204 changed files with 19843 additions and 24030 deletions
--- a/.esdoc.json
+++ b/.esdoc.json
@ -0,0 +1,10 @@
+{
+  "source": "./src",
+  "destination": "./docs",
+  "plugins": [{
+    "name": "esdoc-standard-plugin",
+    "option": {
+      "accessor": {"access": ["public"], "autoPrivate": true}
+    }
+  }]
+}
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@ -1,31 +0,0 @@
-# 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: [16.x, 20.x]
-
-    steps:
-    - uses: actions/checkout@v4
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v3
-      with:
-        node-version: ${{ matrix.node-version }}
-    - run: npm ci
-    - run: npm run lint
-    - run: npm run test
-      env:
-        CI: true
--- a/.gitignore
+++ b/.gitignore
@ -1,4 +1,8 @@
 node_modules
-dist
-.vscode
+bower_components
 docs
+/y.*
+/examples/yjs-dist.js*
+.vscode
+.yjsPersisted
+build
--- a/.jsdoc.json
+++ b/.jsdoc.json
@ -1,52 +0,0 @@
-{
-  "sourceType": "module",
-  "tags": {
-    "allowUnknownTags": true,
-    "dictionaries": ["jsdoc"]
-  },
-  "source": {
-    "include": ["./src"],
-    "includePattern": ".js$"
-  },
-  "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"
-  }
-}
--- a/.markdownlint.json
+++ b/.markdownlint.json
@ -1,4 +0,0 @@
-{
-  "default": true,
-  "no-inline-html": false
-}
--- a/INTERNALS.md
+++ b/INTERNALS.md
@ -1,179 +0,0 @@
-# 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 \[JavaScript uses IEEE 754 floats\]).
-
-## 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 preceding 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 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 80 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 update that allows clients to sync with each other.
-The update object is a Uint8Array that efficiently encodes `Item` objects and
-the delete set.
-* `state vector`: A state vector defines the known state of each user (a set of
-  tuples `(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`. A 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.
--- a/4
+++ b/4
@ -1,7 +1,7 @@
 The MIT License (MIT)

-Copyright (c) 2023
-  - Kevin Jahns <kevin.jahns@protonmail.com>.
+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
--- a/README.md
+++ b/README.md
--- a/examples/ace/index.html
+++ b/examples/ace/index.html
@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <style type="text/css" media="screen">
+    #aceContainer {
+        position: absolute;
+        top: 0;
+        right: 0;
+        bottom: 0;
+        left: 0;
+    }
+    .inserted {
+      position:absolute;
+      z-index:20;
+      background-color: #FFC107;
+    }
+    .deleted {
+      position:absolute;
+      z-index:20;
+      background-color: #FFC107;
+    }
+    </style>
+  </head>
+  <body>
+
+    <div id="aceContainer"></div>
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src="../bower_components/ace-builds/src/ace.js"></script>
+
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/ace/index.js
+++ b/examples/ace/index.js
@ -0,0 +1,17 @@
+/* global Y, ace */
+
+let y = new Y('ace-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yAce = y
+
+// bind the textarea to a shared text element
+var editor = ace.edit('aceContainer')
+editor.setTheme('ace/theme/chrome')
+editor.getSession().setMode('ace/mode/javascript')
+
+y.define('ace', Y.Text).bindAce(editor)
--- a/examples/bower.json
+++ b/examples/bower.json
@ -0,0 +1,19 @@
+{
+  "name": "yjs-examples",
+  "version": "0.0.0",
+  "homepage": "y-js.org",
+  "authors": [
+    "Kevin Jahns <kevin.jahns@rwth-aachen.de>"
+  ],
+  "description": "Examples for Yjs",
+  "license": "MIT",
+  "ignore": [],
+  "dependencies": {
+    "quill": "^1.0.0-rc.2",
+    "ace": "~1.2.3",
+    "ace-builds": "~1.2.3",
+    "jquery": "~2.2.2",
+    "d3": "^3.5.16",
+    "codemirror": "^5.25.0"
+  }
+}
--- a/examples/chat/index.html
+++ b/examples/chat/index.html
@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+  <body>
+    <style>
+      #chat p span {
+        color: blue;
+      }
+    </style>
+    <div id="chat"></div>
+    <form id="chatform">
+      <input name="username" type="text" style="width:15%;">
+      <input name="message" type="text" style="width:60%;">
+      <input type="submit" value="Send">
+    </form>
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/chat/index.js
+++ b/examples/chat/index.js
@ -0,0 +1,65 @@
+/* global Y */
+
+let y = new Y('chat-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yChat = y
+
+let chatprotocol = y.define('chatprotocol', Y.Array)
+
+let chatcontainer = document.querySelector('#chat')
+
+// This functions inserts a message at the specified position in the DOM
+function appendMessage (message, position) {
+  var p = document.createElement('p')
+  var uname = document.createElement('span')
+  uname.appendChild(document.createTextNode(message.username + ': '))
+  p.appendChild(uname)
+  p.appendChild(document.createTextNode(message.message))
+  chatcontainer.insertBefore(p, chatcontainer.children[position] || null)
+}
+
+// This function makes sure that only 7 messages exist in the chat history.
+// The rest is deleted
+function cleanupChat () {
+  if (chatprotocol.length > 7) {
+    chatprotocol.delete(0, chatprotocol.length - 7)
+  }
+}
+cleanupChat()
+
+// Insert the initial content
+chatprotocol.toArray().forEach(appendMessage)
+
+// whenever content changes, make sure to reflect the changes in the DOM
+chatprotocol.observe(function (event) {
+  // concurrent insertions may result in a history > 7, so cleanup here
+  cleanupChat()
+  chatcontainer.innerHTML = ''
+  chatprotocol.toArray().forEach(appendMessage)
+})
+document.querySelector('#chatform').onsubmit = function (event) {
+  // the form is submitted
+  var message = {
+    username: this.querySelector('[name=username]').value,
+    message: this.querySelector('[name=message]').value
+  }
+  if (message.username.length > 0 && message.message.length > 0) {
+    if (chatprotocol.length > 6) {
+      // If we are goint to insert the 8th element, make sure to delete first.
