
-  ready: function() {
-    if (this.connector != null) {
-      this.val = new Y(this.connector);
-      return bindToChildren(this);
-    } else if (this.val != null) {
-      return bindToChildren(this);
-    }
-  },
-  valChanged: function() {
-    if ((this.val != null) && this.val._name === "Object") {
-      return bindToChildren(this);
-    }
-  },
-  connectorChanged: function() {
-    if (this.val == null) {
-      this.val = new Y(this.connector);
-      return bindToChildren(this);
-    }
-  }
-});
-
-Polymer("y-property", {
-  ready: function() {
-    if ((this.val != null) && (this.name != null)) {
-      if (this.val.constructor === Object) {
-        this.val = this.parentElement.val(this.name, new Y.Object(this.val)).val(this.name);
-      } else if (typeof this.val === "string") {
-        this.parentElement.val(this.name, this.val);
-      }
-      if (this.val._name === "Object") {
-        return bindToChildren(this);
-      }
-    }
-  },
-  valChanged: function() {
-    var ref;
-    if ((this.val != null) && (this.name != null)) {
-      if (this.val.constructor === Object) {
-        return this.val = this.parentElement.val.val(this.name, new Y.Object(this.val)).val(this.name);
-      } else if (this.val._name === "Object") {
-        return bindToChildren(this);
-      } else if ((((ref = this.parentElement.val) != null ? ref.val : void 0) != null) && this.val !== this.parentElement.val.val(this.name)) {
-        return this.parentElement.val.val(this.name, this.val);
-      }
-    }
-  }
-});

build/node/y.js

@@ -1,45 +0,0 @@
-var Engine, HistoryBuffer, adaptConnector, createY, structured_ops_uninitialized;
-
-structured_ops_uninitialized = require("./Operations/Structured");
-
-HistoryBuffer = require("./HistoryBuffer");
-
-Engine = require("./Engine");
-
-adaptConnector = require("./ConnectorAdapter");
-
-createY = function(connector) {
-  var HB, ct, engine, model, ops, ops_manager, user_id;
-  if (connector.user_id != null) {
-    user_id = connector.user_id;
-  } else {
-    user_id = "_temp";
-    connector.when_received_state_vector_listeners = [
-      function(state_vector) {
-        return HB.setUserId(this.user_id, state_vector);
-      }
-    ];
-  }
-  HB = new HistoryBuffer(user_id);
-  ops_manager = structured_ops_uninitialized(HB, this.constructor);
-  ops = ops_manager.operations;
-  engine = new Engine(HB, ops);
-  adaptConnector(connector, engine, HB, ops_manager.execution_listener);
-  ops.Operation.prototype.HB = HB;
-  ops.Operation.prototype.operations = ops;
-  ops.Operation.prototype.engine = engine;
-  ops.Operation.prototype.connector = connector;
-  ops.Operation.prototype.custom_types = this.constructor;
-  ct = new createY.Object();
-  model = new ops.MapManager(ct, HB.getReservedUniqueIdentifier()).execute();
-  ct._setModel(model);
-  return ct;
-};
-
-module.exports = createY;
-
-if (typeof window !== "undefined" && window !== null) {
-  window.Y = createY;
-}
-
-createY.Object = require("./ObjectType");

build/test/index.html

@@ -1,27 +0,0 @@
-<html>
-<head>
-  <meta charset="utf-8">
-  <title>Test Yjs!</title>
-  <link rel="stylesheet" href="../../node_modules/mocha/mocha.css" />
-</head>
-<body>
-  <div id="mocha"></div>
-  <script src="../../node_modules/mocha/mocha.js" class="awesome"></script>
-  <script>
-    mocha.setup('bdd');
-    mocha.ui('bdd');
-    mocha.reporter('html');
-  </script>
-  <script src="object-test.js"></script>
-  <script src="xml-test.js"></script>
-  <script src="list-test.js"></script>
-  <script src="text-test.js"></script>
-  <script>
-    //mocha.checkLeaks();
-    //mocha.run();
-    window.onerror = null;
-    if (window.mochaPhantomJS) { mochaPhantomJS.run(); }
-    else { mocha.run(); }
-  </script>
-</body>
-</html>

examples/README.md

@@ -1,5 +0,0 @@
-# Examples
-
-Here you find some (hopefully) usefull examples on how to use Yjs!
-
-Feel free to use the code of the examples in your own project. They include basic examples how to use Yjs.

examples/XMPP-Polymer/index.html

@@ -1,14 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-  <head>
-    <meta charset=utf-8 />
-    <title>Y Example</title>
-    <script src="../../../webcomponentsjs/webcomponents.min.js"></script>
-    <link rel="import" href="../../../polymer/polymer.html">
-
-    <link rel="import" href="y-test.html">
-  </head>
-  <body>
-    <y-test></y-test>
-  </body>
-</html>

examples/XMPP-Polymer/y-test.html

@@ -1,57 +0,0 @@
-<script src="../../build/browser/y.js"></script>
-<script src="../../../y-text/build/browser/y-text.js"></script>
-<link rel="import" href="../../build/browser/y-object.html">
-<link rel="import" href="../../../y-xmpp/build/browser/y-xmpp.html">
-<link rel="import" href="../../../paper-slider/paper-slider.html">
-
-<polymer-element name="y-test" attributes="y connector stuff">
-  <template>
-    <h1 id="text" contentEditable> Check this out !</h1>
-    <y-xmpp id="connector" connector={{connector}} room="testy-xmpp-polymer" syncMode="syncAll" debug="true"></y-xmpp>
-    <y-object connector={{connector}} val={{y}}>
-      <y-property name="slider" val={{slider}}>
-      </y-property>
-      <y-property name="stuff" val={{stuff}}>
-        <y-property id="otherstuff" name="otherstuff" val={{otherstuff}}>
-        </y-property>
-      </y-property>
-    </y-object>
-    <y-object val={{otherstuff}}>
-      <y-property name="nostuff" val={{nostuff}}>
-      </y-property>
-    </y-object>
-    <paper-slider min="0" max="200" immediateValue={{slider}}></paper-slider>
-  </template>
-  <script>
-  Polymer({
-    ready: function(){
-      window.y_stuff_property = this.$.otherstuff;
-      this.y.val("slider",50)
-      var that = this;
-      this.connector.whenSynced(function(){
-        if(that.y.val("text") == null){
-          that.y.val("text",new Y.Text("stuff"));
-        }
-        that.y.val("text").bind(that.$.text,that.shadowRoot)
-      })
-
-      // Everything is initialized. Lets test stuff!
-      window.y_test = this;
-      window.y_test.y.val("stuff",{otherstuff:{nostuff:"this is no stuff"}})
-      setTimeout(function(){
-        var res = y_test.y.val("stuff");
-        if(!(y_test.nostuff === "this is no stuff")){
-          console.log("Deep inherit doesn't work!")
-        }
-        window.y_stuff_property.val = {nostuff: "this is also no stuff"};
-        setTimeout(function(){
-          if(!(y_test.nostuff === "this is also no stuff")){
-            console.log("Element val overwrite doesn't work")
-          }
-          console.log("Everything is fine :)");
-        },500)
-      },500);
-    }
-  })
-  </script>
-</polymer-element>

examples/XMPP/index.html

@@ -1,21 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-        <meta charset=utf-8 />
-        <title>Y Example</title>
-        <script src="../../build/browser/y.js"></script>
-        <script src="../../../y-text/build/browser/y-text.js"></script>
-        <script src="../../../y-xmpp/y-xmpp.js"></script>
-        <script src="./index.js"></script>
-</head>
-<body>
-<h1 contentEditable> yjs Tutorial</h1>
-<p> Collaborative Json editing with <a href="https://github.com/rwth-acis/yjs/">yjs</a>
-and XMPP Connector. </p>
-
-<textarea style="width:80%;" rows=40 id="textfield"></textarea>
-
-<p> <a href="https://github.com/y-js/yjs/">yjs</a> is a Framework for Real-Time collaboration on arbitrary data types.
-</p>
-</body>
-</html>

examples/XMPP/index.js

@@ -1,26 +0,0 @@
-
-
-connector = new Y.XMPP().join("testy-xmpp-json3", {syncMode: "syncAll"});
-connector.debug = true
-
-y = new Y(connector);
-
-window.onload = function(){
-  var textbox = document.getElementById("textfield");
-  y.observe(function(events){
-    for(var i=0; i<events.length; i++){
-      var event = events[i];
-      if(event.name === "textfield" && event.type !== "delete"){
-        y.val("textfield").bind(textbox);
-        y.val("headline").bind(document.querySelector("h1"))
-      }
-    }
-  });
-  connector.whenSynced(function(){
-    if(y.val("textfield") == null){
-      y.val("headline", new Y.Text("headline"));
-      y.val("textfield",new Y.Text("stuff"))
-    }
-  })
-
-};

gulpfile.coffee

@@ -1,114 +0,0 @@
-gulp = require('gulp')
-coffee = require('gulp-coffee')
-concat = require('gulp-concat')
-uglify = require 'gulp-uglify'
-sourcemaps = require('gulp-sourcemaps')
-browserify = require('gulp-browserify')
-rename = require 'gulp-rename'
-rimraf = require 'gulp-rimraf'
-gulpif = require 'gulp-if'
-ignore = require 'gulp-ignore'
-git = require 'gulp-git'
-debug = require 'gulp-debug'
-coffeelint = require 'gulp-coffeelint'
-mocha = require 'gulp-mocha'
-run = require 'gulp-run'
-ljs = require 'gulp-ljs'
-plumber = require 'gulp-plumber'
-cache = require 'gulp-cached'
-coffeeify = require 'gulp-coffeeify'
-exit = require 'gulp-exit'
-
-gulp.task 'default', ['build_browser']
-
-files =
-  lib : ['./lib/**/*.coffee']
-  browser : ['./lib/y.coffee','./lib/y-object.coffee']
-  test : ['./test/**/*test.coffee', '../y-*/test/*test.coffee']
-  #test : ['./test/Json_test.coffee', './test/Text_test.coffee']
-  gulp : ['./gulpfile.coffee']
-  examples : ['./examples/**/*.js']
-  other: ['./lib/**/*', './test/*']
-
-files.all = []
-for name,file_list of files
-  if name isnt 'build'
-    files.all = files.all.concat file_list
-
-gulp.task 'deploy_nodejs', ->
-  gulp.src files.lib
-    .pipe sourcemaps.init()
-    .pipe coffee()
-    .pipe sourcemaps.write './'
-    .pipe gulp.dest 'build/node/'
-    .pipe gulpif '!**/', git.add({args : "-A"})
-
-gulp.task 'deploy', ['mocha', 'build_browser', 'deploy_nodejs', 'lint', 'codo']
-
-gulp.task 'build_browser', ->
-  gulp.src files.browser, { read: false }
-    .pipe plumber()
-    .pipe browserify
-      transform: ['coffeeify']
-      extensions: ['.coffee']
-      debug : true
-    .pipe rename
-      extname: ".js"
-    .pipe gulp.dest './build/browser/'
-    .pipe uglify()
-    .pipe gulp.dest '.'
-
-  gulp.src files.test, {read: false}
-    .pipe plumber()
-    .pipe browserify
-      transform: ['coffeeify']
-      extensions: ['.coffee']
-      debug: true
-    .pipe rename
-      extname: ".js"
-      dirname: "./"
-    .pipe gulp.dest './build/test/'
-
-gulp.task 'build_node', ->
-  gulp.src files.lib
-    .pipe plumber()
-    .pipe coffee({bare:true})
-    .pipe gulp.dest './build/node'
-
-gulp.task 'build', ['build_node', 'build_browser'], ->
-
-gulp.task 'watch', ['build'], ->
-  gulp.watch files.all, ['build']
-
-gulp.task 'mocha', ->
-  gulp.src files.test, { read: false }
-    .pipe mocha {reporter : 'list'}
-    .pipe exit()
-
-gulp.task 'lint', ->
-  gulp.src files.all
-    .pipe ignore.include '**/*.coffee'
-    .pipe coffeelint {
-      "max_line_length":
-        "level": "ignore"
-      }
-    .pipe coffeelint.reporter()
-
-gulp.task 'literate', ->
-  gulp.src files.examples
-    .pipe ljs { code : true }
-    .pipe rename
-      basename : "README"
-      extname : ".md"
-    .pipe gulp.dest 'examples/'
-    .pipe gulpif '!**/', git.add({args : "-A"})
-
-gulp.task 'codo', [], ()->
-  command = './node_modules/codo/bin/codo -o "./doc" --name "yjs" --readme "README.md" --undocumented false --private true --title "yjs API" ./lib - LICENSE.txt '
-  run(command).exec()
-
-gulp.task 'clean', ->
-  gulp.src ['./build/{browser,test,node}/**/*.{js,map}','./doc/'], { read: false }
-    .pipe rimraf()
-
-gulp.task 'default', ['clean','build'], ->

lib/ConnectorAdapter.coffee

@@ -1,61 +0,0 @@
-
-ConnectorClass = require "./ConnectorClass"
-#
-# @param {Engine} engine The transformation engine
-# @param {HistoryBuffer} HB
-# @param {Array<Function>} execution_listener You must ensure that whenever an operation is executed, every function in this Array is called.
-#
-adaptConnector = (connector, engine, HB, execution_listener)->
-
-  for name, f of ConnectorClass
-    connector[name] = f
-
-  connector.setIsBoundToY()
-
-  send_ = (o)->
-    if (o.uid.creator is HB.getUserId()) and
-        (typeof o.uid.op_number isnt "string") and # TODO: i don't think that we need this anymore..
-        (HB.getUserId() isnt "_temp")
-      connector.broadcast o
-
-  if connector.invokeSync?
-    HB.setInvokeSyncHandler connector.invokeSync
-
-  execution_listener.push send_
-  # For the XMPPConnector: lets send it as an array
-  # therefore, we have to restructure it later
-  encode_state_vector = (v)->
-    for name,value of v
-      user: name
-      state: value
-  parse_state_vector = (v)->
-    state_vector = {}
-    for s in v
-      state_vector[s.user] = s.state
-    state_vector
-
-  getStateVector = ()->
-    encode_state_vector HB.getOperationCounter()
-
-  getHB = (v)->
-    state_vector = parse_state_vector v
-    hb = HB._encode state_vector
-    json =
-      hb: hb
-      state_vector: encode_state_vector HB.getOperationCounter()
-    json
-
-  applyHB = (hb, fromHB)->
-    engine.applyOp hb, fromHB
-
-  connector.getStateVector = getStateVector
-  connector.getHB = getHB
-  connector.applyHB = applyHB
-
-  connector.receive_handlers ?= []
-  connector.receive_handlers.push (sender, op)->
-    if op.uid.creator isnt HB.getUserId()
-      engine.applyOp op
-
-
-module.exports = adaptConnector

lib/ConnectorClass.coffee

@@ -1,355 +0,0 @@
-
-module.exports =
-  #
-  # @params new Connector(options)
-  #   @param options.syncMethod {String}  is either "syncAll" or "master-slave".
-  #   @param options.role {String} The role of this client
-  #            (slave or master (only used when syncMethod is master-slave))
-  #   @param options.perform_send_again {Boolean} Whetehr to whether to resend the HB after some time period. This reduces sync errors, but has some overhead (optional)
-  #
-  init: (options)->
-    req = (name, choices)=>
-      if options[name]?
-        if (not choices?) or choices.some((c)->c is options[name])
-          @[name] = options[name]
-        else
-          throw new Error "You can set the '"+name+"' option to one of the following choices: "+JSON.encode(choices)
-      else
-        throw new Error "You must specify "+name+", when initializing the Connector!"
-
-    req "syncMethod", ["syncAll", "master-slave"]
-    req "role", ["master", "slave"]
-    req "user_id"
-    @on_user_id_set?(@user_id)
-
-    # whether to resend the HB after some time period. This reduces sync errors.
-    # But this is not necessary in the test-connector
-    if options.perform_send_again?
-      @perform_send_again = options.perform_send_again
-    else
-      @perform_send_again = true
-
-    # A Master should sync with everyone! TODO: really? - for now its safer this way!
-    if @role is "master"
-      @syncMethod = "syncAll"
-
-    # is set to true when this is synced with all other connections
-    @is_synced = false
-    # Peerjs Connections: key: conn-id, value: object
-    @connections = {}
-    # List of functions that shall process incoming data
-    @receive_handlers ?= []
-
-    # whether this instance is bound to any y instance
-    @connections = {}
-    @current_sync_target = null
-    @sent_hb_to_all_users = false
-    @is_initialized = true
-
-  onUserEvent: (f)->
-    @connections_listeners ?= []
-    @connections_listeners.push f
-
-  isRoleMaster: ->
-    @role is "master"
-
-  isRoleSlave: ->
-    @role is "slave"
-
-  findNewSyncTarget: ()->
-    @current_sync_target = null
-    if @syncMethod is "syncAll"
-      for user, c of @connections
-        if not c.is_synced
-          @performSync user
-          break
-    if not @current_sync_target?
-      @setStateSynced()
-    null
-
-  userLeft: (user)->
-    delete @connections[user]
-    @findNewSyncTarget()
-    if @connections_listeners?
-      for f in @connections_listeners
-        f {
-          action: "userLeft"
-          user: user
-        }
-
-
-  userJoined: (user, role)->
-    if not role?
-      throw new Error "Internal: You must specify the role of the joined user! E.g. userJoined('uid:3939','slave')"
-    # a user joined the room
-    @connections[user] ?= {}
-    @connections[user].is_synced = false
-
-    if (not @is_synced) or @syncMethod is "syncAll"
-      if @syncMethod is "syncAll"
-        @performSync user
-      else if role is "master"
-        # TODO: What if there are two masters? Prevent sending everything two times!
-        @performSyncWithMaster user
-
-    if @connections_listeners?
-      for f in @connections_listeners
-        f {
-          action: "userJoined"
-          user: user
-          role: role
-        }
-
-  #
-  # Execute a function _when_ we are connected. If not connected, wait until connected.
-  # @param f {Function} Will be executed on the Connector context.
-  #
-  whenSynced: (args)->
-    if args.constructor is Function
-      args = [args]
-    if @is_synced
-      args[0].apply this, args[1..]
-    else
-      @compute_when_synced ?= []
-      @compute_when_synced.push args
-
-  #
-  # Execute an function when a message is received.
-  # @param f {Function} Will be executed on the PeerJs-Connector context. f will be called with (sender_id, broadcast {true|false}, message).
-  #
-  onReceive: (f)->
-    @receive_handlers.push f
-
-  ###
-  # Broadcast a message to all connected peers.
-  # @param message {Object} The message to broadcast.
-  #
-  broadcast: (message)->
-    throw new Error "You must implement broadcast!"
-
-  #
-  # Send a message to a peer, or set of peers
-  #
-  send: (peer_s, message)->
-    throw new Error "You must implement send!"
-  ###
-
-  #
-  # perform a sync with a specific user.
-  #
-  performSync: (user)->
-    if not @current_sync_target?
-      @current_sync_target = user
-      @send user,
-        sync_step: "getHB"
-        send_again: "true"
-        data: @getStateVector()
-      if not @sent_hb_to_all_users
-        @sent_hb_to_all_users = true
-
-        hb = @getHB([]).hb
-        _hb = []
-        for o in hb
-          _hb.push o
-          if _hb.length > 10
-            @broadcast
-              sync_step: "applyHB_"
-              data: _hb
-            _hb = []
-        @broadcast
-          sync_step: "applyHB"
-          data: _hb
-
-
-
-  #
-  # When a master node joined the room, perform this sync with him. It will ask the master for the HB,
-  # and will broadcast his own HB
-  #
-  performSyncWithMaster: (user)->
-    @current_sync_target = user
-    @send user,
-      sync_step: "getHB"
-      send_again: "true"
-      data: @getStateVector()
-    hb = @getHB([]).hb
-    _hb = []
-    for o in hb
-      _hb.push o
-      if _hb.length > 10
-        @broadcast
-          sync_step: "applyHB_"
-          data: _hb
-        _hb = []
-    @broadcast
-      sync_step: "applyHB"
-      data: _hb
-
-  #
-  # You are sure that all clients are synced, call this function.
-  #
-  setStateSynced: ()->
-    if not @is_synced
-      @is_synced = true
-      if @compute_when_synced?
-        for el in @compute_when_synced
-          f = el[0]
-          args = el[1..]
-          f.apply(args)
-        delete @compute_when_synced
-      null
-
-  # executed when the a state_vector is received. listener will be called only once!
-  whenReceivedStateVector: (f)->
-    @when_received_state_vector_listeners ?= []
-    @when_received_state_vector_listeners.push f
-
-
-  #
-  # You received a raw message, and you know that it is intended for to Yjs. Then call this function.
-  #
-  receiveMessage: (sender, res)->
-    if not res.sync_step?
-      for f in @receive_handlers
-        f sender, res
-    else
-      if sender is @user_id
-        return
-      if res.sync_step is "getHB"
-        # call listeners
-        if @when_received_state_vector_listeners?
-          for f in @when_received_state_vector_listeners
-            f.call this, res.data
-        delete @when_received_state_vector_listeners
-
-        data = @getHB(res.data)
-        hb = data.hb
-        _hb = []
-        # always broadcast, when not synced.
-        # This reduces errors, when the clients goes offline prematurely.
-        # When this client only syncs to one other clients, but looses connectors,
-        # before syncing to the other clients, the online clients have different states.
-        # Since we do not want to perform regular syncs, this is a good alternative
-        if @is_synced
-          sendApplyHB = (m)=>
-            @send sender, m
-        else
-          sendApplyHB = (m)=>
-            @broadcast m
-
-        for o in hb
-          _hb.push o
-          if _hb.length > 10
-            sendApplyHB
-              sync_step: "applyHB_"
-              data: _hb
-            _hb = []
-
-        sendApplyHB
-          sync_step : "applyHB"
-          data: _hb
-
-        if res.send_again? and @perform_send_again
-          send_again = do (sv = data.state_vector)=>
-            ()=>
-              hb = @getHB(sv).hb
-              for o in hb
-                _hb.push o
-                if _hb.length > 10
-                  @send sender,
-                    sync_step: "applyHB_"
-                    data: _hb
-                  _hb = []
-              @send sender,
-                sync_step: "applyHB",
-                data: _hb
-                sent_again: "true"
-          setTimeout send_again, 3000
-      else if res.sync_step is "applyHB"
-        @applyHB(res.data, sender is @current_sync_target)
-
-        if (@syncMethod is "syncAll" or res.sent_again?) and (not @is_synced) and ((@current_sync_target is sender) or (not @current_sync_target?))
-          @connections[sender].is_synced = true
-          @findNewSyncTarget()
-
-      else if res.sync_step is "applyHB_"
-        @applyHB(res.data, sender is @current_sync_target)
-
-
-  # Currently, the HB encodes operations as JSON. For the moment I want to keep it
-  # that way. Maybe we support encoding in the HB as XML in the future, but for now I don't want
-  # too much overhead. Y is very likely to get changed a lot in the future
-  #
-  # Because we don't want to encode JSON as string (with character escaping, wich makes it pretty much unreadable)
-  # we encode the JSON as XML.
-  #
-  # When the HB support encoding as XML, the format should look pretty much like this.
-
-  # does not support primitive values as array elements
-  # expects an ltx (less than xml) object
-  parseMessageFromXml: (m)->
-    parse_array = (node)->
-      for n in node.children
-        if n.getAttribute("isArray") is "true"
-          parse_array n
-        else
-          parse_object n
-
-    parse_object = (node)->
-      json = {}
-      for name, value  of node.attrs
-        int = parseInt(value)
-        if isNaN(int) or (""+int) isnt value
-          json[name] = value
-        else
-          json[name] = int
-      for n in node.children
-        name = n.name
-        if n.getAttribute("isArray") is "true"
-          json[name] = parse_array n
-        else
-          json[name] = parse_object n
-      json
-    parse_object m
-
-  # encode message in xml
-  # we use string because Strophe only accepts an "xml-string"..
-  # So {a:4,b:{c:5}} will look like
-  # <y a="4">
-  #   <b c="5"></b>
-  # </y>
-  # m - ltx element
-  # json - guess it ;)
-  #
-  encodeMessageToXml: (m, json)->
-    # attributes is optional
-    encode_object = (m, json)->
-      for name,value of json
-        if not value?
-          # nop
-        else if value.constructor is Object
-          encode_object m.c(name), value
-        else if value.constructor is Array
-          encode_array m.c(name), value
-        else
-          m.setAttribute(name,value)
-      m
-    encode_array = (m, array)->
-      m.setAttribute("isArray","true")
-      for e in array
-        if e.constructor is Object
-          encode_object m.c("array-element"), e
-        else
-          encode_array m.c("array-element"), e
-      m
-    if json.constructor is Object
-      encode_object m.c("y",{xmlns:"http://y.ninja/connector-stanza"}), json
-    else if json.constructor is Array
-      encode_array m.c("y",{xmlns:"http://y.ninja/connector-stanza"}), json
-    else
-      throw new Error "I can't encode this json!"
-
-  setIsBoundToY: ()->
-    @on_bound_to_y?()
-    delete @when_bound_to_y
-    @is_bound_to_y = true

lib/Engine.coffee

@@ -1,115 +0,0 @@
-
-window?.unprocessed_counter = 0 # del this
-window?.unprocessed_exec_counter = 0 # TODO
-window?.unprocessed_types = []
-
-#
-# @nodoc
-# The Engine handles how and in which order to execute operations and add operations to the HistoryBuffer.
-#
-class Engine
-
-  #
-  # @param {HistoryBuffer} HB
-  # @param {Object} types list of available types
-  #
-  constructor: (@HB, @types)->
-    @unprocessed_ops = []
-
-  #
-  # Parses an operatio from the json format. It uses the specified parser in your OperationType module.
-  #
-  parseOperation: (json)->
-    type = @types[json.type]
-    if type?.parse?
-      type.parse json
-    else
-      throw new Error "You forgot to specify a parser for type #{json.type}. The message is #{JSON.stringify json}."
-
-
-  #
-  # Apply a set of operations. E.g. the operations you received from another users HB._encode().
-  # @note You must not use this method when you already have ops in your HB!
-  ###
-  applyOpsBundle: (ops_json)->
-    ops = []
-    for o in ops_json
-      ops.push @parseOperation o
-    for o in ops
-      if not o.execute()
-        @unprocessed_ops.push o
-    @tryUnprocessed()
-  ###
-
-  #
-  # Same as applyOps but operations that are already in the HB are not applied.
-  # @see Engine.applyOps
-  #
-  applyOpsCheckDouble: (ops_json)->
-    for o in ops_json
-      if not @HB.getOperation(o.uid)?
-        @applyOp o
-
-  #
-  # Apply a set of operations. (Helper for using applyOp on Arrays)
-  # @see Engine.applyOp
-  applyOps: (ops_json)->
-    @applyOp ops_json
-
-  #
-  # Apply an operation that you received from another peer.
-  # TODO: make this more efficient!!
-  # - operations may only executed in order by creator, order them in object of arrays (key by creator)
-  # - you can probably make something like dependencies (creator1 waits for creator2)
-  applyOp: (op_json_array, fromHB = false)->
-    if op_json_array.constructor isnt Array
-      op_json_array = [op_json_array]
-    for op_json in op_json_array
-      if fromHB
-        op_json.fromHB = "true" # execute immediately, if
-      # $parse_and_execute will return false if $o_json was parsed and executed, otherwise the parsed operadion
-      o = @parseOperation op_json
-      o.parsed_from_json = op_json
-      if op_json.fromHB?
-        o.fromHB = op_json.fromHB
-      # @HB.addOperation o
-      if @HB.getOperation(o)?
-        # nop
-      else if ((not @HB.isExpectedOperation(o)) and (not o.fromHB?)) or (not o.execute())
-        @unprocessed_ops.push o
-        window?.unprocessed_types.push o.type # TODO: delete this
-    @tryUnprocessed()
-
-  #
-  # Call this method when you applied a new operation.
-  # It checks if operations that were previously not executable are now executable.
-  #
-  tryUnprocessed: ()->
-    while true
-      old_length = @unprocessed_ops.length
-      unprocessed = []
-      for op in @unprocessed_ops
-        if @HB.getOperation(op)?
-          # nop
-        else if (not @HB.isExpectedOperation(op) and (not op.fromHB?)) or (not op.execute())
-          unprocessed.push op
-      @unprocessed_ops = unprocessed
-      if @unprocessed_ops.length is old_length
-        break
-    if @unprocessed_ops.length isnt 0
-      @HB.invokeSync()
-
-
-module.exports = Engine
-
-
-
-
-
-
-
-
-
-
-
-

lib/HistoryBuffer.coffee

@@ -1,227 +0,0 @@
-
-#
-# @nodoc
-# An object that holds all applied operations.
-#
-# @note The HistoryBuffer is commonly abbreviated to HB.
-#
-class HistoryBuffer
-
-  #
-  # Creates an empty HB.
-  # @param {Object} user_id Creator of the HB.
-  #
-  constructor: (@user_id)->
-    @operation_counter = {}
-    @buffer = {}
-    @change_listeners = []
-    @garbage = [] # Will be cleaned on next call of garbageCollector
-    @trash = [] # Is deleted. Wait until it is not used anymore.
-    @performGarbageCollection = true
-    @garbageCollectTimeout = 30000
-    @reserved_identifier_counter = 0
-    setTimeout @emptyGarbage, @garbageCollectTimeout
-
-  # At the beginning (when the user id was not assigned yet),
-  # the operations are added to buffer._temp. When you finally get your user id,
-  # the operations are copies from buffer._temp to buffer[id]. Furthermore, when buffer[id] does already contain operations
-  # (because of a previous session), the uid.op_numbers of the operations have to be reassigned.
-  # This is what this function does. It adds them to buffer[id],
-  # and assigns them the correct uid.op_number and uid.creator
-  setUserId: (@user_id, state_vector)->
-    @buffer[@user_id] ?= []
-    buff = @buffer[@user_id]
-
-    # we assumed that we started with counter = 0.
-    # when we receive tha state_vector, and actually have
-    # counter = 10. Then we have to add 10 to every op_counter
-    counter_diff = state_vector[@user_id] or 0
-
-    if @buffer._temp?
-      for o_name,o of @buffer._temp
-        o.uid.creator = @user_id
-        o.uid.op_number += counter_diff
-        buff[o.uid.op_number] = o
-
-    @operation_counter[@user_id] = (@operation_counter._temp or 0) + counter_diff
-
-    delete @operation_counter._temp
-    delete @buffer._temp
-
-
-  emptyGarbage: ()=>
-    for o in @garbage
-      #if @getOperationCounter(o.uid.creator) > o.uid.op_number
-      o.cleanup?()
-
-    @garbage = @trash
-    @trash = []
-    if @garbageCollectTimeout isnt -1
-      @garbageCollectTimeoutId = setTimeout @emptyGarbage, @garbageCollectTimeout
-    undefined
-
-  #
-  # Get the user id with wich the History Buffer was initialized.
-  #
-  getUserId: ()->
-    @user_id
-
-  addToGarbageCollector: ()->
-    if @performGarbageCollection
-      for o in arguments
-        if o?
-          @garbage.push o
-
-  stopGarbageCollection: ()->
-    @performGarbageCollection = false
-    @setManualGarbageCollect()
-    @garbage = []
-    @trash = []
-
-  setManualGarbageCollect: ()->
-    @garbageCollectTimeout = -1
-    clearTimeout @garbageCollectTimeoutId
-    @garbageCollectTimeoutId = undefined
-
-  setGarbageCollectTimeout: (@garbageCollectTimeout)->
-
-  #
-  # I propose to use it in your Framework, to create something like a root element.
-  # An operation with this identifier is not propagated to other clients.
-  # This is why everybode must create the same operation with this uid.
-  #
-  getReservedUniqueIdentifier: ()->
-    {
-      creator : '_'
-      op_number : "_#{@reserved_identifier_counter++}"
-    }
-
-  #
-  # Get the operation counter that describes the current state of the document.
-  #
-  getOperationCounter: (user_id)->
-    if not user_id?
-      res = {}
-      for user,ctn of @operation_counter
-        res[user] = ctn
-      res
-    else
-      @operation_counter[user_id]
-
-  isExpectedOperation: (o)->
-    @operation_counter[o.uid.creator] ?= 0
-    o.uid.op_number <= @operation_counter[o.uid.creator]
-    true #TODO: !! this could break stuff. But I dunno why
-
-  #
-  # Encode this operation in such a way that it can be parsed by remote peers.
-  # TODO: Make this more efficient!
-  _encode: (state_vector={})->
-    json = []
-    unknown = (user, o_number)->
-      if (not user?) or (not o_number?)
-        throw new Error "dah!"
-      not state_vector[user]? or state_vector[user] <= o_number
-
-    for u_name,user of @buffer
-      # TODO next, if @state_vector[user] <= state_vector[user]
-      if u_name is "_"
-        continue
-      for o_number,o of user
-        if (not o.uid.noOperation?) and unknown(u_name, o_number)
-          # its necessary to send it, and not known in state_vector
-          o_json = o._encode()
-          if o.next_cl? # applies for all ops but the most right delimiter!
-            # search for the next _known_ operation. (When state_vector is {} then this is the Delimiter)
-            o_next = o.next_cl
-            while o_next.next_cl? and unknown(o_next.uid.creator, o_next.uid.op_number)
-              o_next = o_next.next_cl
-            o_json.next = o_next.getUid()
-          else if o.prev_cl? # most right delimiter only!
-            # same as the above with prev.
-            o_prev = o.prev_cl
-            while o_prev.prev_cl? and unknown(o_prev.uid.creator, o_prev.uid.op_number)
-              o_prev = o_prev.prev_cl
-            o_json.prev = o_prev.getUid()
-          json.push o_json
-
-    json
-
-  #
-  # Get the number of operations that were created by a user.
-  # Accordingly you will get the next operation number that is expected from that user.
-  # This will increment the operation counter.
-  #
-  getNextOperationIdentifier: (user_id)->
-    if not user_id?
-      user_id = @user_id
-    if not @operation_counter[user_id]?
-      @operation_counter[user_id] = 0
-    uid =
-      'creator' : user_id
-      'op_number' : @operation_counter[user_id]
-    @operation_counter[user_id]++
-    uid
-
-  #
-  # Retrieve an operation from a unique id.
-  #
-  # when uid has a "sub" property, the value of it will be applied
-  # on the operations retrieveSub method (which must! be defined)
-  #
-  getOperation: (uid)->
-    if uid.uid?
-      uid = uid.uid
-    o = @buffer[uid.creator]?[uid.op_number]
-    if uid.sub? and o?
-      o.retrieveSub uid.sub
-    else
-      o
-
-  #
-  # Add an operation to the HB. Note that this will not link it against
-  # other operations (it wont executed)
-  #
-  addOperation: (o)->
-    if not @buffer[o.uid.creator]?
-      @buffer[o.uid.creator] = {}
-    if @buffer[o.uid.creator][o.uid.op_number]?
-      throw new Error "You must not overwrite operations!"
-    if (o.uid.op_number.constructor isnt String) and (not @isExpectedOperation(o)) and (not o.fromHB?) # you already do this in the engine, so delete it here!
-      throw new Error "this operation was not expected!"
-    @addToCounter(o)
-    @buffer[o.uid.creator][o.uid.op_number] = o
-    o
-
-  removeOperation: (o)->
-    delete @buffer[o.uid.creator]?[o.uid.op_number]
-
-  # When the HB determines inconsistencies, then the invokeSync
-  # handler wil be called, which should somehow invoke the sync with another collaborator.
-  # The parameter of the sync handler is the user_id with wich an inconsistency was determined
-  setInvokeSyncHandler: (f)->
-    @invokeSync = f
-
-  # empty per default # TODO: do i need this?
-  invokeSync: ()->
-
-  # after you received the HB of another user (in the sync process),
-  # you renew your own state_vector to the state_vector of the other user
-  renewStateVector: (state_vector)->
-    for user,state of state_vector
-      if ((not @operation_counter[user]?) or (@operation_counter[user] < state_vector[user])) and state_vector[user]?
-        @operation_counter[user] = state_vector[user]
-
-  #
-  # Increment the operation_counter that defines the current state of the Engine.
-  #
-  addToCounter: (o)->
-    @operation_counter[o.uid.creator] ?= 0
-    # TODO: check if operations are send in order
-    if o.uid.op_number is @operation_counter[o.uid.creator]
-      @operation_counter[o.uid.creator]++
-    while @buffer[o.uid.creator][@operation_counter[o.uid.creator]]?
-      @operation_counter[o.uid.creator]++
-    undefined
-
-module.exports = HistoryBuffer

lib/ObjectType.coffee

@@ -1,74 +0,0 @@
-
-class YObject
-
-  constructor: (@_object = {})->
-    if @_object.constructor is Object
-      for name, val of @_object
-        if val.constructor is Object
-          @_object[name] = new YObject(val)
-    else
-      throw new Error "Y.Object accepts Json Objects only"
-
-  _name: "Object"
-
-  _getModel: (types, ops)->
-    if not @_model?
-      @_model = new ops.MapManager(@).execute()
-      for n,o of @_object
-        @_model.val n, o
-    delete @_object
-    @_model
-
-  _setModel: (@_model)->
-    delete @_object
-
-  observe: (f)->
-    @_model.observe f
-    @
-
-  unobserve: (f)->
-    @_model.unobserve f
-    @
-
-  #
-  # @overload val()
-  #   Get this as a Json object.
-  #   @return [Json]
-  #
-  # @overload val(name)
-  #   Get value of a property.
-  #   @param {String} name Name of the object property.
-  #   @return [*] Depends on the value of the property.
-  #
-  # @overload val(name, content)
-  #   Set a new property.
-  #   @param {String} name Name of the object property.
-  #   @param {Object|String} content Content of the object property.
-  #   @return [Object Type] This object. (supports chaining)
-  #
-  val: (name, content)->
-    if @_model?
-      @_model.val.apply @_model, arguments
-    else
-      if content?
-        @_object[name] = content
-      else if name?
-        @_object[name]
-      else
-        res = {}
-        for n,v of @_object
-          res[n] = v
-        res
-
-  delete: (name)->
-    @_model.delete(name)
-    @
-
-if window?
-  if window.Y?
-    window.Y.Object = YObject
-  else
-    throw new Error "You must first import Y!"
-
-if module?
-  module.exports = YObject