+      chatprotocol.delete(0)
+    }
+    // Here we insert a message in the shared chat type.
+    // This will call the observe function (see line 40)
+    // and reflect the change in the DOM
+    chatprotocol.push([message])
+    this.querySelector('[name=message]').value = ''
+  }
+  // Do not send this form!
+  event.preventDefault()
+  return false
+}
--- a/examples/codemirror/index.html
+++ b/examples/codemirror/index.html
@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+  <head>
+  </head>
+  <body>
+    <div id="codeMirrorContainer"></div>
+
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src="../bower_components/codemirror/lib/codemirror.js"></script>
+    <script src="../bower_components/codemirror/mode/javascript/javascript.js"></script>
+    <link rel="stylesheet" href="../bower_components/codemirror/lib/codemirror.css">
+    <style>
+      .CodeMirror {
+        position: fixed;
+        top: 0;
+        left: 0;
+        height: 100%;
+        width: 100%;
+      }
+    </style>
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/codemirror/index.js
+++ b/examples/codemirror/index.js
@ -0,0 +1,16 @@
+/* global Y, CodeMirror */
+
+let y = new Y('codemirror-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yCodeMirror = y
+
+var editor = CodeMirror(document.querySelector('#codeMirrorContainer'), {
+  mode: 'javascript',
+  lineNumbers: true
+})
+y.define('codemirror', Y.Text).bindCodeMirror(editor)
--- a/examples/drawing/index.html
+++ b/examples/drawing/index.html
@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html>
+<body>
+  <style>
+    path {
+      fill: none;
+      stroke: blue;
+      stroke-width: 1px;
+      stroke-linejoin: round;
+      stroke-linecap: round;
+    }
+  </style>
+  <button type="button" id="clearDrawingCanvas">Clear Drawing</button>
+  <svg id="drawingCanvas" viewbox="0 0 100 100" width="100%"></svg>
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+  <script src="../bower_components/d3/d3.min.js"></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/drawing/index.js
+++ b/examples/drawing/index.js
@ -0,0 +1,74 @@
+/* globals Y, d3 */
+
+let y = new Y('drawing-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yDrawing = y
+var drawing = y.define('drawing', Y.Array)
+var renderPath = d3.svg.line()
+  .x(function (d) { return d[0] })
+  .y(function (d) { return d[1] })
+  .interpolate('basic')
+
+var svg = d3.select('#drawingCanvas')
+  .call(d3.behavior.drag()
+    .on('dragstart', dragstart)
+    .on('drag', drag)
+    .on('dragend', dragend))
+
+// create line from a shared array object and update the line when the array changes
+function drawLine (yarray) {
+  var line = svg.append('path').datum(yarray.toArray())
+  line.attr('d', renderPath)
+  yarray.observe(function (event) {
+    line.remove()
+    line = svg.append('path').datum(yarray.toArray())
+    line.attr('d', renderPath)
+  })
+}
+// call drawLine every time an array is appended
+drawing.observe(function (event) {
+  event.removedElements.forEach(function () {
+    // if one is deleted, all will be deleted!!
+    svg.selectAll('path').remove()
+  })
+  event.addedElements.forEach(function (path) {
+    drawLine(path)
+  })
+})
+// draw all existing content
+for (var i = 0; i < drawing.length; i++) {
+  drawLine(drawing.get(i))
+}
+
+// clear canvas on request
+document.querySelector('#clearDrawingCanvas').onclick = function () {
+  drawing.delete(0, drawing.length)
+}
+
+var sharedLine = null
+function dragstart () {
+  drawing.insert(drawing.length, [Y.Array])
+  sharedLine = drawing.get(drawing.length - 1)
+}
+
+// After one dragged event is recognized, we ignore them for 33ms.
+var ignoreDrag = null
+function drag () {
+  if (sharedLine != null && ignoreDrag == null) {
+    ignoreDrag = window.setTimeout(function () {
+      ignoreDrag = null
+    }, 10)
+    sharedLine.push([d3.mouse(this)])
+  }
+}
+
+function dragend () {
+  sharedLine = null
+  window.clearTimeout(ignoreDrag)
+  ignoreDrag = null
+}
--- a/examples/html-editor-drawing-hook/index.html
+++ b/examples/html-editor-drawing-hook/index.html
@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<html>
+</head>
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+  <script src="../bower_components/d3/d3.min.js"></script>
+  <script src="./index.js"></script>
+  <style>
+    magic-drawing .drawingCanvas path {
+      fill: none;
+      stroke: blue;
+      stroke-width: 2px;
+      stroke-linejoin: round;
+      stroke-linecap: round;
+    }
+    magic-drawing .drawingCanvas {
+      width: 500px;
+      height: 500px;
+      cursor: default;
+      padding:1px;
+      border:1px solid #021a40;
+    }
+    magic-drawing .clearDrawingButton {
+      position: absolute;
+      top: 0;
+      left: 0;
+    }
+    magic-drawing {
+      position: relative;
+      display: block;
+    }
+  </style>
+</head>
+<body contenteditable="true">
+</body>
+</html>
--- a/examples/html-editor-drawing-hook/index.js
+++ b/examples/html-editor-drawing-hook/index.js
@ -0,0 +1,134 @@
+/* global Y, d3 */
+
+const hooks = {
+  'magic-drawing': {
+    fillType: function (dom, type) {
+      initDrawingBindings(type, dom)
+    },
+    createDom: function (type) {
+      const dom = document.createElement('magic-drawing')
+      initDrawingBindings(type, dom)
+      return dom
+    }
+  }
+}
+
+window.onload = function () {
+  window.domBinding = new Y.DomBinding(window.yXmlType, document.body, { hooks })