lib/Operations/Basic.coffee

@@ -1,678 +0,0 @@
-module.exports = ()->
-  # @see Engine.parse
-  ops = {}
-  execution_listener = []
-
-  #
-  # @private
-  # @abstract
-  # @nodoc
-  # A generic interface to ops.
-  #
-  # An operation has the following methods:
-  # * _encode: encodes an operation (needed only if instance of this operation is sent).
-  # * execute: execute the effects of this operations. Good examples are Insert-type and AddName-type
-  # * val: in the case that the operation holds a value
-  #
-  # Furthermore an encodable operation has a parser. We extend the parser object in order to parse encoded operations.
-  #
-  class ops.Operation
-
-    #
-    # @param {Object} uid A unique identifier.
-    # If uid is undefined, a new uid will be created before at the end of the execution sequence
-    #
-    constructor: (custom_type, uid, content, content_operations)->
-      if custom_type?
-        @custom_type = custom_type
-      @is_deleted = false
-      @garbage_collected = false
-      @event_listeners = [] # TODO: rename to observers or sth like that
-      if uid?
-        @uid = uid
-
-      # see encode to see, why we are doing it this way
-      if content is undefined
-        # nop
-      else if content? and content.creator?
-        @saveOperation 'content', content
-      else
-        @content = content
-      if content_operations?
-        @content_operations = {}
-        for name, op of content_operations
-          @saveOperation name, op, 'content_operations'
-
-    type: "Operation"
-
-    getContent: (name)->
-      if @content?
-        if @content.getCustomType?
-          @content.getCustomType()
-        else if @content.constructor is Object
-          if name?
-            if @content[name]?
-              @content[name]
-            else
-              @content_operations[name].getCustomType()
-          else
-            content = {}
-            for n,v of @content
-              content[n] = v
-            if @content_operations?
-              for n,v of @content_operations
-                v = v.getCustomType()
-                content[n] = v
-            content
-        else
-          @content
-      else
-        @content
-
-    retrieveSub: ()->
-      throw new Error "sub properties are not enable on this operation type!"
-
-    #
-    # Add an event listener. It depends on the operation which events are supported.
-    # @param {Function} f f is executed in case the event fires.
-    #
-    observe: (f)->
-      @event_listeners.push f
-
-    #
-    # Deletes function from the observer list
-    # @see Operation.observe
-    #
-    # @overload unobserve(event, f)
-    #   @param f     {Function} The function that you want to delete
-    unobserve: (f)->
-      @event_listeners = @event_listeners.filter (g)->
-        f isnt g
-
-    #
-    # Deletes all subscribed event listeners.
-    # This should be called, e.g. after this has been replaced.
-    # (Then only one replace event should fire. )
-    # This is also called in the cleanup method.
-    deleteAllObservers: ()->
-      @event_listeners = []
-
-    delete: ()->
-      (new ops.Delete undefined, @).execute()
-      null
-
-    #
-    # Fire an event.
-    # TODO: Do something with timeouts. You don't want this to fire for every operation (e.g. insert).
-    # TODO: do you need callEvent+forwardEvent? Only one suffices probably
-    callEvent: ()->
-      if @custom_type?
-        callon = @getCustomType()
-      else
-        callon = @
-      @forwardEvent callon, arguments...
-
-    #
-    # Fire an event and specify in which context the listener is called (set 'this').
-    # TODO: do you need this ?
-    forwardEvent: (op, args...)->
-      for f in @event_listeners
-        f.call op, args...
-
-    isDeleted: ()->
-      @is_deleted
-
-    applyDelete: (garbagecollect = true)->
-      if not @garbage_collected
-        #console.log "applyDelete: #{@type}"
-        @is_deleted = true
-        if garbagecollect
-          @garbage_collected = true
-          @HB.addToGarbageCollector @
-
-    cleanup: ()->
-      #console.log "cleanup: #{@type}"
-      @HB.removeOperation @
-      @deleteAllObservers()
-
-    #
-    # Set the parent of this operation.
-    #
-    setParent: (@parent)->
-
-    #
-    # Get the parent of this operation.
-    #
-    getParent: ()->
-      @parent
-
-    #
-    # Computes a unique identifier (uid) that identifies this operation.
-    #
-    getUid: ()->
-      if not @uid.noOperation?
-        @uid
-      else
-        if @uid.alt? # could be (safely) undefined
-          map_uid = @uid.alt.cloneUid()
-          map_uid.sub = @uid.sub
-          map_uid
-        else
-          undefined
-
-    cloneUid: ()->
-      uid = {}
-      for n,v of @getUid()
-        uid[n] = v
-      uid
-
-    #
-    # @private
-    # If not already done, set the uid
-    # Add this to the HB
-    # Notify the all the listeners.
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        @is_executed = true
-        if not @uid?
-          # When this operation was created without a uid, then set it here.
-          # There is only one other place, where this can be done - before an Insertion
-          # is executed (because we need the creator_id)
-          @uid = @HB.getNextOperationIdentifier()
-        if not @uid.noOperation?
-          @HB.addOperation @
-          for l in execution_listener
-            l @_encode()
-        @
-      else
-        false
-
-    #
-    # @private
-    # Operations may depend on other operations (linked lists, etc.).
-    # The saveOperation and validateSavedOperations methods provide
-    # an easy way to refer to these operations via an uid or object reference.
-    #
-    # For example: We can create a new Delete operation that deletes the operation $o like this
-    #     - var d = new Delete(uid, $o);   or
-    #     - var d = new Delete(uid, $o.getUid());
-    # Either way we want to access $o via d.deletes. In the second case validateSavedOperations must be called first.
-    #
-    # @overload saveOperation(name, op_uid)
-    #   @param {String} name The name of the operation. After validating (with validateSavedOperations) the instantiated operation will be accessible via this[name].
-    #   @param {Object} op_uid A uid that refers to an operation
-    # @overload saveOperation(name, op)
-    #   @param {String} name The name of the operation. After calling this function op is accessible via this[name].
-    #   @param {Operation} op An Operation object
-    #
-    saveOperation: (name, op, base = "this")->
-      if op? and op._getModel?
-        op = op._getModel(@custom_types, @operations)
-      #
-      # Every instance of $Operation must have an $execute function.
-      # We use duck-typing to check if op is instantiated since there
-      # could exist multiple classes of $Operation
-      #
-      if not op?
-        # nop
-      else if op.execute? or not (op.op_number? and op.creator?)
-        # is instantiated, or op is string. Currently "Delimiter" is saved as string
-        # (in combination with @parent you can retrieve the delimiter..)
-        if base is "this"
-          @[name] = op
-        else
-          dest = @[base]
-          paths = name.split("/")
-          last_path = paths.pop()
-          for path in paths
-            dest = dest[path]
-          dest[last_path] = op
-      else
-        # not initialized. Do it when calling $validateSavedOperations()
-        @unchecked ?= {}
-        @unchecked[base] ?= {}
-        @unchecked[base][name] = op
-
-    #
-    # @private
-    # After calling this function all not instantiated operations will be accessible.
-    # @see Operation.saveOperation
-    #
-    # @return [Boolean] Whether it was possible to instantiate all operations.
-    #
-    validateSavedOperations: ()->
-      uninstantiated = {}
-      success = true
-      for base_name, base of @unchecked
-        for name, op_uid of base
-          op = @HB.getOperation op_uid
-          if op
-            if base_name is "this"
-              @[name] = op
-            else
-              dest = @[base_name]
-              paths = name.split("/")
-              last_path = paths.pop()
-              for path in paths
-                dest = dest[path]
-              dest[last_path] = op
-          else
-            uninstantiated[base_name] ?= {}
-            uninstantiated[base_name][name] = op_uid
-            success = false
-      if not success
-        @unchecked = uninstantiated
-        return false
-      else
-        delete @unchecked
-        return @
-
-    getCustomType: ()->
-      if not @custom_type?
-        # throw new Error "This operation was not initialized with a custom type"
-        @
-      else
-        if @custom_type.constructor is String
-          # has not been initialized yet (only the name is specified)
-          Type = @custom_types
-          for t in @custom_type.split(".")
-            Type = Type[t]
-          @custom_type = new Type()
-          @custom_type._setModel @
-        @custom_type
-
-    #
-    # @private
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: (json = {})->
-      json.type = @type
-      json.uid = @getUid()
-      if @custom_type?
-        if @custom_type.constructor is String
-          json.custom_type = @custom_type
-        else
-          json.custom_type = @custom_type._name
-
-      if @content?.getUid?
-        json.content = @content.getUid()
-      else
-        json.content = @content
-      if @content_operations?
-        operations = {}
-        for n,o of @content_operations
-          if o._getModel?
-            o = o._getModel(@custom_types, @operations)
-          operations[n] = o.getUid()
-        json.content_operations = operations
-      json
-
-  #
-  # @nodoc
-  # A simple Delete-type operation that deletes an operation.
-  #
-  class ops.Delete extends ops.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Object} deletes UID or reference of the operation that this to be deleted.
-    #
-    constructor: (custom_type, uid, deletes)->
-      @saveOperation 'deletes', deletes
-      super custom_type, uid
-
-    type: "Delete"
-
-    #
-    # @private
-    # Convert all relevant information of this operation to the json-format.
-    # This result can be sent to other clients.
-    #
-    _encode: ()->
-      {
-        'type': "Delete"
-        'uid': @getUid()
-        'deletes': @deletes.getUid()
-      }
-
-    #
-    # @private
-    # Apply the deletion.
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        res = super
-        if res
-          @deletes.applyDelete @
-        res
-      else
-        false
-
-  #
-  # Define how to parse Delete operations.
-  #
-  ops.Delete.parse = (o)->
-    {
-      'uid' : uid
-      'deletes': deletes_uid
-    } = o
-    new this(null, uid, deletes_uid)
-
-  #
-  # @nodoc
-  # A simple insert-type operation.
-  #
-  # An insert operation is always positioned between two other insert operations.
-  # Internally this is realized as associative lists, whereby each insert operation has a predecessor and a successor.
-  # For the sake of efficiency we maintain two lists:
-  #   - The short-list (abbrev. sl) maintains only the operations that are not deleted (unimplemented, good idea?)
-  #   - The complete-list (abbrev. cl) maintains all operations
-  #
-  class ops.Insert extends ops.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Operation} prev_cl The predecessor of this operation in the complete-list (cl)
-    # @param {Operation} next_cl The successor of this operation in the complete-list (cl)
-    #
-    constructor: (custom_type, content, content_operations, parent, uid, prev_cl, next_cl, origin)->
-      @saveOperation 'parent', parent
-      @saveOperation 'prev_cl', prev_cl
-      @saveOperation 'next_cl', next_cl
-      if origin?
-        @saveOperation 'origin', origin
-      else
-        @saveOperation 'origin', prev_cl
-      super custom_type, uid, content, content_operations
-
-    type: "Insert"
-
-    val: ()->
-      @getContent()
-
-    getNext: (i=1)->
-      n = @
-      while i > 0 and n.next_cl?
-        n = n.next_cl
-        if not n.is_deleted
-          i--
-      if n.is_deleted
-        null
-      n
-
-    getPrev: (i=1)->
-      n = @
-      while i > 0 and n.prev_cl?
-        n = n.prev_cl
-        if not n.is_deleted
-          i--
-      if n.is_deleted
-        null
-      else
-        n
-
-    #
-    # set content to null and other stuff
-    # @private
-    #
-    applyDelete: (o)->
-      @deleted_by ?= []
-      callLater = false
-      if @parent? and not @is_deleted and o? # o? : if not o?, then the delimiter deleted this Insertion. Furthermore, it would be wrong to call it. TODO: make this more expressive and save
-        # call iff wasn't deleted earlyer
-        callLater = true
-      if o?
-        @deleted_by.push o
-      garbagecollect = false
-      if @next_cl.isDeleted()
-        garbagecollect = true
-      super garbagecollect
-      if callLater
-        @parent.callOperationSpecificDeleteEvents(this, o)
-      if @prev_cl? and @prev_cl.isDeleted()
-        # garbage collect prev_cl
-        @prev_cl.applyDelete()
-
-    cleanup: ()->
-      if @next_cl.isDeleted()
-        # delete all ops that delete this insertion
-        for d in @deleted_by
-          d.cleanup()
-
-        # throw new Error "right is not deleted. inconsistency!, wrararar"
-        # change origin references to the right
-        o = @next_cl
-        while o.type isnt "Delimiter"
-          if o.origin is @
-            o.origin = @prev_cl
-          o = o.next_cl
-        # reconnect left/right
-        @prev_cl.next_cl = @next_cl
-        @next_cl.prev_cl = @prev_cl
-
-        # delete content
-        # - we must not do this in applyDelete, because this would lead to inconsistencies
-        # (e.g. the following operation order must be invertible :
-        #   Insert refers to content, then the content is deleted)
-        # Therefore, we have to do this in the cleanup
-        # * NODE: We never delete Insertions!
-        if @content instanceof ops.Operation and not (@content instanceof ops.Insert)
-          @content.referenced_by--
-          if @content.referenced_by <= 0 and not @content.is_deleted
-            @content.applyDelete()
-        delete @content
-        super
-      # else
-      #   Someone inserted something in the meantime.
-      #   Remember: this can only be garbage collected when next_cl is deleted
-
-    #
-    # @private
-    # The amount of positions that $this operation was moved to the right.
-    #
-    getDistanceToOrigin: ()->
-      d = 0
-      o = @prev_cl
-      while true
-        if @origin is o
-          break
-        d++
-        o = o.prev_cl
-      d
-
-    #
-    # @private
-    # Include this operation in the associative lists.
-    execute: ()->
-      if not @validateSavedOperations()
-        return false
-      else
-        if @content instanceof ops.Operation
-          @content.insert_parent = @ # TODO: this is probably not necessary and only nice for debugging
-          @content.referenced_by ?= 0
-          @content.referenced_by++
-        if @parent?
-          if not @prev_cl?
-            @prev_cl = @parent.beginning
-          if not @origin?
-            @origin = @prev_cl
-          else if @origin is "Delimiter"
-            @origin = @parent.beginning
-          if not @next_cl?
-            @next_cl = @parent.end
-        if @prev_cl?
-          distance_to_origin = @getDistanceToOrigin() # most cases: 0
-          o = @prev_cl.next_cl
-          i = distance_to_origin # loop counter
-
-          # $this has to find a unique position between origin and the next known character
-          # case 1: $origin equals $o.origin: the $creator parameter decides if left or right
-          #         let $OL= [o1,o2,o3,o4], whereby $this is to be inserted between o1 and o4
-          #         o2,o3 and o4 origin is 1 (the position of o2)
-          #         there is the case that $this.creator < o2.creator, but o3.creator < $this.creator
-          #         then o2 knows o3. Since on another client $OL could be [o1,o3,o4] the problem is complex
-          #         therefore $this would be always to the right of o3
-          # case 2: $origin < $o.origin
-          #         if current $this insert_position > $o origin: $this ins
-          #         else $insert_position will not change
-          #         (maybe we encounter case 1 later, then this will be to the right of $o)
-          # case 3: $origin > $o.origin
-          #         $this insert_position is to the left of $o (forever!)
-          while true
-            if o isnt @next_cl
-              # $o happened concurrently
-              if o.getDistanceToOrigin() is i
-                # case 1
-                if o.uid.creator < @uid.creator
-                  @prev_cl = o
-                  distance_to_origin = i + 1
-                else
-                  # nop
-              else if o.getDistanceToOrigin() < i
-                # case 2
-                if i - distance_to_origin <= o.getDistanceToOrigin()
-                  @prev_cl = o
-                  distance_to_origin = i + 1
-                else
-                  #nop
-              else
-                # case 3
-                break
-              i++
-              o = o.next_cl
-            else
-              # $this knows that $o exists,
-              break
-          # now reconnect everything
-          @next_cl = @prev_cl.next_cl
-          @prev_cl.next_cl = @
-          @next_cl.prev_cl = @
-
-        @setParent @prev_cl.getParent() # do Insertions always have a parent?
-        super # notify the execution_listeners
-        @parent.callOperationSpecificInsertEvents(this)
-        @
-
-    #
-    # Compute the position of this operation.
-    #
-    getPosition: ()->
-      position = 0
-      prev = @prev_cl
-      while true
-        if prev instanceof ops.Delimiter
-          break
-        if not prev.isDeleted()
-          position++
-        prev = prev.prev_cl
-      position
-
-    #
-    # Convert all relevant information of this operation to the json-format.
-    # This result can be send to other clients.
-    #
-    _encode: (json = {})->
-      json.prev = @prev_cl.getUid()
-      json.next = @next_cl.getUid()
-
-      if @origin.type is "Delimiter"
-        json.origin = "Delimiter"
-      else if @origin isnt @prev_cl
-        json.origin = @origin.getUid()
-
-      # if not (json.prev? and json.next?)
-      json.parent = @parent.getUid()
-
-      super json
-
-  ops.Insert.parse = (json)->
-    {
-      'content' : content
-      'content_operations' : content_operations
-      'uid' : uid
-      'prev': prev
-      'next': next
-      'origin' : origin
-      'parent' : parent
-    } = json
-    new this null, content, content_operations, parent, uid, prev, next, origin
-
-  #
-  # @nodoc
-  # A delimiter is placed at the end and at the beginning of the associative lists.
-  # This is necessary in order to have a beginning and an end even if the content
-  # of the Engine is empty.
-  #
-  class ops.Delimiter extends ops.Operation
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Operation} prev_cl The predecessor of this operation in the complete-list (cl)
-    # @param {Operation} next_cl The successor of this operation in the complete-list (cl)
-    #
-    constructor: (prev_cl, next_cl, origin)->
-      @saveOperation 'prev_cl', prev_cl
-      @saveOperation 'next_cl', next_cl
-      @saveOperation 'origin', prev_cl
-      super null, {noOperation: true}
-
-    type: "Delimiter"
-
-    applyDelete: ()->
-      super()
-      o = @prev_cl
-      while o?
-        o.applyDelete()
-        o = o.prev_cl
-      undefined
-
-    cleanup: ()->
-      super()
-
-    #
-    # @private
-    #
-    execute: ()->
-      if @unchecked?['next_cl']?
-        super
-      else if @unchecked?['prev_cl']
-        if @validateSavedOperations()
-          if @prev_cl.next_cl?
-            throw new Error "Probably duplicated operations"
-          @prev_cl.next_cl = @
-          super
-        else
-          false
-      else if @prev_cl? and not @prev_cl.next_cl?
-        delete @prev_cl.unchecked.next_cl
-        @prev_cl.next_cl = @
-        super
-      else if @prev_cl? or @next_cl? or true # TODO: are you sure? This can happen right?
-        super
-      #else
-      #  throw new Error "Delimiter is unsufficient defined!"
-
-    #
-    # @private
-    #
-    _encode: ()->
-      {
-        'type' : @type
-        'uid' : @getUid()
-        'prev' : @prev_cl?.getUid()
-        'next' : @next_cl?.getUid()
-      }
-
-  ops.Delimiter.parse = (json)->
-    {
-    'uid' : uid
-    'prev' : prev
-    'next' : next
-    } = json
-    new this(uid, prev, next)
-
-  # This is what this module exports after initializing it with the HistoryBuffer
-  {
-    'operations' : ops
-    'execution_listener' : execution_listener
-  }

lib/Operations/Structured.coffee

@@ -1,533 +0,0 @@
-basic_ops_uninitialized = require "./Basic"
-
-module.exports = ()->
-  basic_ops = basic_ops_uninitialized()
-  ops = basic_ops.operations
-
-  #
-  # @nodoc
-  # Manages map like objects. E.g. Json-Type and XML attributes.
-  #
-  class ops.MapManager extends ops.Operation
-
-    #
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    #
-    constructor: (custom_type, uid, content, content_operations)->
-      @_map = {}
-      super custom_type, uid, content, content_operations
-
-    type: "MapManager"
-
-    applyDelete: ()->
-      for name,p of @_map
-        p.applyDelete()
-      super()
-
-    cleanup: ()->
-      super()
-
-    map: (f)->
-      for n,v of @_map
-        f(n,v)
-      undefined
-
-    #
-    # @see JsonOperations.val
-    #
-    val: (name, content)->
-      if arguments.length > 1
-        if content? and content._getModel?
-          rep = content._getModel(@custom_types, @operations)
-        else
-          rep = content
-        @retrieveSub(name).replace rep
-        @getCustomType()
-      else if name?
-        prop = @_map[name]
-        if prop? and not prop.isContentDeleted()
-          res = prop.val()
-          if res instanceof ops.Operation
-            res.getCustomType()
-          else
-            res
-        else
-          undefined
-      else
-        result = {}
-        for name,o of @_map
-          if not o.isContentDeleted()
-            result[name] = o.val()
-        result
-
-    delete: (name)->
-      @_map[name]?.deleteContent()
-      @
-
-    retrieveSub: (property_name)->
-      if not @_map[property_name]?
-        event_properties =
-          name: property_name
-        event_this = @
-        rm_uid =
-          noOperation: true
-          sub: property_name
-          alt: @
-        rm = new ops.ReplaceManager null, event_properties, event_this, rm_uid # this operation shall not be saved in the HB
-        @_map[property_name] = rm
-        rm.setParent @, property_name
-        rm.execute()
-      @_map[property_name]
-
-  ops.MapManager.parse = (json)->
-    {
-      'uid' : uid
-      'custom_type' : custom_type
-      'content' : content
-      'content_operations' : content_operations
-    } = json
-    new this(custom_type, uid, content, content_operations)
-
-
-
-  #
-  # @nodoc
-  # Manages a list of Insert-type operations.
-  #
-  class ops.ListManager extends ops.Operation
-
-    #
-    # A ListManager maintains a non-empty list that has a beginning and an end (both Delimiters!)
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Delimiter} beginning Reference or Object.
-    # @param {Delimiter} end Reference or Object.
-    constructor: (custom_type, uid, content, content_operations)->
-      @beginning = new ops.Delimiter undefined, undefined
-      @end =       new ops.Delimiter @beginning, undefined
-      @beginning.next_cl = @end
-      @beginning.execute()
-      @end.execute()
-      super custom_type, uid, content, content_operations
-
-    type: "ListManager"
-
-
-    applyDelete: ()->
-      o = @beginning
-      while o?
-        o.applyDelete()
-        o = o.next_cl
-      super()
-
-    cleanup: ()->
-      super()
-
-
-    toJson: (transform_to_value = false)->
-      val = @val()
-      for i, o in val
-        if o instanceof ops.Object
-          o.toJson(transform_to_value)
-        else if o instanceof ops.ListManager
-          o.toJson(transform_to_value)
-        else if transform_to_value and o instanceof ops.Operation
-          o.val()
-        else
-          o
-
-    #
-    # @private
-    # @see Operation.execute
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        @beginning.setParent @
-        @end.setParent @
-        super
-      else
-        false
-
-    # Get the element previous to the delemiter at the end
-    getLastOperation: ()->
-      @end.prev_cl
-
-    # similar to the above
-    getFirstOperation: ()->
-      @beginning.next_cl
-
-    # Transforms the the list to an array
-    # Doesn't return left-right delimiter.
-    toArray: ()->
-      o = @beginning.next_cl
-      result = []
-      while o isnt @end
-        if not o.is_deleted
-          result.push o.val()
-        o = o.next_cl
-      result
-
-    map: (f)->
-      o = @beginning.next_cl
-      result = []
-      while o isnt @end
-        if not o.is_deleted
-          result.push f(o)
-        o = o.next_cl
-      result
-
-    fold: (init, f)->
-      o = @beginning.next_cl
-      while o isnt @end
-        if not o.is_deleted
-          init = f(init, o)
-        o = o.next_cl
-      init
-
-    val: (pos)->
-      if pos?
-        o = @getOperationByPosition(pos+1)
-        if not (o instanceof ops.Delimiter)
-          o.val()
-        else
-          throw new Error "this position does not exist"
-      else
-        @toArray()
-
-    ref: (pos)->
-      if pos?
-        o = @getOperationByPosition(pos+1)
-        if not (o instanceof ops.Delimiter)
-          o
-        else
-          null
-          # throw new Error "this position does not exist"
-      else
-        throw new Error "you must specify a position parameter"
-
-    #
-    # Retrieves the x-th not deleted element.
-    # e.g. "abc" : the 1th character is "a"
-    # the 0th character is the left Delimiter
-    #
-    getOperationByPosition: (position)->
-      o = @beginning
-      while true
-        # find the i-th op
-        if o instanceof ops.Delimiter and o.prev_cl?
-          # the user or you gave a position parameter that is to big
-          # for the current array. Therefore we reach a Delimiter.
-          # Then, we'll just return the last character.
-          o = o.prev_cl
-          while o.isDeleted() and o.prev_cl?
-            o = o.prev_cl
-          break
-        if position <= 0 and not o.isDeleted()
-          break
-
-        o = o.next_cl
-        if not o.isDeleted()
-          position -= 1
-      o
-
-    push: (content)->
-      @insertAfter @end.prev_cl, [content]
-
-    insertAfter: (left, contents)->
-      right = left.next_cl
-      while right.isDeleted()
-        right = right.next_cl # find the first character to the right, that is not deleted. In the case that position is 0, its the Delimiter.
-      left = right.prev_cl
-
-      # TODO: always expect an array as content. Then you can combine this with the other option (else)
-      if contents instanceof ops.Operation
-        (new ops.Insert null, content, null, undefined, undefined, left, right).execute()
-      else
-        for c in contents
-          if c? and c._name? and c._getModel?
-            c = c._getModel(@custom_types, @operations)
-          tmp = (new ops.Insert null, c, null, undefined, undefined, left, right).execute()
-          left = tmp
-      @
-
-    #
-    # Inserts an array of content into this list.
-    # @Note: This expects an array as content!
-    #
-    # @return {ListManager Type} This String object.
-    #
-    insert: (position, contents)->
-      ith = @getOperationByPosition position
-      # the (i-1)th character. e.g. "abc" the 1th character is "a"
-      # the 0th character is the left Delimiter
-      @insertAfter ith, contents
-
-    #
-    # Deletes a part of the word.
-    #
-    # @return {ListManager Type} This String object
-    #
-    delete: (position, length = 1)->
-      o = @getOperationByPosition(position+1) # position 0 in this case is the deletion of the first character
-
-      delete_ops = []
-      for i in [0...length]
-        if o instanceof ops.Delimiter
-          break
-        d = (new ops.Delete null, undefined, o).execute()
-        o = o.next_cl
-        while (not (o instanceof ops.Delimiter)) and o.isDeleted()
-          o = o.next_cl
-        delete_ops.push d._encode()
-      @
-
-
-    callOperationSpecificInsertEvents: (op)->
-      getContentType = (content)->
-        if content instanceof ops.Operation
-          content.getCustomType()
-        else
-          content
-      @callEvent [
-        type: "insert"
-        reference: op
-        position: op.getPosition()
-        object: @getCustomType()
-        changedBy: op.uid.creator
-        value: getContentType op.val()
-      ]
-
-    callOperationSpecificDeleteEvents: (op, del_op)->
-      @callEvent [
-        type: "delete"
-        reference: op
-        position: op.getPosition()
-        object: @getCustomType() # TODO: You can combine getPosition + getParent in a more efficient manner! (only left Delimiter will hold @parent)
-        length: 1
-        changedBy: del_op.uid.creator
-        oldValue: op.val()
-      ]
-
-  ops.ListManager.parse = (json)->
-    {
-      'uid' : uid
-      'custom_type': custom_type
-      'content' : content
-      'content_operations' : content_operations
-    } = json
-    new this(custom_type, uid, content, content_operations)
-
-  class ops.Composition extends ops.ListManager
-
-    constructor: (custom_type, @_composition_value, composition_value_operations, uid, tmp_composition_ref)->
-      # we can't use @seveOperation 'composition_ref', tmp_composition_ref here,
-      # because then there is a "loop" (insertion refers to parent, refers to insertion..)
-      # This is why we have to check in @callOperationSpecificInsertEvents until we find it
-      super custom_type, uid
-      if tmp_composition_ref?
-        @tmp_composition_ref = tmp_composition_ref
-      else
-        @composition_ref = @end.prev_cl
-      if composition_value_operations?
-        @composition_value_operations = {}
-        for n,o of composition_value_operations
-          @saveOperation n, o, '_composition_value'
-
-    type: "Composition"
-
-    #
-    # @private
-    # @see Operation.execute
-    #
-    execute: ()->
-      if @validateSavedOperations()
-        @getCustomType()._setCompositionValue @_composition_value
-        delete @_composition_value
-        # check if tmp_composition_ref already exists
-        if @tmp_composition_ref
-          composition_ref = @HB.getOperation @tmp_composition_ref
-          if composition_ref?
-            delete @tmp_composition_ref
-            @composition_ref = composition_ref
-        super
-      else
-        false
-
-    #
-    # This is called, when the Insert-operation was successfully executed.
-    #
-    callOperationSpecificInsertEvents: (op)->
-      if @tmp_composition_ref?
-        if op.uid.creator is @tmp_composition_ref.creator and op.uid.op_number is @tmp_composition_ref.op_number
-          @composition_ref = op
-          delete @tmp_composition_ref
-          op = op.next_cl
-          if op is @end
-            return
-        else
-          return
-
-      o = @end.prev_cl
-      while o isnt op
-        @getCustomType()._unapply o.undo_delta
-        o = o.prev_cl
-      while o isnt @end
-        o.undo_delta = @getCustomType()._apply o.val()
-        o = o.next_cl
-      @composition_ref = @end.prev_cl
-
-      @callEvent [
-        type: "update"
-        changedBy: op.uid.creator
-        newValue: @val()
-      ]
-
-    callOperationSpecificDeleteEvents: (op, del_op)->
-      return
-
-    #
-    # Create a new Delta
-    # - inserts new Content at the end of the list
-    # - updates the composition_value
-    # - updates the composition_ref
-    #
-    # @param delta The delta that is applied to the composition_value
-    #
-    applyDelta: (delta, operations)->
-      (new ops.Insert null, delta, operations, @, null, @end.prev_cl, @end).execute()
-      undefined
-
-    #
-    # Encode this operation in such a way that it can be parsed by remote peers.
-    #
-    _encode: (json = {})->
-      custom = @getCustomType()._getCompositionValue()
-      json.composition_value = custom.composition_value
-      if custom.composition_value_operations?
-        json.composition_value_operations = {}
-        for n,o of custom.composition_value_operations
-          json.composition_value_operations[n] = o.getUid()
-      if @composition_ref?
-        json.composition_ref = @composition_ref.getUid()
-      else
-        json.composition_ref = @tmp_composition_ref
-      super json
-
-  ops.Composition.parse = (json)->
-    {
-      'uid' : uid
-      'custom_type': custom_type
-      'composition_value' : composition_value
-      'composition_value_operations' : composition_value_operations
-      'composition_ref' : composition_ref
-    } = json
-    new this(custom_type, composition_value, composition_value_operations, uid, composition_ref)
-
-
-  #
-  # @nodoc
-  # Adds support for replace. The ReplaceManager manages Replaceable operations.
-  # Each Replaceable holds a value that is now replaceable.
-  #
-  # The TextType-type has implemented support for replace
-  # @see TextType
-  #
-  class ops.ReplaceManager extends ops.ListManager
-    #
-    # @param {Object} event_properties Decorates the event that is thrown by the RM
-    # @param {Object} event_this The object on which the event shall be executed
-    # @param {Operation} initial_content Initialize this with a Replaceable that holds the initial_content.
-    # @param {Object} uid A unique identifier. If uid is undefined, a new uid will be created.
-    # @param {Delimiter} beginning Reference or Object.
-    # @param {Delimiter} end Reference or Object.
-    constructor: (custom_type, @event_properties, @event_this, uid)->
-      if not @event_properties['object']?
-        @event_properties['object'] = @event_this.getCustomType()
-      super custom_type, uid
-
-    type: "ReplaceManager"
-
-    #
-    # This doesn't throw the same events as the ListManager. Therefore, the
-    # Replaceables also not throw the same events.
-    # So, ReplaceManager and ListManager both implement
-    # these functions that are called when an Insertion is executed (at the end).
-    #
-    #
-    callEventDecorator: (events)->
-      if not @isDeleted()
-        for event in events
-          for name,prop of @event_properties
-            event[name] = prop
-        @event_this.callEvent events
-      undefined
-
-    #
-    # This is called, when the Insert-type was successfully executed.
-    # TODO: consider doing this in a more consistent manner. This could also be
-    # done with execute. But currently, there are no specital Insert-ops for ListManager.
-    #
-    callOperationSpecificInsertEvents: (op)->
-      if op.next_cl.type is "Delimiter" and op.prev_cl.type isnt "Delimiter"
-        # this replaces another Replaceable
-        if not op.is_deleted # When this is received from the HB, this could already be deleted!
-          old_value = op.prev_cl.val()
-          @callEventDecorator [
-            type: "update"
-            changedBy: op.uid.creator
-            oldValue: old_value
-          ]
-        op.prev_cl.applyDelete()
-      else if op.next_cl.type isnt "Delimiter"
-        # This won't be recognized by the user, because another
-        # concurrent operation is set as the current value of the RM
-        op.applyDelete()
-      else # prev _and_ next are Delimiters. This is the first created Replaceable in the RM
-        @callEventDecorator [
-          type: "add"
-          changedBy: op.uid.creator
-        ]
-      undefined
-
-    callOperationSpecificDeleteEvents: (op, del_op)->
-      if op.next_cl.type is "Delimiter"
-        @callEventDecorator [
-          type: "delete"
-          changedBy: del_op.uid.creator
-          oldValue: op.val()
-        ]
-
-
-    #
-    # Replace the existing word with a new word.
-    #
-    # @param content {Operation} The new value of this ReplaceManager.
-    # @param replaceable_uid {UID} Optional: Unique id of the Replaceable that is created
-    #
-    replace: (content, replaceable_uid)->
-      o = @getLastOperation()
-      relp = (new ops.Insert null, content, null, @, replaceable_uid, o, o.next_cl).execute()
-      # TODO: delete repl (for debugging)
-      undefined
-
-    isContentDeleted: ()->
-      @getLastOperation().isDeleted()
-
-    deleteContent: ()->
-      last_op = @getLastOperation()
-      if (not last_op.isDeleted()) and last_op.type isnt "Delimiter"
-        (new ops.Delete null, undefined, @getLastOperation().uid).execute()
-      undefined
-
-    #
-    # Get the value of this
-    # @return {String}
-    #
-    val: ()->
-      o = @getLastOperation()
-      #if o instanceof ops.Delimiter
-        # throw new Error "Replace Manager doesn't contain anything."
-      o.val?() # ? - for the case that (currently) the RM does not contain anything (then o is a Delimiter)
-
-
-
-  basic_ops

lib/y-object.coffee

@@ -1,55 +0,0 @@
-
-bindToChildren = (that)->
-  for i in [0...that.children.length]
-    attr = that.children.item(i)
-    if attr.name?
-      attr.val = that.val.val(attr.name)
-  that.val.observe (events)->
-    for event in events
-      if event.name?
-        for i in [0...that.children.length]
-          attr = that.children.item(i)
-          if attr.name? and attr.name is event.name
-            newVal = that.val.val(attr.name)
-            if attr.val isnt newVal
-              attr.val = newVal
-
-Polymer "y-object",
-  ready: ()->
-    if @connector?
-      @val = new Y @connector
-      bindToChildren @
-    else if @val?
-      bindToChildren @
-
-  valChanged: ()->
-    if @val? and @val._name is "Object"
-      bindToChildren @
-
-  connectorChanged: ()->
-    if (not @val?)
-      @val = new Y @connector
-      bindToChildren @
-
-Polymer "y-property",
-  ready: ()->
-    if @val? and @name?
-      if @val.constructor is Object
-        @val = @parentElement.val(@name,new Y.Object(@val)).val(@name)
-        # TODO: please use instanceof instead of ._name,
-        # since it is more safe (consider someone putting a custom Object type here)
-      else if typeof @val is "string"
-        @parentElement.val(@name,@val)
-      if @val._name is "Object"
-        bindToChildren @
-
-  valChanged: ()->
-    if @val? and @name?
-      if @val.constructor is Object
-        @val = @parentElement.val.val(@name, new Y.Object(@val)).val(@name)
-        # TODO: please use instanceof instead of ._name,
-        # since it is more safe (consider someone putting a custom Object type here)
-      else if @val._name is "Object"
-        bindToChildren @
-      else if @parentElement.val?.val? and @val isnt @parentElement.val.val(@name)
-        @parentElement.val.val @name, @val

lib/y.coffee

@@ -1,38 +0,0 @@
-
-structured_ops_uninitialized = require "./Operations/Structured"
-
-HistoryBuffer = require "./HistoryBuffer"
-Engine = require "./Engine"
-adaptConnector = require "./ConnectorAdapter"
-
-createY = (connector)->
-  if connector.user_id?
-    user_id = connector.user_id # TODO: change to getUniqueId()
-  else
-    user_id = "_temp"
-    connector.when_received_state_vector_listeners = [(state_vector)->
-        HB.setUserId this.user_id, state_vector
-      ]
-  HB = new HistoryBuffer user_id
-  ops_manager = structured_ops_uninitialized HB, this.constructor
-  ops = ops_manager.operations
-
-  engine = new Engine HB, ops
-  adaptConnector connector, engine, HB, ops_manager.execution_listener
-
-  ops.Operation.prototype.HB = HB
-  ops.Operation.prototype.operations = ops
-  ops.Operation.prototype.engine = engine
-  ops.Operation.prototype.connector = connector
-  ops.Operation.prototype.custom_types = this.constructor
-
-  ct = new createY.Object()
-  model = new ops.MapManager(ct, HB.getReservedUniqueIdentifier()).execute()
-  ct._setModel model
-  ct
-
-module.exports = createY
-if window?
-  window.Y = createY
-
-createY.Object = require "./ObjectType"

package.json

@@ -1,65 +1,92 @@
 {
   "name": "yjs",
-  "version": "0.5.2",
-  "description": "A Framework that enables Real-Time Collaboration on arbitrary data structures.",
-  "main": "./build/node/y.js",
+  "version": "14.0.0-1",
+  "description": "Shared Editing Library",
+  "main": "./dist/yjs.cjs",
+  "module": "./dist/yjs.mjs",
+  "types": "./dist/src/index.d.ts",
+  "type": "module",
+  "sideEffects": false,
+  "funding": {
+    "type": "GitHub Sponsors ❤",
+    "url": "https://github.com/sponsors/dmonad"
+  },
   "scripts": {
-    "prepublish": "./node_modules/gulp/bin/gulp.js build_node",
-    "test": "./node_modules/gulp/bin/gulp.js mocha"
+    "test": "npm run dist && node ./dist/tests.cjs --repetition-time 50",
+    "test-extensive": "npm run lint && npm run dist && node ./dist/tests.cjs --production --repetition-time 10000",
+    "dist": "rm -rf dist && rollup -c && tsc",
+    "watch": "rollup -wc",
+    "lint": "markdownlint README.md && standard && tsc",
+    "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.md --package ./package.json || true",
+    "serve-docs": "npm run docs && http-server ./docs/",
+    "preversion": "npm run lint && PRODUCTION=1 npm run dist && npm run docs && test -e dist/src/index.d.ts && test -e dist/yjs.cjs && test -e dist/yjs.cjs",
+    "debug": "concurrently 'http-server -o test.html' 'npm run watch'",
+    "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.cjs",
+    "trace-opt": "clear && rollup -c  && node --trace-opt dist/test.cjs",
+    "postinstall": "node ./sponsor-y.js"
+  },
+  "exports": {
+    ".": {
+      "import": "./dist/yjs.mjs",
+      "require": "./dist/yjs.cjs"
+    },
+    "./src/index.js": "./src/index.js",
+    "./tests/testHelper.js": "./tests/testHelper.js",
+    "./testHelper": "./dist/testHelper.mjs",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "dist/yjs.*",
+    "dist/src",
+    "src",
+    "tests/testHelper.js",
+    "dist/testHelper.mjs",
+    "sponsor-y.js"
+  ],
+  "dictionaries": {
+    "test": "tests"
+  },
+  "standard": {
+    "ignore": [
+      "/dist",
+      "/node_modules",
+      "/docs"
+    ]
   },
   "repository": {
     "type": "git",
-    "url": "https://github.com/rwth-acis/yjs"
+    "url": "https://github.com/yjs/yjs.git"
   },
   "keywords": [
-    "OT",
-    "collaboration",
-    "synchronization",
-    "ShareJS",
-    "Coweb",
-    "concurrency"
+    "Yjs",
+    "CRDT",
+    "offline",
+    "offline-first",
+    "shared-editing",
+    "concurrency",
+    "collaboration"
   ],
   "author": "Kevin Jahns",
-  "email": "kevin.jahns@rwth-aachen.de",
+  "email": "kevin.jahns@protonmail.com",
   "license": "MIT",
   "bugs": {
-    "url": "https://github.com/rwth-acis/yjs/issues"
+    "url": "https://github.com/yjs/yjs/issues"
   },
-  "homepage": "https://dadamonad.github.io/yjs/",
+  "homepage": "https://docs.yjs.dev",
   "dependencies": {
+    "lib0": "^0.2.43"
   },
   "devDependencies": {
-    "chai": "^2.2.0",
-    "codo": "^2.0.9",
-    "coffee-errors": "~0.8.6",
-    "coffee-script": "^1.7.1",
-    "coffeeify": "^0.6.0",
-    "gulp": "^3.8.7",
-    "gulp-browserify": "^0.5.0",
-    "gulp-cached": "^1.0.1",
-    "gulp-coffee": "^2.1.1",
-    "gulp-coffeeify": "^0.1.2",
-    "gulp-coffeelint": "^0.3.3",
-    "gulp-concat": "^2.3.4",
-    "gulp-copy": "0.0.2",
-    "gulp-debug": "^1.0.0",
-    "gulp-exit": "0.0.2",
-    "gulp-git": "^0.5.0",
-    "gulp-if": "^1.2.4",
-    "gulp-ignore": "^1.2.0",
-    "gulp-ljs": "^0.1.1",
-    "gulp-mocha": "^0.5.2",
-    "gulp-plumber": "^0.6.6",
-    "gulp-rename": "^1.2.0",
-    "gulp-rimraf": "^0.1.0",
-    "gulp-run": "^1.6.3",
-    "gulp-sourcemaps": "^1.1.1",
-    "gulp-uglify": "^0.3.1",
-    "gulp-watch": "^3.0.0",
-    "jquery": "^2.1.1",
-    "underscore": "^1.6.0",
-    "mocha": "^2.1.0",
-    "sinon": "^1.12.2",
-    "sinon-chai": "^2.7.0"
+    "@rollup/plugin-commonjs": "^17.0.0",
+    "@rollup/plugin-node-resolve": "^11.2.1",
+    "concurrently": "^3.6.1",
+    "http-server": "^0.12.3",
+    "jsdoc": "^3.6.7",
+    "markdownlint-cli": "^0.23.2",
+    "rollup": "^2.60.0",
+    "standard": "^16.0.4",
+    "tui-jsdoc-template": "^1.2.2",
+    "typescript": "^4.4.4",
+    "y-protocols": "^1.0.5"
   }
 }

rollup.config.js

@@ -0,0 +1,111 @@
+import nodeResolve from '@rollup/plugin-node-resolve'
+import commonjs from '@rollup/plugin-commonjs'
+
+const localImports = process.env.LOCALIMPORTS
+
+const customModules = new Set([
+  'y-websocket',
+  'y-codemirror',
+  'y-ace',
+  'y-textarea',
+  'y-quill',
+  'y-dom',
+  'y-prosemirror'
+])
+/**
+ * @type {Set<any>}
+ */
+const customLibModules = new Set([
+  'lib0',
+  'y-protocols'
+])
+const debugResolve = {
+  resolveId (importee) {
+    if (importee === 'yjs') {
+      return `${process.cwd()}/src/index.js`
+    }
+    if (localImports) {
+      if (customModules.has(importee.split('/')[0])) {
+        return `${process.cwd()}/../${importee}/src/${importee}.js`
+      }
+      if (customLibModules.has(importee.split('/')[0])) {
+        return `${process.cwd()}/../${importee}`
+      }
+    }
+    return null
+  }
+}
+
+export default [{
+  input: './src/index.js',
+  output: {
+    name: 'Y',
+    file: 'dist/yjs.cjs',
+    format: 'cjs',
+    sourcemap: true,
+    paths: path => {
+      if (/^lib0\//.test(path)) {
+        return `lib0/dist/${path.slice(5)}.cjs`
+      }
+      return path
+    }
+  },
+  external: id => /^lib0\//.test(id)
+}, {
+  input: './src/index.js',
+  output: {
+    name: 'Y',
+    file: 'dist/yjs.mjs',
+    format: 'esm',
+    sourcemap: true
+  },
+  external: id => /^lib0\//.test(id)
+}, {
+  input: './tests/testHelper.js',
+  output: {
+    name: 'Y',
+    file: 'dist/testHelper.mjs',
+    format: 'esm',
+    sourcemap: true
+  },
+  external: id => /^lib0\//.test(id) || id === 'yjs',
+  plugins: [{
+    resolveId (importee) {
+      if (importee === '../src/index.js') {
+        return 'yjs'
+      }
+      return null
+    }
+  }]
+}, {
+  input: './tests/index.js',
+  output: {
+    name: 'test',
+    file: 'dist/tests.js',
+    format: 'iife',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      mainFields: ['module', 'browser', 'main']
+    }),
+    commonjs()
+  ]
+}, {
+  input: './tests/index.js',
+  output: {
+    name: 'test',
+    file: 'dist/tests.cjs',
+    format: 'cjs',
+    sourcemap: true
+  },
+  plugins: [
+    debugResolve,
+    nodeResolve({
+      mainFields: ['module', 'main']
+    }),
+    commonjs()
+  ],
+  external: ['isomorphic.js']
+}]

sponsor-y.js

@@ -0,0 +1,12 @@
+
+try {
+  const log = require('lib0/dist/logging.cjs')
+
+  log.print()
+  log.print(log.BOLD, log.GREEN, log.BOLD, 'Thank you for using Yjs ', log.RED, '❤\n')
+  log.print(
+    log.GREY,
+    'The project has grown considerably in the past year. Too much for me to maintain\nin my spare time. Several companies built their products with Yjs.\nYet, this project receives very little funding. Yjs is far from done. I want to\ncreate more awesome extensions and work on the growing number of open issues.\n', log.BOLD, 'Dear user, the future of this project entirely depends on you.\n')
+  log.print(log.BLUE, log.BOLD, 'Please start funding the project now: https://github.com/sponsors/dmonad \n')
+  log.print(log.GREY, '(This message will be removed when I achieved my funding goal)\n\n')
+} catch (e) { }

src/index.js

@@ -0,0 +1,110 @@
+/** eslint-env browser */
+
+export {
+  Doc,
+  Transaction,
+  YArray as Array,
+  YMap as Map,
+  YText as Text,
+  YXmlText as XmlText,
+  YXmlHook as XmlHook,
+  YXmlElement as XmlElement,
+  YXmlFragment as XmlFragment,
+  YXmlEvent,
+  YMapEvent,
+  YArrayEvent,
+  YTextEvent,
+  YEvent,
+  Item,
+  AbstractStruct,
+  GC,
+  ContentBinary,
+  ContentDeleted,
+  ContentEmbed,
+  ContentFormat,
+  ContentJSON,
+  ContentAny,
+  ContentString,
+  ContentType,
+  AbstractType,
+  getTypeChildren,
+  createRelativePositionFromTypeIndex,
+  createRelativePositionFromJSON,
+  createAbsolutePositionFromRelativePosition,
+  compareRelativePositions,
+  AbsolutePosition,
+  RelativePosition,
+  ID,
+  createID,
+  compareIDs,
+  getState,
+  Snapshot,
+  createSnapshot,
+  createDeleteSet,
+  createDeleteSetFromStructStore,
+  cleanupYTextFormatting,
+  snapshot,
+  emptySnapshot,
+  findRootTypeKey,
+  findIndexSS,
+  getItem,
+  typeMapGetSnapshot,
+  createDocFromSnapshot,
+  iterateDeletedStructs,
+  applyUpdate,
+  applyUpdateV2,
+  readUpdate,
+  readUpdateV2,
+  encodeStateAsUpdate,
+  encodeStateAsUpdateV2,
+  encodeStateVector,
+  UndoManager,
+  decodeSnapshot,
+  encodeSnapshot,
+  decodeSnapshotV2,
+  encodeSnapshotV2,
+  decodeStateVector,
+  logUpdate,
+  logUpdateV2,
+  relativePositionToJSON,
+  isDeleted,
+  isParentOf,
+  equalSnapshots,
+  PermanentUserData, // @TODO experimental
+  tryGc,
+  transact,
+  AbstractConnector,
+  logType,
+  mergeUpdates,
+  mergeUpdatesV2,
+  parseUpdateMeta,
+  parseUpdateMetaV2,
+  encodeStateVectorFromUpdate,
+  encodeStateVectorFromUpdateV2,
+  encodeRelativePosition,
+  decodeRelativePosition,
+  diffUpdate,
+  diffUpdateV2
+} from './internals.js'
+
+const glo = /** @type {any} */ (typeof window !== 'undefined'
+  ? window
+  : typeof global !== 'undefined' ? global : {})
+const importIdentifier = '__ $YJS$ __'
+
+if (glo[importIdentifier] === true) {
+  /**
+   * Dear reader of this warning message. Please take this seriously.
+   *
+   * If you see this message, please make sure that you only import one version of Yjs. In many cases,
+   * your package manager installs two versions of Yjs that are used by different packages within your project.
+   * Another reason for this message is that some parts of your project use the commonjs version of Yjs
+   * and others use the EcmaScript version of Yjs.
+   *
+   * This often leads to issues that are hard to debug. We often need to perform constructor checks,
+   * e.g. `struct instanceof GC`. If you imported different versions of Yjs, it is impossible for us to
+   * do the constructor checks anymore - which might break the CRDT algorithm.
+   */
+  console.warn('Yjs was already imported. Importing different versions of Yjs often leads to issues.')
+}
+glo[importIdentifier] = true

src/internals.js

@@ -0,0 +1,45 @@
+
+export * from './utils/AbstractConnector.js'
+export * from './utils/DeleteSet.js'
+export * from './utils/Doc.js'
+export * from './utils/UpdateDecoder.js'
+export * from './utils/UpdateEncoder.js'
+export * from './utils/encoding.js'
+export * from './utils/EventHandler.js'
+export * from './utils/ID.js'
+export * from './utils/isParentOf.js'
+export * from './utils/ListCursor.js'
+export * from './utils/logging.js'
+export * from './utils/PermanentUserData.js'
+export * from './utils/RelativePosition.js'
+export * from './utils/Snapshot.js'
+export * from './utils/StructStore.js'
+export * from './utils/Transaction.js'
+export * from './utils/UndoManager.js'
+export * from './utils/updates.js'
+export * from './utils/YEvent.js'
+
+export * from './types/AbstractType.js'
+export * from './types/YArray.js'
+export * from './types/YMap.js'
+export * from './types/YText.js'
+export * from './types/YXmlFragment.js'
+export * from './types/YXmlElement.js'
+export * from './types/YXmlEvent.js'
+export * from './types/YXmlHook.js'
+export * from './types/YXmlText.js'
+
+export * from './structs/AbstractStruct.js'
+export * from './structs/GC.js'
+export * from './structs/ContentBinary.js'
+export * from './structs/ContentDeleted.js'
+export * from './structs/ContentDoc.js'
+export * from './structs/ContentEmbed.js'
+export * from './structs/ContentFormat.js'
+export * from './structs/ContentJSON.js'
+export * from './structs/ContentAny.js'
+export * from './structs/ContentString.js'
+export * from './structs/ContentMove.js'
+export * from './structs/ContentType.js'
+export * from './structs/Item.js'
+export * from './structs/Skip.js'

src/structs/AbstractStruct.js

@@ -0,0 +1,52 @@
+
+import {
+  UpdateEncoderV1, UpdateEncoderV2, ID, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+export class AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {number} length
+   */
+  constructor (id, length) {
+    this.id = id
+    this.length = length
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get deleted () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * Merge this struct with the item to the right.
+   * This method is already assuming that `this.id.clock + this.length === this.id.clock`.
+   * Also this method does *not* remove right from StructStore!
+   * @param {AbstractStruct} right
+   * @return {boolean} wether this merged with right
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   * @param {number} offset
+   * @param {number} encodingRef
+   */
+  write (encoder, offset, encodingRef) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    throw error.methodUnimplemented()
+  }
+}

src/structs/ContentAny.js

@@ -0,0 +1,108 @@
+import {
+  UpdateEncoderV1, UpdateEncoderV2, UpdateDecoderV1, UpdateDecoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+export class ContentAny {
+  /**
+   * @param {Array<any>} arr
+   */
+  constructor (arr) {
+    /**
+     * @type {Array<any>}
+     */
+    this.arr = arr
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.arr.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.arr
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentAny}
+   */
+  copy () {
+    return new ContentAny(this.arr)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentAny}
+   */
+  splice (offset) {
+    const right = new ContentAny(this.arr.slice(offset))
+    this.arr = this.arr.slice(0, offset)
+    return right
+  }
+
+  /**
+   * @param {ContentAny} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.arr = this.arr.concat(right.arr)
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const len = this.arr.length
+    encoder.writeLen(len - offset)
+    for (let i = offset; i < len; i++) {
+      const c = this.arr[i]
+      encoder.writeAny(c)
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 8
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentAny}
+ */
+export const readContentAny = decoder => {
+  const len = decoder.readLen()
+  const cs = []
+  for (let i = 0; i < len; i++) {
+    cs.push(decoder.readAny())
+  }
+  return new ContentAny(cs)
+}

src/structs/ContentBinary.js

@@ -0,0 +1,92 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+export class ContentBinary {
+  /**
+   * @param {Uint8Array} content
+   */
+  constructor (content) {
+    this.content = content
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.content]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentBinary}
+   */
+  copy () {
+    return new ContentBinary(this.content)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentBinary}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentBinary} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeBuf(this.content)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 3
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2 } decoder
+ * @return {ContentBinary}
+ */
+export const readContentBinary = decoder => new ContentBinary(decoder.readBuf())

src/structs/ContentDeleted.js

@@ -0,0 +1,101 @@
+
+import {
+  addToDeleteSet,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+export class ContentDeleted {
+  /**
+   * @param {number} len
+   */
+  constructor (len) {
+    this.len = len
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.len
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return []
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentDeleted}
+   */
+  copy () {
+    return new ContentDeleted(this.len)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentDeleted}
+   */
+  splice (offset) {
+    const right = new ContentDeleted(this.len - offset)
+    this.len = offset
+    return right
+  }
+
+  /**
+   * @param {ContentDeleted} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.len += right.len
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    addToDeleteSet(transaction.deleteSet, item.id.client, item.id.clock, this.len)
+    item.markDeleted()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeLen(this.len - offset)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 1
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2 } decoder
+ * @return {ContentDeleted}
+ */
+export const readContentDeleted = decoder => new ContentDeleted(decoder.readLen())

src/structs/ContentDoc.js

@@ -0,0 +1,141 @@
+
+import {
+  Doc, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @param {string} guid
+ * @param {Object<string, any>} opts
+ */
+const createDocFromOpts = (guid, opts) => new Doc({ guid, ...opts, shouldLoad: opts.shouldLoad || opts.autoLoad || false })
+
+/**
+ * @private
+ */
+export class ContentDoc {
+  /**
+   * @param {Doc} doc
+   */
+  constructor (doc) {
+    if (doc._item) {
+      console.error('This document was already integrated as a sub-document. You should create a second instance instead with the same guid.')
+    }
+    /**
+     * @type {Doc}
+     */
+    this.doc = doc
+    /**
+     * @type {any}
+     */
+    const opts = {}
+    this.opts = opts
+    if (!doc.gc) {
+      opts.gc = false
+    }
+    if (doc.autoLoad) {
+      opts.autoLoad = true
+    }
+    if (doc.meta !== null) {
+      opts.meta = doc.meta
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.doc]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentDoc}
+   */
+  copy () {
+    return new ContentDoc(createDocFromOpts(this.doc.guid, this.opts))
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentDoc}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentDoc} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    // this needs to be reflected in doc.destroy as well
+    this.doc._item = item
+    transaction.subdocsAdded.add(this.doc)
+    if (this.doc.shouldLoad) {
+      transaction.subdocsLoaded.add(this.doc)
+    }
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    if (transaction.subdocsAdded.has(this.doc)) {
+      transaction.subdocsAdded.delete(this.doc)
+    } else {
+      transaction.subdocsRemoved.add(this.doc)
+    }
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) { }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeString(this.doc.guid)
+    encoder.writeAny(this.opts)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 9
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentDoc}
+ */
+export const readContentDoc = decoder => new ContentDoc(createDocFromOpts(decoder.readString(), decoder.readAny()))

src/structs/ContentEmbed.js

@@ -0,0 +1,98 @@
+
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Item, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @private
+ */
+export class ContentEmbed {
+  /**
+   * @param {Object} embed
+   */
+  constructor (embed) {
+    this.embed = embed
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.embed]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentEmbed}
+   */
+  copy () {
+    return new ContentEmbed(this.embed)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentEmbed}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentEmbed} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeJSON(this.embed)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 5
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentEmbed}
+ */
+export const readContentEmbed = decoder => new ContentEmbed(decoder.readJSON())

src/structs/ContentFormat.js

@@ -0,0 +1,103 @@
+
+import {
+  AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Item, StructStore, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @private
+ */
+export class ContentFormat {
+  /**
+   * @param {string} key
+   * @param {Object} value
+   */
+  constructor (key, value) {
+    this.key = key
+    this.value = value
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return []
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentFormat}
+   */
+  copy () {
+    return new ContentFormat(this.key, this.value)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentFormat}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentFormat} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    // @todo searchmarker are currently unsupported for rich text documents
+    /** @type {AbstractType<any>} */ (item.parent)._searchMarker = null
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeKey(this.key)
+    encoder.writeJSON(this.value)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 6
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentFormat}
+ */
+export const readContentFormat = decoder => new ContentFormat(decoder.readString(), decoder.readJSON())

src/structs/ContentJSON.js

@@ -0,0 +1,118 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @private
+ */
+export class ContentJSON {
+  /**
+   * @param {Array<any>} arr
+   */
+  constructor (arr) {
+    /**
+     * @type {Array<any>}
+     */
+    this.arr = arr
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.arr.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.arr
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentJSON}
+   */
+  copy () {
+    return new ContentJSON(this.arr)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentJSON}
+   */
+  splice (offset) {
+    const right = new ContentJSON(this.arr.slice(offset))
+    this.arr = this.arr.slice(0, offset)
+    return right
+  }
+
+  /**
+   * @param {ContentJSON} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.arr = this.arr.concat(right.arr)
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const len = this.arr.length
+    encoder.writeLen(len - offset)
+    for (let i = offset; i < len; i++) {
+      const c = this.arr[i]
+      encoder.writeString(c === undefined ? 'undefined' : JSON.stringify(c))
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 2
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentJSON}
+ */
+export const readContentJSON = decoder => {
+  const len = decoder.readLen()
+  const cs = []
+  for (let i = 0; i < len; i++) {
+    const c = decoder.readString()
+    if (c === 'undefined') {
+      cs.push(undefined)
+    } else {
+      cs.push(JSON.parse(c))
+    }
+  }
+  return new ContentJSON(cs)
+}

src/structs/ContentMove.js

@@ -0,0 +1,296 @@
+
+import * as error from 'lib0/error'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as math from 'lib0/math'
+import {
+  writeID,
+  readID,
+  ID, AbstractType, ContentType, RelativePosition, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore, getItem, getItemCleanStart, getItemCleanEnd, // eslint-disable-line
+  addsStruct
+} from '../internals.js'
+
+/**
+ * @param {ContentMove | { start: RelativePosition, end: RelativePosition }} moved
+ * @param {Transaction} tr
+ * @param {boolean} split
+ * @return {{ start: Item, end: Item }} $start (inclusive) is the beginning and $end (inclusive) is the end of the moved area
+ */
+export const getMovedCoords = (moved, tr, split) => {
+  const store = tr.doc.store
+  const startItem = moved.start.item
+  const endItem = moved.end.item
+  let start // this (inclusive) is the beginning of the moved area
+  let end // this (exclusive) is the first item after start that is not part of the moved area
+  if (startItem) {
+    if (moved.start.assoc < 0) {
+      // We know that the items have already been split, hence getItem suffices.
+      start = split ? getItemCleanEnd(tr, startItem) : getItem(store, startItem)
+      start = start.right
+    } else {
+      start = split ? getItemCleanStart(tr, startItem) : getItem(store, startItem)
+    }
+  } else if (moved.start.tname != null) {
+    start = tr.doc.get(moved.start.tname)._start
+  } else if (moved.start.type) {
+    start = /** @type {ContentType} */ (getItem(store, moved.start.type).content).type._start
+  } else {
+    error.unexpectedCase()
+  }
+  if (endItem) {
+    if (moved.end.assoc < 0) {
+      end = split ? getItemCleanEnd(tr, endItem) : getItem(store, endItem)
+      end = end.right
+    } else {
+      end = split ? getItemCleanStart(tr, endItem) : getItem(store, endItem)
+    }
+  } else {
+    error.unexpectedCase()
+  }
+  return { start: /** @type {Item} */ (start), end: /** @type {Item} */ (end) }
+}
+
+/**
+ * @param {Transaction} tr
+ * @param {ContentMove} moved
+ * @param {Item} movedItem
+ * @param {Set<Item>} trackedMovedItems
+ * @return {boolean} true if there is a loop
+ */
+export const findMoveLoop = (tr, moved, movedItem, trackedMovedItems) => {
+  if (trackedMovedItems.has(movedItem)) {
+    return true
+  }
+  trackedMovedItems.add(movedItem)
+  /**
+   * @type {{ start: Item | null, end: Item | null }}
+   */
+  let { start, end } = getMovedCoords(moved, tr, false)
+  while (start !== end && start != null) {
+    if (
+      !start.deleted &&
+      start.moved === movedItem &&
+      start.content.constructor === ContentMove &&
+      findMoveLoop(tr, start.content, start, trackedMovedItems)
+    ) {
+      return true
+    }
+    start = start.right
+  }
+  return false
+}
+
+/**
+ * @private
+ */
+export class ContentMove {
+  /**
+   * @param {RelativePosition} start
+   * @param {RelativePosition} end
+   * @param {number} priority if we want to move content that is already moved, we need to assign a higher priority to this move operation.
+   */
+  constructor (start, end, priority) {
+    this.start = start
+    this.end = end
+    this.priority = priority
+    /**
+     * We store which Items+ContentMove we override. Once we delete
+     * this ContentMove, we need to re-integrate the overridden items.
+     *
+     * This representation can be improved if we ever run into memory issues because of too many overrides.
+     * Ideally, we should probably just re-iterate the document and re-integrate all moved items.
+     * This is fast enough and reduces memory footprint significantly.
+     *
+     * @type {Set<Item>}
+     */
+    this.overrides = new Set()
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [null]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return false
+  }
+
+  /**
+   * @return {ContentMove}
+   */
+  copy () {
+    return new ContentMove(this.start, this.end, this.priority)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentMove}
+   */
+  splice (offset) {
+    return this
+  }
+
+  /**
+   * @param {ContentMove} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    const sm = /** @type {AbstractType<any>} */ (item.parent)._searchMarker
+    if (sm) sm.length = 0
+    const movedCoords = getMovedCoords(this, transaction, true)
+    /**
+     * @type {{ start: Item | null, end: item | null }}
+     */
+    let { start, end } = movedCoords
+    let maxPriority = 0
+    // If this ContentMove was created locally, we set prio = -1. This indicates
+    // that we want to set prio to the current prio-maximum of the moved range.
+    const adaptPriority = this.priority < 0
+    while (start !== end && start != null) {
+      const prevMove = start.moved // this is the same as prevMove
+      const nextPrio = prevMove ? /** @type {ContentMove} */ (prevMove.content).priority : -1
+      if (adaptPriority || nextPrio < this.priority || (prevMove != null && nextPrio === this.priority && (prevMove.id.client < item.id.client || (prevMove.id.client === item.id.client && prevMove.id.clock < item.id.clock)))) {
+        if (prevMove !== null) {
+          if (/** @type {ContentMove} */ (prevMove.content).isCollapsed()) {
+            prevMove.deleteAsCleanup(transaction, adaptPriority)
+          }
+          this.overrides.add(prevMove)
+          if (start !== movedCoords.start) {
+            // only add this to mergeStructs if this is not the first item
+            transaction._mergeStructs.push(start)
+          }
+        }
+        maxPriority = math.max(maxPriority, nextPrio)
+        // was already moved
+        if (prevMove && !transaction.prevMoved.has(start) && !addsStruct(transaction, prevMove)) {
+          // only override prevMoved if the prevMoved item is not new
+          // we need to know which item previously moved an item
+          transaction.prevMoved.set(start, prevMove)
+        }
+        start.moved = item
+        if (!start.deleted && start.content.constructor === ContentMove && findMoveLoop(transaction, start.content, start, new Set([item]))) {
+          item.deleteAsCleanup(transaction, adaptPriority)
+          return
+        }
+      } else if (prevMove != null) {
+        /** @type {ContentMove} */ (prevMove.content).overrides.add(item)
+      }
+      start = start.right
+    }
+    if (adaptPriority) {
+      this.priority = maxPriority + 1
+    }
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  delete (transaction, item) {
+    /**
+     * @type {{ start: Item | null, end: Item | null }}
+     */
+    let { start, end } = getMovedCoords(this, transaction, false)
+    while (start !== end && start != null) {
+      if (start.moved === item) {
+        const prevMoved = transaction.prevMoved.get(start)
+        if (addsStruct(transaction, item)) {
+          if (prevMoved === item) {
+            // Edge case: Item has been moved by this move op and it has been created & deleted in the same transaction (hence no effect that should be emitted by the change computation)
+            transaction.prevMoved.delete(start)
+          }
+        } else if (prevMoved == null) { // && !addsStruct(tr, item)
+          // Normal case: item has been moved by this move and it has not been created & deleted in the same transaction
+          transaction.prevMoved.set(start, item)
+        }
+        start.moved = null
+      }
+      start = start.right
+    }
+    /**
+     * @param {Item} reIntegrateItem
+     */
+    const reIntegrate = reIntegrateItem => {
+      const content = /** @type {ContentMove} */ (reIntegrateItem.content)
+      // content is not yet transformed to a ContentDeleted
+      if (content.getRef() === 11) {
+        if (reIntegrateItem.deleted) {
+          // potentially we can integrate the items that reIntegrateItem overrides
+          content.overrides.forEach(reIntegrate)
+        } else {
+          content.integrate(transaction, reIntegrateItem)
+        }
+      }
+    }
+    this.overrides.forEach(reIntegrate)
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const isCollapsed = this.isCollapsed()
+    encoding.writeVarUint(encoder.restEncoder, (isCollapsed ? 1 : 0) | (this.start.assoc >= 0 ? 2 : 0) | (this.end.assoc >= 0 ? 4 : 0) | this.priority << 6)
+    writeID(encoder.restEncoder, /** @type {ID} */ (this.start.item))
+    if (!isCollapsed) {
+      writeID(encoder.restEncoder, /** @type {ID} */ (this.end.item))
+    }
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 11
+  }
+
+  isCollapsed () {
+    return this.start.item === this.end.item && this.start.item !== null
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentMove}
+ */
+export const readContentMove = decoder => {
+  const info = decoding.readVarUint(decoder.restDecoder)
+  const isCollapsed = (info & 1) === 1
+  const startAssoc = (info & 2) === 2 ? 0 : -1
+  const endAssoc = (info & 4) === 4 ? 0 : -1
+  // @TODO use BIT3 & BIT4 to indicate the case `null` is the start/end
+  // BIT5 is reserved for future extensions
+  const priority = info >>> 6
+  const startId = readID(decoder.restDecoder)
+  const start = new RelativePosition(null, null, startId, startAssoc)
+  const end = new RelativePosition(null, null, isCollapsed ? startId : readID(decoder.restDecoder), endAssoc)
+  return new ContentMove(start, end, priority)
+}

src/structs/ContentString.js

@@ -0,0 +1,112 @@
+import {
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Transaction, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @private
+ */
+export class ContentString {
+  /**
+   * @param {string} str
+   */
+  constructor (str) {
+    /**
+     * @type {string}
+     */
+    this.str = str
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return this.str.length
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return this.str.split('')
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentString}
+   */
+  copy () {
+    return new ContentString(this.str)
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentString}
+   */
+  splice (offset) {
+    const right = new ContentString(this.str.slice(offset))
+    this.str = this.str.slice(0, offset)
+
+    // Prevent encoding invalid documents because of splitting of surrogate pairs: https://github.com/yjs/yjs/issues/248
+    const firstCharCode = this.str.charCodeAt(offset - 1)
+    if (firstCharCode >= 0xD800 && firstCharCode <= 0xDBFF) {
+      // Last character of the left split is the start of a surrogate utf16/ucs2 pair.
+      // We don't support splitting of surrogate pairs because this may lead to invalid documents.
+      // Replace the invalid character with a unicode replacement character (<28> / U+FFFD)
+      this.str = this.str.slice(0, offset - 1) + '<27>'
+      // replace right as well
+      right.str = '<27>' + right.str.slice(1)
+    }
+    return right
+  }
+
+  /**
+   * @param {ContentString} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    this.str += right.str
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {}
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {}
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {}
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeString(offset === 0 ? this.str : this.str.slice(offset))
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 4
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentString}
+ */
+export const readContentString = decoder => new ContentString(decoder.readString())

src/structs/ContentType.js

@@ -0,0 +1,172 @@
+
+import {
+  readYArray,
+  readYMap,
+  readYText,
+  readYXmlElement,
+  readYXmlFragment,
+  readYXmlHook,
+  readYXmlText,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, Item, YEvent, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * @type {Array<function(UpdateDecoderV1 | UpdateDecoderV2):AbstractType<any>>}
+ * @private
+ */
+export const typeRefs = [
+  readYArray,
+  readYMap,
+  readYText,
+  readYXmlElement,
+  readYXmlFragment,
+  readYXmlHook,
+  readYXmlText
+]
+
+export const YArrayRefID = 0
+export const YMapRefID = 1
+export const YTextRefID = 2
+export const YXmlElementRefID = 3
+export const YXmlFragmentRefID = 4
+export const YXmlHookRefID = 5
+export const YXmlTextRefID = 6
+
+/**
+ * @private
+ */
+export class ContentType {
+  /**
+   * @param {AbstractType<YEvent>} type
+   */
+  constructor (type) {
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = type
+  }
+
+  /**
+   * @return {number}
+   */
+  getLength () {
+    return 1
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    return [this.type]
+  }
+
+  /**
+   * @return {boolean}
+   */
+  isCountable () {
+    return true
+  }
+
+  /**
+   * @return {ContentType}
+   */
+  copy () {
+    return new ContentType(this.type._copy())
+  }
+
+  /**
+   * @param {number} offset
+   * @return {ContentType}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {ContentType} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    return false
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    this.type._integrate(transaction.doc, item)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    let item = this.type._start
+    while (item !== null) {
+      if (!item.deleted) {
+        item.delete(transaction)
+      } else {
+        // Whis will be gc'd later and we want to merge it if possible
+        // We try to merge all deleted items after each transaction,
+        // but we have no knowledge about that this needs to be merged
+        // since it is not in transaction.ds. Hence we add it to transaction._mergeStructs
+        transaction._mergeStructs.push(item)
+      }
+      item = item.right
+    }
+    this.type._map.forEach(item => {
+      if (!item.deleted) {
+        item.delete(transaction)
+      } else {
+        // same as above
+        transaction._mergeStructs.push(item)
+      }
+    })
+    transaction.changed.delete(this.type)
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {
+    let item = this.type._start
+    while (item !== null) {
+      item.gc(store, true)
+      item = item.right
+    }
+    this.type._start = null
+    this.type._map.forEach(/** @param {Item | null} item */ (item) => {
+      while (item !== null) {
+        item.gc(store, true)
+        item = item.left
+      }
+    })
+    this.type._map = new Map()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    this.type._write(encoder)
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    return 7
+  }
+}
+
+/**
+ * @private
+ *
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {ContentType}
+ */
+export const readContentType = decoder => new ContentType(typeRefs[decoder.readTypeRef()](decoder))

src/structs/GC.js

@@ -0,0 +1,61 @@
+
+import {
+  AbstractStruct,
+  addStruct,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+export const structGCRefNumber = 0
+
+/**
+ * @private
+ */
+export class GC extends AbstractStruct {
+  get deleted () {
+    return true
+  }
+
+  delete () {}
+
+  /**
+   * @param {GC} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (this.constructor !== right.constructor) {
+      return false
+    }
+    this.length += right.length
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    if (offset > 0) {
+      this.id.clock += offset
+      this.length -= offset
+    }
+    addStruct(transaction.doc.store, this)
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeInfo(structGCRefNumber)
+    encoder.writeLen(this.length - offset)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    return null
+  }
+}

src/structs/Item.js

@@ -0,0 +1,870 @@
+
+import {
+  GC,
+  getState,
+  AbstractStruct,
+  replaceStruct,
+  addStruct,
+  addToDeleteSet,
+  findRootTypeKey,
+  compareIDs,
+  getItem,
+  getItemCleanEnd,
+  getItemCleanStart,
+  readContentDeleted,
+  readContentBinary,
+  readContentJSON,
+  readContentAny,
+  readContentString,
+  readContentEmbed,
+  readContentDoc,
+  createID,
+  readContentFormat,
+  readContentType,
+  readContentMove,
+  addChangedTypeToTransaction,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, ContentType, ContentDeleted, StructStore, ID, AbstractType, Transaction // eslint-disable-line
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+import * as binary from 'lib0/binary'
+import { ContentMove } from './ContentMove.js'
+
+/**
+ * @todo This should return several items
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {{item:Item, diff:number}}
+ */
+export const followRedone = (store, id) => {
+  /**
+   * @type {ID|null}
+   */
+  let nextID = id
+  let diff = 0
+  let item
+  do {
+    if (diff > 0) {
+      nextID = createID(nextID.client, nextID.clock + diff)
+    }
+    item = getItem(store, nextID)
+    diff = nextID.clock - item.id.clock
+    nextID = item.redone
+  } while (nextID !== null && item instanceof Item)
+  return {
+    item, diff
+  }
+}
+
+/**
+ * Make sure that neither item nor any of its parents is ever deleted.
+ *
+ * This property does not persist when storing it into a database or when
+ * sending it to other peers
+ *
+ * @param {Item|null} item
+ * @param {boolean} keep
+ */
+export const keepItem = (item, keep) => {
+  while (item !== null && item.keep !== keep) {
+    item.keep = keep
+    item = /** @type {AbstractType<any>} */ (item.parent)._item
+  }
+}
+
+/**
+ * Split leftItem into two items
+ * @param {Transaction} transaction
+ * @param {Item} leftItem
+ * @param {number} diff
+ * @return {Item}
+ *
+ * @function
+ * @private
+ */
+export const splitItem = (transaction, leftItem, diff) => {
+  // create rightItem
+  const { client, clock } = leftItem.id
+  const rightItem = new Item(
+    createID(client, clock + diff),
+    leftItem,
+    createID(client, clock + diff - 1),
+    leftItem.right,
+    leftItem.rightOrigin,
+    leftItem.parent,
+    leftItem.parentSub,
+    leftItem.content.splice(diff)
+  )
+  if (leftItem.deleted) {
+    rightItem.markDeleted()
+  }
+  if (leftItem.keep) {
+    rightItem.keep = true
+  }
+  if (leftItem.redone !== null) {
+    rightItem.redone = createID(leftItem.redone.client, leftItem.redone.clock + diff)
+  }
+  // update left (do not set leftItem.rightOrigin as it will lead to problems when syncing)
+  leftItem.right = rightItem
+  // update right
+  if (rightItem.right !== null) {
+    rightItem.right.left = rightItem
+  }
+  // right is more specific.
+  transaction._mergeStructs.push(rightItem)
+  // update parent._map
+  if (rightItem.parentSub !== null && rightItem.right === null) {
+    /** @type {AbstractType<any>} */ (rightItem.parent)._map.set(rightItem.parentSub, rightItem)
+  }
+  leftItem.length = diff
+  if (leftItem.moved) {
+    rightItem.moved = leftItem.moved
+    const m = transaction.prevMoved.get(leftItem)
+    if (m) {
+      transaction.prevMoved.set(rightItem, m)
+    }
+  }
+  return rightItem
+}
+
+/**
+ * Redoes the effect of this operation.
+ *
+ * @param {Transaction} transaction The Yjs instance.
+ * @param {Item} item
+ * @param {Set<Item>} redoitems
+ * @param {Array<Item>} itemsToDelete
+ *
+ * @return {Item|null}
+ *
+ * @private
+ */
+export const redoItem = (transaction, item, redoitems, itemsToDelete) => {
+  const doc = transaction.doc
+  const store = doc.store
+  const ownClientID = doc.clientID
+  const redone = item.redone
+  if (redone !== null) {
+    return getItemCleanStart(transaction, redone)
+  }
+  let parentItem = /** @type {AbstractType<any>} */ (item.parent)._item
+  /**
+   * @type {Item|null}
+   */
+  let left
+  /**
+   * @type {Item|null}
+   */
+  let right
+  if (item.parentSub === null) {
+    // Is an array item. Insert at the old position
+    left = item.left
+    right = item
+  } else {
+    // Is a map item. Insert as current value
+    left = item
+    while (left.right !== null) {
+      left = left.right
+      if (left.id.client !== ownClientID) {
+        // It is not possible to redo this item because it conflicts with a
+        // change from another client
+        return null
+      }
+    }
+    if (left.right !== null) {
+      left = /** @type {Item} */ (/** @type {AbstractType<any>} */ (item.parent)._map.get(item.parentSub))
+    }
+    right = null
+  }
+  // make sure that parent is redone
+  if (parentItem !== null && parentItem.deleted === true && parentItem.redone === null) {
+    // try to undo parent if it will be undone anyway
+    if (!redoitems.has(parentItem) || redoItem(transaction, parentItem, redoitems, itemsToDelete) === null) {
+      return null
+    }
+  }
+  if (parentItem !== null && parentItem.redone !== null) {
+    while (parentItem.redone !== null) {
+      parentItem = getItemCleanStart(transaction, parentItem.redone)
+    }
+    // find next cloned_redo items
+    while (left !== null) {
+      /**
+       * @type {Item|null}
+       */
+      let leftTrace = left
+      // trace redone until parent matches
+      while (leftTrace !== null && /** @type {AbstractType<any>} */ (leftTrace.parent)._item !== parentItem) {
+        leftTrace = leftTrace.redone === null ? null : getItemCleanStart(transaction, leftTrace.redone)
+      }
+      if (leftTrace !== null && /** @type {AbstractType<any>} */ (leftTrace.parent)._item === parentItem) {
+        left = leftTrace
+        break
+      }
+      left = left.left
+    }
+    while (right !== null) {
+      /**
+       * @type {Item|null}
+       */
+      let rightTrace = right
+      // trace redone until parent matches
+      while (rightTrace !== null && /** @type {AbstractType<any>} */ (rightTrace.parent)._item !== parentItem) {
+        rightTrace = rightTrace.redone === null ? null : getItemCleanStart(transaction, rightTrace.redone)
+      }
+      if (rightTrace !== null && /** @type {AbstractType<any>} */ (rightTrace.parent)._item === parentItem) {
+        right = rightTrace
+        break
+      }
+      right = right.right
+    }
+    // Iterate right while right is in itemsToDelete
+    // If it is intended to delete right while item is redone, we can expect that item should replace right.
+    while (left !== null && left.right !== null && left.right !== right && itemsToDelete.findIndex(d => d === /** @type {Item} */ (left).right) >= 0) {
+      left = left.right
+    }
+  }
+  const nextClock = getState(store, ownClientID)
+  const nextId = createID(ownClientID, nextClock)
+  const redoneItem = new Item(
+    nextId,
+    left, left && left.lastId,
+    right, right && right.id,
+    parentItem === null ? item.parent : /** @type {ContentType} */ (parentItem.content).type,
+    item.parentSub,
+    item.content.copy()
+  )
+  item.redone = nextId
+  keepItem(redoneItem, true)
+  redoneItem.integrate(transaction, 0)
+  return redoneItem
+}
+
+/**
+ * Abstract class that represents any content.
+ */
+export class Item extends AbstractStruct {
+  /**
+   * @param {ID} id
+   * @param {Item | null} left
+   * @param {ID | null} origin
+   * @param {Item | null} right
+   * @param {ID | null} rightOrigin
+   * @param {AbstractType<any>|ID|null} parent Is a type if integrated, is null if it is possible to copy parent from left or right, is ID before integration to search for it.
+   * @param {string | null} parentSub
+   * @param {AbstractContent} content
+   */
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, content.getLength())
+    /**
+     * The item that was originally to the left of this item.
+     * @type {ID | null}
+     */
+    this.origin = origin
+    /**
+     * The item that is currently to the left of this item.
+     * @type {Item | null}
+     */
+    this.left = left
+    /**
+     * The item that is currently to the right of this item.
+     * @type {Item | null}
+     */
+    this.right = right
+    /**
+     * The item that was originally to the right of this item.
+     * @type {ID | null}
+     */
+    this.rightOrigin = rightOrigin
+    /**
+     * @type {AbstractType<any>|ID|null}
+     */
+    this.parent = parent
+    /**
+     * If the parent refers to this item with some kind of key (e.g. YMap, the
+     * key is specified here. The key is then used to refer to the list in which
+     * to insert this item. If `parentSub = null` type._start is the list in
+     * which to insert to. Otherwise it is `parent._map`.
+     * @type {String | null}
+     */
+    this.parentSub = parentSub
+    /**
+     * If this type's effect is reundone this type refers to the type-id that undid
+     * this operation.
+     *
+     * @type {ID | null}
+     */
+    this.redone = null
+    /**
+     * This property is reused by the moved prop. In this case this property refers to an Item.
+     *
+     * @type {Item | null}
+     */
+    this.moved = null
+    /**
+     * @type {AbstractContent}
+     */
+    this.content = content
+    /**
+     * bit1: keep
+     * bit2: countable
+     * bit3: deleted
+     * bit4: mark - mark node as fast-search-marker
+     * @type {number} byte
+     */
+    this.info = this.content.isCountable() ? binary.BIT2 : 0
+  }
+
+  /**
+   * This is used to mark the item as an indexed fast-search marker
+   *
+   * @type {boolean}
+   */
+  set marker (isMarked) {
+    if (((this.info & binary.BIT4) > 0) !== isMarked) {
+      this.info ^= binary.BIT4
+    }
+  }
+
+  get marker () {
+    return (this.info & binary.BIT4) > 0
+  }
+
+  /**
+   * If true, do not garbage collect this Item.
+   */
+  get keep () {
+    return (this.info & binary.BIT1) > 0
+  }
+
+  set keep (doKeep) {
+    if (this.keep !== doKeep) {
+      this.info ^= binary.BIT1
+    }
+  }
+
+  get countable () {
+    return (this.info & binary.BIT2) > 0
+  }
+
+  /**
+   * Whether this item was deleted or not.
+   * @type {Boolean}
+   */
+  get deleted () {
+    return (this.info & binary.BIT3) > 0
+  }
+
+  set deleted (doDelete) {
+    if (this.deleted !== doDelete) {
+      this.info ^= binary.BIT3
+    }
+  }
+
+  markDeleted () {
+    this.info |= binary.BIT3
+  }
+
+  /**
+   * Return the creator clientID of the missing op or define missing items and return null.
+   *
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    if (this.origin && this.origin.client !== this.id.client && this.origin.clock >= getState(store, this.origin.client)) {
+      return this.origin.client
+    }
+    if (this.rightOrigin && this.rightOrigin.client !== this.id.client && this.rightOrigin.clock >= getState(store, this.rightOrigin.client)) {
+      return this.rightOrigin.client
+    }
+    if (this.parent && this.parent.constructor === ID && this.id.client !== this.parent.client && this.parent.clock >= getState(store, this.parent.client)) {
+      return this.parent.client
+    }
+    if (this.content.constructor === ContentMove) {
+      const c = /** @type {ContentMove} */ (this.content)
+      const start = c.start.item
+      const end = c.isCollapsed() ? null : c.end.item
+      if (start && start.clock >= getState(store, start.client)) {
+        return start.client
+      }
+      if (end && end.clock >= getState(store, end.client)) {
+        return end.client
+      }
+    }
+
+    // We have all missing ids, now find the items
+    if (this.origin) {
+      this.left = getItemCleanEnd(transaction, this.origin)
+      this.origin = this.left.lastId
+    }
+    if (this.rightOrigin) {
+      this.right = getItemCleanStart(transaction, this.rightOrigin)
+      this.rightOrigin = this.right.id
+    }
+    if ((this.left && this.left.constructor === GC) || (this.right && this.right.constructor === GC)) {
+      this.parent = null
+    }
+    // only set parent if this shouldn't be garbage collected
+    if (!this.parent) {
+      if (this.left && this.left.constructor === Item) {
+        this.parent = this.left.parent
+        this.parentSub = this.left.parentSub
+      }
+      if (this.right && this.right.constructor === Item) {
+        this.parent = this.right.parent
+        this.parentSub = this.right.parentSub
+      }
+    } else if (this.parent.constructor === ID) {
+      const parentItem = getItem(store, this.parent)
+      if (parentItem.constructor === GC) {
+        this.parent = null
+      } else {
+        this.parent = /** @type {ContentType} */ (parentItem.content).type
+      }
+    }
+
+    return null
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    if (offset > 0) {
+      this.id.clock += offset
+      this.left = getItemCleanEnd(transaction, createID(this.id.client, this.id.clock - 1))
+      this.origin = this.left.lastId
+      this.content = this.content.splice(offset)
+      this.length -= offset
+    }
+
+    if (this.parent) {
+      if ((!this.left && (!this.right || this.right.left !== null)) || (this.left && this.left.right !== this.right)) {
+        /**
+         * @type {Item|null}
+         */
+        let left = this.left
+
+        /**
+         * @type {Item|null}
+         */
+        let o
+        // set o to the first conflicting item
+        if (left !== null) {
+          o = left.right
+        } else if (this.parentSub !== null) {
+          o = /** @type {AbstractType<any>} */ (this.parent)._map.get(this.parentSub) || null
+          while (o !== null && o.left !== null) {
+            o = o.left
+          }
+        } else {
+          o = /** @type {AbstractType<any>} */ (this.parent)._start
+        }
+        // TODO: use something like DeleteSet here (a tree implementation would be best)
+        // @todo use global set definitions
+        /**
+         * @type {Set<Item>}
+         */
+        const conflictingItems = new Set()
+        /**
+         * @type {Set<Item>}
+         */
+        const itemsBeforeOrigin = new Set()
+        // Let c in conflictingItems, b in itemsBeforeOrigin
+        // ***{origin}bbbb{this}{c,b}{c,b}{o}***
+        // Note that conflictingItems is a subset of itemsBeforeOrigin
+        while (o !== null && o !== this.right) {
+          itemsBeforeOrigin.add(o)
+          conflictingItems.add(o)
+          if (compareIDs(this.origin, o.origin)) {
+            // case 1
+            if (o.id.client < this.id.client) {
+              left = o
+              conflictingItems.clear()
+            } else if (compareIDs(this.rightOrigin, o.rightOrigin)) {
+              // this and o are conflicting and point to the same integration points. The id decides which item comes first.
+              // Since this is to the left of o, we can break here
+              break
+            } // else, o might be integrated before an item that this conflicts with. If so, we will find it in the next iterations
+          } else if (o.origin !== null && itemsBeforeOrigin.has(getItem(transaction.doc.store, o.origin))) { // use getItem instead of getItemCleanEnd because we don't want / need to split items.
+            // case 2
+            if (!conflictingItems.has(getItem(transaction.doc.store, o.origin))) {
+              left = o
+              conflictingItems.clear()
+            }
+          } else {
+            break
+          }
+          o = o.right
+        }
+        this.left = left
+      }
+      // reconnect left/right + update parent map/start if necessary
+      if (this.left !== null) {
+        const right = this.left.right
+        this.right = right
+        this.left.right = this
+      } else {
+        let r
+        if (this.parentSub !== null) {
+          r = /** @type {AbstractType<any>} */ (this.parent)._map.get(this.parentSub) || null
+          while (r !== null && r.left !== null) {
+            r = r.left
+          }
+        } else {
+          r = /** @type {AbstractType<any>} */ (this.parent)._start
+          ;/** @type {AbstractType<any>} */ (this.parent)._start = this
+        }
+        this.right = r
+      }
+      if (this.right !== null) {
+        this.right.left = this
+      } else if (this.parentSub !== null) {
+        // set as current parent value if right === null and this is parentSub
+        /** @type {AbstractType<any>} */ (this.parent)._map.set(this.parentSub, this)
+        if (this.left !== null) {
+          // this is the current attribute value of parent. delete right
+          this.left.delete(transaction)
+        }
+      }
+      // adjust length of parent
+      if (this.parentSub === null && this.countable && !this.deleted) {
+        /** @type {AbstractType<any>} */ (this.parent)._length += this.length
+      }
+      // check if this item is in a moved range
+      if ((this.left && this.left.moved) || (this.right && this.right.moved)) {
+        const leftMoved = this.left && this.left.moved && /** @type {ContentMove} */ (this.left.moved.content)
+        const rightMoved = this.right && this.right.moved && /** @type {ContentMove} */ (this.right.moved.content)
+        if (leftMoved === rightMoved) {
+          this.moved = /** @type {Item} */ (this.left).moved
+        } else if (
+          (leftMoved != null && !leftMoved.isCollapsed()) ||
+          (rightMoved != null && !rightMoved.isCollapsed())
+        ) {
+          // We know that this item is on the edge of a moved range.
+          // @todo Instead, we could check to which moved-range this item belongs
+          // This approach (reintegration) is pretty expensive in some scenarios
+          leftMoved && leftMoved.integrate(transaction, /** @type {any} */ (this.left).moved)
+          rightMoved && rightMoved.integrate(transaction, /** @type {any} */ (this.right).moved)
+        }
+      }
+
+      addStruct(transaction.doc.store, this)
+      this.content.integrate(transaction, this)
+      // add parent to transaction.changed
+      addChangedTypeToTransaction(transaction, /** @type {AbstractType<any>} */ (this.parent), this.parentSub)
+      if ((/** @type {AbstractType<any>} */ (this.parent)._item !== null && /** @type {AbstractType<any>} */ (this.parent)._item.deleted) || (this.parentSub !== null && this.right !== null)) {
+        // delete if parent is deleted or if this is not the current attribute value of parent
+        this.delete(transaction)
+      }
+    } else {
+      // parent is not defined. Integrate GC struct instead
+      new GC(this.id, this.length).integrate(transaction, 0)
+    }
+  }
+
+  /**
+   * Returns the next non-deleted item
+   */
+  get next () {
+    let n = this.right
+    while (n !== null && n.deleted) {
+      n = n.right
+    }
+    return n
+  }
+
+  /**
+   * Returns the previous non-deleted item
+   */
+  get prev () {
+    let n = this.left
+    while (n !== null && n.deleted) {
+      n = n.left
+    }
+    return n
+  }
+
+  /**
+   * Computes the last content address of this Item.
+   */
+  get lastId () {
+    // allocating ids is pretty costly because of the amount of ids created, so we try to reuse whenever possible
+    return this.length === 1 ? this.id : createID(this.id.client, this.id.clock + this.length - 1)
+  }
+
+  /**
+   * Try to merge two items
+   *
+   * @param {Item} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (
+      this.constructor === right.constructor &&
+      compareIDs(right.origin, this.lastId) &&
+      this.right === right &&
+      compareIDs(this.rightOrigin, right.rightOrigin) &&
+      this.id.client === right.id.client &&
+      this.id.clock + this.length === right.id.clock &&
+      this.deleted === right.deleted &&
+      this.redone === null &&
+      right.redone === null &&
+      this.moved === right.moved &&
+      this.content.constructor === right.content.constructor &&
+      this.content.mergeWith(right.content)
+    ) {
+      if (right.marker) {
+        // Right will be "forgotten", so we delete all
+        // search markers that reference right.
+        const searchMarker = /** @type {AbstractType<any>} */ (this.parent)._searchMarker
+        if (searchMarker) {
+          for (let i = searchMarker.length - 1; i >= 0; i--) {
+            if (searchMarker[i].nextItem === right) {
+              // @todo do something more efficient than splicing..
+              searchMarker.splice(i, 1)
+            }
+          }
+        }
+      }
+      if (right.keep) {
+        this.keep = true
+      }
+      this.right = right.right
+      if (this.right !== null) {
+        this.right.left = this
+      }
+      this.length += right.length
+      return true
+    }
+    return false
+  }
+
+  /**
+   * Mark this Item as deleted.
+   *
+   * @param {Transaction} transaction
+   */
+  delete (transaction) {
+    if (!this.deleted) {
+      const parent = /** @type {AbstractType<any>} */ (this.parent)
+      // adjust the length of parent
+      if (this.countable && this.parentSub === null) {
+        parent._length -= this.length
+      }
+      this.markDeleted()
+      addToDeleteSet(transaction.deleteSet, this.id.client, this.id.clock, this.length)
+      addChangedTypeToTransaction(transaction, parent, this.parentSub)
+      this.content.delete(transaction, this)
+    }
+  }
+
+  /**
+   * Similar to `this.delete(tr)`, but additionally ensures
+   * that the deleted range is broadcasted using a different
+   * origin/source in a separate update event, so that
+   * the providers don't filter this message.
+   *
+   * @param {Transaction} transaction
+   * @param {boolean} isLocal
+   */
+  deleteAsCleanup (transaction, isLocal) {
+    this.delete(transaction)
+    if (!isLocal) {
+      addToDeleteSet(transaction.cleanupDeletions, this.id.client, this.id.clock, this.length)
+    }
+  }
+
+  /**
+   * @param {StructStore} store
+   * @param {boolean} parentGCd
+   */
+  gc (store, parentGCd) {
+    if (!this.deleted) {
+      throw error.unexpectedCase()
+    }
+    this.content.gc(store)
+    if (parentGCd) {
+      replaceStruct(store, this, new GC(this.id, this.length))
+    } else {
+      this.content = new ContentDeleted(this.length)
+    }
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    const origin = offset > 0 ? createID(this.id.client, this.id.clock + offset - 1) : this.origin
+    const rightOrigin = this.rightOrigin
+    const parentSub = this.parentSub
+    const info = (this.content.getRef() & binary.BITS5) |
+      (origin === null ? 0 : binary.BIT8) | // origin is defined
+      (rightOrigin === null ? 0 : binary.BIT7) | // right origin is defined
+      (parentSub === null ? 0 : binary.BIT6) // parentSub is non-null
+    encoder.writeInfo(info)
+    if (origin !== null) {
+      encoder.writeLeftID(origin)
+    }
+    if (rightOrigin !== null) {
+      encoder.writeRightID(rightOrigin)
+    }
+    if (origin === null && rightOrigin === null) {
+      const parent = /** @type {AbstractType<any>} */ (this.parent)
+      if (parent._item !== undefined) {
+        const parentItem = parent._item
+        if (parentItem === null) {
+          // parent type on y._map
+          // find the correct key
+          const ykey = findRootTypeKey(parent)
+          encoder.writeParentInfo(true) // write parentYKey
+          encoder.writeString(ykey)
+        } else {
+          encoder.writeParentInfo(false) // write parent id
+          encoder.writeLeftID(parentItem.id)
+        }
+      } else if (parent.constructor === String) { // this edge case was added by differential updates
+        encoder.writeParentInfo(true) // write parentYKey
+        encoder.writeString(parent)
+      } else if (parent.constructor === ID) {
+        encoder.writeParentInfo(false) // write parent id
+        encoder.writeLeftID(parent)
+      } else {
+        error.unexpectedCase()
+      }
+      if (parentSub !== null) {
+        encoder.writeString(parentSub)
+      }
+    }
+    this.content.write(encoder, offset)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @param {number} info
+ */
+export const readItemContent = (decoder, info) => contentRefs[info & binary.BITS5](decoder)
+
+/**
+ * A lookup map for reading Item content.
+ *
+ * @type {Array<function(UpdateDecoderV1 | UpdateDecoderV2):AbstractContent>}
+ */
+export const contentRefs = [
+  error.unexpectedCase, // GC is not ItemContent
+  readContentDeleted, // 1
+  readContentJSON, // 2
+  readContentBinary, // 3
+  readContentString, // 4
+  readContentEmbed, // 5
+  readContentFormat, // 6
+  readContentType, // 7
+  readContentAny, // 8
+  readContentDoc, // 9
+  error.unexpectedCase, // 10 - Skip is not ItemContent
+  readContentMove // 11
+]
+
+/**
+ * Do not implement this class!
+ */
+export class AbstractContent {
+  /**
+   * @return {number}
+   */
+  getLength () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {Array<any>}
+   */
+  getContent () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * Should return false if this Item is some kind of meta information
+   * (e.g. format information).
+   *
+   * * Whether this Item should be addressable via `yarray.get(i)`
+   * * Whether this Item should be counted when computing yarray.length
+   *
+   * @return {boolean}
+   */
+  isCountable () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {AbstractContent}
+   */
+  copy () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {number} offset
+   * @return {AbstractContent}
+   */
+  splice (offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {AbstractContent} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  integrate (transaction, item) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {Item} item
+   */
+  delete (transaction, item) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {StructStore} store
+   */
+  gc (store) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {number}
+   */
+  getRef () {
+    throw error.methodUnimplemented()
+  }
+}

src/structs/Skip.js

@@ -0,0 +1,60 @@
+
+import {
+  AbstractStruct,
+  UpdateEncoderV1, UpdateEncoderV2, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+import * as error from 'lib0/error'
+import * as encoding from 'lib0/encoding'
+
+export const structSkipRefNumber = 10
+
+/**
+ * @private
+ */
+export class Skip extends AbstractStruct {
+  get deleted () {
+    return true
+  }
+
+  delete () {}
+
+  /**
+   * @param {Skip} right
+   * @return {boolean}
+   */
+  mergeWith (right) {
+    if (this.constructor !== right.constructor) {
+      return false
+    }
+    this.length += right.length
+    return true
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {number} offset
+   */
+  integrate (transaction, offset) {
+    // skip structs cannot be integrated
+    error.unexpectedCase()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   * @param {number} offset
+   */
+  write (encoder, offset) {
+    encoder.writeInfo(structSkipRefNumber)
+    // write as VarUint because Skips can't make use of predictable length-encoding
+    encoding.writeVarUint(encoder.restEncoder, this.length - offset)
+  }
+
+  /**
+   * @param {Transaction} transaction
+   * @param {StructStore} store
+   * @return {null | number}
+   */
+  getMissing (transaction, store) {
+    return null
+  }
+}