+}
+
+window.addMagicDrawing = function addMagicDrawing () {
+  let mt = document.createElement('magic-drawing')
+  mt.setAttribute('data-yjs-hook', 'magic-drawing')
+  document.body.append(mt)
+}
+
+var renderPath = d3.svg.line()
+  .x(function (d) { return d[0] })
+  .y(function (d) { return d[1] })
+  .interpolate('basic')
+
+function initDrawingBindings (type, dom) {
+  dom.contentEditable = 'false'
+  dom.setAttribute('data-yjs-hook', 'magic-drawing')
+  var drawing = type.get('drawing')
+  if (drawing === undefined) {
+    drawing = type.set('drawing', new Y.Array())
+  }
+  var canvas = dom.querySelector('.drawingCanvas')
+  if (canvas == null) {
+    canvas = document.createElementNS('http://www.w3.org/2000/svg', 'svg')
+    canvas.setAttribute('class', 'drawingCanvas')
+    canvas.setAttribute('viewbox', '0 0 100 100')
+    dom.insertBefore(canvas, null)
+  }
+  var clearDrawingButton = dom.querySelector('.clearDrawingButton')
+  if (clearDrawingButton == null) {
+    clearDrawingButton = document.createElement('button')
+    clearDrawingButton.setAttribute('type', 'button')
+    clearDrawingButton.setAttribute('class', 'clearDrawingButton')
+    clearDrawingButton.innerText = 'Clear Drawing'
+    dom.insertBefore(clearDrawingButton, null)
+  }
+  var svg = d3.select(canvas)
+    .call(d3.behavior.drag()
+      .on('dragstart', dragstart)
+      .on('drag', drag)
+      .on('dragend', dragend))
+  // create line from a shared array object and update the line when the array changes
+  function drawLine (yarray, svg) {
+    var line = svg.append('path').datum(yarray.toArray())
+    line.attr('d', renderPath)
+    yarray.observe(function (event) {
+      line.remove()
+      line = svg.append('path').datum(yarray.toArray())
+      line.attr('d', renderPath)
+    })
+  }
+  // call drawLine every time an array is appended
+  drawing.observe(function (event) {
+    event.removedElements.forEach(function () {
+      // if one is deleted, all will be deleted!!
+      svg.selectAll('path').remove()
+    })
+    event.addedElements.forEach(function (path) {
+      drawLine(path, svg)
+    })
+  })
+  // draw all existing content
+  for (var i = 0; i < drawing.length; i++) {
+    drawLine(drawing.get(i), svg)
+  }
+
+  // clear canvas on request
+  clearDrawingButton.onclick = function () {
+    drawing.delete(0, drawing.length)
+  }
+
+  var sharedLine = null
+  function dragstart () {
+    drawing.insert(drawing.length, [Y.Array])
+    sharedLine = drawing.get(drawing.length - 1)
+  }
+
+  // After one dragged event is recognized, we ignore them for 33ms.
+  var ignoreDrag = null
+  function drag () {
+    if (sharedLine != null && ignoreDrag == null) {
+      ignoreDrag = window.setTimeout(function () {
+        ignoreDrag = null
+      }, 10)
+      sharedLine.push([d3.mouse(this)])
+    }
+  }
+
+  function dragend () {
+    sharedLine = null
+    window.clearTimeout(ignoreDrag)
+    ignoreDrag = null
+  }
+}
+
+let y = new Y('html-editor-drawing-hook-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yXml = y
+window.yXmlType = y.define('xml', Y.XmlFragment)
+window.undoManager = new Y.utils.UndoManager(window.yXmlType, {
+  captureTimeout: 500
+})
+
+document.onkeydown = function interceptUndoRedo (e) {
+  if (e.keyCode === 90 && e.metaKey) {
+    if (!e.shiftKey) {
+      window.undoManager.undo()
+    } else {
+      window.undoManager.redo()
+    }
+    e.preventDefault()
+  }
+}
--- a/examples/html-editor/index.html
+++ b/examples/html-editor/index.html
@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+</head>
+  <script src="./index.js" type="module"></script>
+</head>
+<body>
+    <label for="room">Room: </label>
+    <input type="text" id="room" name="room">
+    <div id="content" contenteditable style="position:absolute;top:35px;left:0;right:0;bottom:0;outline: 0px solid transparent;"></div>
+</body>
+</html>
--- a/examples/html-editor/index.js
+++ b/examples/html-editor/index.js
@ -0,0 +1,77 @@
+
+import YWebsocketsConnector from '../../src/Connectors/WebsocketsConnector/WebsocketsConnector.js'
+import Y from '../../src/Y.js'
+import DomBinding from '../../src/Bindings/DomBinding/DomBinding.js'
+import UndoManager from '../../src/Util/UndoManager.js'
+import YXmlFragment from '../../src/Types/YXml/YXmlFragment.js'
+import YXmlText from '../../src/Types/YXml/YXmlText.js'
+import YXmlElement from '../../src/Types/YXml/YXmlElement.js'
+import YIndexdDBPersistence from '../../src/Persistences/IndexedDBPersistence.js'
+
+const connector = new YWebsocketsConnector()
+const persistence = new YIndexdDBPersistence()
+
+const roomInput = document.querySelector('#room')
+
+let currentRoomName = null
+let y = null
+let domBinding = null
+
+function setRoomName (roomName) {
+  if (currentRoomName !== roomName) {
+    console.log(`change room: "${roomName}"`)
+    roomInput.value = roomName
+    currentRoomName = roomName
+    location.hash = '#' + roomName
+    if (y !== null) {
+      domBinding.destroy()
+    }
+
+    const room = connector._rooms.get(roomName)
+    if (room !== undefined) {
+      y = room.y
+    } else {
+      y = new Y(roomName, null, null, { gc: true })
+      persistence.connectY(roomName, y).then(() => {
+        // connect after persisted content was applied to y
+        // If we don't wait for persistence, the other peer will send all data, waisting
+        // network bandwidth..