src/types/AbstractType.js

@@ -0,0 +1,563 @@
+
+import {
+  removeEventHandlerListener,
+  callEventHandlerListeners,
+  addEventHandlerListener,
+  createEventHandler,
+  getState,
+  isVisible,
+  ContentType,
+  createID,
+  ContentAny,
+  ContentBinary,
+  ListCursor,
+  ContentDoc, UpdateEncoderV1, UpdateEncoderV2, Doc, Snapshot, Transaction, EventHandler, YEvent, Item, // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map'
+import * as iterator from 'lib0/iterator'
+import * as error from 'lib0/error'
+import * as math from 'lib0/math'
+
+const maxSearchMarker = 300
+const freshSearchMarkerDistance = 30
+
+/**
+ * Search marker help us to find positions in the associative array faster.
+ *
+ * They speed up the process of finding a position without much bookkeeping.
+ *
+ * A maximum of `maxSearchMarker` objects are created.
+ *
+ * @template T
+ * @param {Transaction} tr
+ * @param {AbstractType<any>} yarray
+ * @param {number} index
+ * @param {function(ListCursor):T} f
+ * @return T
+ */
+export const useSearchMarker = (tr, yarray, index, f) => {
+  const searchMarker = yarray._searchMarker
+  if (searchMarker === null || yarray._start === null || index < freshSearchMarkerDistance) {
+    return f(new ListCursor(yarray).forward(tr, index, true))
+  }
+  if (searchMarker.length === 0) {
+    const sm = new ListCursor(yarray).forward(tr, index, true)
+    searchMarker.push(sm)
+    if (sm.nextItem) sm.nextItem.marker = true
+  }
+  const sm = searchMarker.reduce(
+    (a, b, arrayIndex) => math.abs(index - a.index) < math.abs(index - b.index) ? a : b
+  )
+  const newIsCheaper = math.abs(sm.index - index) >= index
+  const createFreshMarker = searchMarker.length < maxSearchMarker && (math.abs(sm.index - index) > freshSearchMarkerDistance || newIsCheaper)
+  const fsm = createFreshMarker ? (newIsCheaper ? new ListCursor(yarray) : sm.clone()) : sm
+  const prevItem = /** @type {Item} */ (sm.nextItem)
+  if (createFreshMarker) {
+    searchMarker.push(fsm)
+  }
+  const diff = fsm.index - index
+  if (diff > 0) {
+    fsm.backward(tr, diff)
+  } else {
+    fsm.forward(tr, -diff, true)
+  }
+  const result = f(fsm)
+  if (fsm.reachedEnd) {
+    fsm.reachedEnd = false
+    const nextItem = /** @type {Item} */ (fsm.nextItem)
+    if (nextItem.countable && !nextItem.deleted) {
+      fsm.index -= nextItem.length
+    }
+    fsm.rel = 0
+  }
+  fsm.index -= fsm.rel
+  fsm.rel = 0
+  if (!createFreshMarker) {
+    // reused old marker and we moved to a different position
+    prevItem.marker = false
+  }
+  const fsmItem = fsm.nextItem
+  if (fsmItem) {
+    if (fsmItem.marker) {
+      // already marked, forget current iterator
+      searchMarker.splice(searchMarker.findIndex(m => m === fsm), 1)
+    } else {
+      fsmItem.marker = true
+    }
+  }
+  return result
+}
+
+/**
+ * Update markers when a change happened.
+ *
+ * This should be called before doing a deletion!
+ *
+ * @param {Array<ListCursor>} searchMarker
+ * @param {number} index
+ * @param {number} len If insertion, len is positive. If deletion, len is negative.
+ * @param {ListCursor|null} origSearchMarker Do not update this searchmarker because it is the one we used to manipulate. @todo !=null for improved perf in ytext
+ */
+export const updateMarkerChanges = (searchMarker, index, len, origSearchMarker) => {
+  for (let i = searchMarker.length - 1; i >= 0; i--) {
+    const marker = searchMarker[i]
+    if (marker !== origSearchMarker) {
+      if (len > 0 && index === marker.index) {
+        // inserting at a marked position deletes the marked position because we can't do a simple transformation
+        // (we don't know whether to insert directly before or directly after the position)
+        searchMarker.splice(i, 1)
+        if (marker.nextItem) marker.nextItem.marker = false
+        continue
+      }
+      if (index < marker.index) { // a simple index <= m.index check would actually suffice
+        marker.index = math.max(index, marker.index + len)
+      }
+    }
+  }
+}
+
+/**
+ * Accumulate all (list) children of a type and return them as an Array.
+ *
+ * @param {AbstractType<any>} t
+ * @return {Array<Item>}
+ */
+export const getTypeChildren = t => {
+  let s = t._start
+  const arr = []
+  while (s) {
+    arr.push(s)
+    s = s.right
+  }
+  return arr
+}
+
+/**
+ * Call event listeners with an event. This will also add an event to all
+ * parents (for `.observeDeep` handlers).
+ *
+ * @template EventType
+ * @param {AbstractType<EventType>} type
+ * @param {Transaction} transaction
+ * @param {EventType} event
+ */
+export const callTypeObservers = (type, transaction, event) => {
+  const changedType = type
+  const changedParentTypes = transaction.changedParentTypes
+  while (true) {
+    // @ts-ignore
+    map.setIfUndefined(changedParentTypes, type, () => []).push(event)
+    if (type._item === null) {
+      break
+    }
+    type = /** @type {AbstractType<any>} */ (type._item.parent)
+  }
+  callEventHandlerListeners(changedType._eH, event, transaction)
+}
+
+/**
+ * @template EventType
+ * Abstract Yjs Type class
+ */
+export class AbstractType {
+  constructor () {
+    /**
+     * @type {Item|null}
+     */
+    this._item = null
+    /**
+     * @type {Map<string,Item>}
+     */
+    this._map = new Map()
+    /**
+     * @type {Item|null}
+     */
+    this._start = null
+    /**
+     * @type {Doc|null}
+     */
+    this.doc = null
+    this._length = 0
+    /**
+     * Event handlers
+     * @type {EventHandler<EventType,Transaction>}
+     */
+    this._eH = createEventHandler()
+    /**
+     * Deep event handlers
+     * @type {EventHandler<Array<YEvent>,Transaction>}
+     */
+    this._dEH = createEventHandler()
+    /**
+     * @type {null | Array<ListCursor>}
+     */
+    this._searchMarker = null
+    /**
+     * You can store custom stuff here.
+     * This might be useful to associate your application state to this shared type.
+     *
+     * @type {Map<any, any>}
+     */
+    this.meta = new Map()
+  }
+
+  /**
+   * @return {AbstractType<any>|null}
+   */
+  get parent () {
+    return this._item ? /** @type {AbstractType<any>} */ (this._item.parent) : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item|null} item
+   */
+  _integrate (y, item) {
+    this.doc = y
+    this._item = item
+  }
+
+  /**
+   * @return {AbstractType<EventType>}
+   */
+  _copy () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @return {AbstractType<EventType>}
+   */
+  clone () {
+    throw error.methodUnimplemented()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) { }
+
+  /**
+   * The first non-deleted item
+   */
+  get _first () {
+    let n = this._start
+    while (n !== null && n.deleted) {
+      n = n.right
+    }
+    return n
+  }
+
+  /**
+   * Creates YEvent and calls all type observers.
+   * Must be implemented by each type.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    if (!transaction.local && this._searchMarker) {
+      this._searchMarker.length = 0
+    }
+  }
+
+  /**
+   * Observe all events that are created on this type.
+   *
+   * @param {function(EventType, Transaction):void} f Observer function
+   */
+  observe (f) {
+    addEventHandlerListener(this._eH, f)
+  }
+
+  /**
+   * Observe all events that are created by this type and its children.
+   *
+   * @param {function(Array<YEvent>,Transaction):void} f Observer function
+   */
+  observeDeep (f) {
+    addEventHandlerListener(this._dEH, f)
+  }
+
+  /**
+   * Unregister an observer function.
+   *
+   * @param {function(EventType,Transaction):void} f Observer function
+   */
+  unobserve (f) {
+    removeEventHandlerListener(this._eH, f)
+  }
+
+  /**
+   * Unregister an observer function.
+   *
+   * @param {function(Array<YEvent>,Transaction):void} f Observer function
+   */
+  unobserveDeep (f) {
+    removeEventHandlerListener(this._dEH, f)
+  }
+
+  /**
+   * @abstract
+   * @return {any}
+   */
+  toJSON () {}
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} start
+ * @param {number} end
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListSlice = (type, start, end) => {
+  if (start < 0) {
+    start = type._length + start
+  }
+  if (end < 0) {
+    end = type._length + end
+  }
+  let len = end - start
+  const cs = []
+  let n = type._start
+  while (n !== null && len > 0) {
+    if (n.countable && !n.deleted) {
+      const c = n.content.getContent()
+      if (c.length <= start) {
+        start -= c.length
+      } else {
+        for (let i = start; i < c.length && len > 0; i++) {
+          cs.push(c[i])
+          len--
+        }
+        start = 0
+      }
+    }
+    n = n.right
+  }
+  return cs
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @return {Array<any>}
+ *
+ * @private
+ * @function
+ */
+export const typeListToArray = type => {
+  const cs = []
+  let n = type._start
+  while (n !== null) {
+    if (n.countable && !n.deleted) {
+      const c = n.content.getContent()
+      for (let i = 0; i < c.length; i++) {
+        cs.push(c[i])
+      }
+    }
+    n = n.right
+  }
+  return cs
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {Item?} referenceItem
+ * @param {Array<Object<string,any>|Array<any>|boolean|number|null|string|Uint8Array>} content
+ *
+ * @private
+ * @function
+ */
+export const typeListInsertGenericsAfter = (transaction, parent, referenceItem, content) => {
+  let left = referenceItem
+  const doc = transaction.doc
+  const ownClientId = doc.clientID
+  const store = doc.store
+  const right = referenceItem === null ? parent._start : referenceItem.right
+  /**
+   * @type {Array<Object|Array<any>|number|null>}
+   */
+  let jsonContent = []
+  const packJsonContent = () => {
+    if (jsonContent.length > 0) {
+      left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentAny(jsonContent))
+      left.integrate(transaction, 0)
+      jsonContent = []
+    }
+  }
+  content.forEach(c => {
+    if (c === null) {
+      jsonContent.push(c)
+    } else {
+      switch (c.constructor) {
+        case Number:
+        case Object:
+        case Boolean:
+        case Array:
+        case String:
+          jsonContent.push(c)
+          break
+        default:
+          packJsonContent()
+          switch (c.constructor) {
+            case Uint8Array:
+            case ArrayBuffer:
+              left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentBinary(new Uint8Array(/** @type {Uint8Array} */ (c))))
+              left.integrate(transaction, 0)
+              break
+            case Doc:
+              left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentDoc(/** @type {Doc} */ (c)))
+              left.integrate(transaction, 0)
+              break
+            default:
+              if (c instanceof AbstractType) {
+                left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, new ContentType(c))
+                left.integrate(transaction, 0)
+              } else {
+                throw new Error('Unexpected content type in insert operation')
+              }
+          }
+      }
+    }
+  })
+  packJsonContent()
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ *
+ * @private
+ * @function
+ */
+export const typeMapDelete = (transaction, parent, key) => {
+  const c = parent._map.get(key)
+  if (c !== undefined) {
+    c.delete(transaction)
+  }
+}
+
+/**
+ * @param {Transaction} transaction
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @param {Object|number|null|Array<any>|string|Uint8Array|AbstractType<any>} value
+ *
+ * @private
+ * @function
+ */
+export const typeMapSet = (transaction, parent, key, value) => {
+  const left = parent._map.get(key) || null
+  const doc = transaction.doc
+  const ownClientId = doc.clientID
+  let content
+  if (value == null) {
+    content = new ContentAny([value])
+  } else {
+    switch (value.constructor) {
+      case Number:
+      case Object:
+      case Boolean:
+      case Array:
+      case String:
+        content = new ContentAny([value])
+        break
+      case Uint8Array:
+        content = new ContentBinary(/** @type {Uint8Array} */ (value))
+        break
+      case Doc:
+        content = new ContentDoc(/** @type {Doc} */ (value))
+        break
+      default:
+        if (value instanceof AbstractType) {
+          content = new ContentType(value)
+        } else {
+          throw new Error('Unexpected content type')
+        }
+    }
+  }
+  new Item(createID(ownClientId, getState(doc.store, ownClientId)), left, left && left.lastId, null, null, parent, key, content).integrate(transaction, 0)
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @return {Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGet = (parent, key) => {
+  const val = parent._map.get(key)
+  return val !== undefined && !val.deleted ? val.content.getContent()[val.length - 1] : undefined
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @return {Object<string,Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined>}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetAll = (parent) => {
+  /**
+   * @type {Object<string,any>}
+   */
+  const res = {}
+  parent._map.forEach((value, key) => {
+    if (!value.deleted) {
+      res[key] = value.content.getContent()[value.length - 1]
+    }
+  })
+  return res
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @return {boolean}
+ *
+ * @private
+ * @function
+ */
+export const typeMapHas = (parent, key) => {
+  const val = parent._map.get(key)
+  return val !== undefined && !val.deleted
+}
+
+/**
+ * @param {AbstractType<any>} parent
+ * @param {string} key
+ * @param {Snapshot} snapshot
+ * @return {Object<string,any>|number|null|Array<any>|string|Uint8Array|AbstractType<any>|undefined}
+ *
+ * @private
+ * @function
+ */
+export const typeMapGetSnapshot = (parent, key, snapshot) => {
+  let v = parent._map.get(key) || null
+  while (v !== null && (!snapshot.sv.has(v.id.client) || v.id.clock >= (snapshot.sv.get(v.id.client) || 0))) {
+    v = v.left
+  }
+  return v !== null && isVisible(v, snapshot) ? v.content.getContent()[v.length - 1] : undefined
+}
+
+/**
+ * @param {Map<string,Item>} map
+ * @return {IterableIterator<Array<any>>}
+ *
+ * @private
+ * @function
+ */
+export const createMapIterator = map => iterator.iteratorFilter(map.entries(), /** @param {any} entry */ entry => !entry[1].deleted)

src/types/YArray.js

@@ -0,0 +1,341 @@
+/**
+ * @module YArray
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  YArrayRefID,
+  callTypeObservers,
+  transact,
+  ListCursor,
+  useSearchMarker,
+  createRelativePositionFromTypeIndex,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, Transaction, Item, // eslint-disable-line
+  getMinimalListViewRanges
+} from '../internals.js'
+
+/**
+ * Event that describes the changes on a YArray
+ * @template T
+ */
+export class YArrayEvent extends YEvent {
+  /**
+   * @param {YArray<T>} yarray The changed type
+   * @param {Transaction} transaction The transaction object
+   */
+  constructor (yarray, transaction) {
+    super(yarray, transaction)
+    this._transaction = transaction
+  }
+}
+
+/**
+ * A shared Array implementation.
+ * @template T
+ * @extends AbstractType<YArrayEvent<T>>
+ * @implements {Iterable<T>}
+ */
+export class YArray extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Array<any>?}
+     * @private
+     */
+    this._prelimContent = []
+    /**
+     * @type {Array<ListCursor>}
+     */
+    this._searchMarker = []
+  }
+
+  /**
+   * Construct a new YArray containing the specified items.
+   * @template T
+   * @param {Array<T>} items
+   * @return {YArray<T>}
+   */
+  static from (items) {
+    const a = new YArray()
+    a.push(items)
+    return a
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    this.insert(0, /** @type {Array<any>} */ (this._prelimContent))
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YArray()
+  }
+
+  /**
+   * @return {YArray<T>}
+   */
+  clone () {
+    const arr = new YArray()
+    arr.insert(0, this.toArray().map(el =>
+      el instanceof AbstractType ? el.clone() : el
+    ))
+    return arr
+  }
+
+  get length () {
+    return this._prelimContent === null ? this._length : this._prelimContent.length
+  }
+
+  /**
+   * Creates YArrayEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    super._callObserver(transaction, parentSubs)
+    callTypeObservers(this, transaction, new YArrayEvent(this, transaction))
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * Important: This function expects an array of content. Not just a content
+   * object. The reason for this "weirdness" is that inserting several elements
+   * is very efficient when it is done as a single operation.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  yarray.insert(0, ['a'])
+   *  // Insert numbers 1, 2 at position 1
+   *  yarray.insert(1, [1, 2])
+   *
+   * @param {number} index The index to insert content at.
+   * @param {Array<T>} content The array of content
+   */
+  insert (index, content) {
+    if (content.length > 0) {
+      if (this.doc !== null) {
+        transact(this.doc, transaction => {
+          useSearchMarker(transaction, this, index, walker =>
+            walker.insertArrayValue(transaction, content)
+          )
+        })
+      } else {
+        /** @type {Array<any>} */ (this._prelimContent).splice(index, 0, ...content)
+      }
+    }
+  }
+
+  /**
+   * Move a single item from $index to $target.
+   *
+   * If the original item is to the left of $target, then the index of the item will decrement.
+   *
+   * ```js
+   * yarray.insert(0, [1, 2, 3])
+   * yarray.move(0, 3) // move "1" to index 3
+   * yarray.toArray() // => [2, 3, 1]
+   * yarray.move(2, 0) // move "1" to index 0
+   * yarray.toArray() // => [1, 2, 3]
+   * ```
+   *
+   * @param {number} index
+   * @param {number} target
+   */
+  move (index, target) {
+    if (index === target || index + 1 === target || index >= this.length) {
+      // It doesn't make sense to move a range into the same range (it's basically a no-op).
+      return
+    }
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const start = createRelativePositionFromTypeIndex(this, index, 1)
+        const end = start.clone()
+        end.assoc = -1
+        useSearchMarker(transaction, this, target, walker => {
+          walker.insertMove(transaction, [{ start, end }])
+        })
+      })
+    } else {
+      const content = /** @type {Array<any>} */ (this._prelimContent).splice(index, 1)
+      ;/** @type {Array<any>} */ (this._prelimContent).splice(target, 0, ...content)
+    }
+  }
+
+  /**
+   * @experimental
+   *
+   * @param {number} startIndex Inclusive move-start
+   * @param {number} endIndex Inclusive move-end
+   * @param {number} target
+   * @param {number} assocStart >=0 if start should be associated with the right character. See relative-position assoc parameter.
+   * @param {number} assocEnd >= 0 if end should be associated with the right character.
+   */
+  moveRange (startIndex, endIndex, target, assocStart = 1, assocEnd = -1) {
+    if (
+      (startIndex <= target && target <= endIndex) || // It doesn't make sense to move a range into the same range (it's basically a no-op).
+      endIndex - startIndex < 0 // require length of >= 0
+    ) {
+      return
+    }
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const ranges = useSearchMarker(transaction, this, startIndex, walker =>
+          getMinimalListViewRanges(transaction, walker, endIndex - startIndex + 1)
+        )
+        useSearchMarker(transaction, this, target, walker => {
+          walker.insertMove(transaction, ranges)
+        })
+      })
+    } else {
+      const content = /** @type {Array<any>} */ (this._prelimContent).splice(startIndex, endIndex - startIndex + 1)
+      ;/** @type {Array<any>} */ (this._prelimContent).splice(target, 0, ...content)
+    }
+  }
+
+  /**
+   * Appends content to this YArray.
+   *
+   * @param {Array<T>} content Array of content to append.
+   */
+  push (content) {
+    this.insert(this.length, content)
+  }
+
+  /**
+   * Preppends content to this YArray.
+   *
+   * @param {Array<T>} content Array of content to preppend.
+   */
+  unshift (content) {
+    this.insert(0, content)
+  }
+
+  /**
+   * Deletes elements starting from an index.
+   *
+   * @param {number} index Index at which to start deleting elements
+   * @param {number} length The number of elements to remove. Defaults to 1.
+   */
+  delete (index, length = 1) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        useSearchMarker(transaction, this, index, walker =>
+          walker.delete(transaction, length)
+        )
+      })
+    } else {
+      /** @type {Array<any>} */ (this._prelimContent).splice(index, length)
+    }
+  }
+
+  /**
+   * Returns the i-th element from a YArray.
+   *
+   * @param {number} index The index of the element to return from the YArray
+   * @return {T}
+   */
+  get (index) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, index, walker =>
+        walker.slice(transaction, 1)[0]
+      )
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @return {Array<T>}
+   */
+  toArray () {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListCursor(this).slice(tr, this.length)
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @param {number} [start]
+   * @param {number} [end]
+   * @return {Array<T>}
+   */
+  slice (start = 0, end = this.length) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, start, walker =>
+        walker.slice(transaction, end < 0 ? this.length + end - start : end - start)
+      )
+    )
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Array<any>}
+   */
+  toJSON () {
+    return this.map(c => c instanceof AbstractType ? c.toJSON() : c)
+  }
+
+  /**
+   * Returns an Array with the result of calling a provided function on every
+   * element of this YArray.
+   *
+   * @template M
+   * @param {function(T,number,YArray<T>):M} f Function that produces an element of the new Array
+   * @return {Array<M>} A new array with each element being the result of the
+   *                 callback function
+   */
+  map (f) {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListCursor(this).map(tr, f)
+    )
+  }
+
+  /**
+   * Executes a provided function on once on overy element of this YArray.
+   *
+   * @param {function(T,number,YArray<T>):void} f A function to execute on every element of this YArray.
+   */
+  forEach (f) {
+    return transact(/** @type {Doc} */ (this.doc), tr =>
+      new ListCursor(this).forEach(tr, f)
+    )
+  }
+
+  /**
+   * @return {IterableIterator<T>}
+   */
+  [Symbol.iterator] () {
+    // @todo, this could be optimized using a real iterator
+    return this.toArray().values()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YArrayRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYArray = decoder => new YArray()

src/types/YMap.js

@@ -0,0 +1,269 @@
+
+/**
+ * @module YMap
+ */
+
+import {
+  YEvent,
+  AbstractType,
+  typeMapDelete,
+  typeMapSet,
+  typeMapGet,
+  typeMapHas,
+  createMapIterator,
+  YMapRefID,
+  callTypeObservers,
+  transact,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, Transaction, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as iterator from 'lib0/iterator'
+
+/**
+ * @template T
+ * Event that describes the changes on a YMap.
+ */
+export class YMapEvent extends YEvent {
+  /**
+   * @param {YMap<T>} ymap The YArray that changed.
+   * @param {Transaction} transaction
+   * @param {Set<any>} subs The keys that changed.
+   */
+  constructor (ymap, transaction, subs) {
+    super(ymap, transaction)
+    this.keysChanged = subs
+  }
+}
+
+/**
+ * @template MapType
+ * A shared Map implementation.
+ *
+ * @extends AbstractType<YMapEvent<MapType>>
+ * @implements {Iterable<MapType>}
+ */
+export class YMap extends AbstractType {
+  /**
+   *
+   * @param {Iterable<readonly [string, any]>=} entries - an optional iterable to initialize the YMap
+   */
+  constructor (entries) {
+    super()
+    /**
+     * @type {Map<string,any>?}
+     * @private
+     */
+    this._prelimContent = null
+
+    if (entries === undefined) {
+      this._prelimContent = new Map()
+    } else {
+      this._prelimContent = new Map(entries)
+    }
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    ;/** @type {Map<string, any>} */ (this._prelimContent).forEach((value, key) => {
+      this.set(key, value)
+    })
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YMap()
+  }
+
+  /**
+   * @return {YMap<MapType>}
+   */
+  clone () {
+    const map = new YMap()
+    this.forEach((value, key) => {
+      map.set(key, value instanceof AbstractType ? value.clone() : value)
+    })
+    return map
+  }
+
+  /**
+   * Creates YMapEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YMapEvent(this, transaction, parentSubs))
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Object<string,any>}
+   */
+  toJSON () {
+    /**
+     * @type {Object<string,MapType>}
+     */
+    const map = {}
+    this._map.forEach((item, key) => {
+      if (!item.deleted) {
+        const v = item.content.getContent()[item.length - 1]
+        map[key] = v instanceof AbstractType ? v.toJSON() : v
+      }
+    })
+    return map
+  }
+
+  /**
+   * Returns the size of the YMap (count of key/value pairs)
+   *
+   * @return {number}
+   */
+  get size () {
+    return [...createMapIterator(this._map)].length
+  }
+
+  /**
+   * Returns the keys for each element in the YMap Type.
+   *
+   * @return {IterableIterator<string>}
+   */
+  keys () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => v[0])
+  }
+
+  /**
+   * Returns the values for each element in the YMap Type.
+   *
+   * @return {IterableIterator<any>}
+   */
+  values () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => v[1].content.getContent()[v[1].length - 1])
+  }
+
+  /**
+   * Returns an Iterator of [key, value] pairs
+   *
+   * @return {IterableIterator<any>}
+   */
+  entries () {
+    return iterator.iteratorMap(createMapIterator(this._map), /** @param {any} v */ v => [v[0], v[1].content.getContent()[v[1].length - 1]])
+  }
+
+  /**
+   * Executes a provided function on once on every key-value pair.
+   *
+   * @param {function(MapType,string,YMap<MapType>):void} f A function to execute on every element of this YArray.
+   */
+  forEach (f) {
+    /**
+     * @type {Object<string,MapType>}
+     */
+    const map = {}
+    this._map.forEach((item, key) => {
+      if (!item.deleted) {
+        f(item.content.getContent()[item.length - 1], key, this)
+      }
+    })
+    return map
+  }
+
+  /**
+   * @return {IterableIterator<MapType>}
+   */
+  [Symbol.iterator] () {
+    return this.entries()
+  }
+
+  /**
+   * Remove a specified element from this YMap.
+   *
+   * @param {string} key The key of the element to remove.
+   */
+  delete (key) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapDelete(transaction, this, key)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).delete(key)
+    }
+  }
+
+  /**
+   * Adds or updates an element with a specified key and value.
+   *
+   * @param {string} key The key of the element to add to this YMap
+   * @param {MapType} value The value of the element to add
+   */
+  set (key, value) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapSet(transaction, this, key, value)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).set(key, value)
+    }
+    return value
+  }
+
+  /**
+   * Returns a specified element from this YMap.
+   *
+   * @param {string} key
+   * @return {MapType|undefined}
+   */
+  get (key) {
+    return /** @type {any} */ (typeMapGet(this, key))
+  }
+
+  /**
+   * Returns a boolean indicating whether the specified key exists or not.
+   *
+   * @param {string} key The key to test.
+   * @return {boolean}
+   */
+  has (key) {
+    return typeMapHas(this, key)
+  }
+
+  /**
+   * Removes all elements from this YMap.
+   */
+  clear () {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        this.forEach(function (value, key, map) {
+          typeMapDelete(transaction, map, key)
+        })
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimContent).clear()
+    }
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YMapRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ *
+ * @private
+ * @function
+ */
+export const readYMap = decoder => new YMap()

src/types/YXmlElement.js

@@ -0,0 +1,207 @@
+
+import {
+  YXmlFragment,
+  transact,
+  typeMapDelete,
+  typeMapHas,
+  typeMapSet,
+  typeMapGet,
+  typeMapGetAll,
+  YXmlElementRefID,
+  YXmlText, ContentType, AbstractType, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Snapshot, Doc, Item // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * An YXmlElement imitates the behavior of a
+ * {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}.
+ *
+ * * An YXmlElement has attributes (key value pairs)
+ * * An YXmlElement has childElements that must inherit from YXmlElement
+ */
+export class YXmlElement extends YXmlFragment {
+  constructor (nodeName = 'UNDEFINED') {
+    super()
+    this.nodeName = nodeName
+    /**
+     * @type {Map<string, any>|null}
+     */
+    this._prelimAttrs = new Map()
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get nextSibling () {
+    const n = this._item ? this._item.next : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get prevSibling () {
+    const n = this._item ? this._item.prev : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    ;(/** @type {Map<string, any>} */ (this._prelimAttrs)).forEach((value, key) => {
+      this.setAttribute(key, value)
+    })
+    this._prelimAttrs = null
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   *
+   * @return {YXmlElement}
+   */
+  _copy () {
+    return new YXmlElement(this.nodeName)
+  }
+
+  /**
+   * @return {YXmlElement}
+   */
+  clone () {
+    const el = new YXmlElement(this.nodeName)
+    const attrs = this.getAttributes()
+    for (const key in attrs) {
+      el.setAttribute(key, attrs[key])
+    }
+    // @ts-ignore
+    el.insert(0, this.toArray().map(item => item instanceof AbstractType ? item.clone() : item))
+    return el
+  }
+
+  /**
+   * Returns the XML serialization of this YXmlElement.
+   * The attributes are ordered by attribute-name, so you can easily use this
+   * method to compare YXmlElements
+   *
+   * @return {string} The string representation of this type.
+   *
+   * @public
+   */
+  toString () {
+    const attrs = this.getAttributes()
+    const stringBuilder = []
+    const keys = []
+    for (const key in attrs) {
+      keys.push(key)
+    }
+    keys.sort()
+    const keysLen = keys.length
+    for (let i = 0; i < keysLen; i++) {
+      const key = keys[i]
+      stringBuilder.push(key + '="' + attrs[key] + '"')
+    }
+    const nodeName = this.nodeName.toLocaleLowerCase()
+    const attrsString = stringBuilder.length > 0 ? ' ' + stringBuilder.join(' ') : ''
+    return `<${nodeName}${attrsString}>${super.toString()}</${nodeName}>`
+  }
+
+  /**
+   * Removes an attribute from this YXmlElement.
+   *
+   * @param {String} attributeName The attribute name that is to be removed.
+   *
+   * @public
+   */
+  removeAttribute (attributeName) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapDelete(transaction, this, attributeName)
+      })
+    } else {
+      /** @type {Map<string,any>} */ (this._prelimAttrs).delete(attributeName)
+    }
+  }
+
+  /**
+   * Sets or updates an attribute.
+   *
+   * @param {String} attributeName The attribute name that is to be set.
+   * @param {String} attributeValue The attribute value that is to be set.
+   *
+   * @public
+   */
+  setAttribute (attributeName, attributeValue) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        typeMapSet(transaction, this, attributeName, attributeValue)
+      })
+    } else {
+      /** @type {Map<string, any>} */ (this._prelimAttrs).set(attributeName, attributeValue)
+    }
+  }
+
+  /**
+   * Returns an attribute value that belongs to the attribute name.
+   *
+   * @param {String} attributeName The attribute name that identifies the
+   *                               queried value.
+   * @return {String} The queried attribute value.
+   *
+   * @public
+   */
+  getAttribute (attributeName) {
+    return /** @type {any} */ (typeMapGet(this, attributeName))
+  }
+
+  /**
+   * Returns whether an attribute exists
+   *
+   * @param {String} attributeName The attribute name to check for existence.
+   * @return {boolean} whether the attribute exists.
+   *
+   * @public
+   */
+  hasAttribute (attributeName) {
+    return /** @type {any} */ (typeMapHas(this, attributeName))
+  }
+
+  /**
+   * Returns all attribute name/value pairs in a JSON Object.
+   *
+   * @param {Snapshot} [snapshot]
+   * @return {Object<string, any>} A JSON Object that describes the attributes.
+   *
+   * @public
+   */
+  getAttributes (snapshot) {
+    return typeMapGetAll(this)
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlElementRefID)
+    encoder.writeKey(this.nodeName)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlElement}
+ *
+ * @function
+ */
+export const readYXmlElement = decoder => new YXmlElement(decoder.readKey())

src/types/YXmlEvent.js

@@ -0,0 +1,39 @@
+
+import {
+  YEvent,
+  YXmlText, YXmlElement, YXmlFragment, Transaction // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * An Event that describes changes on a YXml Element or Yxml Fragment
+ */
+export class YXmlEvent extends YEvent {
+  /**
+   * @param {YXmlElement|YXmlText|YXmlFragment} target The target on which the event is created.
+   * @param {Set<string|null>} subs The set of changed attributes. `null` is included if the
+   *                   child list changed.
+   * @param {Transaction} transaction The transaction instance with wich the
+   *                                  change was created.
+   */
+  constructor (target, subs, transaction) {
+    super(target, transaction)
+    /**
+     * Whether the children changed.
+     * @type {Boolean}
+     * @private
+     */
+    this.childListChanged = false
+    /**
+     * Set of all changed attributes.
+     * @type {Set<string>}
+     */
+    this.attributesChanged = new Set()
+    subs.forEach((sub) => {
+      if (sub === null) {
+        this.childListChanged = true
+      } else {
+        this.attributesChanged.add(sub)
+      }
+    })
+  }
+}

src/types/YXmlFragment.js

@@ -0,0 +1,409 @@
+/**
+ * @module YXml
+ */
+
+import {
+  YXmlEvent,
+  YXmlElement,
+  AbstractType,
+  typeListInsertGenericsAfter,
+  typeListToArray,
+  YXmlFragmentRefID,
+  callTypeObservers,
+  transact,
+  typeListSlice,
+  useSearchMarker,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, Doc, ContentType, Transaction, Item, YXmlText, YXmlHook, Snapshot, // eslint-disable-line
+  ListCursor
+} from '../internals.js'
+
+import * as error from 'lib0/error'
+
+/**
+ * Define the elements to which a set of CSS queries apply.
+ * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors|CSS_Selectors}
+ *
+ * @example
+ *   query = '.classSelector'
+ *   query = 'nodeSelector'
+ *   query = '#idSelector'
+ *
+ * @typedef {string} CSS_Selector
+ */
+
+/**
+ * Dom filter function.
+ *
+ * @callback domFilter
+ * @param {string} nodeName The nodeName of the element
+ * @param {Map} attributes The map of attributes.
+ * @return {boolean} Whether to include the Dom node in the YXmlElement.
+ */
+
+/**
+ * Represents a subset of the nodes of a YXmlElement / YXmlFragment and a
+ * position within them.
+ *
+ * Can be created with {@link YXmlFragment#createTreeWalker}
+ *
+ * @public
+ * @implements {Iterable<YXmlElement|YXmlText|YXmlElement|YXmlHook>}
+ */
+export class YXmlTreeWalker {
+  /**
+   * @param {YXmlFragment | YXmlElement} root
+   * @param {function(AbstractType<any>):boolean} [f]
+   */
+  constructor (root, f = () => true) {
+    this._filter = f
+    this._root = root
+    /**
+     * @type {Item}
+     */
+    this._currentNode = /** @type {Item} */ (root._start)
+    this._firstCall = true
+  }
+
+  [Symbol.iterator] () {
+    return this
+  }
+
+  /**
+   * Get the next node.
+   *
+   * @return {IteratorResult<YXmlElement|YXmlText|YXmlHook>} The next node.
+   *
+   * @public
+   */
+  next () {
+    /**
+     * @type {Item|null}
+     */
+    let n = this._currentNode
+    let type = n && n.content && /** @type {any} */ (n.content).type
+    if (n !== null && (!this._firstCall || n.deleted || !this._filter(type))) { // if first call, we check if we can use the first item
+      do {
+        type = /** @type {any} */ (n.content).type
+        if (!n.deleted && (type.constructor === YXmlElement || type.constructor === YXmlFragment) && type._start !== null) {
+          // walk down in the tree
+          n = type._start
+        } else {
+          // walk right or up in the tree
+          while (n !== null) {
+            if (n.right !== null) {
+              n = n.right
+              break
+            } else if (n.parent === this._root) {
+              n = null
+            } else {
+              n = /** @type {AbstractType<any>} */ (n.parent)._item
+            }
+          }
+        }
+      } while (n !== null && (n.deleted || !this._filter(/** @type {ContentType} */ (n.content).type)))
+    }
+    this._firstCall = false
+    if (n === null) {
+      // @ts-ignore
+      return { value: undefined, done: true }
+    }
+    this._currentNode = n
+    return { value: /** @type {any} */ (n.content).type, done: false }
+  }
+}
+
+/**
+ * Represents a list of {@link YXmlElement}.and {@link YXmlText} types.
+ * A YxmlFragment is similar to a {@link YXmlElement}, but it does not have a
+ * nodeName and it does not have attributes. Though it can be bound to a DOM
+ * element - in this case the attributes and the nodeName are not shared.
+ *
+ * @public
+ * @extends AbstractType<YXmlEvent>
+ */
+export class YXmlFragment extends AbstractType {
+  constructor () {
+    super()
+    /**
+     * @type {Array<any>|null}
+     */
+    this._prelimContent = []
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get firstChild () {
+    const first = this._first
+    return first ? first.content.getContent()[0] : null
+  }
+
+  /**
+   * Integrate this type into the Yjs instance.
+   *
+   * * Save this struct in the os
+   * * This type is sent to other client
+   * * Observer functions are fired
+   *
+   * @param {Doc} y The Yjs instance
+   * @param {Item} item
+   */
+  _integrate (y, item) {
+    super._integrate(y, item)
+    this.insert(0, /** @type {Array<any>} */ (this._prelimContent))
+    this._prelimContent = null
+  }
+
+  _copy () {
+    return new YXmlFragment()
+  }
+
+  /**
+   * @return {YXmlFragment}
+   */
+  clone () {
+    const el = new YXmlFragment()
+    // @ts-ignore
+    el.insert(0, this.toArray().map(item => item instanceof AbstractType ? item.clone() : item))
+    return el
+  }
+
+  get length () {
+    return this._prelimContent === null ? this._length : this._prelimContent.length
+  }
+
+  /**
+   * Create a subtree of childNodes.
+   *
+   * @example
+   * const walker = elem.createTreeWalker(dom => dom.nodeName === 'div')
+   * for (let node in walker) {
+   *   // `node` is a div node
+   *   nop(node)
+   * }
+   *
+   * @param {function(AbstractType<any>):boolean} filter Function that is called on each child element and
+   *                          returns a Boolean indicating whether the child
+   *                          is to be included in the subtree.
+   * @return {YXmlTreeWalker} A subtree and a position within it.
+   *
+   * @public
+   */
+  createTreeWalker (filter) {
+    return new YXmlTreeWalker(this, filter)
+  }
+
+  /**
+   * Returns the first YXmlElement that matches the query.
+   * Similar to DOM's {@link querySelector}.
+   *
+   * Query support:
+   *   - tagname
+   * TODO:
+   *   - id
+   *   - attribute
+   *
+   * @param {CSS_Selector} query The query on the children.
+   * @return {YXmlElement|YXmlText|YXmlHook|null} The first element that matches the query or null.
+   *
+   * @public
+   */
+  querySelector (query) {
+    query = query.toUpperCase()
+    // @ts-ignore
+    const iterator = new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query)
+    const next = iterator.next()
+    if (next.done) {
+      return null
+    } else {
+      return next.value
+    }
+  }
+
+  /**
+   * Returns all YXmlElements that match the query.
+   * Similar to Dom's {@link querySelectorAll}.
+   *
+   * @todo Does not yet support all queries. Currently only query by tagName.
+   *
+   * @param {CSS_Selector} query The query on the children
+   * @return {Array<YXmlElement|YXmlText|YXmlHook|null>} The elements that match this query.
+   *
+   * @public
+   */
+  querySelectorAll (query) {
+    query = query.toUpperCase()
+    // @ts-ignore
+    return Array.from(new YXmlTreeWalker(this, element => element.nodeName && element.nodeName.toUpperCase() === query))
+  }
+
+  /**
+   * Creates YXmlEvent and calls observers.
+   *
+   * @param {Transaction} transaction
+   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
+   */
+  _callObserver (transaction, parentSubs) {
+    callTypeObservers(this, transaction, new YXmlEvent(this, parentSubs, transaction))
+  }
+
+  /**
+   * Get the string representation of all the children of this YXmlFragment.
+   *
+   * @return {string} The string representation of all children.
+   */
+  toString () {
+    if (this.doc != null) {
+      return transact(this.doc, tr => new ListCursor(this).map(tr, xml => xml.toString()).join(''))
+    }
+    return ''
+  }
+
+  /**
+   * @return {string}
+   */
+  toJSON () {
+    return this.toString()
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  xml.insert(0, [new Y.XmlText('text')])
+   *
+   * @param {number} index The index to insert content at
+   * @param {Array<YXmlElement|YXmlText>} content The array of content
+   */
+  insert (index, content) {
+    if (this.doc !== null) {
+      return transact(this.doc, transaction =>
+        useSearchMarker(transaction, this, index, walker =>
+          walker.insertArrayValue(transaction, content)
+        )
+      )
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, 0, ...content)
+    }
+  }
+
+  /**
+   * Inserts new content at an index.
+   *
+   * @example
+   *  // Insert character 'a' at position 0
+   *  xml.insert(0, [new Y.XmlText('text')])
+   *
+   * @param {null|Item|YXmlElement|YXmlText} ref The index to insert content at
+   * @param {Array<YXmlElement|YXmlText>} content The array of content
+   */
+  insertAfter (ref, content) {
+    if (this.doc !== null) {
+      transact(this.doc, transaction => {
+        const refItem = (ref && ref instanceof AbstractType) ? ref._item : ref
+        typeListInsertGenericsAfter(transaction, this, refItem, content)
+      })
+    } else {
+      const pc = /** @type {Array<any>} */ (this._prelimContent)
+      const index = ref === null ? 0 : pc.findIndex(el => el === ref) + 1
+      if (index === 0 && ref !== null) {
+        throw error.create('Reference item not found')
+      }
+      pc.splice(index, 0, ...content)
+    }
+  }
+
+  /**
+   * Deletes elements starting from an index.
+   *
+   * @param {number} index Index at which to start deleting elements
+   * @param {number} [length=1] The number of elements to remove. Defaults to 1.
+   */
+  delete (index, length = 1) {
+    if (this.doc !== null) {
+      transact(/** @type {Doc} */ (this.doc), transaction =>
+        useSearchMarker(transaction, this, index, walker =>
+          walker.delete(transaction, length)
+        )
+      )
+    } else {
+      // @ts-ignore _prelimContent is defined because this is not yet integrated
+      this._prelimContent.splice(index, length)
+    }
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @return {Array<YXmlElement|YXmlText|YXmlHook>}
+   */
+  toArray () {
+    return typeListToArray(this)
+  }
+
+  /**
+   * Appends content to this YArray.
+   *
+   * @param {Array<YXmlElement|YXmlText>} content Array of content to append.
+   */
+  push (content) {
+    this.insert(this.length, content)
+  }
+
+  /**
+   * Preppends content to this YArray.
+   *
+   * @param {Array<YXmlElement|YXmlText>} content Array of content to preppend.
+   */
+  unshift (content) {
+    this.insert(0, content)
+  }
+
+  /**
+   * Returns the i-th element from a YArray.
+   *
+   * @param {number} index The index of the element to return from the YArray
+   * @return {YXmlElement|YXmlText}
+   */
+  get (index) {
+    return transact(/** @type {Doc} */ (this.doc), transaction =>
+      useSearchMarker(transaction, this, index, walker =>
+        walker.slice(transaction, 1)[0]
+      )
+    )
+  }
+
+  /**
+   * Transforms this YArray to a JavaScript Array.
+   *
+   * @param {number} [start]
+   * @param {number} [end]
+   * @return {Array<YXmlElement|YXmlText>}
+   */
+  slice (start = 0, end = this.length) {
+    return typeListSlice(this, start, end)
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlFragmentRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlFragment}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlFragment = decoder => new YXmlFragment()

src/types/YXmlHook.js

@@ -0,0 +1,65 @@
+
+import {
+  YMap,
+  YXmlHookRefID,
+  UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2 // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * You can manage binding to a custom type with YXmlHook.
+ *
+ * @extends {YMap<any>}
+ */
+export class YXmlHook extends YMap {
+  /**
+   * @param {string} hookName nodeName of the Dom Node.
+   */
+  constructor (hookName) {
+    super()
+    /**
+     * @type {string}
+     */
+    this.hookName = hookName
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   */
+  _copy () {
+    return new YXmlHook(this.hookName)
+  }
+
+  /**
+   * @return {YXmlHook}
+   */
+  clone () {
+    const el = new YXmlHook(this.hookName)
+    this.forEach((value, key) => {
+      el.set(key, value)
+    })
+    return el
+  }
+
+  /**
+   * Transform the properties of this type to binary and write it to an
+   * BinaryEncoder.
+   *
+   * This is called when this Item is sent to a remote peer.
+   *
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder The encoder to write data to.
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlHookRefID)
+    encoder.writeKey(this.hookName)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlHook}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlHook = decoder =>
+  new YXmlHook(decoder.readKey())

src/types/YXmlText.js

@@ -0,0 +1,98 @@
+
+import {
+  YText,
+  YXmlTextRefID,
+  ContentType, YXmlElement, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2, // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * Represents text in a Dom Element. In the future this type will also handle
+ * simple formatting information like bold and italic.
+ */
+export class YXmlText extends YText {
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get nextSibling () {
+    const n = this._item ? this._item.next : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  /**
+   * @type {YXmlElement|YXmlText|null}
+   */
+  get prevSibling () {
+    const n = this._item ? this._item.prev : null
+    return n ? /** @type {YXmlElement|YXmlText} */ (/** @type {ContentType} */ (n.content).type) : null
+  }
+
+  _copy () {
+    return new YXmlText()
+  }
+
+  /**
+   * @return {YXmlText}
+   */
+  clone () {
+    const text = new YXmlText()
+    text.applyDelta(this.toDelta())
+    return text
+  }
+
+  toString () {
+    // @ts-ignore
+    return this.toDelta().map(delta => {
+      const nestedNodes = []
+      for (const nodeName in delta.attributes) {
+        const attrs = []
+        for (const key in delta.attributes[nodeName]) {
+          attrs.push({ key, value: delta.attributes[nodeName][key] })
+        }
+        // sort attributes to get a unique order
+        attrs.sort((a, b) => a.key < b.key ? -1 : 1)
+        nestedNodes.push({ nodeName, attrs })
+      }
+      // sort node order to get a unique order
+      nestedNodes.sort((a, b) => a.nodeName < b.nodeName ? -1 : 1)
+      // now convert to dom string
+      let str = ''
+      for (let i = 0; i < nestedNodes.length; i++) {
+        const node = nestedNodes[i]
+        str += `<${node.nodeName}`
+        for (let j = 0; j < node.attrs.length; j++) {
+          const attr = node.attrs[j]
+          str += ` ${attr.key}="${attr.value}"`
+        }
+        str += '>'
+      }
+      str += delta.insert
+      for (let i = nestedNodes.length - 1; i >= 0; i--) {
+        str += `</${nestedNodes[i].nodeName}>`
+      }
+      return str
+    }).join('')
+  }
+
+  /**
+   * @return {string}
+   */
+  toJSON () {
+    return this.toString()
+  }
+
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  _write (encoder) {
+    encoder.writeTypeRef(YXmlTextRefID)
+  }
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ * @return {YXmlText}
+ *
+ * @private
+ * @function
+ */
+export const readYXmlText = decoder => new YXmlText()

src/utils/AbstractConnector.js

@@ -0,0 +1,26 @@
+
+import { Observable } from 'lib0/observable'
+
+import {
+  Doc // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * This is an abstract interface that all Connectors should implement to keep them interchangeable.
+ *
+ * @note This interface is experimental and it is not advised to actually inherit this class.
+ *       It just serves as typing information.
+ *
+ * @extends {Observable<any>}
+ */
+export class AbstractConnector extends Observable {
+  /**
+   * @param {Doc} ydoc
+   * @param {any} awareness
+   */
+  constructor (ydoc, awareness) {
+    super()
+    this.doc = ydoc
+    this.awareness = awareness
+  }
+}

src/utils/DeleteSet.js

@@ -0,0 +1,326 @@
+
+import {
+  findIndexSS,
+  getState,
+  splitItem,
+  iterateStructs,
+  UpdateEncoderV2,
+  DSDecoderV1, DSEncoderV1, DSDecoderV2, DSEncoderV2, Item, GC, StructStore, Transaction, ID // eslint-disable-line
+} from '../internals.js'
+
+import * as array from 'lib0/array'
+import * as math from 'lib0/math'
+import * as map from 'lib0/map'
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+
+export class DeleteItem {
+  /**
+   * @param {number} clock
+   * @param {number} len
+   */
+  constructor (clock, len) {
+    /**
+     * @type {number}
+     */
+    this.clock = clock
+    /**
+     * @type {number}
+     */
+    this.len = len
+  }
+}
+
+/**
+ * We no longer maintain a DeleteStore. DeleteSet is a temporary object that is created when needed.
+ * - When created in a transaction, it must only be accessed after sorting, and merging
+ *   - This DeleteSet is send to other clients
+ * - We do not create a DeleteSet when we send a sync message. The DeleteSet message is created directly from StructStore
+ * - We read a DeleteSet as part of a sync/update message. In this case the DeleteSet is already sorted and merged.
+ */
+export class DeleteSet {
+  constructor () {
+    /**
+     * @type {Map<number,Array<DeleteItem>>}
+     */
+    this.clients = new Map()
+  }
+}
+
+/**
+ * Iterate over all structs that the DeleteSet gc's.
+ *
+ * @param {Transaction} transaction
+ * @param {DeleteSet} ds
+ * @param {function(GC|Item):void} f
+ *
+ * @function
+ */
+export const iterateDeletedStructs = (transaction, ds, f) =>
+  ds.clients.forEach((deletes, clientid) => {
+    const structs = /** @type {Array<GC|Item>} */ (transaction.doc.store.clients.get(clientid))
+    for (let i = 0; i < deletes.length; i++) {
+      const del = deletes[i]
+      iterateStructs(transaction, structs, del.clock, del.len, f)
+    }
+  })
+
+/**
+ * @param {Array<DeleteItem>} dis
+ * @param {number} clock
+ * @return {number|null}
+ *
+ * @private
+ * @function
+ */
+export const findIndexDS = (dis, clock) => {
+  let left = 0
+  let right = dis.length - 1
+  while (left <= right) {
+    const midindex = math.floor((left + right) / 2)
+    const mid = dis[midindex]
+    const midclock = mid.clock
+    if (midclock <= clock) {
+      if (clock < midclock + mid.len) {
+        return midindex
+      }
+      left = midindex + 1
+    } else {
+      right = midindex - 1
+    }
+  }
+  return null
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {ID} id
+ * @return {boolean}
+ *
+ * @private
+ * @function
+ */
+export const isDeleted = (ds, id) => {
+  const dis = ds.clients.get(id.client)
+  return dis !== undefined && findIndexDS(dis, id.clock) !== null
+}
+
+/**
+ * @param {DeleteSet} ds
+ *
+ * @private
+ * @function
+ */
+export const sortAndMergeDeleteSet = ds => {
+  ds.clients.forEach(dels => {
+    dels.sort((a, b) => a.clock - b.clock)
+    // merge items without filtering or splicing the array
+    // i is the current pointer
+    // j refers to the current insert position for the pointed item
+    // try to merge dels[i] into dels[j-1] or set dels[j]=dels[i]
+    let i, j
+    for (i = 1, j = 1; i < dels.length; i++) {
+      const left = dels[j - 1]
+      const right = dels[i]
+      if (left.clock + left.len >= right.clock) {
+        left.len = math.max(left.len, right.clock + right.len - left.clock)
+      } else {
+        if (j < i) {
+          dels[j] = right
+        }
+        j++
+      }
+    }
+    dels.length = j
+  })
+}
+
+/**
+ * @param {Array<DeleteSet>} dss
+ * @return {DeleteSet} A fresh DeleteSet
+ */
+export const mergeDeleteSets = dss => {
+  const merged = new DeleteSet()
+  for (let dssI = 0; dssI < dss.length; dssI++) {
+    dss[dssI].clients.forEach((delsLeft, client) => {
+      if (!merged.clients.has(client)) {
+        // Write all missing keys from current ds and all following.
+        // If merged already contains `client` current ds has already been added.
+        /**
+         * @type {Array<DeleteItem>}
+         */
+        const dels = delsLeft.slice()
+        for (let i = dssI + 1; i < dss.length; i++) {
+          array.appendTo(dels, dss[i].clients.get(client) || [])
+        }
+        merged.clients.set(client, dels)
+      }
+    })
+  }
+  sortAndMergeDeleteSet(merged)
+  return merged
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {number} client
+ * @param {number} clock
+ * @param {number} length
+ *
+ * @private
+ * @function
+ */
+export const addToDeleteSet = (ds, client, clock, length) => {
+  map.setIfUndefined(ds.clients, client, () => []).push(new DeleteItem(clock, length))
+}
+
+export const createDeleteSet = () => new DeleteSet()
+
+/**
+ * @param {StructStore} ss
+ * @return {DeleteSet} Merged and sorted DeleteSet
+ *
+ * @private
+ * @function
+ */
+export const createDeleteSetFromStructStore = ss => {
+  const ds = createDeleteSet()
+  ss.clients.forEach((structs, client) => {
+    /**
+     * @type {Array<DeleteItem>}
+     */
+    const dsitems = []
+    for (let i = 0; i < structs.length; i++) {
+      const struct = structs[i]
+      if (struct.deleted) {
+        const clock = struct.id.clock
+        let len = struct.length
+        if (i + 1 < structs.length) {
+          for (let next = structs[i + 1]; i + 1 < structs.length && next.deleted; next = structs[++i + 1]) {
+            len += next.length
+          }
+        }
+        dsitems.push(new DeleteItem(clock, len))
+      }
+    }
+    if (dsitems.length > 0) {
+      ds.clients.set(client, dsitems)
+    }
+  })
+  return ds
+}
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {DeleteSet} ds
+ *
+ * @private
+ * @function
+ */
+export const writeDeleteSet = (encoder, ds) => {
+  encoding.writeVarUint(encoder.restEncoder, ds.clients.size)
+  ds.clients.forEach((dsitems, client) => {
+    encoder.resetDsCurVal()
+    encoding.writeVarUint(encoder.restEncoder, client)
+    const len = dsitems.length
+    encoding.writeVarUint(encoder.restEncoder, len)
+    for (let i = 0; i < len; i++) {
+      const item = dsitems[i]
+      encoder.writeDsClock(item.clock)
+      encoder.writeDsLen(item.len)
+    }
+  })
+}
+
+/**
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @return {DeleteSet}
+ *
+ * @private
+ * @function
+ */
+export const readDeleteSet = decoder => {
+  const ds = new DeleteSet()
+  const numClients = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numClients; i++) {
+    decoder.resetDsCurVal()
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const numberOfDeletes = decoding.readVarUint(decoder.restDecoder)
+    if (numberOfDeletes > 0) {
+      const dsField = map.setIfUndefined(ds.clients, client, () => [])
+      for (let i = 0; i < numberOfDeletes; i++) {
+        dsField.push(new DeleteItem(decoder.readDsClock(), decoder.readDsLen()))
+      }
+    }
+  }
+  return ds
+}
+
+/**
+ * @todo YDecoder also contains references to String and other Decoders. Would make sense to exchange YDecoder.toUint8Array for YDecoder.DsToUint8Array()..
+ */
+
+/**
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @return {Uint8Array|null} Returns a v2 update containing all deletes that couldn't be applied yet; or null if all deletes were applied successfully.
+ *
+ * @private
+ * @function
+ */
+export const readAndApplyDeleteSet = (decoder, transaction, store) => {
+  const unappliedDS = new DeleteSet()
+  const numClients = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numClients; i++) {
+    decoder.resetDsCurVal()
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const numberOfDeletes = decoding.readVarUint(decoder.restDecoder)
+    const structs = store.clients.get(client) || []
+    const state = getState(store, client)
+    for (let i = 0; i < numberOfDeletes; i++) {
+      const clock = decoder.readDsClock()
+      const clockEnd = clock + decoder.readDsLen()
+      if (clock < state) {
+        if (state < clockEnd) {
+          addToDeleteSet(unappliedDS, client, state, clockEnd - state)
+        }
+        let index = findIndexSS(structs, clock)
+        /**
+         * We can ignore the case of GC and Delete structs, because we are going to skip them
+         * @type {Item}
+         */
+        // @ts-ignore
+        let struct = structs[index]
+        // split the first item if necessary
+        if (!struct.deleted && struct.id.clock < clock) {
+          structs.splice(index + 1, 0, splitItem(transaction, struct, clock - struct.id.clock))
+          index++ // increase we now want to use the next struct
+        }
+        while (index < structs.length) {
+          // @ts-ignore
+          struct = structs[index++]
+          if (struct.id.clock < clockEnd) {
+            if (!struct.deleted) {
+              if (clockEnd < struct.id.clock + struct.length) {
+                structs.splice(index, 0, splitItem(transaction, struct, clockEnd - struct.id.clock))
+              }
+              struct.delete(transaction)
+            }
+          } else {
+            break
+          }
+        }
+      } else {
+        addToDeleteSet(unappliedDS, client, clock, clockEnd - clock)
+      }
+    }
+  }
+  if (unappliedDS.clients.size > 0) {
+    const ds = new UpdateEncoderV2()
+    encoding.writeVarUint(ds.restEncoder, 0) // encode 0 structs
+    writeDeleteSet(ds, unappliedDS)
+    return ds.toUint8Array()
+  }
+  return null
+}

src/utils/Doc.js

@@ -0,0 +1,290 @@
+/**
+ * @module Y
+ */
+
+import {
+  StructStore,
+  AbstractType,
+  YArray,
+  YText,
+  YMap,
+  YXmlFragment,
+  transact,
+  ContentDoc, Item, Transaction, YEvent // eslint-disable-line
+} from '../internals.js'
+
+import { Observable } from 'lib0/observable'
+import * as random from 'lib0/random'
+import * as map from 'lib0/map'
+import * as array from 'lib0/array'
+import * as promise from 'lib0/promise'
+
+export const generateNewClientId = random.uint32
+
+/**
+ * @typedef {Object} DocOpts
+ * @property {boolean} [DocOpts.gc=true] Disable garbage collection (default: gc=true)
+ * @property {function(Item):boolean} [DocOpts.gcFilter] Will be called before an Item is garbage collected. Return false to keep the Item.
+ * @property {string} [DocOpts.guid] Define a globally unique identifier for this document
+ * @property {string | null} [DocOpts.collectionid] Associate this document with a collection. This only plays a role if your provider has a concept of collection.
+ * @property {any} [DocOpts.meta] Any kind of meta information you want to associate with this document. If this is a subdocument, remote peers will store the meta information as well.
+ * @property {boolean} [DocOpts.autoLoad] If a subdocument, automatically load document. If this is a subdocument, remote peers will load the document as well automatically.
+ * @property {boolean} [DocOpts.shouldLoad] Whether the document should be synced by the provider now. This is toggled to true when you call ydoc.load()
+ */
+
+/**
+ * A Yjs instance handles the state of shared data.
+ * @extends Observable<string>
+ */
+export class Doc extends Observable {
+  /**
+   * @param {DocOpts} [opts] configuration
+   */
+  constructor ({ guid = random.uuidv4(), collectionid = null, gc = true, gcFilter = () => true, meta = null, autoLoad = false, shouldLoad = true } = {}) {
+    super()
+    this.gc = gc
+    this.gcFilter = gcFilter
+    this.clientID = generateNewClientId()
+    this.guid = guid
+    this.collectionid = collectionid
+    /**
+     * @type {Map<string, AbstractType<YEvent>>}
+     */
+    this.share = new Map()
+    this.store = new StructStore()
+    /**
+     * @type {Transaction | null}
+     */
+    this._transaction = null
+    /**
+     * @type {Array<Transaction>}
+     */
+    this._transactionCleanups = []
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocs = new Set()
+    /**
+     * If this document is a subdocument - a document integrated into another document - then _item is defined.
+     * @type {Item?}
+     */
+    this._item = null
+    this.shouldLoad = shouldLoad
+    this.autoLoad = autoLoad
+    this.meta = meta
+    this.isLoaded = false
+    this.whenLoaded = promise.create(resolve => {
+      this.on('load', () => {
+        this.isLoaded = true
+        resolve(this)
+      })
+    })
+  }
+
+  /**
+   * Notify the parent document that you request to load data into this subdocument (if it is a subdocument).
+   *
+   * `load()` might be used in the future to request any provider to load the most current data.
+   *
+   * It is safe to call `load()` multiple times.
+   */
+  load () {
+    const item = this._item
+    if (item !== null && !this.shouldLoad) {
+      transact(/** @type {any} */ (item.parent).doc, transaction => {
+        transaction.subdocsLoaded.add(this)
+      }, null, true)
+    }
+    this.shouldLoad = true
+  }
+
+  getSubdocs () {
+    return this.subdocs
+  }
+
+  getSubdocGuids () {
+    return new Set(Array.from(this.subdocs).map(doc => doc.guid))
+  }
+
+  /**
+   * Changes that happen inside of a transaction are bundled. This means that
+   * the observer fires _after_ the transaction is finished and that all changes
+   * that happened inside of the transaction are sent as one message to the
+   * other peers.
+   *
+   * @param {function(Transaction):void} f The function that should be executed as a transaction
+   * @param {any} [origin] Origin of who started the transaction. Will be stored on transaction.origin
+   *
+   * @public
+   */
+  transact (f, origin = null) {
+    transact(this, f, origin)
+  }
+
+  /**
+   * Define a shared data type.
+   *
+   * Multiple calls of `y.get(name, TypeConstructor)` yield the same result
+   * and do not overwrite each other. I.e.
+   * `y.define(name, Y.Array) === y.define(name, Y.Array)`
+   *
+   * After this method is called, the type is also available on `y.share.get(name)`.
+   *
+   * *Best Practices:*
+   * Define all types right after the Yjs instance is created and store them in a separate object.
+   * Also use the typed methods `getText(name)`, `getArray(name)`, ..
+   *
+   * @example
+   *   const y = new Y(..)
+   *   const appState = {
+   *     document: y.getText('document')
+   *     comments: y.getArray('comments')
+   *   }
+   *
+   * @param {string} name
+   * @param {Function} TypeConstructor The constructor of the type definition. E.g. Y.Text, Y.Array, Y.Map, ...
+   * @return {AbstractType<any>} The created type. Constructed with TypeConstructor
+   *
+   * @public
+   */
+  get (name, TypeConstructor = AbstractType) {
+    const type = map.setIfUndefined(this.share, name, () => {
+      // @ts-ignore
+      const t = new TypeConstructor()
+      t._integrate(this, null)
+      return t
+    })
+    const Constr = type.constructor
+    if (TypeConstructor !== AbstractType && Constr !== TypeConstructor) {
+      if (Constr === AbstractType) {
+        // @ts-ignore
+        const t = new TypeConstructor()
+        t._map = type._map
+        type._map.forEach(/** @param {Item?} n */ n => {
+          for (; n !== null; n = n.left) {
+            // @ts-ignore
+            n.parent = t
+          }
+        })
+        t._start = type._start
+        for (let n = t._start; n !== null; n = n.right) {
+          n.parent = t
+        }
+        t._length = type._length
+        this.share.set(name, t)
+        t._integrate(this, null)
+        return t
+      } else {
+        throw new Error(`Type with the name ${name} has already been defined with a different constructor`)
+      }
+    }
+    return type
+  }
+
+  /**
+   * @template T
+   * @param {string} [name]
+   * @return {YArray<T>}
+   *
+   * @public
+   */
+  getArray (name = '') {
+    // @ts-ignore
+    return this.get(name, YArray)
+  }
+
+  /**
+   * @param {string} [name]
+   * @return {YText}
+   *
+   * @public
+   */
+  getText (name = '') {
+    // @ts-ignore
+    return this.get(name, YText)
+  }
+
+  /**
+   * @template T
+   * @param {string} [name]
+   * @return {YMap<T>}
+   *
+   * @public
+   */
+  getMap (name = '') {
+    // @ts-ignore
+    return this.get(name, YMap)
+  }
+
+  /**
+   * @param {string} [name]
+   * @return {YXmlFragment}
+   *
+   * @public
+   */
+  getXmlFragment (name = '') {
+    // @ts-ignore
+    return this.get(name, YXmlFragment)
+  }
+
+  /**
+   * Converts the entire document into a js object, recursively traversing each yjs type
+   * Doesn't log types that have not been defined (using ydoc.getType(..)).
+   *
+   * @deprecated Do not use this method and rather call toJSON directly on the shared types.
+   *
+   * @return {Object<string, any>}
+   */
+  toJSON () {
+    /**
+     * @type {Object<string, any>}
+     */
+    const doc = {}
+
+    this.share.forEach((value, key) => {
+      doc[key] = value.toJSON()
+    })
+
+    return doc
+  }
+
+  /**
+   * Emit `destroy` event and unregister all event handlers.
+   */
+  destroy () {
+    array.from(this.subdocs).forEach(subdoc => subdoc.destroy())
+    const item = this._item
+    if (item !== null) {
+      this._item = null
+      const content = /** @type {ContentDoc} */ (item.content)
+      content.doc = new Doc({ guid: this.guid, ...content.opts, shouldLoad: false })
+      content.doc._item = item
+      transact(/** @type {any} */ (item).parent.doc, transaction => {
+        const doc = content.doc
+        if (!item.deleted) {
+          transaction.subdocsAdded.add(doc)
+        }
+        transaction.subdocsRemoved.add(this)
+      }, null, true)
+    }
+    this.emit('destroyed', [true])
+    this.emit('destroy', [this])
+    super.destroy()
+  }
+
+  /**
+   * @param {string} eventName
+   * @param {function(...any):any} f
+   */
+  on (eventName, f) {
+    super.on(eventName, f)
+  }
+
+  /**
+   * @param {string} eventName
+   * @param {function} f
+   */
+  off (eventName, f) {
+    super.off(eventName, f)
+  }
+}

src/utils/EventHandler.js

@@ -0,0 +1,87 @@
+import * as f from 'lib0/function'
+
+/**
+ * General event handler implementation.
+ *
+ * @template ARG0, ARG1
+ *
+ * @private
+ */
+export class EventHandler {
+  constructor () {
+    /**
+     * @type {Array<function(ARG0, ARG1):void>}
+     */
+    this.l = []
+  }
+}
+
+/**
+ * @template ARG0,ARG1
+ * @returns {EventHandler<ARG0,ARG1>}
+ *
+ * @private
+ * @function
+ */
+export const createEventHandler = () => new EventHandler()
+
+/**
+ * Adds an event listener that is called when
+ * {@link EventHandler#callEventListeners} is called.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler.
+ *
+ * @private
+ * @function
+ */
+export const addEventHandlerListener = (eventHandler, f) =>
+  eventHandler.l.push(f)
+
+/**
+ * Removes an event listener.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {function(ARG0,ARG1):void} f The event handler that was added with
+ *                     {@link EventHandler#addEventListener}
+ *
+ * @private
+ * @function
+ */
+export const removeEventHandlerListener = (eventHandler, f) => {
+  const l = eventHandler.l
+  const len = l.length
+  eventHandler.l = l.filter(g => f !== g)
+  if (len === eventHandler.l.length) {
+    console.error('[yjs] Tried to remove event handler that doesn\'t exist.')
+  }
+}
+
+/**
+ * Removes all event listeners.
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ *
+ * @private
+ * @function
+ */
+export const removeAllEventHandlerListeners = eventHandler => {
+  eventHandler.l.length = 0
+}
+
+/**
+ * Call all event listeners that were added via
+ * {@link EventHandler#addEventListener}.
+ *
+ * @template ARG0,ARG1
+ * @param {EventHandler<ARG0,ARG1>} eventHandler
+ * @param {ARG0} arg0
+ * @param {ARG1} arg1
+ *
+ * @private
+ * @function
+ */
+export const callEventHandlerListeners = (eventHandler, arg0, arg1) =>
+  f.callAll(eventHandler.l, [arg0, arg1])

src/utils/ID.js

@@ -0,0 +1,90 @@
+
+import { AbstractType } from '../internals.js' // eslint-disable-line
+
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as error from 'lib0/error'
+
+export class ID {
+  /**
+   * @param {number} client client id
+   * @param {number} clock unique per client id, continuous number
+   */
+  constructor (client, clock) {
+    /**
+     * Client id
+     * @type {number}
+     */
+    this.client = client
+    /**
+     * unique per client id, continuous number
+     * @type {number}
+     */
+    this.clock = clock
+  }
+}
+
+/**
+ * @param {ID | null} a
+ * @param {ID | null} b
+ * @return {boolean}
+ *
+ * @function
+ */
+export const compareIDs = (a, b) => a === b || (a !== null && b !== null && a.client === b.client && a.clock === b.clock)
+
+/**
+ * @param {number} client
+ * @param {number} clock
+ *
+ * @private
+ * @function
+ */
+export const createID = (client, clock) => new ID(client, clock)
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {ID} id
+ *
+ * @private
+ * @function
+ */
+export const writeID = (encoder, id) => {
+  encoding.writeVarUint(encoder, id.client)
+  encoding.writeVarUint(encoder, id.clock)
+}
+
+/**
+ * Read ID.
+ * * If first varUint read is 0xFFFFFF a RootID is returned.
+ * * Otherwise an ID is returned
+ *
+ * @param {decoding.Decoder} decoder
+ * @return {ID}
+ *
+ * @private
+ * @function
+ */
+export const readID = decoder =>
+  createID(decoding.readVarUint(decoder), decoding.readVarUint(decoder))
+
+/**
+ * The top types are mapped from y.share.get(keyname) => type.
+ * `type` does not store any information about the `keyname`.
+ * This function finds the correct `keyname` for `type` and throws otherwise.
+ *
+ * @param {AbstractType<any>} type
+ * @return {string}
+ *
+ * @private
+ * @function
+ */
+export const findRootTypeKey = type => {
+  // @ts-ignore _y must be defined, otherwise unexpected case
+  for (const [key, value] of type.doc.share.entries()) {
+    if (value === type) {
+      return key
+    }
+  }
+  throw error.unexpectedCase()
+}

src/utils/ListCursor.js

@@ -0,0 +1,740 @@
+import * as error from 'lib0/error'
+
+import {
+  getItemCleanStart,
+  createID,
+  getMovedCoords,
+  updateMarkerChanges,
+  getState,
+  ContentAny,
+  ContentBinary,
+  ContentType,
+  ContentDoc,
+  Doc,
+  compareIDs,
+  createRelativePosition,
+  RelativePosition, ID, AbstractContent, ContentMove, Transaction, Item, AbstractType // eslint-disable-line
+} from '../internals.js'
+import { compareRelativePositions } from './RelativePosition.js'
+import * as array from 'lib0/array'
+
+const lengthExceeded = error.create('Length exceeded!')
+
+/**
+ * We keep the moved-stack across several transactions. Local or remote changes can invalidate
+ * "moved coords" on the moved-stack.
+ *
+ * The reason for this is that if assoc < 0, then getMovedCoords will return the target.right item.
+ * While the computed item is on the stack, it is possible that a user inserts something between target
+ * and the item on the stack. Then we expect that the newly inserted item is supposed to be on the new
+ * computed item.
+ *
+ * @param {Transaction} tr
+ * @param {ListCursor} li
+ */
+const popMovedStack = (tr, li) => {
+  let { start, end, move } = li.movedStack.pop() || { start: null, end: null, move: null }
+  if (move) {
+    const moveContent = /** @type {ContentMove} */ (move.content)
+    if (
+      (
+        moveContent.start.assoc < 0 && (
+          (start === null && moveContent.start.item !== null) ||
+          (start !== null && !compareIDs(/** @type {Item} */ (start.left).lastId, moveContent.start.item))
+        )
+      ) || (
+        moveContent.end.assoc < 0 && (
+          (end === null && moveContent.end.item !== null) ||
+          (end !== null && !compareIDs(/** @type {Item} */ (end.left).lastId, moveContent.end.item))
+        )
+      )
+    ) {
+      const coords = getMovedCoords(moveContent, tr, false)
+      start = coords.start
+      end = coords.end
+    }
+  }
+  li.currMove = move
+  li.currMoveStart = start
+  li.currMoveEnd = end
+  li.reachedEnd = false
+}
+
+/**
+ * Structure that helps to iterate through list-like structures. This is a useful abstraction that keeps track of move operations.
+ */
+export class ListCursor {
+  /**
+   * @param {AbstractType<any>} type
+   */
+  constructor (type) {
+    this.type = type
+    /**
+     * Current index-position
+     */
+    this.index = 0
+    /**
+     * Relative position to the current item (if item.content.length > 1)
+     */
+    this.rel = 0
+    /**
+     * This refers to the current right item, unless reachedEnd is true. Then it refers to the left item.
+     *
+     * @public
+     * @type {Item | null}
+     */
+    this.nextItem = type._start
+    this.reachedEnd = type._start === null
+    /**
+     * @type {Item | null}
+     */
+    this.currMove = null
+    /**
+     * @type {Item | null}
+     */
+    this.currMoveStart = null
+    /**
+     * @type {Item | null}
+     */
+    this.currMoveEnd = null
+    /**
+     * @type {Array<{ start: Item | null, end: Item | null, move: Item }>}
+     */
+    this.movedStack = []
+  }
+
+  clone () {
+    const iter = new ListCursor(this.type)
+    iter.index = this.index
+    iter.rel = this.rel
+    iter.nextItem = this.nextItem
+    iter.reachedEnd = this.reachedEnd
+    iter.currMove = this.currMove
+    iter.currMoveStart = this.currMoveStart
+    iter.currMoveEnd = this.currMoveEnd
+    iter.movedStack = this.movedStack.slice()
+    return iter
+  }
+
+  /**
+   * @type {Item | null}
+   */
+  get left () {
+    if (this.reachedEnd) {
+      return this.nextItem
+    } else {
+      return this.nextItem && this.nextItem.left
+    }
+  }
+
+  /**
+   * @type {Item | null}
+   */
+  get right () {
+    if (this.reachedEnd) {
+      return null
+    } else {
+      return this.nextItem
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} index
+   */
+  moveTo (tr, index) {
+    const diff = index - this.index
+    if (diff > 0) {
+      this.forward(tr, diff, true)
+    } else if (diff < 0) {
+      this.backward(tr, -diff)
+    }
+  }
+
+  /**
+   * When using skipUncountables=false within a "useSearchMarker" call, it is recommended
+   * to move the marker to the end. @todo do this after each useSearchMarkerCall
+   *
+   * @param {Transaction} tr
+   * @param {number} len
+   * @param {boolean} skipUncountables Iterate as much as possible iterating over uncountables until we find the next item.
+   */
+  forward (tr, len, skipUncountables) {
+    if (len === 0 && this.nextItem == null) {
+      return this
+    }
+    if (this.index + len > this.type._length || this.nextItem == null) {
+      throw lengthExceeded
+    }
+    let item = /** @type {Item} */ (this.nextItem)
+    this.index += len
+    // eslint-disable-next-line no-unmodified-loop-condition
+    while ((!this.reachedEnd || this.currMove !== null) && (len > 0 || (skipUncountables && len === 0 && item && (!item.countable || item.deleted || item === this.currMoveEnd || (this.reachedEnd && this.currMoveEnd === null) || item.moved !== this.currMove)))) {
+      if (item === this.currMoveEnd || (this.currMoveEnd === null && this.reachedEnd && this.currMove)) {
+        item = /** @type {Item} */ (this.currMove) // we iterate to the right after the current condition
+        popMovedStack(tr, this)
+      } else if (item === null) {
+        error.unexpectedCase() // should never happen
+      } else if (item.countable && !item.deleted && item.moved === this.currMove && len > 0) {
+        len -= item.length
+        if (len < 0) {
+          this.rel = item.length + len
+          len = 0
+          break
+        }
+      } else if (item.content.constructor === ContentMove && item.moved === this.currMove) {
+        if (this.currMove) {
+          this.movedStack.push({ start: this.currMoveStart, end: this.currMoveEnd, move: this.currMove })
+        }
+        const { start, end } = getMovedCoords(item.content, tr, false)
+        this.currMove = item
+        this.currMoveStart = start
+        this.currMoveEnd = end
+        item = start
+        continue
+      }
+      if (this.reachedEnd) {
+        throw error.unexpectedCase
+      }
+      if (item.right) {
+        item = item.right
+      } else {
+        this.reachedEnd = true
+      }
+    }
+    this.index -= len
+    this.nextItem = item
+    return this
+  }
+
+  /**
+   * We prefer to insert content outside of a moved range.
+   * Try to escape the moved range by walking to the left over deleted items.
+   *
+   * @param {Transaction} tr
+   */
+  reduceMoveDepth (tr) {
+    let nextItem = this.nextItem
+    if (nextItem !== null) {
+      while (this.currMove) {
+        if (nextItem === this.currMoveStart) {
+          nextItem = /** @type {Item} */ (this.currMove) // we iterate to the left after the current condition
+          popMovedStack(tr, this)
+          continue
+        }
+        // check if we can iterate to the left while stepping over deleted items until we find an item === this.currMoveStart
+        /**
+         * @type {Item} nextItem
+         */
+        let item = nextItem
+        while (item.deleted && item.moved === this.currMove && item !== this.currMoveStart) {
+          item = /** @type {Item} */ (item.left) // this must exist otherwise we miscalculated the move
+        }
+        if (item === this.currMoveStart) {
+          // we only want to iterate over deleted items if we can escape a move
+          nextItem = item
+        } else {
+          break
+        }
+      }
+      this.nextItem = nextItem
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   * @return {ListCursor}
+   */
+  backward (tr, len) {
+    if (this.index - len < 0) {
+      throw lengthExceeded
+    }
+    this.index -= len
+    if (this.reachedEnd) {
+      const nextItem = /** @type {Item} */ (this.nextItem)
+      this.rel = nextItem.countable && !nextItem.deleted ? nextItem.length : 0
+      this.reachedEnd = false
+    }
+    if (this.rel >= len) {
+      this.rel -= len
+      return this
+    }
+    let item = this.nextItem
+    if (item && item.content.constructor === ContentMove) {
+      item = item.left
+    } else {
+      len += ((item && item.countable && !item.deleted && item.moved === this.currMove) ? item.length : 0) - this.rel
+    }
+    this.rel = 0
+    while (item && len > 0) {
+      if (item.countable && !item.deleted && item.moved === this.currMove) {
+        len -= item.length
+        if (len < 0) {
+          this.rel = -len
+          len = 0
+        }
+        if (len === 0) {
+          break
+        }
+      } else if (item.content.constructor === ContentMove && item.moved === this.currMove) {
+        if (this.currMove) {
+          this.movedStack.push({ start: this.currMoveStart, end: this.currMoveEnd, move: this.currMove })
+        }
+        const { start, end } = getMovedCoords(item.content, tr, false)
+        this.currMove = item
+        this.currMoveStart = start
+        this.currMoveEnd = end
+        item = start
+        continue
+      }
+      if (item === this.currMoveStart) {
+        item = /** @type {Item} */ (this.currMove) // we iterate to the left after the current condition
+        popMovedStack(tr, this)
+      }
+      item = item.left
+    }
+    this.nextItem = item
+    return this
+  }
+
+  /**
+   * @template {{length: number}} T
+   * @param {Transaction} tr
+   * @param {number} len
+   * @param {T} value the initial content
+   * @param {function(AbstractContent, number, number):T} slice
+   * @param {function(T, T): T} concat
+   */
+  _slice (tr, len, value, slice, concat) {
+    if (this.index + len > this.type._length) {
+      throw lengthExceeded
+    }
+    this.index += len
+    /**
+     * We store nextItem in a variable because this version cannot be null.
+     */
+    let nextItem = /** @type {Item} */ (this.nextItem)
+    while (len > 0 && !this.reachedEnd) {
+      while (nextItem.countable && !this.reachedEnd && len > 0 && nextItem !== this.currMoveEnd) {
+        if (!nextItem.deleted && nextItem.moved === this.currMove) {
+          const slicedContent = slice(nextItem.content, this.rel, len)
+          len -= slicedContent.length
+          value = concat(value, slicedContent)
+          if (this.rel + slicedContent.length === nextItem.length) {
+            this.rel = 0
+          } else {
+            this.rel += slicedContent.length
+            continue // do not iterate to item.right
+          }
+        }
+        if (nextItem.right) {
+          nextItem = nextItem.right
+        } else {
+          this.reachedEnd = true
+        }
+      }
+      if ((!this.reachedEnd || this.currMove !== null) && len > 0) {
+        // always set nextItem before any method call
+        this.nextItem = nextItem
+        this.forward(tr, 0, true)
+        nextItem = this.nextItem
+      }
+    }
+    this.nextItem = nextItem
+    if (len < 0) {
+      this.index -= len
+    }
+    return value
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   */
+  delete (tr, len) {
+    const startLength = len
+    const sm = this.type._searchMarker
+    let item = this.nextItem
+    if (this.index + len > this.type._length) {
+      throw lengthExceeded
+    }
+    while (len > 0) {
+      while (item && !item.deleted && item.countable && !this.reachedEnd && len > 0 && item.moved === this.currMove && item !== this.currMoveEnd) {
+        if (this.rel > 0) {
+          item = getItemCleanStart(tr, createID(item.id.client, item.id.clock + this.rel))
+          this.rel = 0
+        }
+        if (len < item.length) {
+          getItemCleanStart(tr, createID(item.id.client, item.id.clock + len))
+        }
+        len -= item.length
+        item.delete(tr)
+        if (item.right) {
+          item = item.right
+        } else {
+          this.reachedEnd = true
+        }
+      }
+      if (len > 0) {
+        this.nextItem = item
+        this.forward(tr, 0, true)
+        item = this.nextItem
+      }
+    }
+    this.nextItem = item
+    if (sm) {
+      updateMarkerChanges(sm, this.index, -startLength + len, this)
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   */
+  _splitRel (tr) {
+    if (this.rel > 0) {
+      /**
+       * @type {ID}
+       */
+      const itemid = /** @type {Item} */ (this.nextItem).id
+      this.nextItem = getItemCleanStart(tr, createID(itemid.client, itemid.clock + this.rel))
+      this.rel = 0
+    }
+  }
+
+  /**
+   * Important: you must update markers after calling this method!
+   *
+   * @param {Transaction} tr
+   * @param {Array<AbstractContent>} content
+   */
+  insertContents (tr, content) {
+    this.reduceMoveDepth(tr)
+    this._splitRel(tr)
+    const parent = this.type
+    const store = tr.doc.store
+    const ownClientId = tr.doc.clientID
+    /**
+     * @type {Item | null}
+     */
+    const right = this.right
+
+    /**
+     * @type {Item | null}
+     */
+    let left = this.left
+    content.forEach(c => {
+      left = new Item(createID(ownClientId, getState(store, ownClientId)), left, left && left.lastId, right, right && right.id, parent, null, c)
+      left.integrate(tr, 0)
+    })
+    if (right === null) {
+      this.nextItem = left
+      this.reachedEnd = true
+    } else {
+      this.nextItem = right
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {Array<{ start: RelativePosition, end: RelativePosition }>} ranges
+   */
+  insertMove (tr, ranges) {
+    this.insertContents(tr, ranges.map(range => new ContentMove(range.start, range.end, -1)))
+    // @todo is there a better alrogirthm to update searchmarkers? We could simply remove the markers that are in the updated range.
+    // Also note that searchmarkers are updated in insertContents as well.
+    const sm = this.type._searchMarker
+    if (sm) sm.length = 0 // @todo instead, iterate through sm and delete all marked properties on items
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {Array<Object<string,any>|Array<any>|boolean|number|null|string|Uint8Array>} values
+   */
+  insertArrayValue (tr, values) {
+    this._splitRel(tr)
+    const sm = this.type._searchMarker
+    /**
+     * @type {Array<AbstractContent>}
+     */
+    const contents = []
+    /**
+     * @type {Array<Object|Array<any>|number|null>}
+     */
+    let jsonContent = []
+    const packJsonContent = () => {
+      if (jsonContent.length > 0) {
+        contents.push(new ContentAny(jsonContent))
+        jsonContent = []
+      }
+    }
+    values.forEach(c => {
+      if (c === null) {
+        jsonContent.push(c)
+      } else {
+        switch (c.constructor) {
+          case Number:
+          case Object:
+          case Boolean:
+          case Array:
+          case String:
+            jsonContent.push(c)
+            break
+          default:
+            packJsonContent()
+            switch (c.constructor) {
+              case Uint8Array:
+              case ArrayBuffer:
+                contents.push(new ContentBinary(new Uint8Array(/** @type {Uint8Array} */ (c))))
+                break
+              case Doc:
+                contents.push(new ContentDoc(/** @type {Doc} */ (c)))
+                break
+              default:
+                if (c instanceof AbstractType) {
+                  contents.push(new ContentType(c))
+                } else {
+                  throw new Error('Unexpected content type in insert operation')
+                }
+            }
+        }
+      }
+    })
+    packJsonContent()
+    this.insertContents(tr, contents)
+    this.index += values.length
+    if (sm) {
+      updateMarkerChanges(sm, this.index - values.length, values.length, this)
+    }
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {number} len
+   */
+  slice (tr, len) {
+    return this._slice(tr, len, [], sliceArrayContent, concatArrayContent)
+  }
+
+  /**
+   * @param {Transaction} tr
+   * @param {function(any, number, any):void} f
+   */
+  forEach (tr, f) {
+    for (const val of this.values(tr)) {
+      // decrease index because retrieving value will increase index
+      f(val, this.index - 1, this.type)
+    }
+  }
+
+  /**
+   * @template T
+   * @param {Transaction} tr
+   * @param {function(any, number, any):T} f
+   * @return {Array<T>}
+   */
+  map (tr, f) {
+    const arr = new Array(this.type._length - this.index)
+    let i = 0
+    for (const val of this.values(tr)) {
+      arr[i++] = f(val, this.index - 1, this.type)
+    }
+    return arr
+  }
+
+  /**
+   * @param {Transaction} tr
+   */
+  values (tr) {
+    return {
+      [Symbol.iterator] () {
+        return this
+      },
+      next: () => {
+        if (this.reachedEnd || this.index === this.type._length) {
+          return { done: true }
+        }
+        const [value] = this.slice(tr, 1)
+        return {
+          done: false,
+          value: value
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @param {AbstractContent} itemcontent
+ * @param {number} start
+ * @param {number} len
+ */
+const sliceArrayContent = (itemcontent, start, len) => {
+  const content = itemcontent.getContent()
+  return content.length <= len && start === 0 ? content : content.slice(start, start + len)
+}
+/**
+ * @param {Array<any>} content
+ * @param {Array<any>} added
+ */
+const concatArrayContent = (content, added) => {
+  content.push(...added)
+  return content
+}
+
+/**
+ * Move-ranges must not cross each other.
+ *
+ * This function computes the minimal amount of ranges to move a range of content to
+ * a different place.
+ *
+ * Algorithm:
+ * * Store the current stack in $preStack and $preItem = walker.nextItem
+ * * Iterate forward $len items.
+ * * The current stack is stored is $afterStack and $
+ * * Delete the stack-items that both of them have in common
+ *
+ * @param {Transaction} tr
+ * @param {ListCursor} walker
+ * @param {number} len
+ * @return {Array<{ start: RelativePosition, end: RelativePosition }>}
+ */
+export const getMinimalListViewRanges = (tr, walker, len) => {
+  if (len === 0) return []
+  if (walker.index + len > walker.type._length) {
+    throw lengthExceeded
+  }
+  // stepping outside the current move-range as much as possible
+  walker.reduceMoveDepth(tr)
+
+  /**
+   * @type {Array<{ start: RelativePosition, end: RelativePosition, move: Item | null }>}
+   */
+  const ranges = []
+  // store relevant information for the beginning, before we iterate forward
+  /**
+   * @type {Array<Item>}
+   */
+  const preStack = walker.movedStack.map(si => si.move)
+  const preMove = walker.currMove
+  const preItem = /** @type {Item} */ (walker.nextItem)
+  const preRel = walker.rel
+
+  walker.forward(tr, len, false)
+
+  // store the same information for the end, after we iterate forward
+  /**
+   * @type {Array<Item>}
+   */
+  const afterStack = walker.movedStack.map(si => si.move)
+  const afterMove = walker.currMove
+  /**
+  const nextIsCurrMoveStart = walker.nextItem === walker.currMoveStart
+    const afterItem = /** @type {Item} / (nextIsCurrMoveStart
+    ? walker.currMove
+    : (walker.rel > 0 || walker.reachedEnd)
+        ? walker.nextItem
+        : /** @type {Item} / (walker.nextItem).left
+  ) */
+  const afterItem = /** @type {Item} */ (
+    (walker.rel > 0 || walker.reachedEnd)
+      ? walker.nextItem
+      : /** @type {Item} */ (walker.nextItem).left
+  )
+  /**
+   * afterRel is always > 0
+   */
+  const afterRel = walker.rel > 0
+    ? walker.rel
+    : afterItem.length
+
+  walker.forward(tr, 0, false) // @todo remove once this is done is useSearchMarker
+
+  let start = createRelativePosition(walker.type, createID(preItem.id.client, preItem.id.clock + preRel), 0)
+  let end = createRelativePosition(
+    walker.type,
+    createID(afterItem.id.client, afterItem.id.clock + afterRel - 1),
+    -1
+  )
+
+  if (preMove) {
+    preStack.push(preMove)
+  }
+  if (afterMove) {
+    afterStack.push(afterMove)
+  }
+
+  // remove common stack-items
+  while (preStack.length > 0 && preStack[0] === afterStack[0]) {
+    preStack.shift()
+    afterStack.shift()
+  }
+  const topLevelMove = preStack.length > 0 ? preStack[0].moved : (afterStack.length > 0 ? afterStack[0].moved : null)
+
+  // remove stack-items that are useless for our computation (that wouldn't produce meaningful ranges)
+  // @todo
+
+  while (preStack.length > 0) {
+    const move = /** @type {Item} */ (preStack.pop())
+    ranges.push({
+      start,
+      end: /** @type {ContentMove} */ (move.content).end,
+      move
+    })
+    start = createRelativePosition(walker.type, createID(move.id.client, move.id.clock), -1)
+  }
+
+  const middleMove = { start, end, move: topLevelMove }
+  ranges.push(middleMove)
+
+  while (afterStack.length > 0) {
+    const move = /** @type {Item} */ (afterStack.pop())
+    ranges.push({
+      start: /** @type {ContentMove} */ (move.content).start,
+      end,
+      move
+    })
+    end = createRelativePosition(walker.type, createID(move.id.client, move.id.clock), 0)
+  }
+
+  // Update end of the center move operation
+  // Move ranges must be applied in order
+  middleMove.end = end
+
+  const normalizedRanges = array.flatten(ranges.map(range => {
+    // A subset of a range could be moved by another move with a higher priority.
+    // If that is the case, we need to ignore those moved items.
+    const { start, end } = getMovedCoords(range, tr, false)
+    const move = range.move
+    const ranges = []
+    /**
+     * @type {RelativePosition | null}
+     */
+    let rangeStart = range.start
+    /**
+     * @type {Item}
+     */
+    let item = start
+    while (item !== end) {
+      if (item.moved !== move && rangeStart != null) {
+        ranges.push({ start: rangeStart, end: createRelativePosition(walker.type, createID(item.id.client, item.id.clock), 0) })
+        rangeStart = null
+      }
+      if (item.moved === move && rangeStart === null) {
+        // @todo It might be better to set this to item.left, with assoc -1
+        rangeStart = createRelativePosition(walker.type, createID(item.id.client, item.id.clock), 0)
+      }
+      item = /** @type {Item} */ (item.right)
+    }
+    if (rangeStart != null) {
+      ranges.push({
+        start: rangeStart,
+        end: range.end
+      })
+    }
+    return ranges
+  }))
+
+  // filter out unnecessary ranges
+  return normalizedRanges.filter(range => !compareRelativePositions(range.start, range.end))
+}

src/utils/PermanentUserData.js

@@ -0,0 +1,142 @@
+
+import {
+  YArray,
+  YMap,
+  readDeleteSet,
+  writeDeleteSet,
+  createDeleteSet,
+  DSEncoderV1, DSDecoderV1, ID, DeleteSet, YArrayEvent, Transaction, Doc // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding'
+
+import { mergeDeleteSets, isDeleted } from './DeleteSet.js'
+
+export class PermanentUserData {
+  /**
+   * @param {Doc} doc
+   * @param {YMap<any>} [storeType]
+   */
+  constructor (doc, storeType = doc.getMap('users')) {
+    /**
+     * @type {Map<string,DeleteSet>}
+     */
+    const dss = new Map()
+    this.yusers = storeType
+    this.doc = doc
+    /**
+     * Maps from clientid to userDescription
+     *
+     * @type {Map<number,string>}
+     */
+    this.clients = new Map()
+    this.dss = dss
+    /**
+     * @param {YMap<any>} user
+     * @param {string} userDescription
+     */
+    const initUser = (user, userDescription) => {
+      /**
+       * @type {YArray<Uint8Array>}
+       */
+      const ds = user.get('ds')
+      const ids = user.get('ids')
+      const addClientId = /** @param {number} clientid */ clientid => this.clients.set(clientid, userDescription)
+      ds.observe(/** @param {YArrayEvent<any>} event */ event => {
+        event.changes.added.forEach(item => {
+          item.content.getContent().forEach(encodedDs => {
+            if (encodedDs instanceof Uint8Array) {
+              this.dss.set(userDescription, mergeDeleteSets([this.dss.get(userDescription) || createDeleteSet(), readDeleteSet(new DSDecoderV1(decoding.createDecoder(encodedDs)))]))
+            }
+          })
+        })
+      })
+      this.dss.set(userDescription, mergeDeleteSets(ds.map(encodedDs => readDeleteSet(new DSDecoderV1(decoding.createDecoder(encodedDs))))))
+      ids.observe(/** @param {YArrayEvent<any>} event */ event =>
+        event.changes.added.forEach(item => item.content.getContent().forEach(addClientId))
+      )
+      ids.forEach(addClientId)
+    }
+    // observe users
+    storeType.observe(event => {
+      event.keysChanged.forEach(userDescription =>
+        initUser(storeType.get(userDescription), userDescription)
+      )
+    })
+    // add intial data
+    storeType.forEach(initUser)
+  }
+
+  /**
+   * @param {Doc} doc
+   * @param {number} clientid
+   * @param {string} userDescription
+   * @param {Object} [conf]
+   * @param {function(Transaction, DeleteSet):boolean} [conf.filter]
+   */
+  setUserMapping (doc, clientid, userDescription, { filter = () => true } = {}) {
+    const users = this.yusers
+    let user = users.get(userDescription)
+    if (!user) {
+      user = new YMap()
+      user.set('ids', new YArray())
+      user.set('ds', new YArray())
+      users.set(userDescription, user)
+    }
+    user.get('ids').push([clientid])
+    users.observe(event => {
+      setTimeout(() => {
+        const userOverwrite = users.get(userDescription)
+        if (userOverwrite !== user) {
+          // user was overwritten, port all data over to the next user object
+          // @todo Experiment with Y.Sets here
+          user = userOverwrite
+          // @todo iterate over old type
+          this.clients.forEach((_userDescription, clientid) => {
+            if (userDescription === _userDescription) {
+              user.get('ids').push([clientid])
+            }
+          })
+          const encoder = new DSEncoderV1()
+          const ds = this.dss.get(userDescription)
+          if (ds) {
+            writeDeleteSet(encoder, ds)
+            user.get('ds').push([encoder.toUint8Array()])
+          }
+        }
+      }, 0)
+    })
+    doc.on('afterTransaction', /** @param {Transaction} transaction */ transaction => {
+      setTimeout(() => {
+        const yds = user.get('ds')
+        const ds = transaction.deleteSet
+        if (transaction.local && ds.clients.size > 0 && filter(transaction, ds)) {
+          const encoder = new DSEncoderV1()
+          writeDeleteSet(encoder, ds)
+          yds.push([encoder.toUint8Array()])
+        }
+      })
+    })
+  }
+
+  /**
+   * @param {number} clientid
+   * @return {any}
+   */
+  getUserByClientId (clientid) {
+    return this.clients.get(clientid) || null
+  }
+
+  /**
+   * @param {ID} id
+   * @return {string | null}
+   */
+  getUserByDeletedId (id) {
+    for (const [userDescription, ds] of this.dss.entries()) {
+      if (isDeleted(ds, id)) {
+        return userDescription
+      }
+    }
+    return null
+  }
+}