+        connector.connectY(roomName, y)
+      })
+      window.y = y
+    }
+
+    window.y = y
+    window.yXmlType = y.define('xml', YXmlFragment)
+
+    domBinding = new DomBinding(window.yXmlType, document.querySelector('#content'), { scrollingElement: document.scrollingElement })
+  }
+}
+window.setRoomName = setRoomName
+
+window.createRooms = function (i = 0) {
+  setInterval(function () {
+    setRoomName(i + '')
+    i++
+    const nodes = []
+    for (let j = 0; j < 100; j++) {
+      const node = new YXmlElement('p')
+      node.insert(0, [new YXmlText(`This is the ${i}th paragraph of room ${i}`)])
+      nodes.push(node)
+    }
+    y.share.xml.insert(0, nodes)
+  }, 100)
+}
+
+connector.syncPersistence(persistence)
+
+window.connector = connector
+window.persistence = persistence
+
+window.onload = function () {
+  setRoomName((location.hash || '#default').slice(1))
+  roomInput.addEventListener('input', e => {
+    const roomName = e.target.value
+    setRoomName(roomName)
+  })
+}
--- a/examples/indexeddb/index.html
+++ b/examples/indexeddb/index.html
@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+  <head>
+  </head>
+  <body>
+    <div id="codeMirrorContainer"></div>
+    <script src="../bower_components/codemirror/lib/codemirror.js"></script>
+    <script src="../bower_components/codemirror/mode/javascript/javascript.js"></script>
+    <link rel="stylesheet" href="../bower_components/codemirror/lib/codemirror.css">
+    <style>
+      .CodeMirror {
+        position: fixed;
+        top: 0;
+        left: 0;
+        height: 100%;
+        width: 100%;
+      }
+    </style>
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src='../../../y-indexeddb/y-indexeddb.js'></script>
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/indexeddb/index.js
+++ b/examples/indexeddb/index.js
@ -0,0 +1,19 @@
+/* global Y, CodeMirror */
+
+const persistence = new Y.IndexedDB()
+const connector = {
+  connector: {
+    name: 'websockets-client',
+    room: 'codemirror-example'
+  }
+}
+
+const y = new Y('codemirror-example', connector, persistence)
+window.yCodeMirror = y
+
+var editor = CodeMirror(document.querySelector('#codeMirrorContainer'), {
+  mode: 'javascript',
+  lineNumbers: true
+})
+
+y.define('codemirror', Y.Text).bindCodeMirror(editor)
--- a/examples/infiniteyjs/index.html
+++ b/examples/infiniteyjs/index.html
@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<html>
+<body>
+  <style>
+    .wrapper {
+      display: grid;
+      grid-template-columns: repeat(3, 1fr);
+      grid-gap: 7px;
+    }
+    .one {
+      grid-column: 1 ;
+    }
+    .two {
+      grid-column: 2;
+    }
+    .three {
+      grid-column: 3;
+    }
+    textarea {
+      width: calc(100% - 10px)
+    }
+    .editor-container {
+      background-color: #4caf50;
+      padding: 4px 5px 10px 5px;
+      border-radius: 11px;
+    }
+    .editor-container[disconnected] {
+      background-color: red;
+    }
+    .disconnected-info {
+      display: none;
+    }
+    .editor-container[disconnected] .disconnected-info {
+      display: inline;
+    }
+  </style>
+  <div class="wrapper">
+    <div id="container1" class="one editor-container">
+      <h1>Server 1 <span class="disconnected-info">(disconnected)</span></h1>
+      <textarea id="textarea1" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+    </div>
+    <div id="container2" class="two editor-container">
+      <h1>Server 2 <span class="disconnected-info">(disconnected)</span></h1>
+      <textarea id="textarea2" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+    </div>
+    <div id="container3" class="three editor-container">
+      <h1>Server 3 <span class="disconnected-info">(disconnected)</span></h1>
+      <textarea id="textarea3" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+    </div>
+  </div>
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/infiniteyjs/index.js
+++ b/examples/infiniteyjs/index.js
@ -0,0 +1,38 @@
+/* global Y */
+
+function bindYjsInstance (y, suffix) {
+  y.define('textarea', Y.Text).bind(document.getElementById('textarea' + suffix))
+  y.connector.socket.on('connection', function () {
+    document.getElementById('container' + suffix).removeAttribute('disconnected')
+  })
+  y.connector.socket.on('disconnect', function () {
+    document.getElementById('container' + suffix).setAttribute('disconnected', true)
+  })
+}
+
+let y1 = new Y('infinite-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+window.y1 = y1
+bindYjsInstance(y1, '1')
+
+let y2 = new Y('infinite-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+window.y2 = y2
+bindYjsInstance(y2, '2')
+
+let y3 = new Y('infinite-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+window.y3 = y3
+bindYjsInstance(y1, '3')
--- a/examples/jigsaw/index.html
+++ b/examples/jigsaw/index.html
@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <style type="text/css">
+    .draggable {
+      cursor: move;
+    }
+  </style>
+</head>
+<body>
+  <svg id="puzzle-example" width="100%" viewBox="0 0 800 800">
+    <g>
+      <path d="M 311.76636,154.23389 C 312.14136,171.85693 318.14087,184.97998 336.13843,184.23047 C 354.13647,183.48047 351.88647,180.48096 354.88599,178.98096 C 357.8855,177.48096 368.38452,170.35693 380.00806,169.98193 C 424.61841,168.54297 419.78296,223.6001 382.25757,223.6001 C 377.75806,223.6001 363.51001,219.10107 356.38599,211.97656 C 349.26196,204.85254 310.64185,207.10254 314.76636,236.34863 C 316.34888,247.5708 324.08374,267.90723 324.84595,286.23486 C 325.29321,296.99414 323.17603,307.00635 321.58911,315.6377 C 360.11353,305.4585 367.73462,304.30518 404.00513,312.83936 C 410.37915,314.33887 436.62573,310.21436 421.25269,290.3418 C 405.87964,270.46924 406.25464,248.34717 417.12817,240.84814 C 428.00171,233.34912 446.74976,228.84961 457.99829,234.09912 C 469.24683,239.34814 484.61987,255.84619 475.24585,271.59424 C 465.87231,287.34229 452.74878,290.7168 456.49829,303.84033 C 460.2478,316.96387 479.74536,320.33838 500.74292,321.83789 C 509.70142,322.47803 527.97192,323.28467 542.10864,320.12939 C 549.91821,318.38672 556.92212,315.89502 562.46753,313.56396 C 561.40796,277.80664 560.84888,245.71729 560.3606,241.97314 C 558.85278,230.41455 542.49536,217.28564 525.86499,223.2251 C 520.61548,225.1001 519.86548,231.84912 505.24243,232.59912 C 444.92798,235.69238 462.06958,143.26709 525.86499,180.48096 C 539.52759,188.45068 575.19409,190.7583 570.10913,156.85889 C 567.85962,141.86035 553.98608,102.86523 553.98608,102.86523 C 553.98608,102.86523 477.23755,111.82227 451.99878,91.991699 C 441.50024,83.74292 444.87476,69.494629 449.37427,61.245605 C 453.87378,52.996582 465.12231,46.622559 464.74731,36.123779 C 463.02563,-12.086426 392.96704,-10.902832 396.5061,36.873535 C 397.25562,46.997314 406.62964,52.621582 410.75415,60.495605 C 420.00757,78.161377 405.50024,96.073486 384.50757,99.490723 C 377.36206,100.65381 349.17505,102.65332 320.39429,102.23486 C 319.677,102.22461 318.95923,102.21143 318.24194,102.19775 C 315.08423,120.9751 311.55688,144.39697 311.76636,154.23389 z " style="fill:#f2c569;stroke:#000000" id="path2502"/>
+      <path d="M 500.74292,321.83789 C 479.74536,320.33838 460.2478,316.96387 456.49829,303.84033 C 452.74878,290.7168 465.87231,287.34229 475.24585,271.59424 C 484.61987,255.84619 469.24683,239.34814 457.99829,234.09912 C 446.74976,228.84961 428.00171,233.34912 417.12817,240.84814 C 406.25464,248.34717 405.87964,270.46924 421.25269,290.3418 C 436.62573,310.21436 410.37915,314.33887 404.00513,312.83936 C 367.73462,304.30518 360.11353,305.4585 321.58911,315.6377 C 320.56372,321.21484 319.75854,326.2207 320.01538,330.46191 C 320.76538,342.83545 329.3894,385.95508 327.8894,392.7041 C 326.3894,399.45312 313.64136,418.20117 297.89331,407.32715 C 282.14526,396.45361 276.52075,393.4541 265.27222,394.5791 C 254.02368,395.70361 239.77563,402.07812 239.77563,419.32568 C 239.77563,436.57373 250.27417,449.69727 268.64673,447.82227 C 287.36353,445.9126 317.92163,423.11035 325.63989,452.69678 C 330.1394,469.94434 330.51392,487.19238 330.1394,498.44092 C 329.95825,503.87646 326.09985,518.06592 322.16089,531.28125 C 353.2854,532.73682 386.47095,531.26611 394.2561,529.93701 C 430.30933,523.78174 429.31909,496.09766 412.62866,477.44385 C 406.25464,470.31934 401.75513,455.32129 405.87964,444.82275 C 414.07056,423.97314 458.8064,422.17773 473.37134,438.82324 C 483.86987,450.82178 475.99585,477.44385 468.49683,482.69287 C 453.52222,493.17529 457.22485,516.83008 473.37134,528.06201 C 504.79126,549.91943 572.35913,535.56152 572.35913,535.56152 C 572.35913,535.56152 567.85962,498.06592 567.48462,471.81934 C 567.10962,445.57275 589.60669,450.07227 593.3562,450.07227 C 597.10571,450.07227 604.22974,455.32129 609.47925,459.4458 C 614.72876,463.57031 618.85327,469.94434 630.85181,470.69434 C 677.43726,473.60596 674.58813,420.7373 631.97632,413.32666 C 623.35229,411.82666 614.72876,416.32617 603.10522,424.57519 C 591.48169,432.82422 577.23315,425.32519 570.10913,417.45117 C 566.07788,412.99561 563.8479,360.16406 562.46753,313.56396 C 556.92212,315.89502 549.91821,318.38672 542.10864,320.12939 C 527.97192,323.28467 509.70142,322.47803 500.74292,321.83789 z " style="fill:#f3f3d6;stroke:#000000" id="path2504"/>
+      <path d="M 240.52563,141.86035 C 257.60327,159.6499 243.94507,188.68799 214.65356,190.22949 C 185.09448,191.78516 164.66675,157.17822 190.28589,136.61621 C 200.49585,128.42139 198.05786,114.12158 179.78296,106.98975 C 154.4187,97.091553 90.54419,107.73975 90.54419,107.73975 C 90.54419,107.73975 100.88794,135.11328 101.41772,168.48242 C 101.79272,192.104 68.796875,189.47949 63.172607,186.85498 C 57.54834,184.23047 45.924805,173.73145 37.675781,173.73145 C -14.411865,173.73145 -10.013184,245.84375 39.925537,232.22412 C 48.174316,229.97461 56.42334,220.97559 68.796875,222.47559 C 81.17041,223.9751 87.544434,232.59912 87.544434,246.09766 C 87.544434,252.51709 87.0354,281.24268 86.340576,312.87012 C 119.15894,313.67676 160.60962,314.46582 170.03442,313.58887 C 186.15698,312.08936 195.90601,301.59033 188.40698,293.3418 C 180.90796,285.09277 156.16089,256.59619 179.03296,239.34814 C 201.90503,222.10059 235.65112,231.84912 239.77563,247.22217 C 243.90015,262.59521 240.52563,273.46924 234.90112,279.09326 C 229.27661,284.71777 210.52905,298.96582 221.40259,308.71484 C 232.27661,318.46338 