src/utils/RelativePosition.js

@@ -0,0 +1,331 @@
+
+import {
+  writeID,
+  readID,
+  compareIDs,
+  getState,
+  findRootTypeKey,
+  Item,
+  createID,
+  ContentType,
+  followRedone,
+  transact,
+  useSearchMarker,
+  ID, Doc, AbstractType // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+import * as error from 'lib0/error'
+
+/**
+ * A relative position is based on the Yjs model and is not affected by document changes.
+ * E.g. If you place a relative position before a certain character, it will always point to this character.
+ * If you place a relative position at the end of a type, it will always point to the end of the type.
+ *
+ * A numeric position is often unsuited for user selections, because it does not change when content is inserted
+ * before or after.
+ *
+ * ```Insert(0, 'x')('a|bc') = 'xa|bc'``` Where | is the relative position.
+ *
+ * One of the properties must be defined.
+ *
+ * @example
+ *   // Current cursor position is at position 10
+ *   const relativePosition = createRelativePositionFromIndex(yText, 10)
+ *   // modify yText
+ *   yText.insert(0, 'abc')
+ *   yText.delete(3, 10)
+ *   // Compute the cursor position
+ *   const absolutePosition = createAbsolutePositionFromRelativePosition(y, relativePosition)
+ *   absolutePosition.type === yText // => true
+ *   console.log('cursor location is ' + absolutePosition.index) // => cursor location is 3
+ *
+ */
+export class RelativePosition {
+  /**
+   * @param {ID|null} type
+   * @param {string|null} tname
+   * @param {ID|null} item
+   * @param {number} assoc
+   */
+  constructor (type, tname, item, assoc = 0) {
+    /**
+     * @type {ID|null}
+     */
+    this.type = type
+    /**
+     * @type {string|null}
+     */
+    this.tname = tname
+    /**
+     * @type {ID | null}
+     */
+    this.item = item
+    /**
+     * A relative position is associated to a specific character. By default
+     * assoc >= 0, the relative position is associated to the character
+     * after the meant position.
+     * I.e. position 1 in 'ab' is associated to character 'b'.
+     *
+     * If assoc < 0, then the relative position is associated to the caharacter
+     * before the meant position.
+     *
+     * @type {number}
+     */
+    this.assoc = assoc
+  }
+
+  clone () {
+    return new RelativePosition(this.type, this.tname, this.item, this.assoc)
+  }
+}
+
+/**
+ * @param {RelativePosition} rpos
+ * @return {any}
+ */
+export const relativePositionToJSON = rpos => {
+  const json = {}
+  if (rpos.type) {
+    json.type = rpos.type
+  }
+  if (rpos.tname) {
+    json.tname = rpos.tname
+  }
+  if (rpos.item) {
+    json.item = rpos.item
+  }
+  if (rpos.assoc != null) {
+    json.assoc = rpos.assoc
+  }
+  return json
+}
+
+/**
+ * @param {any} json
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const createRelativePositionFromJSON = json => new RelativePosition(json.type == null ? null : createID(json.type.client, json.type.clock), json.tname || null, json.item == null ? null : createID(json.item.client, json.item.clock), json.assoc == null ? 0 : json.assoc)
+
+export class AbsolutePosition {
+  /**
+   * @param {AbstractType<any>} type
+   * @param {number} index
+   * @param {number} [assoc]
+   */
+  constructor (type, index, assoc = 0) {
+    /**
+     * @type {AbstractType<any>}
+     */
+    this.type = type
+    /**
+     * @type {number}
+     */
+    this.index = index
+    this.assoc = assoc
+  }
+}
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {number} index
+ * @param {number} [assoc]
+ *
+ * @function
+ */
+export const createAbsolutePosition = (type, index, assoc = 0) => new AbsolutePosition(type, index, assoc)
+
+/**
+ * @param {AbstractType<any>} type
+ * @param {ID|null} item
+ * @param {number} [assoc]
+ *
+ * @function
+ */
+export const createRelativePosition = (type, item, assoc) => {
+  let typeid = null
+  let tname = null
+  if (type._item === null) {
+    tname = findRootTypeKey(type)
+  } else {
+    typeid = createID(type._item.id.client, type._item.id.clock)
+  }
+  return new RelativePosition(typeid, tname, item, assoc)
+}
+
+/**
+ * Create a relativePosition based on a absolute position.
+ *
+ * @param {AbstractType<any>} type The base type (e.g. YText or YArray).
+ * @param {number} index The absolute position.
+ * @param {number} [assoc]
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const createRelativePositionFromTypeIndex = (type, index, assoc = 0) => {
+  if (assoc < 0) {
+    // associated to the left character or the beginning of a type, increment index if possible.
+    if (index === 0) {
+      return createRelativePosition(type, null, assoc)
+    }
+    index--
+  }
+  return transact(/** @type {Doc} */ (type.doc), tr =>
+    useSearchMarker(tr, type, index, walker => {
+      if (walker.reachedEnd) {
+        const item = assoc < 0 ? /** @type {Item} */ (walker.nextItem).lastId : null
+        return createRelativePosition(type, item, assoc)
+      } else {
+        const id = /** @type {Item} */ (walker.nextItem).id
+        return createRelativePosition(type, createID(id.client, id.clock + walker.rel), assoc)
+      }
+    })
+  )
+}
+
+/**
+ * @param {encoding.Encoder} encoder
+ * @param {RelativePosition} rpos
+ *
+ * @function
+ */
+export const writeRelativePosition = (encoder, rpos) => {
+  const { type, tname, item, assoc } = rpos
+  if (item !== null) {
+    encoding.writeUint8(encoder, 0)
+    writeID(encoder, item)
+  } else if (tname !== null) {
+    // case 2: found position at the end of the list and type is stored in y.share
+    encoding.writeUint8(encoder, 1)
+    encoding.writeVarString(encoder, tname)
+  } else if (type !== null) {
+    // case 3: found position at the end of the list and type is attached to an item
+    encoding.writeUint8(encoder, 2)
+    writeID(encoder, type)
+  } else {
+    throw error.unexpectedCase()
+  }
+  encoding.writeVarInt(encoder, assoc)
+  return encoder
+}
+
+/**
+ * @param {RelativePosition} rpos
+ * @return {Uint8Array}
+ */
+export const encodeRelativePosition = rpos => {
+  const encoder = encoding.createEncoder()
+  writeRelativePosition(encoder, rpos)
+  return encoding.toUint8Array(encoder)
+}
+
+/**
+ * @param {decoding.Decoder} decoder
+ * @return {RelativePosition}
+ *
+ * @function
+ */
+export const readRelativePosition = decoder => {
+  let type = null
+  let tname = null
+  let itemID = null
+  switch (decoding.readUint8(decoder)) {
+    case 0:
+      // case 1: found position somewhere in the linked list
+      itemID = readID(decoder)
+      break
+    case 1:
+      // case 2: found position at the end of the list and type is stored in y.share
+      tname = decoding.readVarString(decoder)
+      break
+    case 2: {
+      // case 3: found position at the end of the list and type is attached to an item
+      type = readID(decoder)
+    }
+  }
+  const assoc = decoding.hasContent(decoder) ? decoding.readVarInt(decoder) : 0
+  return new RelativePosition(type, tname, itemID, assoc)
+}
+
+/**
+ * @param {Uint8Array} uint8Array
+ * @return {RelativePosition}
+ */
+export const decodeRelativePosition = uint8Array => readRelativePosition(decoding.createDecoder(uint8Array))
+
+/**
+ * @param {RelativePosition} rpos
+ * @param {Doc} doc
+ * @return {AbsolutePosition|null}
+ *
+ * @function
+ */
+export const createAbsolutePositionFromRelativePosition = (rpos, doc) => {
+  const store = doc.store
+  const rightID = rpos.item
+  const typeID = rpos.type
+  const tname = rpos.tname
+  const assoc = rpos.assoc
+  let type = null
+  let index = 0
+  if (rightID !== null) {
+    if (getState(store, rightID.client) <= rightID.clock) {
+      return null
+    }
+    const res = followRedone(store, rightID)
+    const right = res.item
+    if (!(right instanceof Item)) {
+      return null
+    }
+    type = /** @type {AbstractType<any>} */ (right.parent)
+    if (type._item === null || !type._item.deleted) {
+      index = (right.deleted || !right.countable) ? 0 : (res.diff + (assoc >= 0 ? 0 : 1)) // adjust position based on left association if necessary
+      let n = right.left
+      while (n !== null) {
+        if (!n.deleted && n.countable) {
+          index += n.length
+        }
+        n = n.left
+      }
+    }
+  } else {
+    if (tname !== null) {
+      type = doc.get(tname)
+    } else if (typeID !== null) {
+      if (getState(store, typeID.client) <= typeID.clock) {
+        // type does not exist yet
+        return null
+      }
+      const { item } = followRedone(store, typeID)
+      if (item instanceof Item && item.content instanceof ContentType) {
+        type = item.content.type
+      } else {
+        // struct is garbage collected
+        return null
+      }
+    } else {
+      throw error.unexpectedCase()
+    }
+    if (assoc >= 0) {
+      index = type._length
+    } else {
+      index = 0
+    }
+  }
+  return createAbsolutePosition(type, index, rpos.assoc)
+}
+
+/**
+ * @param {RelativePosition|null} a
+ * @param {RelativePosition|null} b
+ * @return {boolean}
+ *
+ * @function
+ */
+export const compareRelativePositions = (a, b) => a === b || (
+  a !== null && b !== null && a.tname === b.tname && compareIDs(a.item, b.item) && compareIDs(a.type, b.type) && a.assoc === b.assoc
+)

src/utils/Snapshot.js

@@ -0,0 +1,201 @@
+
+import {
+  isDeleted,
+  createDeleteSetFromStructStore,
+  getStateVector,
+  getItemCleanStart,
+  iterateDeletedStructs,
+  writeDeleteSet,
+  writeStateVector,
+  readDeleteSet,
+  readStateVector,
+  createDeleteSet,
+  createID,
+  getState,
+  findIndexSS,
+  UpdateEncoderV2,
+  applyUpdateV2,
+  DSEncoderV1, DSEncoderV2, DSDecoderV1, DSDecoderV2, Transaction, Doc, DeleteSet, Item // eslint-disable-line
+} from '../internals.js'
+
+import * as map from 'lib0/map'
+import * as set from 'lib0/set'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+
+export class Snapshot {
+  /**
+   * @param {DeleteSet} ds
+   * @param {Map<number,number>} sv state map
+   */
+  constructor (ds, sv) {
+    /**
+     * @type {DeleteSet}
+     */
+    this.ds = ds
+    /**
+     * State Map
+     * @type {Map<number,number>}
+     */
+    this.sv = sv
+  }
+}
+
+/**
+ * @param {Snapshot} snap1
+ * @param {Snapshot} snap2
+ * @return {boolean}
+ */
+export const equalSnapshots = (snap1, snap2) => {
+  const ds1 = snap1.ds.clients
+  const ds2 = snap2.ds.clients
+  const sv1 = snap1.sv
+  const sv2 = snap2.sv
+  if (sv1.size !== sv2.size || ds1.size !== ds2.size) {
+    return false
+  }
+  for (const [key, value] of sv1.entries()) {
+    if (sv2.get(key) !== value) {
+      return false
+    }
+  }
+  for (const [client, dsitems1] of ds1.entries()) {
+    const dsitems2 = ds2.get(client) || []
+    if (dsitems1.length !== dsitems2.length) {
+      return false
+    }
+    for (let i = 0; i < dsitems1.length; i++) {
+      const dsitem1 = dsitems1[i]
+      const dsitem2 = dsitems2[i]
+      if (dsitem1.clock !== dsitem2.clock || dsitem1.len !== dsitem2.len) {
+        return false
+      }
+    }
+  }
+  return true
+}
+
+/**
+ * @param {Snapshot} snapshot
+ * @param {DSEncoderV1 | DSEncoderV2} [encoder]
+ * @return {Uint8Array}
+ */
+export const encodeSnapshotV2 = (snapshot, encoder = new DSEncoderV2()) => {
+  writeDeleteSet(encoder, snapshot.ds)
+  writeStateVector(encoder, snapshot.sv)
+  return encoder.toUint8Array()
+}
+
+/**
+ * @param {Snapshot} snapshot
+ * @return {Uint8Array}
+ */
+export const encodeSnapshot = snapshot => encodeSnapshotV2(snapshot, new DSEncoderV1())
+
+/**
+ * @param {Uint8Array} buf
+ * @param {DSDecoderV1 | DSDecoderV2} [decoder]
+ * @return {Snapshot}
+ */
+export const decodeSnapshotV2 = (buf, decoder = new DSDecoderV2(decoding.createDecoder(buf))) => {
+  return new Snapshot(readDeleteSet(decoder), readStateVector(decoder))
+}
+
+/**
+ * @param {Uint8Array} buf
+ * @return {Snapshot}
+ */
+export const decodeSnapshot = buf => decodeSnapshotV2(buf, new DSDecoderV1(decoding.createDecoder(buf)))
+
+/**
+ * @param {DeleteSet} ds
+ * @param {Map<number,number>} sm
+ * @return {Snapshot}
+ */
+export const createSnapshot = (ds, sm) => new Snapshot(ds, sm)
+
+export const emptySnapshot = createSnapshot(createDeleteSet(), new Map())
+
+/**
+ * @param {Doc} doc
+ * @return {Snapshot}
+ */
+export const snapshot = doc => createSnapshot(createDeleteSetFromStructStore(doc.store), getStateVector(doc.store))
+
+/**
+ * @param {Item} item
+ * @param {Snapshot|undefined} snapshot
+ *
+ * @protected
+ * @function
+ */
+export const isVisible = (item, snapshot) => snapshot === undefined
+  ? !item.deleted
+  : snapshot.sv.has(item.id.client) && (snapshot.sv.get(item.id.client) || 0) > item.id.clock && !isDeleted(snapshot.ds, item.id)
+
+/**
+ * @param {Transaction} transaction
+ * @param {Snapshot} snapshot
+ */
+export const splitSnapshotAffectedStructs = (transaction, snapshot) => {
+  const meta = map.setIfUndefined(transaction.meta, splitSnapshotAffectedStructs, set.create)
+  const store = transaction.doc.store
+  // check if we already split for this snapshot
+  if (!meta.has(snapshot)) {
+    snapshot.sv.forEach((clock, client) => {
+      if (clock < getState(store, client)) {
+        getItemCleanStart(transaction, createID(client, clock))
+      }
+    })
+    iterateDeletedStructs(transaction, snapshot.ds, item => {})
+    meta.add(snapshot)
+  }
+}
+
+/**
+ * @param {Doc} originDoc
+ * @param {Snapshot} snapshot
+ * @param {Doc} [newDoc] Optionally, you may define the Yjs document that receives the data from originDoc
+ * @return {Doc}
+ */
+export const createDocFromSnapshot = (originDoc, snapshot, newDoc = new Doc()) => {
+  if (originDoc.gc) {
+    // we should not try to restore a GC-ed document, because some of the restored items might have their content deleted
+    throw new Error('originDoc must not be garbage collected')
+  }
+  const { sv, ds } = snapshot
+
+  const encoder = new UpdateEncoderV2()
+  originDoc.transact(transaction => {
+    let size = 0
+    sv.forEach(clock => {
+      if (clock > 0) {
+        size++
+      }
+    })
+    encoding.writeVarUint(encoder.restEncoder, size)
+    // splitting the structs before writing them to the encoder
+    for (const [client, clock] of sv) {
+      if (clock === 0) {
+        continue
+      }
+      if (clock < getState(originDoc.store, client)) {
+        getItemCleanStart(transaction, createID(client, clock))
+      }
+      const structs = originDoc.store.clients.get(client) || []
+      const lastStructIndex = findIndexSS(structs, clock - 1)
+      // write # encoded structs
+      encoding.writeVarUint(encoder.restEncoder, lastStructIndex + 1)
+      encoder.writeClient(client)
+      // first clock written is 0
+      encoding.writeVarUint(encoder.restEncoder, 0)
+      for (let i = 0; i <= lastStructIndex; i++) {
+        structs[i].write(encoder, 0)
+      }
+    }
+    writeDeleteSet(encoder, ds)
+  })
+
+  applyUpdateV2(newDoc, encoder.toUint8Array(), 'snapshot')
+  return newDoc
+}

src/utils/StructStore.js

@@ -0,0 +1,261 @@
+
+import {
+  GC,
+  splitItem,
+  Transaction, ID, Item, DSDecoderV2 // eslint-disable-line
+} from '../internals.js'
+
+import * as math from 'lib0/math'
+import * as error from 'lib0/error'
+
+export class StructStore {
+  constructor () {
+    /**
+     * @type {Map<number,Array<GC|Item>>}
+     */
+    this.clients = new Map()
+    /**
+     * @type {null | { missing: Map<number, number>, update: Uint8Array }}
+     */
+    this.pendingStructs = null
+    /**
+     * @type {null | Uint8Array}
+     */
+    this.pendingDs = null
+  }
+}
+
+/**
+ * Return the states as a Map<client,clock>.
+ * Note that clock refers to the next expected clock id.
+ *
+ * @param {StructStore} store
+ * @return {Map<number,number>}
+ *
+ * @public
+ * @function
+ */
+export const getStateVector = store => {
+  const sm = new Map()
+  store.clients.forEach((structs, client) => {
+    const struct = structs[structs.length - 1]
+    sm.set(client, struct.id.clock + struct.length)
+  })
+  return sm
+}
+
+/**
+ * @param {StructStore} store
+ * @param {number} client
+ * @return {number}
+ *
+ * @public
+ * @function
+ */
+export const getState = (store, client) => {
+  const structs = store.clients.get(client)
+  if (structs === undefined) {
+    return 0
+  }
+  const lastStruct = structs[structs.length - 1]
+  return lastStruct.id.clock + lastStruct.length
+}
+
+/**
+ * @param {StructStore} store
+ *
+ * @private
+ * @function
+ */
+export const integretyCheck = store => {
+  store.clients.forEach(structs => {
+    for (let i = 1; i < structs.length; i++) {
+      const l = structs[i - 1]
+      const r = structs[i]
+      if (l.id.clock + l.length !== r.id.clock) {
+        throw new Error('StructStore failed integrety check')
+      }
+    }
+  })
+}
+
+/**
+ * @param {StructStore} store
+ * @param {GC|Item} struct
+ *
+ * @private
+ * @function
+ */
+export const addStruct = (store, struct) => {
+  let structs = store.clients.get(struct.id.client)
+  if (structs === undefined) {
+    structs = []
+    store.clients.set(struct.id.client, structs)
+  } else {
+    const lastStruct = structs[structs.length - 1]
+    if (lastStruct.id.clock + lastStruct.length !== struct.id.clock) {
+      throw error.unexpectedCase()
+    }
+  }
+  structs.push(struct)
+}
+
+/**
+ * Perform a binary search on a sorted array
+ * @param {Array<Item|GC>} structs
+ * @param {number} clock
+ * @return {number}
+ *
+ * @private
+ * @function
+ */
+export const findIndexSS = (structs, clock) => {
+  let left = 0
+  let right = structs.length - 1
+  let mid = structs[right]
+  let midclock = mid.id.clock
+  if (midclock === clock) {
+    return right
+  }
+  // @todo does it even make sense to pivot the search?
+  // If a good split misses, it might actually increase the time to find the correct item.
+  // Currently, the only advantage is that search with pivoting might find the item on the first try.
+  let midindex = math.floor((clock / (midclock + mid.length - 1)) * right) // pivoting the search
+  while (left <= right) {
+    mid = structs[midindex]
+    midclock = mid.id.clock
+    if (midclock <= clock) {
+      if (clock < midclock + mid.length) {
+        return midindex
+      }
+      left = midindex + 1
+    } else {
+      right = midindex - 1
+    }
+    midindex = math.floor((left + right) / 2)
+  }
+  // Always check state before looking for a struct in StructStore
+  // Therefore the case of not finding a struct is unexpected
+  throw error.unexpectedCase()
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {StructStore} store
+ * @param {ID} id
+ * @return {GC|Item}
+ *
+ * @private
+ * @function
+ */
+export const find = (store, id) => {
+  /**
+   * @type {Array<GC|Item>}
+   */
+  // @ts-ignore
+  const structs = store.clients.get(id.client)
+  return structs[findIndexSS(structs, id.clock)]
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ * @private
+ * @function
+ */
+export const getItem = /** @type {function(StructStore,ID):Item} */ (find)
+
+/**
+ * @param {Transaction} transaction
+ * @param {Array<Item|GC>} structs
+ * @param {number} clock
+ */
+export const findIndexCleanStart = (transaction, structs, clock) => {
+  const index = findIndexSS(structs, clock)
+  const struct = structs[index]
+  if (struct.id.clock < clock && struct instanceof Item) {
+    structs.splice(index + 1, 0, splitItem(transaction, struct, clock - struct.id.clock))
+    return index + 1
+  }
+  return index
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {ID} id
+ * @return {Item}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanStart = (transaction, id) => {
+  const structs = /** @type {Array<Item>} */ (transaction.doc.store.clients.get(id.client))
+  return structs[findIndexCleanStart(transaction, structs, id.clock)]
+}
+
+/**
+ * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
+ *
+ * @param {Transaction} transaction
+ * @param {ID} id
+ * @return {Item}
+ *
+ * @private
+ * @function
+ */
+export const getItemCleanEnd = (transaction, id) => {
+  /**
+   * @type {Array<Item>}
+   */
+  // @ts-ignore
+  const structs = transaction.doc.store.clients.get(id.client)
+  const index = findIndexSS(structs, id.clock)
+  const struct = structs[index]
+  if (id.clock !== struct.id.clock + struct.length - 1 && struct.constructor !== GC) {
+    structs.splice(index + 1, 0, splitItem(transaction, struct, id.clock - struct.id.clock + 1))
+  }
+  return struct
+}
+
+/**
+ * Replace `item` with `newitem` in store
+ * @param {StructStore} store
+ * @param {GC|Item} struct
+ * @param {GC|Item} newStruct
+ *
+ * @private
+ * @function
+ */
+export const replaceStruct = (store, struct, newStruct) => {
+  const structs = /** @type {Array<GC|Item>} */ (store.clients.get(struct.id.client))
+  structs[findIndexSS(structs, struct.id.clock)] = newStruct
+}
+
+/**
+ * Iterate over a range of structs
+ *
+ * @param {Transaction} transaction
+ * @param {Array<Item|GC>} structs
+ * @param {number} clockStart Inclusive start
+ * @param {number} len
+ * @param {function(GC|Item):void} f
+ *
+ * @function
+ */
+export const iterateStructs = (transaction, structs, clockStart, len, f) => {
+  if (len === 0) {
+    return
+  }
+  const clockEnd = clockStart + len
+  let index = findIndexCleanStart(transaction, structs, clockStart)
+  let struct
+  do {
+    struct = structs[index++]
+    if (clockEnd < struct.id.clock + struct.length) {
+      findIndexCleanStart(transaction, structs, clockEnd)
+    }
+    f(struct)
+  } while (index < structs.length && structs[index].id.clock < clockEnd)
+}

src/utils/Transaction.js

@@ -0,0 +1,464 @@
+
+import {
+  getState,
+  writeStructsFromTransaction,
+  writeDeleteSet,
+  DeleteSet,
+  sortAndMergeDeleteSet,
+  getStateVector,
+  findIndexSS,
+  callEventHandlerListeners,
+  Item,
+  generateNewClientId,
+  createID,
+  UpdateEncoderV1, UpdateEncoderV2, GC, StructStore, AbstractType, AbstractStruct, YEvent, Doc // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding'
+import * as map from 'lib0/map'
+import * as math from 'lib0/math'
+import * as set from 'lib0/set'
+import * as logging from 'lib0/logging'
+import { callAll } from 'lib0/function'
+
+/**
+ * A transaction is created for every change on the Yjs model. It is possible
+ * to bundle changes on the Yjs model in a single transaction to
+ * minimize the number on messages sent and the number of observer calls.
+ * If possible the user of this library should bundle as many changes as
+ * possible. Here is an example to illustrate the advantages of bundling:
+ *
+ * @example
+ * const map = y.define('map', YMap)
+ * // Log content when change is triggered
+ * map.observe(() => {
+ *   console.log('change triggered')
+ * })
+ * // Each change on the map type triggers a log message:
+ * map.set('a', 0) // => "change triggered"
+ * map.set('b', 0) // => "change triggered"
+ * // When put in a transaction, it will trigger the log after the transaction:
+ * y.transact(() => {
+ *   map.set('a', 1)
+ *   map.set('b', 1)
+ * }) // => "change triggered"
+ *
+ * @public
+ */
+export class Transaction {
+  /**
+   * @param {Doc} doc
+   * @param {any} origin
+   * @param {boolean} local
+   */
+  constructor (doc, origin, local) {
+    /**
+     * The Yjs instance.
+     * @type {Doc}
+     */
+    this.doc = doc
+    /**
+     * Describes the set of deleted items by ids
+     * @type {DeleteSet}
+     */
+    this.deleteSet = new DeleteSet()
+    /**
+     * These deletes were used to cleanup the document and
+     * should be broadcasted again using a different transaction-origin.
+     *
+     * @type {DeleteSet}
+     */
+    this.cleanupDeletions = new DeleteSet()
+    /**
+     * Holds the state before the transaction started.
+     * @type {Map<Number,Number>}
+     */
+    this.beforeState = getStateVector(doc.store)
+    /**
+     * Holds the state after the transaction.
+     * @type {Map<Number,Number>}
+     */
+    this.afterState = new Map()
+    /**
+     * All types that were directly modified (property added or child
+     * inserted/deleted). New types are not included in this Set.
+     * Maps from type to parentSubs (`item.parentSub = null` for YArray)
+     * @type {Map<AbstractType<YEvent>,Set<String|null>>}
+     */
+    this.changed = new Map()
+    /**
+     * Stores the events for the types that observe also child elements.
+     * It is mainly used by `observeDeep`.
+     * @type {Map<AbstractType<YEvent>,Array<YEvent>>}
+     */
+    this.changedParentTypes = new Map()
+    /**
+     * @type {Array<AbstractStruct>}
+     */
+    this._mergeStructs = []
+    /**
+     * @type {any}
+     */
+    this.origin = origin
+    /**
+     * Stores meta information on the transaction
+     * @type {Map<any,any>}
+     */
+    this.meta = new Map()
+    /**
+     * Whether this change originates from this doc.
+     * @type {boolean}
+     */
+    this.local = local
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsAdded = new Set()
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsRemoved = new Set()
+    /**
+     * @type {Set<Doc>}
+     */
+    this.subdocsLoaded = new Set()
+    /**
+     * We store the reference that last moved an item.
+     * This is needed to compute the delta when multiple ContentMove move
+     * the same item.
+     *
+     * @type {Map<Item, Item>}
+     */
+    this.prevMoved = new Map()
+  }
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Transaction} transaction
+ * @return {boolean} Whether data was written.
+ */
+export const writeUpdateMessageFromTransaction = (encoder, transaction) => {
+  if (transaction.deleteSet.clients.size === 0 && !map.any(transaction.afterState, (clock, client) => transaction.beforeState.get(client) !== clock)) {
+    return false
+  }
+  sortAndMergeDeleteSet(transaction.deleteSet)
+  writeStructsFromTransaction(encoder, transaction)
+  writeDeleteSet(encoder, transaction.deleteSet)
+  return true
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Transaction} transaction
+ */
+export const writeCleanupMessageFromTransaction = (encoder, transaction) => {
+  const ds = transaction.cleanupDeletions
+  sortAndMergeDeleteSet(ds)
+  // write structs: 0 structs were created
+  encoding.writeVarUint(encoder.restEncoder, 0)
+  writeDeleteSet(encoder, ds)
+}
+
+/**
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const nextID = transaction => {
+  const y = transaction.doc
+  return createID(y.clientID, getState(y.store, y.clientID))
+}
+
+/**
+ * If `type.parent` was added in current transaction, `type` technically
+ * did not change, it was just added and we should not fire events for `type`.
+ *
+ * @param {Transaction} transaction
+ * @param {AbstractType<YEvent>} type
+ * @param {string|null} parentSub
+ */
+export const addChangedTypeToTransaction = (transaction, type, parentSub) => {
+  const item = type._item
+  if (item === null || (item.id.clock < (transaction.beforeState.get(item.id.client) || 0) && !item.deleted)) {
+    map.setIfUndefined(transaction.changed, type, set.create).add(parentSub)
+  }
+}
+
+/**
+ * @param {Array<AbstractStruct>} structs
+ * @param {number} pos
+ */
+const tryToMergeWithLeft = (structs, pos) => {
+  const left = structs[pos - 1]
+  const right = structs[pos]
+  if (left.deleted === right.deleted && left.constructor === right.constructor) {
+    if (left.mergeWith(right)) {
+      structs.splice(pos, 1)
+      if (right instanceof Item && right.parentSub !== null && /** @type {AbstractType<any>} */ (right.parent)._map.get(right.parentSub) === right) {
+        /** @type {AbstractType<any>} */ (right.parent)._map.set(right.parentSub, /** @type {Item} */ (left))
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+const tryGcDeleteSet = (ds, store, gcFilter) => {
+  for (const [client, deleteItems] of ds.clients.entries()) {
+    const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      const endDeleteItemClock = deleteItem.clock + deleteItem.len
+      for (
+        let si = findIndexSS(structs, deleteItem.clock), struct = structs[si];
+        si < structs.length && struct.id.clock < endDeleteItemClock;
+        struct = structs[++si]
+      ) {
+        const struct = structs[si]
+        if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
+          break
+        }
+        if (struct instanceof Item && struct.deleted && !struct.keep && gcFilter(struct)) {
+          struct.gc(store, false)
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ */
+const tryMergeDeleteSet = (ds, store) => {
+  // try to merge deleted / gc'd items
+  // merge from right to left for better efficiecy and so we don't miss any merge targets
+  ds.clients.forEach((deleteItems, client) => {
+    const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      // start with merging the item next to the last deleted item
+      const mostRightIndexToCheck = math.min(structs.length - 1, 1 + findIndexSS(structs, deleteItem.clock + deleteItem.len - 1))
+      for (
+        let si = mostRightIndexToCheck, struct = structs[si];
+        si > 0 && struct.id.clock >= deleteItem.clock;
+        struct = structs[--si]
+      ) {
+        tryToMergeWithLeft(structs, si)
+      }
+    }
+  })
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+export const tryGc = (ds, store, gcFilter) => {
+  tryGcDeleteSet(ds, store, gcFilter)
+  tryMergeDeleteSet(ds, store)
+}
+
+/**
+ * @param {Array<Transaction>} transactionCleanups
+ * @param {number} i
+ */
+const cleanupTransactions = (transactionCleanups, i) => {
+  if (i < transactionCleanups.length) {
+    const transaction = transactionCleanups[i]
+    const doc = transaction.doc
+    const store = doc.store
+    const ds = transaction.deleteSet
+    const mergeStructs = transaction._mergeStructs
+    try {
+      sortAndMergeDeleteSet(ds)
+      transaction.afterState = getStateVector(transaction.doc.store)
+      doc._transaction = null
+      doc.emit('beforeObserverCalls', [transaction, doc])
+      /**
+       * An array of event callbacks.
+       *
+       * Each callback is called even if the other ones throw errors.
+       *
+       * @type {Array<function():void>}
+       */
+      const fs = []
+      // observe events on changed types
+      transaction.changed.forEach((subs, itemtype) =>
+        fs.push(() => {
+          if (itemtype._item === null || !itemtype._item.deleted) {
+            itemtype._callObserver(transaction, subs)
+          }
+        })
+      )
+      fs.push(() => {
+        // deep observe events
+        transaction.changedParentTypes.forEach((events, type) =>
+          fs.push(() => {
+            // We need to think about the possibility that the user transforms the
+            // Y.Doc in the event.
+            if (type._item === null || !type._item.deleted) {
+              events = events
+                .filter(event =>
+                  event.target._item === null || !event.target._item.deleted
+                )
+              events
+                .forEach(event => {
+                  event.currentTarget = type
+                })
+              // sort events by path length so that top-level events are fired first.
+              events
+                .sort((event1, event2) => event1.path.length - event2.path.length)
+              // We don't need to check for events.length
+              // because we know it has at least one element
+              callEventHandlerListeners(type._dEH, events, transaction)
+            }
+          })
+        )
+        fs.push(() => doc.emit('afterTransaction', [transaction, doc]))
+      })
+      callAll(fs, [])
+    } finally {
+      // Replace deleted items with ItemDeleted / GC.
+      // This is where content is actually remove from the Yjs Doc.
+      if (doc.gc) {
+        tryGcDeleteSet(ds, store, doc.gcFilter)
+      }
+      tryMergeDeleteSet(ds, store)
+
+      // on all affected store.clients props, try to merge
+      transaction.afterState.forEach((clock, client) => {
+        const beforeClock = transaction.beforeState.get(client) || 0
+        if (beforeClock !== clock) {
+          const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+          // we iterate from right to left so we can safely remove entries
+          const firstChangePos = math.max(findIndexSS(structs, beforeClock), 1)
+          for (let i = structs.length - 1; i >= firstChangePos; i--) {
+            tryToMergeWithLeft(structs, i)
+          }
+        }
+      })
+      // try to merge mergeStructs
+      // @todo: it makes more sense to transform mergeStructs to a DS, sort it, and merge from right to left
+      //        but at the moment DS does not handle duplicates
+      for (let i = 0; i < mergeStructs.length; i++) {
+        const { client, clock } = mergeStructs[i].id
+        const structs = /** @type {Array<GC|Item>} */ (store.clients.get(client))
+        const replacedStructPos = findIndexSS(structs, clock)
+        if (replacedStructPos + 1 < structs.length) {
+          tryToMergeWithLeft(structs, replacedStructPos + 1)
+        }
+        if (replacedStructPos > 0) {
+          tryToMergeWithLeft(structs, replacedStructPos)
+        }
+      }
+      if (!transaction.local && transaction.afterState.get(doc.clientID) !== transaction.beforeState.get(doc.clientID)) {
+        logging.print(logging.ORANGE, logging.BOLD, '[yjs] ', logging.UNBOLD, logging.RED, 'Changed the client-id because another client seems to be using it.')
+        doc.clientID = generateNewClientId()
+      }
+      // @todo Merge all the transactions into one and provide send the data as a single update message
+      doc.emit('afterTransactionCleanup', [transaction, doc])
+      const needsCleanupEvent = transaction.cleanupDeletions.clients.size > 0
+      if (doc._observers.has('update')) {
+        const encoder = new UpdateEncoderV1()
+        const hasContent = writeUpdateMessageFromTransaction(encoder, transaction)
+        if (hasContent) {
+          doc.emit('update', [encoder.toUint8Array(), transaction.origin, doc, transaction])
+          if (needsCleanupEvent) {
+            const encoder = new UpdateEncoderV1()
+            writeCleanupMessageFromTransaction(encoder, transaction)
+            doc.emit('update', [encoder.toUint8Array(), 'cleanup', doc, transaction])
+          }
+        }
+      }
+      if (doc._observers.has('updateV2')) {
+        const encoder = new UpdateEncoderV2()
+        const hasContent = writeUpdateMessageFromTransaction(encoder, transaction)
+        if (hasContent) {
+          doc.emit('updateV2', [encoder.toUint8Array(), transaction.origin, doc, transaction])
+          if (needsCleanupEvent) {
+            const encoder = new UpdateEncoderV2()
+            writeCleanupMessageFromTransaction(encoder, transaction)
+            doc.emit('updateV2', [encoder.toUint8Array(), 'cleanup', doc, transaction])
+          }
+        }
+      }
+      const { subdocsAdded, subdocsLoaded, subdocsRemoved } = transaction
+      if (subdocsAdded.size > 0 || subdocsRemoved.size > 0 || subdocsLoaded.size > 0) {
+        subdocsAdded.forEach(subdoc => {
+          subdoc.clientID = doc.clientID
+          if (subdoc.collectionid == null) {
+            subdoc.collectionid = doc.collectionid
+          }
+          doc.subdocs.add(subdoc)
+        })
+        subdocsRemoved.forEach(subdoc => doc.subdocs.delete(subdoc))
+        doc.emit('subdocs', [{ loaded: subdocsLoaded, added: subdocsAdded, removed: subdocsRemoved }, doc, transaction])
+        subdocsRemoved.forEach(subdoc => subdoc.destroy())
+      }
+
+      if (transactionCleanups.length <= i + 1) {
+        doc._transactionCleanups = []
+        doc.emit('afterAllTransactions', [doc, transactionCleanups])
+      } else {
+        cleanupTransactions(transactionCleanups, i + 1)
+      }
+    }
+  }
+}
+
+/**
+ * Implements the functionality of `y.transact(()=>{..})`
+ *
+ * @template T
+ *
+ * @param {Doc} doc
+ * @param {function(Transaction):T} f
+ * @param {any} [origin=true]
+ * @return {T}
+ *
+ * @function
+ */
+export const transact = (doc, f, origin = null, local = true) => {
+  const transactionCleanups = doc._transactionCleanups
+  let initialCall = false
+  if (doc._transaction === null) {
+    initialCall = true
+    doc._transaction = new Transaction(doc, origin, local)
+    transactionCleanups.push(doc._transaction)
+    if (transactionCleanups.length === 1) {
+      doc.emit('beforeAllTransactions', [doc])
+    }
+    doc.emit('beforeTransaction', [doc._transaction, doc])
+  }
+  let res
+  try {
+    res = f(doc._transaction)
+  } finally {
+    if (initialCall && transactionCleanups[0] === doc._transaction) {
+      // The first transaction ended, now process observer calls.
+      // Observer call may create new transactions for which we need to call the observers and do cleanup.
+      // We don't want to nest these calls, so we execute these calls one after
+      // another.
+      // Also we need to ensure that all cleanups are called, even if the
+      // observes throw errors.
+      // This file is full of hacky try {} finally {} blocks to ensure that an
+      // event can throw errors and also that the cleanup is called.
+      cleanupTransactions(transactionCleanups, 0)
+    }
+  }
+  return res
+}
+
+/**
+ * @param {Transaction} tr
+ * @param {AbstractStruct} struct
+ */
+export const addsStruct = (tr, struct) =>
+  struct.id.clock >= (tr.beforeState.get(struct.id.client) || 0)

src/utils/UndoManager.js

@@ -0,0 +1,285 @@
+import {
+  mergeDeleteSets,
+  iterateDeletedStructs,
+  keepItem,
+  transact,
+  createID,
+  redoItem,
+  isParentOf,
+  followRedone,
+  getItemCleanStart,
+  isDeleted,
+  addToDeleteSet,
+  Transaction, Doc, Item, GC, DeleteSet, AbstractType, YEvent // eslint-disable-line
+} from '../internals.js'
+
+import * as time from 'lib0/time'
+import { Observable } from 'lib0/observable'
+
+class StackItem {
+  /**
+   * @param {DeleteSet} deletions
+   * @param {DeleteSet} insertions
+   */
+  constructor (deletions, insertions) {
+    this.insertions = insertions
+    this.deletions = deletions
+    /**
+     * Use this to save and restore metadata like selection range
+     */
+    this.meta = new Map()
+  }
+}
+
+/**
+ * @param {UndoManager} undoManager
+ * @param {Array<StackItem>} stack
+ * @param {string} eventType
+ * @return {StackItem?}
+ */
+const popStackItem = (undoManager, stack, eventType) => {
+  /**
+   * Whether a change happened
+   * @type {StackItem?}
+   */
+  let result = null
+  /**
+   * Keep a reference to the transaction so we can fire the event with the changedParentTypes
+   * @type {any}
+   */
+  let _tr = null
+  const doc = undoManager.doc
+  const scope = undoManager.scope
+  transact(doc, transaction => {
+    while (stack.length > 0 && result === null) {
+      const store = doc.store
+      const stackItem = /** @type {StackItem} */ (stack.pop())
+      /**
+       * @type {Set<Item>}
+       */
+      const itemsToRedo = new Set()
+      /**
+       * @type {Array<Item>}
+       */
+      const itemsToDelete = []
+      let performedChange = false
+      iterateDeletedStructs(transaction, stackItem.insertions, struct => {
+        if (struct instanceof Item) {
+          if (struct.redone !== null) {
+            let { item, diff } = followRedone(store, struct.id)
+            if (diff > 0) {
+              item = getItemCleanStart(transaction, createID(item.id.client, item.id.clock + diff))
+            }
+            struct = item
+          }
+          if (!struct.deleted && scope.some(type => isParentOf(type, /** @type {Item} */ (struct)))) {
+            itemsToDelete.push(struct)
+          }
+        }
+      })
+      iterateDeletedStructs(transaction, stackItem.deletions, struct => {
+        if (
+          struct instanceof Item &&
+          scope.some(type => isParentOf(type, struct)) &&
+          // Never redo structs in stackItem.insertions because they were created and deleted in the same capture interval.
+          !isDeleted(stackItem.insertions, struct.id)
+        ) {
+          itemsToRedo.add(struct)
+        }
+      })
+      itemsToRedo.forEach(struct => {
+        performedChange = redoItem(transaction, struct, itemsToRedo, itemsToDelete) !== null || performedChange
+      })
+      // We want to delete in reverse order so that children are deleted before
+      // parents, so we have more information available when items are filtered.
+      for (let i = itemsToDelete.length - 1; i >= 0; i--) {
+        const item = itemsToDelete[i]
+        if (undoManager.deleteFilter(item)) {
+          item.delete(transaction)
+          performedChange = true
+        }
+      }
+      result = performedChange ? stackItem : null
+    }
+    transaction.changed.forEach((subProps, type) => {
+      // destroy search marker if necessary
+      if (subProps.has(null) && type._searchMarker) {
+        type._searchMarker.length = 0
+      }
+    })
+    _tr = transaction
+  }, undoManager)
+  if (result != null) {
+    const changedParentTypes = _tr.changedParentTypes
+    undoManager.emit('stack-item-popped', [{ stackItem: result, type: eventType, changedParentTypes }, undoManager])
+  }
+  return result
+}
+
+/**
+ * @typedef {Object} UndoManagerOptions
+ * @property {number} [UndoManagerOptions.captureTimeout=500]
+ * @property {function(Item):boolean} [UndoManagerOptions.deleteFilter=()=>true] Sometimes
+ * it is necessary to filter whan an Undo/Redo operation can delete. If this
+ * filter returns false, the type/item won't be deleted even it is in the
+ * undo/redo scope.
+ * @property {Set<any>} [UndoManagerOptions.trackedOrigins=new Set([null])]
+ */
+
+/**
+ * Fires 'stack-item-added' event when a stack item was added to either the undo- or
+ * the redo-stack. You may store additional stack information via the
+ * metadata property on `event.stackItem.meta` (it is a `Map` of metadata properties).
+ * Fires 'stack-item-popped' event when a stack item was popped from either the
+ * undo- or the redo-stack. You may restore the saved stack information from `event.stackItem.meta`.
+ *
+ * @extends {Observable<'stack-item-added'|'stack-item-popped'>}
+ */
+export class UndoManager extends Observable {
+  /**
+   * @param {AbstractType<any>|Array<AbstractType<any>>} typeScope Accepts either a single type, or an array of types
+   * @param {UndoManagerOptions} options
+   */
+  constructor (typeScope, { captureTimeout = 500, deleteFilter = () => true, trackedOrigins = new Set([null]) } = {}) {
+    super()
+    this.scope = typeScope instanceof Array ? typeScope : [typeScope]
+    this.deleteFilter = deleteFilter
+    trackedOrigins.add(this)
+    this.trackedOrigins = trackedOrigins
+    /**
+     * @type {Array<StackItem>}
+     */
+    this.undoStack = []
+    /**
+     * @type {Array<StackItem>}
+     */
+    this.redoStack = []
+    /**
+     * Whether the client is currently undoing (calling UndoManager.undo)
+     *
+     * @type {boolean}
+     */
+    this.undoing = false
+    this.redoing = false
+    this.doc = /** @type {Doc} */ (this.scope[0].doc)
+    this.lastChange = 0
+    this.doc.on('afterTransaction', /** @param {Transaction} transaction */ transaction => {
+      // Only track certain transactions
+      if (!this.scope.some(type => transaction.changedParentTypes.has(type)) || (!this.trackedOrigins.has(transaction.origin) && (!transaction.origin || !this.trackedOrigins.has(transaction.origin.constructor)))) {
+        return
+      }
+      const undoing = this.undoing
+      const redoing = this.redoing
+      const stack = undoing ? this.redoStack : this.undoStack
+      if (undoing) {
+        this.stopCapturing() // next undo should not be appended to last stack item
+      } else if (!redoing) {
+        // neither undoing nor redoing: delete redoStack
+        this.redoStack = []
+      }
+      const insertions = new DeleteSet()
+      transaction.afterState.forEach((endClock, client) => {
+        const startClock = transaction.beforeState.get(client) || 0
+        const len = endClock - startClock
+        if (len > 0) {
+          addToDeleteSet(insertions, client, startClock, len)
+        }
+      })
+      const now = time.getUnixTime()
+      if (now - this.lastChange < captureTimeout && stack.length > 0 && !undoing && !redoing) {
+        // append change to last stack op
+        const lastOp = stack[stack.length - 1]
+        lastOp.deletions = mergeDeleteSets([lastOp.deletions, transaction.deleteSet])
+        lastOp.insertions = mergeDeleteSets([lastOp.insertions, insertions])
+      } else {
+        // create a new stack op
+        stack.push(new StackItem(transaction.deleteSet, insertions))
+      }
+      if (!undoing && !redoing) {
+        this.lastChange = now
+      }
+      // make sure that deleted structs are not gc'd
+      iterateDeletedStructs(transaction, transaction.deleteSet, /** @param {Item|GC} item */ item => {
+        if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
+          keepItem(item, true)
+        }
+      })
+      this.emit('stack-item-added', [{ stackItem: stack[stack.length - 1], origin: transaction.origin, type: undoing ? 'redo' : 'undo', changedParentTypes: transaction.changedParentTypes }, this])
+    })
+  }
+
+  clear () {
+    this.doc.transact(transaction => {
+      /**
+       * @param {StackItem} stackItem
+       */
+      const clearItem = stackItem => {
+        iterateDeletedStructs(transaction, stackItem.deletions, item => {
+          if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
+            keepItem(item, false)
+          }
+        })
+      }
+      this.undoStack.forEach(clearItem)
+      this.redoStack.forEach(clearItem)
+    })
+    this.undoStack = []
+    this.redoStack = []
+  }
+
+  /**
+   * UndoManager merges Undo-StackItem if they are created within time-gap
+   * smaller than `options.captureTimeout`. Call `um.stopCapturing()` so that the next
+   * StackItem won't be merged.
+   *
+   *
+   * @example
+   *     // without stopCapturing
+   *     ytext.insert(0, 'a')
+   *     ytext.insert(1, 'b')
+   *     um.undo()
+   *     ytext.toString() // => '' (note that 'ab' was removed)
+   *     // with stopCapturing
+   *     ytext.insert(0, 'a')
+   *     um.stopCapturing()
+   *     ytext.insert(0, 'b')
+   *     um.undo()
+   *     ytext.toString() // => 'a' (note that only 'b' was removed)
+   *
+   */
+  stopCapturing () {
+    this.lastChange = 0
+  }
+
+  /**
+   * Undo last changes on type.
+   *
+   * @return {StackItem?} Returns StackItem if a change was applied
+   */
+  undo () {
+    this.undoing = true
+    let res
+    try {
+      res = popStackItem(this, this.undoStack, 'undo')
+    } finally {
+      this.undoing = false
+    }
+    return res
+  }
+
+  /**
+   * Redo last undo operation.
+   *
+   * @return {StackItem?} Returns StackItem if a change was applied
+   */
+  redo () {
+    this.redoing = true
+    let res
+    try {
+      res = popStackItem(this, this.redoStack, 'redo')
+    } finally {
+      this.redoing = false
+    }
+    return res
+  }
+}

src/utils/UpdateDecoder.js

@@ -0,0 +1,281 @@
+import * as buffer from 'lib0/buffer'
+import * as decoding from 'lib0/decoding'
+import {
+  ID, createID
+} from '../internals.js'
+
+export class DSDecoderV1 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    this.restDecoder = decoder
+  }
+
+  resetDsCurVal () {
+    // nop
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsClock () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsLen () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+}
+
+export class UpdateDecoderV1 extends DSDecoderV1 {
+  /**
+   * @return {ID}
+   */
+  readLeftID () {
+    return createID(decoding.readVarUint(this.restDecoder), decoding.readVarUint(this.restDecoder))
+  }
+
+  /**
+   * @return {ID}
+   */
+  readRightID () {
+    return createID(decoding.readVarUint(this.restDecoder), decoding.readVarUint(this.restDecoder))
+  }
+
+  /**
+   * Read the next client id.
+   * Use this in favor of readID whenever possible to reduce the number of objects created.
+   */
+  readClient () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readInfo () {
+    return decoding.readUint8(this.restDecoder)
+  }
+
+  /**
+   * @return {string}
+   */
+  readString () {
+    return decoding.readVarString(this.restDecoder)
+  }
+
+  /**
+   * @return {boolean} isKey
+   */
+  readParentInfo () {
+    return decoding.readVarUint(this.restDecoder) === 1
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readTypeRef () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @return {number} len
+   */
+  readLen () {
+    return decoding.readVarUint(this.restDecoder)
+  }
+
+  /**
+   * @return {any}
+   */
+  readAny () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {Uint8Array}
+   */
+  readBuf () {
+    return buffer.copyUint8Array(decoding.readVarUint8Array(this.restDecoder))
+  }
+
+  /**
+   * Legacy implementation uses JSON parse. We use any-decoding in v2.
+   *
+   * @return {any}
+   */
+  readJSON () {
+    return JSON.parse(decoding.readVarString(this.restDecoder))
+  }
+
+  /**
+   * @return {string}
+   */
+  readKey () {
+    return decoding.readVarString(this.restDecoder)
+  }
+}
+
+export class DSDecoderV2 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    /**
+     * @private
+     */
+    this.dsCurrVal = 0
+    this.restDecoder = decoder
+  }
+
+  resetDsCurVal () {
+    this.dsCurrVal = 0
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsClock () {
+    this.dsCurrVal += decoding.readVarUint(this.restDecoder)
+    return this.dsCurrVal
+  }
+
+  /**
+   * @return {number}
+   */
+  readDsLen () {
+    const diff = decoding.readVarUint(this.restDecoder) + 1
+    this.dsCurrVal += diff
+    return diff
+  }
+}
+
+export class UpdateDecoderV2 extends DSDecoderV2 {
+  /**
+   * @param {decoding.Decoder} decoder
+   */
+  constructor (decoder) {
+    super(decoder)
+    /**
+     * List of cached keys. If the keys[id] does not exist, we read a new key
+     * from stringEncoder and push it to keys.
+     *
+     * @type {Array<string>}
+     */
+    this.keys = []
+    decoding.readVarUint(decoder) // read feature flag - currently unused
+    this.keyClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.clientDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.leftClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.rightClockDecoder = new decoding.IntDiffOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.infoDecoder = new decoding.RleDecoder(decoding.readVarUint8Array(decoder), decoding.readUint8)
+    this.stringDecoder = new decoding.StringDecoder(decoding.readVarUint8Array(decoder))
+    this.parentInfoDecoder = new decoding.RleDecoder(decoding.readVarUint8Array(decoder), decoding.readUint8)
+    this.typeRefDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+    this.lenDecoder = new decoding.UintOptRleDecoder(decoding.readVarUint8Array(decoder))
+  }
+
+  /**
+   * @return {ID}
+   */
+  readLeftID () {
+    return new ID(this.clientDecoder.read(), this.leftClockDecoder.read())
+  }
+
+  /**
+   * @return {ID}
+   */
+  readRightID () {
+    return new ID(this.clientDecoder.read(), this.rightClockDecoder.read())
+  }
+
+  /**
+   * Read the next client id.
+   * Use this in favor of readID whenever possible to reduce the number of objects created.
+   */
+  readClient () {
+    return this.clientDecoder.read()
+  }
+
+  /**
+   * @return {number} info An unsigned 8-bit integer
+   */
+  readInfo () {
+    return /** @type {number} */ (this.infoDecoder.read())
+  }
+
+  /**
+   * @return {string}
+   */
+  readString () {
+    return this.stringDecoder.read()
+  }
+
+  /**
+   * @return {boolean}
+   */
+  readParentInfo () {
+    return this.parentInfoDecoder.read() === 1
+  }
+
+  /**
+   * @return {number} An unsigned 8-bit integer
+   */
+  readTypeRef () {
+    return this.typeRefDecoder.read()
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @return {number}
+   */
+  readLen () {
+    return this.lenDecoder.read()
+  }
+
+  /**
+   * @return {any}
+   */
+  readAny () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {Uint8Array}
+   */
+  readBuf () {
+    return decoding.readVarUint8Array(this.restDecoder)
+  }
+
+  /**
+   * This is mainly here for legacy purposes.
+   *
+   * Initial we incoded objects using JSON. Now we use the much faster lib0/any-encoder. This method mainly exists for legacy purposes for the v1 encoder.
+   *
+   * @return {any}
+   */
+  readJSON () {
+    return decoding.readAny(this.restDecoder)
+  }
+
+  /**
+   * @return {string}
+   */
+  readKey () {
+    const keyClock = this.keyClockDecoder.read()
+    if (keyClock < this.keys.length) {
+      return this.keys[keyClock]
+    } else {
+      const key = this.stringDecoder.read()
+      this.keys.push(key)
+      return key
+    }
+  }
+}

src/utils/UpdateEncoder.js

@@ -0,0 +1,307 @@
+
+import * as error from 'lib0/error'
+import * as encoding from 'lib0/encoding'
+
+import {
+  ID // eslint-disable-line
+} from '../internals.js'
+
+export class DSEncoderV1 {
+  constructor () {
+    this.restEncoder = encoding.createEncoder()
+  }
+
+  toUint8Array () {
+    return encoding.toUint8Array(this.restEncoder)
+  }
+
+  resetDsCurVal () {
+    // nop
+  }
+
+  /**
+   * @param {number} clock
+   */
+  writeDsClock (clock) {
+    encoding.writeVarUint(this.restEncoder, clock)
+  }
+
+  /**
+   * @param {number} len
+   */
+  writeDsLen (len) {
+    encoding.writeVarUint(this.restEncoder, len)
+  }
+}
+
+export class UpdateEncoderV1 extends DSEncoderV1 {
+  /**
+   * @param {ID} id
+   */
+  writeLeftID (id) {
+    encoding.writeVarUint(this.restEncoder, id.client)
+    encoding.writeVarUint(this.restEncoder, id.clock)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeRightID (id) {
+    encoding.writeVarUint(this.restEncoder, id.client)
+    encoding.writeVarUint(this.restEncoder, id.clock)
+  }
+
+  /**
+   * Use writeClient and writeClock instead of writeID if possible.
+   * @param {number} client
+   */
+  writeClient (client) {
+    encoding.writeVarUint(this.restEncoder, client)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeInfo (info) {
+    encoding.writeUint8(this.restEncoder, info)
+  }
+
+  /**
+   * @param {string} s
+   */
+  writeString (s) {
+    encoding.writeVarString(this.restEncoder, s)
+  }
+
+  /**
+   * @param {boolean} isYKey
+   */
+  writeParentInfo (isYKey) {
+    encoding.writeVarUint(this.restEncoder, isYKey ? 1 : 0)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeTypeRef (info) {
+    encoding.writeVarUint(this.restEncoder, info)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @param {number} len
+   */
+  writeLen (len) {
+    encoding.writeVarUint(this.restEncoder, len)
+  }
+
+  /**
+   * @param {any} any
+   */
+  writeAny (any) {
+    encoding.writeAny(this.restEncoder, any)
+  }
+
+  /**
+   * @param {Uint8Array} buf
+   */
+  writeBuf (buf) {
+    encoding.writeVarUint8Array(this.restEncoder, buf)
+  }
+
+  /**
+   * @param {any} embed
+   */
+  writeJSON (embed) {
+    encoding.writeVarString(this.restEncoder, JSON.stringify(embed))
+  }
+
+  /**
+   * @param {string} key
+   */
+  writeKey (key) {
+    encoding.writeVarString(this.restEncoder, key)
+  }
+}
+
+export class DSEncoderV2 {
+  constructor () {
+    this.restEncoder = encoding.createEncoder() // encodes all the rest / non-optimized
+    this.dsCurrVal = 0
+  }
+
+  toUint8Array () {
+    return encoding.toUint8Array(this.restEncoder)
+  }
+
+  resetDsCurVal () {
+    this.dsCurrVal = 0
+  }
+
+  /**
+   * @param {number} clock
+   */
+  writeDsClock (clock) {
+    const diff = clock - this.dsCurrVal
+    this.dsCurrVal = clock
+    encoding.writeVarUint(this.restEncoder, diff)
+  }
+
+  /**
+   * @param {number} len
+   */
+  writeDsLen (len) {
+    if (len === 0) {
+      error.unexpectedCase()
+    }
+    encoding.writeVarUint(this.restEncoder, len - 1)
+    this.dsCurrVal += len
+  }
+}
+
+export class UpdateEncoderV2 extends DSEncoderV2 {
+  constructor () {
+    super()
+    /**
+     * @type {Map<string,number>}
+     */
+    this.keyMap = new Map()
+    /**
+     * Refers to the next uniqe key-identifier to me used.
+     * See writeKey method for more information.
+     *
+     * @type {number}
+     */
+    this.keyClock = 0
+    this.keyClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.clientEncoder = new encoding.UintOptRleEncoder()
+    this.leftClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.rightClockEncoder = new encoding.IntDiffOptRleEncoder()
+    this.infoEncoder = new encoding.RleEncoder(encoding.writeUint8)
+    this.stringEncoder = new encoding.StringEncoder()
+    this.parentInfoEncoder = new encoding.RleEncoder(encoding.writeUint8)
+    this.typeRefEncoder = new encoding.UintOptRleEncoder()
+    this.lenEncoder = new encoding.UintOptRleEncoder()
+  }
+
+  toUint8Array () {
+    const encoder = encoding.createEncoder()
+    encoding.writeVarUint(encoder, 0) // this is a feature flag that we might use in the future
+    encoding.writeVarUint8Array(encoder, this.keyClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.clientEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.leftClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.rightClockEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, encoding.toUint8Array(this.infoEncoder))
+    encoding.writeVarUint8Array(encoder, this.stringEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, encoding.toUint8Array(this.parentInfoEncoder))
+    encoding.writeVarUint8Array(encoder, this.typeRefEncoder.toUint8Array())
+    encoding.writeVarUint8Array(encoder, this.lenEncoder.toUint8Array())
+    // @note The rest encoder is appended! (note the missing var)
+    encoding.writeUint8Array(encoder, encoding.toUint8Array(this.restEncoder))
+    return encoding.toUint8Array(encoder)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeLeftID (id) {
+    this.clientEncoder.write(id.client)
+    this.leftClockEncoder.write(id.clock)
+  }
+
+  /**
+   * @param {ID} id
+   */
+  writeRightID (id) {
+    this.clientEncoder.write(id.client)
+    this.rightClockEncoder.write(id.clock)
+  }
+
+  /**
+   * @param {number} client
+   */
+  writeClient (client) {
+    this.clientEncoder.write(client)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeInfo (info) {
+    this.infoEncoder.write(info)
+  }
+
+  /**
+   * @param {string} s
+   */
+  writeString (s) {
+    this.stringEncoder.write(s)
+  }
+
+  /**
+   * @param {boolean} isYKey
+   */
+  writeParentInfo (isYKey) {
+    this.parentInfoEncoder.write(isYKey ? 1 : 0)
+  }
+
+  /**
+   * @param {number} info An unsigned 8-bit integer
+   */
+  writeTypeRef (info) {
+    this.typeRefEncoder.write(info)
+  }
+
+  /**
+   * Write len of a struct - well suited for Opt RLE encoder.
+   *
+   * @param {number} len
+   */
+  writeLen (len) {
+    this.lenEncoder.write(len)
+  }
+
+  /**
+   * @param {any} any
+   */
+  writeAny (any) {
+    encoding.writeAny(this.restEncoder, any)
+  }
+
+  /**
+   * @param {Uint8Array} buf
+   */
+  writeBuf (buf) {
+    encoding.writeVarUint8Array(this.restEncoder, buf)
+  }
+
+  /**
+   * This is mainly here for legacy purposes.
+   *
+   * Initial we incoded objects using JSON. Now we use the much faster lib0/any-encoder. This method mainly exists for legacy purposes for the v1 encoder.
+   *
+   * @param {any} embed
+   */
+  writeJSON (embed) {
+    encoding.writeAny(this.restEncoder, embed)
+  }
+
+  /**
+   * Property keys are often reused. For example, in y-prosemirror the key `bold` might
+   * occur very often. For a 3d application, the key `position` might occur very often.
+   *
+   * We cache these keys in a Map and refer to them via a unique number.
+   *
+   * @param {string} key
+   */
+  writeKey (key) {
+    const clock = this.keyMap.get(key)
+    if (clock === undefined) {
+      this.keyClockEncoder.write(this.keyClock++)
+      this.stringEncoder.write(key)
+    } else {
+      this.keyClockEncoder.write(this.keyClock++)
+    }
+  }
+}

src/utils/YEvent.js

@@ -0,0 +1,324 @@
+
+import {
+  isDeleted,
+  getMovedCoords,
+  ContentMove, Item, AbstractType, Transaction, AbstractStruct // eslint-disable-line
+} from '../internals.js'
+
+import * as set from 'lib0/set'
+import * as array from 'lib0/array'
+import { addsStruct } from './Transaction.js'
+import { ListCursor } from './ListCursor.js'
+
+/**
+ * YEvent describes the changes on a YType.
+ */
+export class YEvent {
+  /**
+   * @param {AbstractType<any>} target The changed type.
+   * @param {Transaction} transaction
+   */
+  constructor (target, transaction) {
+    /**
+     * The type on which this event was created on.
+     * @type {AbstractType<any>}
+     */
+    this.target = target
+    /**
+     * The current target on which the observe callback is called.
+     * @type {AbstractType<any>}
+     */
+    this.currentTarget = target
+    /**
+     * The transaction that triggered this event.
+     * @type {Transaction}
+     */
+    this.transaction = transaction
+    /**
+     * @type {Object|null}
+     */
+    this._changes = null
+    /**
+     * @type {null | Map<string, { action: 'add' | 'update' | 'delete', oldValue: any, newValue: any }>}
+     */
+    this._keys = null
+    /**
+     * @type {null | Array<{ insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any> }>}
+     */
+    this._delta = null
+  }
+
+  /**
+   * Computes the path from `y` to the changed type.
+   *
+   * @todo v14 should standardize on path: Array<{parent, index}> because that is easier to work with.
+   *
+   * The following property holds:
+   * @example
+   *   let type = y
+   *   event.path.forEach(dir => {
+   *     type = type.get(dir)
+   *   })
+   *   type === event.target // => true
+   */
+  get path () {
+    // @ts-ignore _item is defined because target is integrated
+    return getPathTo(this.currentTarget, this.target, this.transaction)
+  }
+
+  /**
+   * Check if a struct is deleted by this event.
+   *
+   * In contrast to change.deleted, this method also returns true if the struct was added and then deleted.
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  deletes (struct) {
+    return isDeleted(this.transaction.deleteSet, struct.id)
+  }
+
+  /**
+   * @type {Map<string, { action: 'add' | 'update' | 'delete', oldValue: any, newValue: any }>}
+   */
+  get keys () {
+    if (this._keys === null) {
+      const keys = new Map()
+      const target = this.target
+      const changed = /** @type Set<string|null> */ (this.transaction.changed.get(target))
+      changed.forEach(key => {
+        if (key !== null) {
+          const item = /** @type {Item} */ (target._map.get(key))
+          /**
+           * @type {'delete' | 'add' | 'update'}
+           */
+          let action
+          let oldValue
+          if (this.adds(item)) {
+            let prev = item.left
+            while (prev !== null && this.adds(prev)) {
+              prev = prev.left
+            }
+            if (this.deletes(item)) {
+              if (prev !== null && this.deletes(prev)) {
+                action = 'delete'
+                oldValue = array.last(prev.content.getContent())
+              } else {
+                return
+              }
+            } else {
+              if (prev !== null && this.deletes(prev)) {
+                action = 'update'
+                oldValue = array.last(prev.content.getContent())
+              } else {
+                action = 'add'
+                oldValue = undefined
+              }
+            }
+          } else {
+            if (this.deletes(item)) {
+              action = 'delete'
+              oldValue = array.last(/** @type {Item} */ item.content.getContent())
+            } else {
+              return // nop
+            }
+          }
+          keys.set(key, { action, oldValue })
+        }
+      })
+      this._keys = keys
+    }
+    return this._keys
+  }
+
+  /**
+   * @type {Array<{insert?: string | Array<any> | object | AbstractType<any>, retain?: number, delete?: number, attributes?: Object<string, any>}>}
+   */
+  get delta () {
+    return this.changes.delta
+  }
+
+  /**
+   * Check if a struct is added by this event.
+   *
+   * In contrast to change.deleted, this method also returns true if the struct was added and then deleted.
+   *
+   * @todo this can be removed in the next release (prefer function)
+   *
+   * @param {AbstractStruct} struct
+   * @return {boolean}
+   */
+  adds (struct) {
+    return addsStruct(this.transaction, struct)
+  }
+
+  /**
+   * @type {{added:Set<Item>,deleted:Set<Item>,keys:Map<string,{action:'add'|'update'|'delete',oldValue:any}>,delta:Array<{insert?:Array<any>|string, delete?:number, retain?:number}>}}
+   */
+  get changes () {
+    let changes = this._changes
+    if (changes === null) {
+      this.transaction.doc.transact(tr => {
+        const target = this.target
+        const added = set.create()
+        const deleted = set.create()
+        /**
+         * @type {Array<{insert:Array<any>}|{delete:number}|{retain:number}>}
+         */
+        const delta = []
+        changes = {
+          added,
+          deleted,
+          delta,
+          keys: this.keys
+        }
+        const changed = /** @type Set<string|null> */ (this.transaction.changed.get(target))
+        if (changed.has(null)) {
+          /**
+           * @type {Array<{ end: Item | null, move: Item | null, isNew: boolean, isDeleted: boolean }>}
+           */
+          const movedStack = []
+          /**
+           * @type {Item | null}
+           */
+          let currMove = null
+          /**
+           * @type {boolean}
+           */
+          let currMoveIsNew = false
+          /**
+           * @type {boolean}
+           */
+          let currMoveIsDeleted = false
+          /**
+           * @type {Item | null}
+           */
+          let currMoveEnd = null
+          /**
+           * @type {any}
+           */
+          let lastOp = null
+          const packOp = () => {
+            if (lastOp) {
+              delta.push(lastOp)
+            }
+          }
+          /**
+           * @param {Item} item
+           */
+          const isMovedByNew = item => {
+            let moved = item.moved
+            while (moved != null) {
+              if (this.adds(moved)) {
+                return true
+              }
+              moved = moved.moved
+            }
+            return false
+          }
+          for (let item = target._start; ;) {
+            if (item === currMoveEnd && currMove) {
+              item = currMove
+              const { end, move, isNew, isDeleted } = movedStack.pop() || { end: null, move: null, isNew: false, isDeleted: false }
+              currMoveIsNew = isNew
+              currMoveIsDeleted = isDeleted
+              currMoveEnd = end
+              currMove = move
+            } else if (item === null) {
+              break
+            } else if (item.content.constructor === ContentMove) {
+              if (item.moved === currMove && (!item.deleted || (this.deletes(item) && !this.adds(item)))) {
+                movedStack.push({ end: currMoveEnd, move: currMove, isNew: currMoveIsNew, isDeleted: currMoveIsDeleted })
+                const { start, end } = getMovedCoords(item.content, tr, true) // We must split items for move-ranges, for single moves no splitting suffices
+                currMove = item
+                currMoveEnd = end
+                currMoveIsNew = this.adds(item) || currMoveIsNew
+                currMoveIsDeleted = item.deleted || currMoveIsDeleted
+                item = start
+                continue // do not move to item.right
+              }
+            } else if (item.moved !== currMove) {
+              if (!currMoveIsNew && item.countable && (!item.deleted || this.deletes(item)) && !this.adds(item) && (item.moved === null || isMovedByNew(item) || currMoveIsDeleted) && (this.transaction.prevMoved.get(item) || null) === currMove) {
+                if (lastOp === null || lastOp.delete === undefined) {
+                  packOp()
+                  lastOp = { delete: 0 }
+                }
+                lastOp.delete += item.length
+              }
+            } else if (item.deleted) {
+              if (!currMoveIsNew && this.deletes(item) && !this.adds(item) && !this.transaction.prevMoved.has(item)) {
+                if (lastOp === null || lastOp.delete === undefined) {
+                  packOp()
+                  lastOp = { delete: 0 }
+                }
+                lastOp.delete += item.length
+                deleted.add(item)
+              }
+            } else {
+              if (currMoveIsNew || this.adds(item) || this.transaction.prevMoved.has(item)) {
+                if (lastOp === null || lastOp.insert === undefined) {
+                  packOp()
+                  lastOp = { insert: [] }
+                }
+                // @todo push items instead (or splice..)
+                lastOp.insert = lastOp.insert.concat(item.content.getContent())
+                if (!currMoveIsNew) {
+                  added.add(item)
+                }
+              } else {
+                if (lastOp === null || lastOp.retain === undefined) {
+                  packOp()
+                  lastOp = { retain: 0 }
+                }
+                lastOp.retain += item.length
+              }
+            }
+            item = /** @type {Item} */ (item).right
+          }
+          if (lastOp !== null && lastOp.retain == null) {
+            packOp()
+          }
+        }
+        this._changes = changes
+      })
+    }
+    return /** @type {any} */ (changes)
+  }
+}
+
+/**
+ * Compute the path from this type to the specified target.
+ *
+ * @example
+ *   // `child` should be accessible via `type.get(path[0]).get(path[1])..`
+ *   const path = type.getPathTo(child)
+ *   // assuming `type instanceof YArray`
+ *   console.log(path) // might look like => [2, 'key1']
+ *   child === type.get(path[0]).get(path[1])
+ *
+ * @param {AbstractType<any>} parent
+ * @param {AbstractType<any>} child target
+ * @param {Transaction} tr
+ * @return {Array<string|number>} Path to the target
+ *
+ * @private
+ * @function
+ */
+const getPathTo = (parent, child, tr) => {
+  const path = []
+  while (child._item !== null && child !== parent) {
+    if (child._item.parentSub !== null) {
+      // parent is map-ish
+      path.unshift(child._item.parentSub)
+    } else {
+      // parent is array-ish
+      const c = new ListCursor(/** @type {AbstractType<any>} */ (child._item.parent))
+      while (c.nextItem != null && !c.reachedEnd && c.nextItem !== child._item) {
+        c.forward(tr, (c.nextItem.countable && !c.nextItem.deleted) ? c.nextItem.length : 0, true)
+      }
+      path.unshift(c.index)
+    }
+    child = /** @type {AbstractType<any>} */ (child._item.parent)
+  }
+  return path
+}

src/utils/encoding.js

@@ -0,0 +1,633 @@
+
+/**
+ * @module encoding
+ */
+/*
+ * We use the first five bits in the info flag for determining the type of the struct.
+ *
+ * 0: GC
+ * 1: Item with Deleted content
+ * 2: Item with JSON content
+ * 3: Item with Binary content
+ * 4: Item with String content
+ * 5: Item with Embed content (for richtext content)
+ * 6: Item with Format content (a formatting marker for richtext content)
+ * 7: Item with Type
+ */
+
+import {
+  findIndexSS,
+  getState,
+  createID,
+  getStateVector,
+  readAndApplyDeleteSet,
+  writeDeleteSet,
+  createDeleteSetFromStructStore,
+  transact,
+  readItemContent,
+  UpdateDecoderV1,
+  UpdateDecoderV2,
+  UpdateEncoderV1,
+  UpdateEncoderV2,
+  DSEncoderV2,
+  DSDecoderV1,
+  DSEncoderV1,
+  mergeUpdates,
+  mergeUpdatesV2,
+  Skip,
+  diffUpdateV2,
+  convertUpdateFormatV2ToV1,
+  DSDecoderV2, Doc, Transaction, GC, Item, StructStore // eslint-disable-line
+} from '../internals.js'
+
+import * as encoding from 'lib0/encoding'
+import * as decoding from 'lib0/decoding'
+import * as binary from 'lib0/binary'
+import * as map from 'lib0/map'
+import * as math from 'lib0/math'
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Array<GC|Item>} structs All structs by `client`
+ * @param {number} client
+ * @param {number} clock write structs starting with `ID(client,clock)`
+ *
+ * @function
+ */
+const writeStructs = (encoder, structs, client, clock) => {
+  // write first id
+  clock = math.max(clock, structs[0].id.clock) // make sure the first id exists
+  const startNewStructs = findIndexSS(structs, clock)
+  // write # encoded structs
+  encoding.writeVarUint(encoder.restEncoder, structs.length - startNewStructs)
+  encoder.writeClient(client)
+  encoding.writeVarUint(encoder.restEncoder, clock)
+  const firstStruct = structs[startNewStructs]
+  // write first struct with an offset
+  firstStruct.write(encoder, clock - firstStruct.id.clock)
+  for (let i = startNewStructs + 1; i < structs.length; i++) {
+    structs[i].write(encoder, 0)
+  }
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {StructStore} store
+ * @param {Map<number,number>} _sm
+ *
+ * @private
+ * @function
+ */
+export const writeClientsStructs = (encoder, store, _sm) => {
+  // we filter all valid _sm entries into sm
+  const sm = new Map()
+  _sm.forEach((clock, client) => {
+    // only write if new structs are available
+    if (getState(store, client) > clock) {
+      sm.set(client, clock)
+    }
+  })
+  getStateVector(store).forEach((clock, client) => {
+    if (!_sm.has(client)) {
+      sm.set(client, 0)
+    }
+  })
+  // write # states that were updated
+  encoding.writeVarUint(encoder.restEncoder, sm.size)
+  // Write items with higher client ids first
+  // This heavily improves the conflict algorithm.
+  Array.from(sm.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+    // @ts-ignore
+    writeStructs(encoder, store.clients.get(client), client, clock)
+  })
+}
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder The decoder object to read data from.
+ * @param {Doc} doc
+ * @return {Map<number, { i: number, refs: Array<Item | GC> }>}
+ *
+ * @private
+ * @function
+ */
+export const readClientsStructRefs = (decoder, doc) => {
+  /**
+   * @type {Map<number, { i: number, refs: Array<Item | GC> }>}
+   */
+  const clientRefs = map.create()
+  const numOfStateUpdates = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numOfStateUpdates; i++) {
+    const numberOfStructs = decoding.readVarUint(decoder.restDecoder)
+    /**
+     * @type {Array<GC|Item>}
+     */
+    const refs = new Array(numberOfStructs)
+    const client = decoder.readClient()
+    let clock = decoding.readVarUint(decoder.restDecoder)
+    // const start = performance.now()
+    clientRefs.set(client, { i: 0, refs })
+    for (let i = 0; i < numberOfStructs; i++) {
+      const info = decoder.readInfo()
+      switch (binary.BITS5 & info) {
+        case 0: { // GC
+          const len = decoder.readLen()
+          refs[i] = new GC(createID(client, clock), len)
+          clock += len
+          break
+        }
+        case 10: { // Skip Struct (nothing to apply)
+          // @todo we could reduce the amount of checks by adding Skip struct to clientRefs so we know that something is missing.
+          const len = decoding.readVarUint(decoder.restDecoder)
+          refs[i] = new Skip(createID(client, clock), len)
+          clock += len
+          break
+        }
+        default: { // Item with content
+          /**
+           * The optimized implementation doesn't use any variables because inlining variables is faster.
+           * Below a non-optimized version is shown that implements the basic algorithm with
+           * a few comments
+           */
+          const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+          // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+          // and we read the next string as parentYKey.
+          // It indicates how we store/retrieve parent from `y.share`
+          // @type {string|null}
+          const struct = new Item(
+            createID(client, clock),
+            null, // leftd
+            (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null, // origin
+            null, // right
+            (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null, // right origin
+            cantCopyParentInfo ? (decoder.readParentInfo() ? doc.get(decoder.readString()) : decoder.readLeftID()) : null, // parent
+            cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+            readItemContent(decoder, info) // item content
+          )
+          /* A non-optimized implementation of the above algorithm:
+
+          // The item that was originally to the left of this item.
+          const origin = (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null
+          // The item that was originally to the right of this item.
+          const rightOrigin = (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null
+          const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+          const hasParentYKey = cantCopyParentInfo ? decoder.readParentInfo() : false
+          // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+          // and we read the next string as parentYKey.
+          // It indicates how we store/retrieve parent from `y.share`
+          // @type {string|null}
+          const parentYKey = cantCopyParentInfo && hasParentYKey ? decoder.readString() : null
+
+          const struct = new Item(
+            createID(client, clock),
+            null, // leftd
+            origin, // origin
+            null, // right
+            rightOrigin, // right origin
+            cantCopyParentInfo && !hasParentYKey ? decoder.readLeftID() : (parentYKey !== null ? doc.get(parentYKey) : null), // parent
+            cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+            readItemContent(decoder, info) // item content
+          )
+          */
+          refs[i] = struct
+          clock += struct.length
+        }
+      }
+    }
+  }
+  return clientRefs
+}
+
+/**
+ * Resume computing structs generated by struct readers.
+ *
+ * While there is something to do, we integrate structs in this order
+ * 1. top element on stack, if stack is not empty
+ * 2. next element from current struct reader (if empty, use next struct reader)
+ *
+ * If struct causally depends on another struct (ref.missing), we put next reader of
+ * `ref.id.client` on top of stack.
+ *
+ * At some point we find a struct that has no causal dependencies,
+ * then we start emptying the stack.
+ *
+ * It is not possible to have circles: i.e. struct1 (from client1) depends on struct2 (from client2)
+ * depends on struct3 (from client1). Therefore the max stack size is eqaul to `structReaders.length`.
+ *
+ * This method is implemented in a way so that we can resume computation if this update
+ * causally depends on another update.
+ *
+ * @param {Transaction} transaction
+ * @param {StructStore} store
+ * @param {Map<number, { i: number, refs: (GC | Item)[] }>} clientsStructRefs
+ * @return { null | { update: Uint8Array, missing: Map<number,number> } }
+ *
+ * @private
+ * @function
+ */
+const integrateStructs = (transaction, store, clientsStructRefs) => {
+  /**
+   * @type {Array<Item | GC>}
+   */
+  const stack = []
+  // sort them so that we take the higher id first, in case of conflicts the lower id will probably not conflict with the id from the higher user.
+  let clientsStructRefsIds = Array.from(clientsStructRefs.keys()).sort((a, b) => a - b)
+  if (clientsStructRefsIds.length === 0) {
+    return null
+  }
+  const getNextStructTarget = () => {
+    if (clientsStructRefsIds.length === 0) {
+      return null
+    }
+    let nextStructsTarget = /** @type {{i:number,refs:Array<GC|Item>}} */ (clientsStructRefs.get(clientsStructRefsIds[clientsStructRefsIds.length - 1]))
+    while (nextStructsTarget.refs.length === nextStructsTarget.i) {
+      clientsStructRefsIds.pop()
+      if (clientsStructRefsIds.length > 0) {
+        nextStructsTarget = /** @type {{i:number,refs:Array<GC|Item>}} */ (clientsStructRefs.get(clientsStructRefsIds[clientsStructRefsIds.length - 1]))
+      } else {
+        return null
+      }
+    }
+    return nextStructsTarget
+  }
+  let curStructsTarget = getNextStructTarget()
+  if (curStructsTarget === null && stack.length === 0) {
+    return null
+  }
+
+  /**
+   * @type {StructStore}
+   */
+  const restStructs = new StructStore()
+  const missingSV = new Map()
+  /**
+   * @param {number} client
+   * @param {number} clock
+   */
+  const updateMissingSv = (client, clock) => {
+    const mclock = missingSV.get(client)
+    if (mclock == null || mclock > clock) {
+      missingSV.set(client, clock)
+    }
+  }
+  /**
+   * @type {GC|Item}
+   */
+  let stackHead = /** @type {any} */ (curStructsTarget).refs[/** @type {any} */ (curStructsTarget).i++]
+  // caching the state because it is used very often
+  const state = new Map()
+
+  const addStackToRestSS = () => {
+    for (const item of stack) {
+      const client = item.id.client
+      const unapplicableItems = clientsStructRefs.get(client)
+      if (unapplicableItems) {
+        // decrement because we weren't able to apply previous operation
+        unapplicableItems.i--
+        restStructs.clients.set(client, unapplicableItems.refs.slice(unapplicableItems.i))
+        clientsStructRefs.delete(client)
+        unapplicableItems.i = 0
+        unapplicableItems.refs = []
+      } else {
+        // item was the last item on clientsStructRefs and the field was already cleared. Add item to restStructs and continue
+        restStructs.clients.set(client, [item])
+      }
+      // remove client from clientsStructRefsIds to prevent users from applying the same update again
+      clientsStructRefsIds = clientsStructRefsIds.filter(c => c !== client)
+    }
+    stack.length = 0
+  }
+
+  // iterate over all struct readers until we are done
+  while (true) {
+    if (stackHead.constructor !== Skip) {
+      const localClock = map.setIfUndefined(state, stackHead.id.client, () => getState(store, stackHead.id.client))
+      const offset = localClock - stackHead.id.clock
+      if (offset < 0) {
+        // update from the same client is missing
+        stack.push(stackHead)
+        updateMissingSv(stackHead.id.client, stackHead.id.clock - 1)
+        // hid a dead wall, add all items from stack to restSS
+        addStackToRestSS()
+      } else {
+        const missing = stackHead.getMissing(transaction, store)
+        if (missing !== null) {
+          stack.push(stackHead)
+          // get the struct reader that has the missing struct
+          /**
+           * @type {{ refs: Array<GC|Item>, i: number }}
+           */
+          const structRefs = clientsStructRefs.get(/** @type {number} */ (missing)) || { refs: [], i: 0 }
+          if (structRefs.refs.length === structRefs.i) {
+            // This update message causally depends on another update message that doesn't exist yet
+            updateMissingSv(/** @type {number} */ (missing), getState(store, missing))
+            addStackToRestSS()
+          } else {
+            stackHead = structRefs.refs[structRefs.i++]
+            continue
+          }
+        } else if (offset === 0 || offset < stackHead.length) {
+          // all fine, apply the stackhead
+          stackHead.integrate(transaction, offset)
+          state.set(stackHead.id.client, stackHead.id.clock + stackHead.length)
+        }
+      }
+    }
+    // iterate to next stackHead
+    if (stack.length > 0) {
+      stackHead = /** @type {GC|Item} */ (stack.pop())
+    } else if (curStructsTarget !== null && curStructsTarget.i < curStructsTarget.refs.length) {
+      stackHead = /** @type {GC|Item} */ (curStructsTarget.refs[curStructsTarget.i++])
+    } else {
+      curStructsTarget = getNextStructTarget()
+      if (curStructsTarget === null) {
+        // we are done!
+        break
+      } else {
+        stackHead = /** @type {GC|Item} */ (curStructsTarget.refs[curStructsTarget.i++])
+      }
+    }
+  }
+  if (restStructs.clients.size > 0) {
+    const encoder = new UpdateEncoderV2()
+    writeClientsStructs(encoder, restStructs, new Map())
+    // write empty deleteset
+    // writeDeleteSet(encoder, new DeleteSet())
+    encoding.writeVarUint(encoder.restEncoder, 0) // => no need for an extra function call, just write 0 deletes
+    return { missing: missingSV, update: encoder.toUint8Array() }
+  }
+  return null
+}
+
+/**
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Transaction} transaction
+ *
+ * @private
+ * @function
+ */
+export const writeStructsFromTransaction = (encoder, transaction) => writeClientsStructs(encoder, transaction.doc.store, transaction.beforeState)
+
+/**
+ * Read and apply a document update.
+ *
+ * This function has the same effect as `applyUpdate` but accepts an decoder.
+ *
+ * @param {decoding.Decoder} decoder
+ * @param {Doc} ydoc
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} [structDecoder]
+ *
+ * @function
+ */
+export const readUpdateV2 = (decoder, ydoc, transactionOrigin, structDecoder = new UpdateDecoderV2(decoder)) =>
+  transact(ydoc, transaction => {
+    // force that transaction.local is set to non-local
+    transaction.local = false
+    let retry = false
+    const doc = transaction.doc
+    const store = doc.store
+    // let start = performance.now()
+    const ss = readClientsStructRefs(structDecoder, doc)
+    const restStructs = integrateStructs(transaction, store, ss)
+    const pending = store.pendingStructs
+    if (pending) {
+      // check if we can apply something
+      for (const [client, clock] of pending.missing) {
+        if (clock < getState(store, client)) {
+          retry = true
+          break
+        }
+      }
+      if (restStructs) {
+        // merge restStructs into store.pending
+        for (const [client, clock] of restStructs.missing) {
+          const mclock = pending.missing.get(client)
+          if (mclock == null || mclock > clock) {
+            pending.missing.set(client, clock)
+          }
+        }
+        pending.update = mergeUpdatesV2([pending.update, restStructs.update])
+      }
+    } else {
+      store.pendingStructs = restStructs
+    }
+    const dsRest = readAndApplyDeleteSet(structDecoder, transaction, store)
+    if (store.pendingDs) {
+      // @todo we could make a lower-bound state-vector check as we do above
+      const pendingDSUpdate = new UpdateDecoderV2(decoding.createDecoder(store.pendingDs))
+      decoding.readVarUint(pendingDSUpdate.restDecoder) // read 0 structs, because we only encode deletes in pendingdsupdate
+      const dsRest2 = readAndApplyDeleteSet(pendingDSUpdate, transaction, store)
+      if (dsRest && dsRest2) {
+        // case 1: ds1 != null && ds2 != null
+        store.pendingDs = mergeUpdatesV2([dsRest, dsRest2])
+      } else {
+        // case 2: ds1 != null
+        // case 3: ds2 != null
+        // case 4: ds1 == null && ds2 == null
+        store.pendingDs = dsRest || dsRest2
+      }
+    } else {
+      // Either dsRest == null && pendingDs == null OR dsRest != null
+      store.pendingDs = dsRest
+    }
+    if (retry) {
+      const update = /** @type {{update: Uint8Array}} */ (store.pendingStructs).update
+      store.pendingStructs = null
+      applyUpdateV2(transaction.doc, update)
+    }
+  }, transactionOrigin, false)
+
+/**
+ * Read and apply a document update.
+ *
+ * This function has the same effect as `applyUpdate` but accepts an decoder.
+ *
+ * @param {decoding.Decoder} decoder
+ * @param {Doc} ydoc
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ *
+ * @function
+ */
+export const readUpdate = (decoder, ydoc, transactionOrigin) => readUpdateV2(decoder, ydoc, transactionOrigin, new UpdateDecoderV1(decoder))
+
+/**
+ * Apply a document update created by, for example, `y.on('update', update => ..)` or `update = encodeStateAsUpdate()`.
+ *
+ * This function has the same effect as `readUpdate` but accepts an Uint8Array instead of a Decoder.
+ *
+ * @param {Doc} ydoc
+ * @param {Uint8Array} update
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ *
+ * @function
+ */
+export const applyUpdateV2 = (ydoc, update, transactionOrigin, YDecoder = UpdateDecoderV2) => {
+  const decoder = decoding.createDecoder(update)
+  readUpdateV2(decoder, ydoc, transactionOrigin, new YDecoder(decoder))
+}
+
+/**
+ * Apply a document update created by, for example, `y.on('update', update => ..)` or `update = encodeStateAsUpdate()`.
+ *
+ * This function has the same effect as `readUpdate` but accepts an Uint8Array instead of a Decoder.
+ *
+ * @param {Doc} ydoc
+ * @param {Uint8Array} update
+ * @param {any} [transactionOrigin] This will be stored on `transaction.origin` and `.on('update', (update, origin))`
+ *
+ * @function
+ */
+export const applyUpdate = (ydoc, update, transactionOrigin) => applyUpdateV2(ydoc, update, transactionOrigin, UpdateDecoderV1)
+
+/**
+ * Write all the document as a single update message. If you specify the state of the remote client (`targetStateVector`) it will
+ * only write the operations that are missing.
+ *
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+ * @param {Doc} doc
+ * @param {Map<number,number>} [targetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ *
+ * @function
+ */
+export const writeStateAsUpdate = (encoder, doc, targetStateVector = new Map()) => {
+  writeClientsStructs(encoder, doc.store, targetStateVector)
+  writeDeleteSet(encoder, createDeleteSetFromStructStore(doc.store))
+}
+
+/**
+ * Write all the document as a single update message that can be applied on the remote document. If you specify the state of the remote client (`targetState`) it will
+ * only write the operations that are missing.
+ *
+ * Use `writeStateAsUpdate` instead if you are working with lib0/encoding.js#Encoder
+ *
+ * @param {Doc} doc
+ * @param {Uint8Array} [encodedTargetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ * @param {UpdateEncoderV1 | UpdateEncoderV2} [encoder]
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateAsUpdateV2 = (doc, encodedTargetStateVector = new Uint8Array([0]), encoder = new UpdateEncoderV2()) => {
+  const targetStateVector = decodeStateVector(encodedTargetStateVector)
+  writeStateAsUpdate(encoder, doc, targetStateVector)
+  const updates = [encoder.toUint8Array()]
+  // also add the pending updates (if there are any)
+  if (doc.store.pendingDs) {
+    updates.push(doc.store.pendingDs)
+  }
+  if (doc.store.pendingStructs) {
+    updates.push(diffUpdateV2(doc.store.pendingStructs.update, encodedTargetStateVector))
+  }
+  if (updates.length > 1) {
+    if (encoder.constructor === UpdateEncoderV1) {
+      return mergeUpdates(updates.map((update, i) => i === 0 ? update : convertUpdateFormatV2ToV1(update)))
+    } else if (encoder.constructor === UpdateEncoderV2) {
+      return mergeUpdatesV2(updates)
+    }
+  }
+  return updates[0]
+}
+
+/**
+ * Write all the document as a single update message that can be applied on the remote document. If you specify the state of the remote client (`targetState`) it will
+ * only write the operations that are missing.
+ *
+ * Use `writeStateAsUpdate` instead if you are working with lib0/encoding.js#Encoder
+ *
+ * @param {Doc} doc
+ * @param {Uint8Array} [encodedTargetStateVector] The state of the target that receives the update. Leave empty to write all known structs
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateAsUpdate = (doc, encodedTargetStateVector) => encodeStateAsUpdateV2(doc, encodedTargetStateVector, new UpdateEncoderV1())
+
+/**
+ * Read state vector from Decoder and return as Map
+ *
+ * @param {DSDecoderV1 | DSDecoderV2} decoder
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+export const readStateVector = decoder => {
+  const ss = new Map()
+  const ssLength = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < ssLength; i++) {
+    const client = decoding.readVarUint(decoder.restDecoder)
+    const clock = decoding.readVarUint(decoder.restDecoder)
+    ss.set(client, clock)
+  }
+  return ss
+}
+
+/**
+ * Read decodedState and return State as Map.
+ *
+ * @param {Uint8Array} decodedState
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+// export const decodeStateVectorV2 = decodedState => readStateVector(new DSDecoderV2(decoding.createDecoder(decodedState)))
+
+/**
+ * Read decodedState and return State as Map.
+ *
+ * @param {Uint8Array} decodedState
+ * @return {Map<number,number>} Maps `client` to the number next expected `clock` from that client.
+ *
+ * @function
+ */
+export const decodeStateVector = decodedState => readStateVector(new DSDecoderV1(decoding.createDecoder(decodedState)))
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {Map<number,number>} sv
+ * @function
+ */
+export const writeStateVector = (encoder, sv) => {
+  encoding.writeVarUint(encoder.restEncoder, sv.size)
+  Array.from(sv.entries()).sort((a, b) => b[0] - a[0]).forEach(([client, clock]) => {
+    encoding.writeVarUint(encoder.restEncoder, client) // @todo use a special client decoder that is based on mapping
+    encoding.writeVarUint(encoder.restEncoder, clock)
+  })
+  return encoder
+}
+
+/**
+ * @param {DSEncoderV1 | DSEncoderV2} encoder
+ * @param {Doc} doc
+ *
+ * @function
+ */
+export const writeDocumentStateVector = (encoder, doc) => writeStateVector(encoder, getStateVector(doc.store))
+
+/**
+ * Encode State as Uint8Array.
+ *
+ * @param {Doc|Map<number,number>} doc
+ * @param {DSEncoderV1 | DSEncoderV2} [encoder]
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateVectorV2 = (doc, encoder = new DSEncoderV2()) => {
+  if (doc instanceof Map) {
+    writeStateVector(encoder, doc)
+  } else {
+    writeDocumentStateVector(encoder, doc)
+  }
+  return encoder.toUint8Array()
+}
+
+/**
+ * Encode State as Uint8Array.
+ *
+ * @param {Doc|Map<number,number>} doc
+ * @return {Uint8Array}
+ *
+ * @function
+ */
+export const encodeStateVector = doc => encodeStateVectorV2(doc, new DSEncoderV1())

src/utils/isParentOf.js

@@ -0,0 +1,22 @@
+
+import { AbstractType, Item } from '../internals.js' // eslint-disable-line
+
+/**
+ * Check if `parent` is a parent of `child`.
+ *
+ * @param {AbstractType<any>} parent
+ * @param {Item|null} child
+ * @return {Boolean} Whether `parent` is a parent of `child`.
+ *
+ * @private
+ * @function
+ */
+export const isParentOf = (parent, child) => {
+  while (child !== null) {
+    if (child.parent === parent) {
+      return true
+    }
+    child = /** @type {AbstractType<any>} */ (child.parent)._item
+  }
+  return false
+}

src/utils/logging.js

@@ -0,0 +1,22 @@
+
+import {
+  AbstractType // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * Convenient helper to log type information.
+ *
+ * Do not use in productive systems as the output can be immense!
+ *
+ * @param {AbstractType<any>} type
+ */
+export const logType = type => {
+  const res = []
+  let n = type._start
+  while (n) {
+    res.push(n)
+    n = n.right
+  }
+  console.log('Children: ', res)
+  console.log('Children content: ', res.filter(m => !m.deleted).map(m => m.content))
+}