263.77222,330.83691 302.39282,320.71338 C 309.58862,318.82715 315.92114,317.13525 321.58911,315.6377 C 323.17603,307.00635 325.29321,296.99414 324.84595,286.23486 C 324.08374,267.90723 316.34888,247.5708 314.76636,236.34863 C 310.64185,207.10254 349.26196,204.85254 356.38599,211.97656 C 363.51001,219.10107 377.75806,223.6001 382.25757,223.6001 C 419.78296,223.6001 424.61841,168.54297 380.00806,169.98193 C 368.38452,170.35693 357.8855,177.48096 354.88599,178.98096 C 351.88647,180.48096 354.13647,183.48047 336.13843,184.23047 C 318.14087,184.97998 312.14136,171.85693 311.76636,154.23389 C 311.55688,144.39697 315.08423,120.9751 318.24194,102.19775 C 290.37524,101.67725 262.46069,98.968262 254.39868,97.991211 C 233.38013,95.443359 217.17456,117.53662 240.52563,141.86035 z " style="fill:#bebcdb;stroke:#000000" id="path2506"/>
+      <path d="M 325.63989,452.69678 C 317.92163,423.11035 287.36353,445.9126 268.64673,447.82227 C 250.27417,449.69727 239.77563,436.57373 239.77563,419.32568 C 239.77563,402.07812 254.02368,395.70361 265.27222,394.5791 C 276.52075,393.4541 282.14526,396.45361 297.89331,407.32715 C 313.64136,418.20117 326.3894,399.45313 327.8894,392.7041 C 329.3894,385.95508 320.76538,342.83545 320.01538,330.46191 C 319.75855,326.2207 320.56372,321.21484 321.58911,315.6377 C 315.92114,317.13525 309.58862,318.82715 302.39282,320.71338 C 263.77222,330.83691 232.27661,318.46338 221.40259,308.71484 C 210.52905,298.96582 229.27661,284.71777 234.90112,279.09326 C 240.52563,273.46924 243.90015,262.59521 239.77563,247.22217 C 235.65112,231.84912 201.90503,222.10059 179.03296,239.34814 C 156.16089,256.59619 180.90796,285.09277 188.40698,293.3418 C 195.90601,301.59033 186.15698,312.08936 170.03442,313.58887 C 160.60962,314.46582 119.15894,313.67676 86.340576,312.87012 C 85.573975,347.74561 84.581299,386.15088 83.794922,402.07812 C 82.295166,432.44922 109.29175,422.32568 115.66577,420.82568 C 122.04028,419.32568 126.16479,409.57715 143.03735,408.45215 C 185.9231,405.59326 186.09985,466.69629 144.16235,467.69482 C 128.41431,468.06982 113.79126,451.19678 108.16675,447.44727 C 102.54272,443.69775 87.919433,442.94775 83.794922,457.9458 C 82.01709,464.41113 78.118652,481.65137 78.098144,496.18994 C 78.071045,515.38037 82.295166,531.81201 82.295166,531.81201 C 82.295166,531.81201 105.54224,526.5625 149.41187,526.5625 C 193.28149,526.5625 199.65552,547.93506 194.78101,558.80859 C 189.90649,569.68213 181.28296,568.93213 179.40796,583.18066 C 172.7063,634.11133 253.34106,631.08203 249.14917,584.68018 C 247.96948,571.62354 237.16528,571.66699 232.27661,557.68359 C 222.17944,528.80273 244.64966,523.56299 257.39819,524.68799 C 263.59351,525.23437 290.95679,529.73389 320.75757,531.21582 C 321.22437,531.23877 321.69312,531.25928 322.16089,531.28125 C 326.09985,518.06592 329.95825,503.87646 330.1394,498.44092 C 330.51392,487.19238 330.1394,469.94434 325.63989,452.69678 z " style="fill:#d3ea9d;stroke:#000000" id="path2508"/>
+		</g>
+  </svg>
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+  <script src="../bower_components/d3/d3.js"></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/jigsaw/index.js
+++ b/examples/jigsaw/index.js
@ -0,0 +1,67 @@
+/* global Y, d3 */
+
+let y = new Y('jigsaw-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+let jigsaw = y.define('jigsaw', Y.Map)
+window.yJigsaw = y
+
+var origin // mouse start position - translation of piece
+var drag = d3.behavior.drag()
+  .on('dragstart', function (params) {
+    // get the translation of the element
+    var translation = d3
+      .select(this)
+      .attr('transform')
+      .slice(10, -1)
+      .split(',')
+      .map(Number)
+    // mouse coordinates
+    var mouse = d3.mouse(this.parentNode)
+    origin = {
+      x: mouse[0] - translation[0],
+      y: mouse[1] - translation[1]
+    }
+  })
+  .on('drag', function () {
+    var mouse = d3.mouse(this.parentNode)
+    var x = mouse[0] - origin.x // =^= mouse - mouse at dragstart + translation at dragstart
+    var y = mouse[1] - origin.y
+    d3.select(this).attr('transform', 'translate(' + x + ',' + y + ')')
+  })
+  .on('dragend', function (piece, i) {
+    // save the current translation of the puzzle piece
+    var mouse = d3.mouse(this.parentNode)
+    var x = mouse[0] - origin.x
+    var y = mouse[1] - origin.y
+    jigsaw.set(piece, {x: x, y: y})
+  })
+
+var data = ['piece1', 'piece2', 'piece3', 'piece4']
+var pieces = d3.select(document.querySelector('#puzzle-example')).selectAll('path').data(data)
+
+pieces
+  .classed('draggable', true)
+  .attr('transform', function (piece) {
+    var translation = piece.get('translation') || {x: 0, y: 0}
+    return 'translate(' + translation.x + ',' + translation.y + ')'
+  }).call(drag)
+
+data.forEach(function (piece) {
+  jigsaw.observe(function () {
+    // whenever a property of a piece changes, update the translation of the pieces
+    pieces
+      .transition()
+      .attr('transform', function (piece) {
+        var translation = piece.get(piece)
+        if (translation == null || typeof translation.x !== 'number' || typeof translation.y !== 'number') {
+          translation = { x: 0, y: 0 }
+        }
+        return 'translate(' + translation.x + ',' + translation.y + ')'
+      })
+  })
+})
--- a/examples/monaco/index.html
+++ b/examples/monaco/index.html
@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+  </head>
+  <body>
+    <div id="monacoContainer"></div>
+    <style>
+      #monacoContainer {
+        position: fixed;
+        top: 0;
+        left: 0;
+        height: 100%;
+        width: 100%;
+      }
+    </style>
+    <script src="../../y.js"></script>
+    <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+    <script src="../node_modules/monaco-editor/min/vs/loader.js"></script>
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/monaco/index.js
+++ b/examples/monaco/index.js
@ -0,0 +1,22 @@
+/* global Y, monaco */
+
+require.config({ paths: { 'vs': '../node_modules/monaco-editor/min/vs' } })
+
+let y = new Y('monaco-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+require(['vs/editor/editor.main'], function () {
+  window.yMonaco = y
+
+  // Create Monaco editor
+  var editor = monaco.editor.create(document.getElementById('monacoContainer'), {
+    language: 'javascript'
+  })
+
+  // Bind to y.share.monaco
+  y.define('monaco', Y.Text).bindMonaco(editor)
+})
--- a/examples/notes/index.html
+++ b/examples/notes/index.html
@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+</head>
+  <script src="./index.js" type="module"></script>
+  <link rel="stylesheet" type="text/css" href="style.css">
+</head>
+<body>
+    <div class="sidebar">
+      <h3 id="createNoteButton">+ Create Note</h3>
+      <div class="notelist"></div>
+    </div>
+    <div class="main">
+      <h1 id="headline"></h1>
+      <div id="editor" contenteditable="true"></div>
+    </div>
+</body>
+</html>
--- a/examples/notes/index.js
+++ b/examples/notes/index.js
@ -0,0 +1,132 @@
+/* eslint-env browser */
+
+import { createYdbClient } from '../../YdbClient/index.js'
+import Y from '../../src/Y.dist.js'
+import * as ydb from '../../YdbClient/YdbClient.js'
+import DomBinding from '../../src/Bindings/DomBinding/DomBinding.js'
+
+const uuidv4 = () => 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
+  const r = Math.random() * 16 | 0
+  return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16)
+})
+
+createYdbClient('ws://localhost:8899/ws').then(ydbclient => {
+  const y = ydbclient.getY('notelist')
+  let ynotelist = y.define('notelist', Y.Array)
+  window.ynotelist = ynotelist
+  const domNoteList = document.querySelector('.notelist')
+
+  // utils
+  const addEventListener = (element, eventname, f) => element.addEventListener(eventname, f)
+
+  // create note button
+  const createNoteButton = event => {
+    ynotelist.insert(0, [{
+      guid: uuidv4(),
+      title: 'Note #' + ynotelist.length
+    }])
+  }
+  addEventListener(document.querySelector('#createNoteButton'), 'click', createNoteButton)
+  window.createNote = createNoteButton
+  window.createNotes = n => {
+    y.transact(() => {
+      for (let i = 0; i < n; i++) {
+        createNoteButton()
+      }
+    })
+  }
+
+  // clear note list function
+  window.clearNotes = () => ynotelist.delete(0, ynotelist.length)
+
+  // update editor and editor title
+  let domBinding = null
+  const updateEditor = () => {
+    domNoteList.querySelectorAll('a').forEach(a => a.classList.remove('selected'))
+    const domNote = document.querySelector('.notelist').querySelector(`[href="${location.hash}"]`)
+    if (domNote !== null) {
+      domNote.classList.add('selected')
+      const note = ynotelist.toArray().find(note => note.guid === location.hash.slice(1))
+      if (note !== undefined) {
+        const ydoc = ydbclient.getY(note.guid)
+        const ycontent = ydoc.define('content', Y.XmlFragment)
+        if (domBinding !== null) {
+          domBinding.destroy()
+        }
+        domBinding = new DomBinding(ycontent, document.querySelector('#editor'))
+        document.querySelector('#headline').innerText = note.title
+        document.querySelector('#editor').focus()
+      }
+    }
+  }
+
+  // listen to url-hash changes
+  addEventListener(window, 'hashchange', updateEditor)
+  updateEditor()
+
+  const styleSyncedState = (div, noteSyncedState) => {
+    let classes = []
+    if (noteSyncedState.persisted) {
+      classes.push('persisted')
+    } else {
+      if (noteSyncedState.upsynced) {
+        classes.push('upsynced')
+      } else {
+        classes.push('noupsynced')
+      }
+      if (noteSyncedState.downsynced) {
+        classes.push('downsynced')
+      } else {
+        classes.push('nodownsynced')
+      }
+    }
+    div.setAttribute('class', classes.join(' '))
+  }
+
+  ydbclient.on('syncstate', event => event.updated.forEach((state, room) => {
+    const a = document.querySelector(`[href="#${room}"]`)
+    if (a !== null) {
+      styleSyncedState(a.firstChild, state)
+    }
+  }))
+
+  // render note list
+  const renderNoteList = (elementList, insertRef = domNoteList.firstChild) => {
+    const fragment = document.createDocumentFragment()
+    const addNow = elementList.splice(0, 100)
+    addNow.forEach(note => {
+      const a = document.createElement('a')