src/utils/updates.js

@@ -0,0 +1,558 @@
+
+import * as binary from 'lib0/binary'
+import * as decoding from 'lib0/decoding'
+import * as encoding from 'lib0/encoding'
+import * as logging from 'lib0/logging'
+import * as math from 'lib0/math'
+import {
+  createID,
+  readItemContent,
+  readDeleteSet,
+  writeDeleteSet,
+  Skip,
+  mergeDeleteSets,
+  DSEncoderV1,
+  DSEncoderV2,
+  decodeStateVector,
+  Item, GC, UpdateDecoderV1, UpdateDecoderV2, UpdateEncoderV1, UpdateEncoderV2 // eslint-disable-line
+} from '../internals.js'
+
+/**
+ * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+ */
+function * lazyStructReaderGenerator (decoder) {
+  const numOfStateUpdates = decoding.readVarUint(decoder.restDecoder)
+  for (let i = 0; i < numOfStateUpdates; i++) {
+    const numberOfStructs = decoding.readVarUint(decoder.restDecoder)
+    const client = decoder.readClient()
+    let clock = decoding.readVarUint(decoder.restDecoder)
+    for (let i = 0; i < numberOfStructs; i++) {
+      const info = decoder.readInfo()
+      // @todo use switch instead of ifs
+      if (info === 10) {
+        const len = decoding.readVarUint(decoder.restDecoder)
+        yield new Skip(createID(client, clock), len)
+        clock += len
+      } else if ((binary.BITS5 & info) !== 0) {
+        const cantCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
+        // If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
+        // and we read the next string as parentYKey.
+        // It indicates how we store/retrieve parent from `y.share`
+        // @type {string|null}
+        const struct = new Item(
+          createID(client, clock),
+          null, // left
+          (info & binary.BIT8) === binary.BIT8 ? decoder.readLeftID() : null, // origin
+          null, // right
+          (info & binary.BIT7) === binary.BIT7 ? decoder.readRightID() : null, // right origin
+          // @ts-ignore Force writing a string here.
+          cantCopyParentInfo ? (decoder.readParentInfo() ? decoder.readString() : decoder.readLeftID()) : null, // parent
+          cantCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoder.readString() : null, // parentSub
+          readItemContent(decoder, info) // item content
+        )
+        yield struct
+        clock += struct.length
+      } else {
+        const len = decoder.readLen()
+        yield new GC(createID(client, clock), len)
+        clock += len
+      }
+    }
+  }
+}
+
+export class LazyStructReader {
+  /**
+   * @param {UpdateDecoderV1 | UpdateDecoderV2} decoder
+   * @param {boolean} filterSkips
+   */
+  constructor (decoder, filterSkips) {
+    this.gen = lazyStructReaderGenerator(decoder)
+    /**
+     * @type {null | Item | Skip | GC}
+     */
+    this.curr = null
+    this.done = false
+    this.filterSkips = filterSkips
+    this.next()
+  }
+
+  /**
+   * @return {Item | GC | Skip |null}
+   */
+  next () {
+    // ignore "Skip" structs
+    do {
+      this.curr = this.gen.next().value || null
+    } while (this.filterSkips && this.curr !== null && this.curr.constructor === Skip)
+    return this.curr
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ *
+ */
+export const logUpdate = update => logUpdateV2(update, UpdateDecoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} [YDecoder]
+ *
+ */
+export const logUpdateV2 = (update, YDecoder = UpdateDecoderV2) => {
+  const structs = []
+  const updateDecoder = new YDecoder(decoding.createDecoder(update))
+  const lazyDecoder = new LazyStructReader(updateDecoder, false)
+  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
+    structs.push(curr)
+  }
+  logging.print('Structs: ', structs)
+  const ds = readDeleteSet(updateDecoder)
+  logging.print('DeleteSet: ', ds)
+}
+
+export class LazyStructWriter {
+  /**
+   * @param {UpdateEncoderV1 | UpdateEncoderV2} encoder
+   */
+  constructor (encoder) {
+    this.currClient = 0
+    this.startClock = 0
+    this.written = 0
+    this.encoder = encoder
+    /**
+     * We want to write operations lazily, but also we need to know beforehand how many operations we want to write for each client.
+     *
+     * This kind of meta-information (#clients, #structs-per-client-written) is written to the restEncoder.
+     *
+     * We fragment the restEncoder and store a slice of it per-client until we know how many clients there are.
+     * When we flush (toUint8Array) we write the restEncoder using the fragments and the meta-information.
+     *
+     * @type {Array<{ written: number, restEncoder: Uint8Array }>}
+     */
+    this.clientStructs = []
+  }
+}
+
+/**
+ * @param {Array<Uint8Array>} updates
+ * @return {Uint8Array}
+ */
+export const mergeUpdates = updates => mergeUpdatesV2(updates, UpdateDecoderV1, UpdateEncoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof DSEncoderV1 | typeof DSEncoderV2} YEncoder
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} YDecoder
+ * @return {Uint8Array}
+ */
+export const encodeStateVectorFromUpdateV2 = (update, YEncoder = DSEncoderV2, YDecoder = UpdateDecoderV2) => {
+  const encoder = new YEncoder()
+  const updateDecoder = new LazyStructReader(new YDecoder(decoding.createDecoder(update)), false)
+  let curr = updateDecoder.curr
+  if (curr !== null) {
+    let size = 0
+    let currClient = curr.id.client
+    let stopCounting = curr.id.clock !== 0 // must start at 0
+    let currClock = stopCounting ? 0 : curr.id.clock + curr.length
+    for (; curr !== null; curr = updateDecoder.next()) {
+      if (currClient !== curr.id.client) {
+        if (currClock !== 0) {
+          size++
+          // We found a new client
+          // write what we have to the encoder
+          encoding.writeVarUint(encoder.restEncoder, currClient)
+          encoding.writeVarUint(encoder.restEncoder, currClock)
+        }
+        currClient = curr.id.client
+        currClock = 0
+        stopCounting = curr.id.clock !== 0
+      }
+      // we ignore skips
+      if (curr.constructor === Skip) {
+        stopCounting = true
+      }
+      if (!stopCounting) {
+        currClock = curr.id.clock + curr.length
+      }
+    }
+    // write what we have
+    if (currClock !== 0) {
+      size++
+      encoding.writeVarUint(encoder.restEncoder, currClient)
+      encoding.writeVarUint(encoder.restEncoder, currClock)
+    }
+    // prepend the size of the state vector
+    const enc = encoding.createEncoder()
+    encoding.writeVarUint(enc, size)
+    encoding.writeBinaryEncoder(enc, encoder.restEncoder)
+    encoder.restEncoder = enc
+    return encoder.toUint8Array()
+  } else {
+    encoding.writeVarUint(encoder.restEncoder, 0)
+    return encoder.toUint8Array()
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @return {Uint8Array}
+ */
+export const encodeStateVectorFromUpdate = update => encodeStateVectorFromUpdateV2(update, DSEncoderV1, UpdateDecoderV1)
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} YDecoder
+ * @return {{ from: Map<number,number>, to: Map<number,number> }}
+ */
+export const parseUpdateMetaV2 = (update, YDecoder = UpdateDecoderV2) => {
+  /**
+   * @type {Map<number, number>}
+   */
+  const from = new Map()
+  /**
+   * @type {Map<number, number>}
+   */
+  const to = new Map()
+  const updateDecoder = new LazyStructReader(new YDecoder(decoding.createDecoder(update)), false)
+  let curr = updateDecoder.curr
+  if (curr !== null) {
+    let currClient = curr.id.client
+    let currClock = curr.id.clock
+    // write the beginning to `from`
+    from.set(currClient, currClock)
+    for (; curr !== null; curr = updateDecoder.next()) {
+      if (currClient !== curr.id.client) {
+        // We found a new client
+        // write the end to `to`
+        to.set(currClient, currClock)
+        // write the beginning to `from`
+        from.set(curr.id.client, curr.id.clock)
+        // update currClient
+        currClient = curr.id.client
+      }
+      currClock = curr.id.clock + curr.length
+    }
+    // write the end to `to`
+    to.set(currClient, currClock)
+  }
+  return { from, to }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @return {{ from: Map<number,number>, to: Map<number,number> }}
+ */
+export const parseUpdateMeta = update => parseUpdateMetaV2(update, UpdateDecoderV1)
+
+/**
+ * This method is intended to slice any kind of struct and retrieve the right part.
+ * It does not handle side-effects, so it should only be used by the lazy-encoder.
+ *
+ * @param {Item | GC | Skip} left
+ * @param {number} diff
+ * @return {Item | GC}
+ */
+const sliceStruct = (left, diff) => {
+  if (left.constructor === GC) {
+    const { client, clock } = left.id
+    return new GC(createID(client, clock + diff), left.length - diff)
+  } else if (left.constructor === Skip) {
+    const { client, clock } = left.id
+    return new Skip(createID(client, clock + diff), left.length - diff)
+  } else {
+    const leftItem = /** @type {Item} */ (left)
+    const { client, clock } = leftItem.id
+    return new Item(
+      createID(client, clock + diff),
+      null,
+      createID(client, clock + diff - 1),
+      null,
+      leftItem.rightOrigin,
+      leftItem.parent,
+      leftItem.parentSub,
+      leftItem.content.splice(diff)
+    )
+  }
+}
+
+/**
+ *
+ * This function works similarly to `readUpdateV2`.
+ *
+ * @param {Array<Uint8Array>} updates
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ * @param {typeof UpdateEncoderV1 | typeof UpdateEncoderV2} [YEncoder]
+ * @return {Uint8Array}
+ */
+export const mergeUpdatesV2 = (updates, YDecoder = UpdateDecoderV2, YEncoder = UpdateEncoderV2) => {
+  if (updates.length === 1) {
+    return updates[0]
+  }
+  const updateDecoders = updates.map(update => new YDecoder(decoding.createDecoder(update)))
+  let lazyStructDecoders = updateDecoders.map(decoder => new LazyStructReader(decoder, true))
+
+  /**
+   * @todo we don't need offset because we always slice before
+   * @type {null | { struct: Item | GC | Skip, offset: number }}
+   */
+  let currWrite = null
+
+  const updateEncoder = new YEncoder()
+  // write structs lazily
+  const lazyStructEncoder = new LazyStructWriter(updateEncoder)
+
+  // Note: We need to ensure that all lazyStructDecoders are fully consumed
+  // Note: Should merge document updates whenever possible - even from different updates
+  // Note: Should handle that some operations cannot be applied yet ()
+
+  while (true) {
+    // @todo this incurs an exponential overhead. We could instead only sort the item that changed.
+    // Write higher clients first ⇒ sort by clientID & clock and remove decoders without content
+    lazyStructDecoders = lazyStructDecoders.filter(dec => dec.curr !== null)
+    lazyStructDecoders.sort(
+      /** @type {function(any,any):number} */ (dec1, dec2) => {
+        if (dec1.curr.id.client === dec2.curr.id.client) {
+          const clockDiff = dec1.curr.id.clock - dec2.curr.id.clock
+          if (clockDiff === 0) {
+            // @todo remove references to skip since the structDecoders must filter Skips.
+            return dec1.curr.constructor === dec2.curr.constructor
+              ? 0
+              : dec1.curr.constructor === Skip ? 1 : -1 // we are filtering skips anyway.
+          } else {
+            return clockDiff
+          }
+        } else {
+          return dec2.curr.id.client - dec1.curr.id.client
+        }
+      }
+    )
+    if (lazyStructDecoders.length === 0) {
+      break
+    }
+    const currDecoder = lazyStructDecoders[0]
+    // write from currDecoder until the next operation is from another client or if filler-struct
+    // then we need to reorder the decoders and find the next operation to write
+    const firstClient = /** @type {Item | GC} */ (currDecoder.curr).id.client
+
+    if (currWrite !== null) {
+      let curr = /** @type {Item | GC | null} */ (currDecoder.curr)
+      let iterated = false
+
+      // iterate until we find something that we haven't written already
+      // remember: first the high client-ids are written
+      while (curr !== null && curr.id.clock + curr.length <= currWrite.struct.id.clock + currWrite.struct.length && curr.id.client >= currWrite.struct.id.client) {
+        curr = currDecoder.next()
+        iterated = true
+      }
+      if (
+        curr === null || // current decoder is empty
+        curr.id.client !== firstClient || // check whether there is another decoder that has has updates from `firstClient`
+        (iterated && curr.id.clock > currWrite.struct.id.clock + currWrite.struct.length) // the above while loop was used and we are potentially missing updates
+      ) {
+        continue
+      }
+
+      if (firstClient !== currWrite.struct.id.client) {
+        writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+        currWrite = { struct: curr, offset: 0 }
+        currDecoder.next()
+      } else {
+        if (currWrite.struct.id.clock + currWrite.struct.length < curr.id.clock) {
+          // @todo write currStruct & set currStruct = Skip(clock = currStruct.id.clock + currStruct.length, length = curr.id.clock - self.clock)
+          if (currWrite.struct.constructor === Skip) {
+            // extend existing skip
+            currWrite.struct.length = curr.id.clock + curr.length - currWrite.struct.id.clock
+          } else {
+            writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+            const diff = curr.id.clock - currWrite.struct.id.clock - currWrite.struct.length
+            /**
+             * @type {Skip}
+             */
+            const struct = new Skip(createID(firstClient, currWrite.struct.id.clock + currWrite.struct.length), diff)
+            currWrite = { struct, offset: 0 }
+          }
+        } else { // if (currWrite.struct.id.clock + currWrite.struct.length >= curr.id.clock) {
+          const diff = currWrite.struct.id.clock + currWrite.struct.length - curr.id.clock
+          if (diff > 0) {
+            if (currWrite.struct.constructor === Skip) {
+              // prefer to slice Skip because the other struct might contain more information
+              currWrite.struct.length -= diff
+            } else {
+              curr = sliceStruct(curr, diff)
+            }
+          }
+          if (!currWrite.struct.mergeWith(/** @type {any} */ (curr))) {
+            writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+            currWrite = { struct: curr, offset: 0 }
+            currDecoder.next()
+          }
+        }
+      }
+    } else {
+      currWrite = { struct: /** @type {Item | GC} */ (currDecoder.curr), offset: 0 }
+      currDecoder.next()
+    }
+    for (
+      let next = currDecoder.curr;
+      next !== null && next.id.client === firstClient && next.id.clock === currWrite.struct.id.clock + currWrite.struct.length && next.constructor !== Skip;
+      next = currDecoder.next()
+    ) {
+      writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+      currWrite = { struct: next, offset: 0 }
+    }
+  }
+  if (currWrite !== null) {
+    writeStructToLazyStructWriter(lazyStructEncoder, currWrite.struct, currWrite.offset)
+    currWrite = null
+  }
+  finishLazyStructWriting(lazyStructEncoder)
+
+  const dss = updateDecoders.map(decoder => readDeleteSet(decoder))
+  const ds = mergeDeleteSets(dss)
+  writeDeleteSet(updateEncoder, ds)
+  return updateEncoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {Uint8Array} sv
+ * @param {typeof UpdateDecoderV1 | typeof UpdateDecoderV2} [YDecoder]
+ * @param {typeof UpdateEncoderV1 | typeof UpdateEncoderV2} [YEncoder]
+ */
+export const diffUpdateV2 = (update, sv, YDecoder = UpdateDecoderV2, YEncoder = UpdateEncoderV2) => {
+  const state = decodeStateVector(sv)
+  const encoder = new YEncoder()
+  const lazyStructWriter = new LazyStructWriter(encoder)
+  const decoder = new YDecoder(decoding.createDecoder(update))
+  const reader = new LazyStructReader(decoder, false)
+  while (reader.curr) {
+    const curr = reader.curr
+    const currClient = curr.id.client
+    const svClock = state.get(currClient) || 0
+    if (reader.curr.constructor === Skip) {
+      // the first written struct shouldn't be a skip
+      reader.next()
+      continue
+    }
+    if (curr.id.clock + curr.length > svClock) {
+      writeStructToLazyStructWriter(lazyStructWriter, curr, math.max(svClock - curr.id.clock, 0))
+      reader.next()
+      while (reader.curr && reader.curr.id.client === currClient) {
+        writeStructToLazyStructWriter(lazyStructWriter, reader.curr, 0)
+        reader.next()
+      }
+    } else {
+      // read until something new comes up
+      while (reader.curr && reader.curr.id.client === currClient && reader.curr.id.clock + reader.curr.length <= svClock) {
+        reader.next()
+      }
+    }
+  }
+  finishLazyStructWriting(lazyStructWriter)
+  // write ds
+  const ds = readDeleteSet(decoder)
+  writeDeleteSet(encoder, ds)
+  return encoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {Uint8Array} sv
+ */
+export const diffUpdate = (update, sv) => diffUpdateV2(update, sv, UpdateDecoderV1, UpdateEncoderV1)
+
+/**
+ * @param {LazyStructWriter} lazyWriter
+ */
+const flushLazyStructWriter = lazyWriter => {
+  if (lazyWriter.written > 0) {
+    lazyWriter.clientStructs.push({ written: lazyWriter.written, restEncoder: encoding.toUint8Array(lazyWriter.encoder.restEncoder) })
+    lazyWriter.encoder.restEncoder = encoding.createEncoder()
+    lazyWriter.written = 0
+  }
+}
+
+/**
+ * @param {LazyStructWriter} lazyWriter
+ * @param {Item | GC} struct
+ * @param {number} offset
+ */
+const writeStructToLazyStructWriter = (lazyWriter, struct, offset) => {
+  // flush curr if we start another client
+  if (lazyWriter.written > 0 && lazyWriter.currClient !== struct.id.client) {
+    flushLazyStructWriter(lazyWriter)
+  }
+  if (lazyWriter.written === 0) {
+    lazyWriter.currClient = struct.id.client
+    // write next client
+    lazyWriter.encoder.writeClient(struct.id.client)
+    // write startClock
+    encoding.writeVarUint(lazyWriter.encoder.restEncoder, struct.id.clock + offset)
+  }
+  struct.write(lazyWriter.encoder, offset)
+  lazyWriter.written++
+}
+/**
+ * Call this function when we collected all parts and want to
+ * put all the parts together. After calling this method,
+ * you can continue using the UpdateEncoder.
+ *
+ * @param {LazyStructWriter} lazyWriter
+ */
+const finishLazyStructWriting = (lazyWriter) => {
+  flushLazyStructWriter(lazyWriter)
+
+  // this is a fresh encoder because we called flushCurr
+  const restEncoder = lazyWriter.encoder.restEncoder
+
+  /**
+   * Now we put all the fragments together.
+   * This works similarly to `writeClientsStructs`
+   */
+
+  // write # states that were updated - i.e. the clients
+  encoding.writeVarUint(restEncoder, lazyWriter.clientStructs.length)
+
+  for (let i = 0; i < lazyWriter.clientStructs.length; i++) {
+    const partStructs = lazyWriter.clientStructs[i]
+    /**
+     * Works similarly to `writeStructs`
+     */
+    // write # encoded structs
+    encoding.writeVarUint(restEncoder, partStructs.written)
+    // write the rest of the fragment
+    encoding.writeUint8Array(restEncoder, partStructs.restEncoder)
+  }
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {typeof UpdateDecoderV2 | typeof UpdateDecoderV1} YDecoder
+ * @param {typeof UpdateEncoderV2 | typeof UpdateEncoderV1 } YEncoder
+ */
+export const convertUpdateFormat = (update, YDecoder, YEncoder) => {
+  const updateDecoder = new YDecoder(decoding.createDecoder(update))
+  const lazyDecoder = new LazyStructReader(updateDecoder, false)
+  const updateEncoder = new YEncoder()
+  const lazyWriter = new LazyStructWriter(updateEncoder)
+
+  for (let curr = lazyDecoder.curr; curr !== null; curr = lazyDecoder.next()) {
+    writeStructToLazyStructWriter(lazyWriter, curr, 0)
+  }
+  finishLazyStructWriting(lazyWriter)
+  const ds = readDeleteSet(updateDecoder)
+  writeDeleteSet(updateEncoder, ds)
+  return updateEncoder.toUint8Array()
+}
+
+/**
+ * @param {Uint8Array} update
+ */
+export const convertUpdateFormatV1ToV2 = update => convertUpdateFormat(update, UpdateDecoderV1, UpdateEncoderV2)
+
+/**
+ * @param {Uint8Array} update
+ */
+export const convertUpdateFormatV2ToV1 = update => convertUpdateFormat(update, UpdateDecoderV2, UpdateEncoderV1)

test.html

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Testing Yjs</title>
+</head>
+<body>
+  <script type="module" src="./dist/tests.js"></script>
+</body>
+</html>

test/TestSuite.coffee

@@ -1,219 +0,0 @@
-chai      = require('chai')
-expect    = chai.expect
-sinon     = require('sinon')
-sinonChai = require('sinon-chai')
-_         = require("underscore")
-
-chai.use(sinonChai)
-
-Connector = require "../../y-test/lib/y-test.coffee"
-Y = null # need global reference!
-
-module.exports = class Test
-  constructor: (@name_suffix = "", Yjs)->
-    Y = Yjs
-    @number_of_test_cases_multiplier = 1
-    @repeat_this = 1 * @number_of_test_cases_multiplier
-    @doSomething_amount = 123 * @number_of_test_cases_multiplier
-    @number_of_engines = 5 + @number_of_test_cases_multiplier - 1
-
-    @time = 0 # denotes to the time when run was started
-    @ops = 0 # number of operations (used with @time)
-    @time_now = 0 # current time
-    @max_depth = 3
-
-    @debug = false
-
-    @reinitialize()
-    for gf in @getGeneratingFunctions(0)
-      if not (gf.types? and gf.f?)
-        throw new Error "Generating Functions are not initialized properly!"
-      for t in gf.types
-        if not t?
-          throw new Error "You havent includedt this type in Y (do require 'y-whatever')"
-
-  reinitialize: ()->
-    @users = []
-    for i in [0...@number_of_engines]
-      u = @makeNewUser (i+@name_suffix)
-      for user in @users
-        u._model.connector.join(user._model.connector) # TODO: change the test-connector to make this more convenient
-      @users.push u
-    @initUsers?(@users[0])
-    @flushAll()
-
-  # is called by implementing class
-  makeNewUser: (user)->
-    user._model.HB.stopGarbageCollection()
-    user
-
-  getSomeUser: ()->
-    i = _.random 0, (@users.length-1)
-    @users[i]
-
-  getRandomText: (chars, min_length = 0)->
-    chars ?= "abcdefghijklmnopqrstuvwxyz"
-    length = _.random min_length, 10
-    #length = 1
-    nextchar = chars[(_.random 0, (chars.length-1))]
-    text = ""
-    _(length).times ()-> text += nextchar
-    text
-
-  getRandomObject: ()->
-    result = {}
-    key1 = @getRandomKey()
-    key2 = @getRandomKey()
-    val1 = @getRandomText()
-    val2 = null
-    if _.random(0,1) is 1
-      val2 = @getRandomObject()
-    else
-      val2 = @getRandomText()
-    result[key1] = val1
-    result[key2] = val2
-    result
-
-  getRandomKey: ()->
-    @getRandomText [1,2,'x','y'], 1 # only 4 keys
-
-  getGeneratingFunctions: (user_num)=>
-    types = @users[user_num]._model.operations
-    []
-  getRandomRoot: (user_num)->
-    throw new Error "implement me!"
-
-  compare: (o1, o2, depth = (@max_depth+1))->
-    if o1 is o2 or depth <= 0
-      true
-    else if o1._name? and o1._name isnt o2._name
-      throw new Error "different types"
-    else if o1._model?
-      @compare o1._model, o2._model, depth
-    else if o1.type is "MapManager"
-      for name, val of o1.val()
-        @compare(val, o2.val(name), depth-1)
-    else if o1.type is "ListManager"
-      for val,i in o1.val()
-        @compare(val, o2.val(i), depth-1)
-    else if o1.constructor is Array and o2.constructor is Array
-      if o1.length isnt o2.length
-        throw new Error "The Arrays do not have the same size!"
-      for o,i in o1
-        @compare o, o2[i], (depth-1)
-    else if o1 isnt o2
-      throw new Error "different values"
-    else
-      throw new Error "I don't know what to do .. "
-
-  generateRandomOp: (user_num)=>
-    y = @getRandomRoot(user_num)
-    choices = @getGeneratingFunctions(user_num).filter (gf)->
-      _.some gf.types, (type)->
-        y instanceof type
-
-    if choices.length is 0
-      console.dir(y)
-      throw new Error "You forgot to specify a test generation methot for this Operation! (#{y.type})"
-    i = _.random 0, (choices.length-1)
-    choices[i].f y
-
-  applyRandomOp: (user_num)=>
-    user = @users[user_num]
-    user._model.connector.flushOneRandom()
-
-  doSomething: ()->
-    user_num = _.random (@number_of_engines-1)
-    choices = [@applyRandomOp, @generateRandomOp]
-    choice = _.random (choices.length-1)
-    choices[choice](user_num)
-
-  flushAll: (final)->
-    # TODO:!!
-    final = false
-    if @users.length <= 1 or not final
-      for user,user_number in @users
-        user._model.connector.flushAll()
-    else
-      for user,user_number in @users[1..]
-        user._model.connector.flushAll()
-      ops = @users[1].getHistoryBuffer()._encode @users[0].HB.getOperationCounter()
-      @users[0].engine.applyOpsCheckDouble ops
-
-
-  compareAll: (test_number)->
-    @flushAll(true)
-
-    @time += (new Date()).getTime() - @time_now
-
-    number_of_created_operations = 0
-    for i in [0...(@users.length)]
-      number_of_created_operations += @users[i]._model.connector.getOpsInExecutionOrder().length
-    @ops += number_of_created_operations*@users.length
-
-    ops_per_msek = Math.floor(@ops/@time)
-    if test_number? # and @debug
-      console.log "#{test_number}/#{@repeat_this}: #{number_of_created_operations} were created and applied on (#{@users.length}) users ops in a different order." + " Over all we consumed #{@ops} operations in #{@time/1000} seconds (#{ops_per_msek} ops/msek)."
-
-    for i in [0...(@users.length-1)]
-      if @debug
-        if not _.isEqual @getContent(i), @getContent(i+1)
-          printOpsInExecutionOrder = (otnumber, otherotnumber)=>
-            ops = _.filter @users[otnumber]._model.connector.getOpsInExecutionOrder(), (o)->
-              typeof o.uid.op_name isnt 'string' and o.uid.creator isnt '_'
-            for s,j in ops
-              console.log "op#{j} = " + (JSON.stringify s)
-            console.log ""
-            s = "ops = ["
-            for o,j in ops
-              if j isnt 0
-                s += ", "
-              s += "op#{j}"
-            s += "]"
-            console.log s
-            console.log "@test_user.engine.applyOps ops"
-            console.log "expect(@test_user.val('name').val()).to.equal(\"#{@users[otherotnumber].val('name').val()}\")"
-            ops
-          console.log ""
-          console.log "Found an OT Puzzle!"
-          console.log "OT states:"
-          for u,j in @users
-            console.log "OT#{j}: "+u.val('name').val()
-          console.log "\nOT execution order (#{i},#{i+1}):"
-          printOpsInExecutionOrder i, i+1
-          console.log ""
-          ops = printOpsInExecutionOrder i+1, i
-
-          console.log ""
-      expect(@compare(@users[i], @users[i+1])).to.not.be.undefined
-
-  run: ()->
-    if @debug
-      console.log ''
-    for times in [1..@repeat_this]
-      @time_now = (new Date).getTime()
-      for i in [1..Math.floor(@doSomething_amount/2)]
-        @doSomething()
-      @flushAll(false)
-      for u in @users
-        u._model.HB.emptyGarbage()
-      for i in [1..Math.floor(@doSomething_amount/2)]
-        @doSomething()
-
-      @compareAll(times)
-      @testHBencoding()
-      if times isnt @repeat_this
-        @reinitialize()
-
-  testHBencoding: ()->
-    # in case of JsonFramework, every user will create its JSON first! therefore, the testusers id must be small than all the others (see InsertType)
-    @users[@users.length] = @makeNewUser (-1) # this does not want to join with anymody
-
-    @users[@users.length-1]._model.HB.renewStateVector @users[0]._model.HB.getOperationCounter()
-    @users[@users.length-1]._model.engine.applyOps @users[0]._model.HB._encode()
-
-    #if @getContent(@users.length-1) isnt @getContent(0)
-    #  console.log "testHBencoding:"
-    #  console.log "Unprocessed ops first: #{@users[0].engine.unprocessed_ops.length}"
-    #  console.log "Unprocessed ops last: #{@users[@users.length-1].engine.unprocessed_ops.length}"
-    expect(@compare(@users[@users.length-1], @users[0])).to.not.be.undefined

test/object-test.coffee

@@ -1,324 +0,0 @@
-chai      = require('chai')
-expect    = chai.expect
-should    = chai.should()
-sinon     = require('sinon')
-sinonChai = require('sinon-chai')
-_         = require("underscore")
-
-chai.use(sinonChai)
-
-Y = require "../lib/y.coffee"
-Y.Test = require "../../y-test/lib/y-test.coffee"
-Y.Text = require "../../y-text/lib/y-text"
-Y.List = require "../../y-list/lib/y-list"
-
-TestSuite = require "./TestSuite"
-class ObjectTest extends TestSuite
-
-  constructor: (suffix)->
-    super suffix, Y
-
-  makeNewUser: (userId)->
-    conn = new Y.Test userId
-    super new Y conn
-
-  type: "ObjectTest"
-
-  getRandomRoot: (user_num, root, depth = @max_depth)->
-    root ?= @users[user_num]
-    if depth is 0 or _.random(0,1) is 1 # take root
-      root
-    else # take child
-      depth--
-      elems = null
-      if root._name is "Object"
-        elems =
-          for oname,val of root.val()
-            val
-      else if root._name is "Array"
-        elems = root.val()
-      else
-        return root
-
-      elems = elems.filter (elem)->
-        elem? and ((elem._name is "Array") or (elem._name is "Object"))
-      if elems.length is 0
-        root
-      else
-        p = elems[_.random(0, elems.length-1)]
-        @getRandomRoot user_num, p, depth
-
-  getGeneratingFunctions: (user_num)->
-    super(user_num).concat [
-        f : (y)=> # Delete Object Property
-          list = for name, o of y.val()
-            name
-          if list.length > 0
-            key = list[_.random(0,list.length-1)]
-            y.delete(key)
-        types: [Y.Object]
-      ,
-        f : (y)=> # SET Object Property
-          y.val(@getRandomKey(), new Y.Object(@getRandomObject()))
-        types: [Y.Object]
-      ,
-        f : (y)=> # SET PROPERTY TEXT
-          y.val(@getRandomKey(), new Y.Text(@getRandomText()))
-        types: [Y.Object]
-      ,
-        f : (y)=> # SET PROPERTY List
-          y.val(@getRandomKey(), new Y.List(@getRandomText().split("")))
-        types: [Y.Object]
-      ,
-        f : (y)=> # Delete Array Element
-          list = y.val()
-          if list.length > 0
-            i = _.random(0,list.length-1)
-            y.delete(i)
-        types: [Y.List]
-      ,
-        f : (y)=> # insert Object mutable
-          l = y.val().length
-          y.insert(_.random(0, l-1), new Y.Object(@getRandomObject()))
-        types: [Y.List]
-      ,
-        f : (y)=> # insert Text mutable
-          l = y.val().length
-          y.insert(_.random(0, l-1), new Y.Text(@getRandomText()))
-        types : [Y.List]
-      ,
-        f : (y)=> # insert List mutable
-          l = y.val().length
-          y.insert(_.random(0, l-1), new Y.List(@getRandomText().split("")))
-        types : [Y.List]
-      ,
-        f : (y)=> # insert Number (primitive object)
-          l = y.val().length
-          y.insert(_.random(0,l-1), _.random(0,42))
-        types : [Y.List]
-      ,
-        f : (y)=> # SET Object Property (circular)
-          y.val(@getRandomKey(), @getRandomRoot user_num)
-        types: [Y.Object]
-      ,
-        f : (y)=> # insert Object mutable (circular)
-          l = y.val().length
-          y.insert(_.random(0, l-1), @getRandomRoot user_num)
-        types: [Y.List]
-      ,
-        f : (y)=> # INSERT TEXT
-          y
-          pos = _.random 0, (y.val().length-1)
-          y.insert pos, @getRandomText()
-          null
-        types: [Y.Text]
-      ,
-        f : (y)-> # DELETE TEXT
-          if y.val().length > 0
-            pos = _.random 0, (y.val().length-1) # TODO: put here also arbitrary number (test behaviour in error cases)
-            length = _.random 0, (y.val().length - pos)
-            ops1 = y.delete pos, length
-          undefined
-        types : [Y.Text]
-      ]
-
-module.exports = ObjectTest
-
-describe "Object Test", ->
-  @timeout 500000
-
-  beforeEach (done)->
-    @yTest = new ObjectTest()
-    @users = @yTest.users
-
-    @test_user = @yTest.makeNewUser "test_user"
-    done()
-
-  it "can handle many engines, many operations, concurrently (random)", ->
-    console.log "" # TODO
-    @yTest.run()
-
-  it "has a working test suite", ->
-    @yTest.compareAll()
-
-  it "handles double-late-join", ->
-    test = new ObjectTest("double")
-    test.run()
-    @yTest.run()
-    u1 = test.users[0]
-    u2 = @yTest.users[1]
-    ops1 = u1._model.HB._encode()
-    ops2 = u2._model.HB._encode()
-    u1._model.engine.applyOp ops2, true
-    u2._model.engine.applyOp ops1, true
-
-    expect(@yTest.compare(u1, u2)).to.not.be.undefined
-
-  it "can handle creaton of complex json (1)", ->
-    @yTest.users[0].val('a', new Y.Text('q'))
-    @yTest.users[1].val('a', new Y.Text('t'))
-    @yTest.compareAll()
-    q = @yTest.users[2].val('a')
-    q.insert(0,'A')
-    @yTest.compareAll()
-    expect(@yTest.getSomeUser().val("a").val()).to.equal("At")
-
-  it "can handle creaton of complex json (2)", ->
-    @yTest.getSomeUser().val('x', new Y.Object({'a':'b'}))
-    @yTest.getSomeUser().val('a', new Y.Object({'a':{q: new Y.Text("dtrndtrtdrntdrnrtdnrtdnrtdnrtdnrdnrdt")}}))
-    @yTest.getSomeUser().val('b', new Y.Object({'a':{}}))
-    @yTest.getSomeUser().val('c', new Y.Object({'a':'c'}))
-    @yTest.getSomeUser().val('c', new Y.Object({'a':'b'}))
-    @yTest.compareAll()
-    q = @yTest.getSomeUser().val("a").val("a").val("q")
-    q.insert(0,'A')
-    @yTest.compareAll()
-    expect(@yTest.getSomeUser().val("a").val("a").val("q").val()).to.equal("Adtrndtrtdrntdrnrtdnrtdnrtdnrtdnrdnrdt")
-
-  it "can handle creaton of complex json (3)", ->
-    @yTest.users[0].val('l', new Y.List([1,2,3]))
-    @yTest.users[1].val('l', new Y.List([4,5,6]))
-    @yTest.compareAll()
-    @yTest.users[2].val('l').insert(0,'A')
-    w = @yTest.users[1].val('l').insert(0,new Y.Text('B')).val(0)
-    w.insert 1, "C"
-    expect(w.val()).to.equal("BC")
-    @yTest.compareAll()
-
-  it "handles immutables and primitive data types", ->
-    @yTest.getSomeUser().val('string', "text")
-    @yTest.getSomeUser().val('number', 4)
-    @yTest.getSomeUser().val('object', new Y.Object({q:"rr"}))
-    @yTest.getSomeUser().val('null', null)
-    @yTest.compareAll()
-    expect(@yTest.getSomeUser().val('string')).to.equal "text"
-    expect(@yTest.getSomeUser().val('number')).to.equal 4
-    expect(@yTest.getSomeUser().val('object').val('q')).to.equal "rr"
-    expect(@yTest.getSomeUser().val('null') is null).to.be.ok
-
-  it "handles immutables and primitive data types (2)", ->
-    @yTest.users[0].val('string', "text")
-    @yTest.users[1].val('number', 4)
-    @yTest.users[2].val('object', new Y.Object({q:"rr"}))
-    @yTest.users[0].val('null', null)
-    @yTest.compareAll()
-    expect(@yTest.getSomeUser().val('string')).to.equal "text"
-    expect(@yTest.getSomeUser().val('number')).to.equal 4
-    expect(@yTest.getSomeUser().val('object').val('q')).to.equal "rr"
-    expect(@yTest.getSomeUser().val('null') is null).to.be.ok
-
-  it "Observers work on JSON Types (add type observers, local and foreign)", ->
-    u = @yTest.users[0]
-    @yTest.flushAll()
-    last_task = null
-    observer1 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("add")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('0')
-      expect(change.name).to.equal("newStuff")
-      last_task = "observer1"
-    u.observe observer1
-    u.val("newStuff",new Y.Text("someStuff"))
-    expect(last_task).to.equal("observer1")
-    u.unobserve observer1
-
-    observer2 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("add")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('1')
-      expect(change.name).to.equal("moreStuff")
-      last_task = "observer2"
-    u.observe observer2
-    v = @yTest.users[1]
-    v.val("moreStuff","someMoreStuff")
-    @yTest.flushAll()
-    expect(last_task).to.equal("observer2")
-    u.unobserve observer2
-
-  it "Observers work on JSON Types (update type observers, local and foreign)", ->
-    u = @yTest.users[0].val("newStuff", new Y.Text("oldStuff")).val("moreStuff",new Y.Text("moreOldStuff"))
-    @yTest.flushAll()
-    last_task = null
-    observer1 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("update")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('0')
-      expect(change.name).to.equal("newStuff")
-      expect(change.oldValue.val()).to.equal("oldStuff")
-      last_task = "observer1"
-    u.observe observer1
-    u.val("newStuff","someStuff")
-    expect(last_task).to.equal("observer1")
-    u.unobserve observer1
-
-    observer2 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("update")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('1')
-      expect(change.name).to.equal("moreStuff")
-      expect(change.oldValue.val()).to.equal("moreOldStuff")
-      last_task = "observer2"
-    u.observe observer2
-    v = @yTest.users[1]
-    v.val("moreStuff","someMoreStuff")
-    @yTest.flushAll()
-    expect(last_task).to.equal("observer2")
-    u.unobserve observer2
-
-
-  it "Observers work on JSON Types (delete type observers, local and foreign)", ->
-    u = @yTest.users[0].val("newStuff",new Y.Text("oldStuff")).val("moreStuff",new Y.Text("moreOldStuff"))
-    @yTest.flushAll()
-    last_task = null
-    observer1 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("delete")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('0')
-      expect(change.name).to.equal("newStuff")
-      expect(change.oldValue.val()).to.equal("oldStuff")
-      last_task = "observer1"
-    u.observe observer1
-    u.delete("newStuff")
-    expect(last_task).to.equal("observer1")
-    u.unobserve observer1
-
-    observer2 = (changes)->
-      expect(changes.length).to.equal(1)
-      change = changes[0]
-      expect(change.type).to.equal("delete")
-      expect(change.object).to.equal(u)
-      expect(change.changedBy).to.equal('1')
-      expect(change.name).to.equal("moreStuff")
-      expect(change.oldValue.val()).to.equal("moreOldStuff")
-      last_task = "observer2"
-    u.observe observer2
-    v = @yTest.users[1]
-    v.delete("moreStuff")
-    @yTest.flushAll()
-    expect(last_task).to.equal("observer2")
-    u.unobserve observer2
-
-  it "can handle circular JSON", ->
-    u = @yTest.users[0]
-    u.val("me", u)
-    @yTest.compareAll()
-    u.val("stuff", new Y.Object({x: true}))
-    u.val("same_stuff", u.val("stuff"))
-    u.val("same_stuff").val("x", 5)
-    expect(u.val("same_stuff").val("x")).to.equal(5)
-    @yTest.compareAll()
-    u.val("stuff").val("y", u.val("stuff"))
-    @yTest.compareAll()
-
-
-

tests/doc.tests.js

@@ -0,0 +1,247 @@
+
+import * as Y from '../src/index.js'
+import * as t from 'lib0/testing'
+
+/**
+ * Client id should be changed when an instance receives updates from another client using the same client id.
+ *
+ * @param {t.TestCase} tc
+ */
+export const testClientIdDuplicateChange = tc => {
+  const doc1 = new Y.Doc()
+  doc1.clientID = 0
+  const doc2 = new Y.Doc()
+  doc2.clientID = 0
+  t.assert(doc2.clientID === doc1.clientID)
+  doc1.getArray('a').insert(0, [1, 2])
+  Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc1))
+  t.assert(doc2.clientID !== doc1.clientID)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testGetTypeEmptyId = tc => {
+  const doc1 = new Y.Doc()
+  doc1.getText('').insert(0, 'h')
+  doc1.getText().insert(1, 'i')
+  const doc2 = new Y.Doc()
+  Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc1))
+  t.assert(doc2.getText().toString() === 'hi')
+  t.assert(doc2.getText('').toString() === 'hi')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testToJSON = tc => {
+  const doc = new Y.Doc()
+  t.compare(doc.toJSON(), {}, 'doc.toJSON yields empty object')
+
+  const arr = doc.getArray('array')
+  arr.push(['test1'])
+  t.compare(arr.toJSON(), ['test1'])
+
+  const map = doc.getMap('map')
+  map.set('k1', 'v1')
+  const map2 = new Y.Map()
+  map.set('k2', map2)
+  map2.set('m2k1', 'm2v1')
+
+  t.compare(doc.toJSON(), {
+    array: ['test1'],
+    map: {
+      k1: 'v1',
+      k2: {
+        m2k1: 'm2v1'
+      }
+    }
+  }, 'doc.toJSON has array and recursive map')
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdoc = tc => {
+  const doc = new Y.Doc()
+  doc.load() // doesn't do anything
+  {
+    /**
+     * @type {Array<any>|null}
+     */
+    let event = /** @type {any} */ (null)
+    doc.on('subdocs', subdocs => {
+      event = [Array.from(subdocs.added).map(x => x.guid), Array.from(subdocs.removed).map(x => x.guid), Array.from(subdocs.loaded).map(x => x.guid)]
+    })
+    const subdocs = doc.getMap('mysubdocs')
+    const docA = new Y.Doc({ guid: 'a' })
+    docA.load()
+    subdocs.set('a', docA)
+    t.compare(event, [['a'], [], ['a']])
+
+    event = null
+    subdocs.get('a').load()
+    t.assert(event === null)
+
+    event = null
+    subdocs.get('a').destroy()
+    t.compare(event, [['a'], ['a'], []])
+    subdocs.get('a').load()
+    t.compare(event, [[], [], ['a']])
+
+    subdocs.set('b', new Y.Doc({ guid: 'a', shouldLoad: false }))
+    t.compare(event, [['a'], [], []])
+    subdocs.get('b').load()
+    t.compare(event, [[], [], ['a']])
+
+    const docC = new Y.Doc({ guid: 'c' })
+    docC.load()
+    subdocs.set('c', docC)
+    t.compare(event, [['c'], [], ['c']])
+
+    t.compare(Array.from(doc.getSubdocGuids()), ['a', 'c'])
+  }
+
+  const doc2 = new Y.Doc()
+  {
+    t.compare(Array.from(doc2.getSubdocs()), [])
+    /**
+     * @type {Array<any>|null}
+     */
+    let event = /** @type {any} */ (null)
+    doc2.on('subdocs', subdocs => {
+      event = [Array.from(subdocs.added).map(d => d.guid), Array.from(subdocs.removed).map(d => d.guid), Array.from(subdocs.loaded).map(d => d.guid)]
+    })
+    Y.applyUpdate(doc2, Y.encodeStateAsUpdate(doc))
+    t.compare(event, [['a', 'a', 'c'], [], []])
+
+    doc2.getMap('mysubdocs').get('a').load()
+    t.compare(event, [[], [], ['a']])
+
+    t.compare(Array.from(doc2.getSubdocGuids()), ['a', 'c'])
+
+    doc2.getMap('mysubdocs').delete('a')
+    t.compare(event, [[], ['a'], []])
+    t.compare(Array.from(doc2.getSubdocGuids()), ['a', 'c'])
+  }
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocLoadEdgeCases = tc => {
+  const ydoc = new Y.Doc()
+  const yarray = ydoc.getArray()
+  const subdoc1 = new Y.Doc()
+  /**
+   * @type {any}
+   */
+  let lastEvent = null
+  ydoc.on('subdocs', event => {
+    lastEvent = event
+  })
+  yarray.insert(0, [subdoc1])
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad === false)
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc1))
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc1))
+  // destroy and check whether lastEvent adds it again to added (it shouldn't)
+  subdoc1.destroy()
+  const subdoc2 = yarray.get(0)
+  t.assert(subdoc1 !== subdoc2)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc2))
+  // load
+  subdoc2.load()
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc2))
+  // apply from remote
+  const ydoc2 = new Y.Doc()
+  ydoc2.on('subdocs', event => {
+    lastEvent = event
+  })
+  Y.applyUpdate(ydoc2, Y.encodeStateAsUpdate(ydoc))
+  const subdoc3 = ydoc2.getArray().get(0)
+  t.assert(subdoc3.shouldLoad === false)
+  t.assert(subdoc3.autoLoad === false)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc3))
+  // load
+  subdoc3.load()
+  t.assert(subdoc3.shouldLoad)
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc3))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocLoadEdgeCasesAutoload = tc => {
+  const ydoc = new Y.Doc()
+  const yarray = ydoc.getArray()
+  const subdoc1 = new Y.Doc({ autoLoad: true })
+  /**
+   * @type {any}
+   */
+  let lastEvent = null
+  ydoc.on('subdocs', event => {
+    lastEvent = event
+  })
+  yarray.insert(0, [subdoc1])
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad)
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc1))
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc1))
+  // destroy and check whether lastEvent adds it again to added (it shouldn't)
+  subdoc1.destroy()
+  const subdoc2 = yarray.get(0)
+  t.assert(subdoc1 !== subdoc2)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && !lastEvent.loaded.has(subdoc2))
+  // load
+  subdoc2.load()
+  t.assert(lastEvent !== null && !lastEvent.added.has(subdoc2))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc2))
+  // apply from remote
+  const ydoc2 = new Y.Doc()
+  ydoc2.on('subdocs', event => {
+    lastEvent = event
+  })
+  Y.applyUpdate(ydoc2, Y.encodeStateAsUpdate(ydoc))
+  const subdoc3 = ydoc2.getArray().get(0)
+  t.assert(subdoc1.shouldLoad)
+  t.assert(subdoc1.autoLoad)
+  t.assert(lastEvent !== null && lastEvent.added.has(subdoc3))
+  t.assert(lastEvent !== null && lastEvent.loaded.has(subdoc3))
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testSubdocsUndo = tc => {
+  const ydoc = new Y.Doc()
+  const elems = ydoc.getXmlFragment()
+  const undoManager = new Y.UndoManager(elems)
+  const subdoc = new Y.Doc()
+  // @ts-ignore
+  elems.insert(0, [subdoc])
+  undoManager.undo()
+  undoManager.redo()
+  t.assert(elems.length === 1)
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testLoadDocs = async tc => {
+  const ydoc = new Y.Doc()
+  t.assert(ydoc.isLoaded === false)
+  let loadedEvent = false
+  ydoc.on('load', () => {
+    loadedEvent = true
+  })
+  ydoc.emit('load', [ydoc])
+  await ydoc.whenLoaded
+  t.assert(loadedEvent)
+  t.assert(ydoc.isLoaded)
+}

tests/encoding.tests.js

@@ -0,0 +1,111 @@
+import * as t from 'lib0/testing'
+import * as promise from 'lib0/promise'
+
+import {
+  contentRefs,
+  readContentBinary,
+  readContentDeleted,
+  readContentString,
+  readContentJSON,
+  readContentEmbed,
+  readContentType,
+  readContentFormat,
+  readContentAny,
+  readContentDoc,
+  readContentMove,
+  Doc,
+  PermanentUserData,
+  encodeStateAsUpdate,
+  applyUpdate
+} from '../src/internals.js'
+
+import * as Y from '../src/index.js'
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testStructReferences = tc => {
+  t.assert(contentRefs.length === 12)
+  // contentRefs[0] is reserved for GC
+  t.assert(contentRefs[1] === readContentDeleted)
+  t.assert(contentRefs[2] === readContentJSON) // TODO: deprecate content json?
+  t.assert(contentRefs[3] === readContentBinary)
+  t.assert(contentRefs[4] === readContentString)
+  t.assert(contentRefs[5] === readContentEmbed)
+  t.assert(contentRefs[6] === readContentFormat)
+  t.assert(contentRefs[7] === readContentType)
+  t.assert(contentRefs[8] === readContentAny)
+  t.assert(contentRefs[9] === readContentDoc)
+  // contentRefs[10] is reserved for Skip structs
+  t.assert(contentRefs[11] === readContentMove)
+}
+
+/**
+ * There is some custom encoding/decoding happening in PermanentUserData.
+ * This is why it landed here.
+ *
+ * @param {t.TestCase} tc
+ */
+export const testPermanentUserData = async tc => {
+  const ydoc1 = new Doc()
+  const ydoc2 = new Doc()
+  const pd1 = new PermanentUserData(ydoc1)
+  const pd2 = new PermanentUserData(ydoc2)
+  pd1.setUserMapping(ydoc1, ydoc1.clientID, 'user a')
+  pd2.setUserMapping(ydoc2, ydoc2.clientID, 'user b')
+  ydoc1.getText().insert(0, 'xhi')
+  ydoc1.getText().delete(0, 1)
+  ydoc2.getText().insert(0, 'hxxi')
+  ydoc2.getText().delete(1, 2)
+  await promise.wait(10)
+  applyUpdate(ydoc2, encodeStateAsUpdate(ydoc1))
+  applyUpdate(ydoc1, encodeStateAsUpdate(ydoc2))
+
+  // now sync a third doc with same name as doc1 and then create PermanentUserData
+  const ydoc3 = new Doc()
+  applyUpdate(ydoc3, encodeStateAsUpdate(ydoc1))
+  const pd3 = new PermanentUserData(ydoc3)
+  pd3.setUserMapping(ydoc3, ydoc3.clientID, 'user a')
+}
+
+/**
+ * Reported here: https://github.com/yjs/yjs/issues/308
+ * @param {t.TestCase} tc
+ */
+export const testDiffStateVectorOfUpdateIsEmpty = tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {null | Uint8Array}
+   */
+  let sv = /** @type {any} */ (null)
+  ydoc.getText().insert(0, 'a')
+  ydoc.on('update', update => {
+    sv = Y.encodeStateVectorFromUpdate(update)
+  })
+  // should produce an update with an empty state vector (because previous ops are missing)
+  ydoc.getText().insert(0, 'a')
+  t.assert(sv !== null && sv.byteLength === 1 && sv[0] === 0)
+}
+
+/**
+ * Reported here: https://github.com/yjs/yjs/issues/308
+ * @param {t.TestCase} tc
+ */
+export const testDiffStateVectorOfUpdateIgnoresSkips = tc => {
+  const ydoc = new Y.Doc()
+  /**
+   * @type {Array<Uint8Array>}
+   */
+  const updates = []
+  ydoc.on('update', update => {
+    updates.push(update)
+  })
+  ydoc.getText().insert(0, 'a')
+  ydoc.getText().insert(0, 'b')
+  ydoc.getText().insert(0, 'c')
+  const update13 = Y.mergeUpdates([updates[0], updates[2]])
+  const sv = Y.encodeStateVectorFromUpdate(update13)
+  const state = Y.decodeStateVector(sv)
+  t.assert(state.get(ydoc.clientID) === 1)
+  t.assert(state.size === 1)
+}