+      const div = document.createElement('div')
+      a.insertBefore(div, null)
+      a.setAttribute('href', '#' + note.guid)
+      div.innerText = note.title
+      styleSyncedState(div, ydbclient.getRoomState(note.guid))
+      fragment.insertBefore(a, null)
+    })
+    if (domBinding == null) {
+      updateEditor()
+    }
+    domNoteList.insertBefore(fragment, insertRef)
+    if (elementList.length > 0) {
+      setTimeout(() => renderNoteList(elementList, insertRef), 100)
+    }
+  }
+  {
+    const notelist = ynotelist.toArray()
+    if (notelist.length > 0) {
+      renderNoteList(notelist)
+      ydb.subscribeRooms(ydbclient, notelist.map(note => note.guid))
+    }
+  }
+  ynotelist.observe(event => {
+    const addedNotes = []
+    event.addedElements.forEach(itemJson => itemJson._content.forEach(json => addedNotes.push(json)))
+    renderNoteList(addedNotes.slice().reverse()) // renderNoteList modifies addedNotes, so first make a copy of it
+    setTimeout(() => {
+      ydb.subscribeRooms(ydbclient, addedNotes.map(note => note.guid))
+    }, 200)
+    if (domBinding === null) {
+      updateEditor()
+    }
+  })
+})
--- a/examples/notes/style.css
+++ b/examples/notes/style.css
@ -0,0 +1,100 @@
+.sidebar {
+    height: 100%; /* Full-height: remove this if you want "auto" height */
+    width: 180px; /* Set the width of the sidebar */
+    position: fixed; /* Fixed Sidebar (stay in place on scroll) */
+    z-index: 1; /* Stay on top */
+    top: 0; /* Stay at the top */
+    left: 0;
+    background-color: #111; /* Black */
+    overflow-x: hidden; /* Disable horizontal scroll */
+    padding-top: 20px;
+    color: #50abff;
+}
+
+#createNoteButton {
+    padding-left: .5em;
+    padding-top: .5em;
+    padding-bottom: .7em;
+    margin: 0;
+    cursor: pointer;
+}
+
+.notelist > a {
+  padding: 6px 8px 6px 16px;
+  text-decoration: none;
+  font-size: 13px;
+  color: #818181;
+  display: block;
+}
+
+.notelist > a.selected {
+  border-style: outset;
+}
+
+.notelist > a > div {
+  position: relative;
+  display: inline;
+}
+
+/* When you mouse over the navigation links, change their color */
+.sidebar a:hover {
+    color: #f1f1f1;
+}
+
+/* Style page content */
+.main {
+    margin-left: 180px; /* Same as the width of the sidebar */
+    padding: 0px 10px;
+}
+
+/* On smaller screens, where height is less than 450px, change the style of the sidebar (less padding and a smaller font size) */
+@media screen and (max-height: 450px) {
+    .sidebar {padding-top: 15px;}
+    .sidebar a {font-size: 18px;}
+}
+
+#editor {
+    min-height: 400px;
+}
+
+[contenteditable]:focus {
+    outline: 0px solid transparent;
+}
+
+.persisted::before { 
+  content: "✔";
+  color: green;
+  position: absolute;
+  right: -14px;
+  top: 0px;
+}
+
+.upsynced::before {
+  content: "↑";
+  color: green;
+  position: absolute;
+  right: -14px;
+  top: 0px;
+}
+
+.noupsynced::before {
+  content: "↑";
+  color: red;
+  position: absolute;
+  right: -14px;
+  top: 0px;
+}
+.downsynced::after {
+  content: "↓";
+  color: green;
+  position: absolute;
+  right: -22px;
+  top: 0px;
+}
+.nodownsynced::after {
+  content: "↓";
+  color: red;
+  position: absolute;
+  right: -22px;
+  top: 0px;
+}
--- a/examples/package.json
+++ b/examples/package.json
@ -0,0 +1,23 @@
+{
+  "name": "examples",
+  "version": "0.0.0",
+  "description": "",
+  "scripts": {
+    "dist": "rollup -c",
+    "watch": "rollup -cw"
+  },
+  "author": "Kevin Jahns",
+  "license": "MIT",
+  "dependencies": {
+    "monaco-editor": "^0.8.3",
+    "rollup": "^0.52.3"
+  },
+  "devDependencies": {
+    "standard": "^10.0.2"
+  },
+  "standard": {
+    "ignore": [
+      "bower_components"
+    ]
+  }
+}
--- a/examples/quill-cursors/index.html
+++ b/examples/quill-cursors/index.html
@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!-- Main quill library -->
+  <script src="../../node_modules/quill/dist/quill.min.js"></script>
+  <link href="../../node_modules/quill/dist/quill.snow.css" rel="stylesheet">
+  <!-- Quill cursors module -->
+  <script src="../../node_modules/quill-cursors/dist/quill-cursors.min.js"></script>
+  <link href="../../node_modules/quill-cursors/dist/quill-cursors.css" rel="stylesheet">
+  <!-- Yjs Library and connector -->
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+</head>
+<body>
+  <div id="quill-container">
+    <div id="quill">
+    </div>
+  </div>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/quill-cursors/index.js
+++ b/examples/quill-cursors/index.js
@ -0,0 +1,78 @@
+/* global Y, Quill, QuillCursors */
+
+Quill.register('modules/cursors', QuillCursors)
+
+let y = new Y('quill-0', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+let users = y.define('users', Y.Array)
+let myUserInfo = new Y.Map()
+myUserInfo.set('name', 'dada')
+myUserInfo.set('color', 'red')
+users.push([myUserInfo])
+
+let quill = new Quill('#quill-container', {
+  modules: {
+    toolbar: [
+      [{ header: [1, 2, false] }],
+      ['bold', 'italic', 'underline'],
+      ['image', 'code-block'],
+      [{ color: [] }, { background: [] }], // Snow theme fills in values
+      [{ script: 'sub' }, { script: 'super' }],
+      ['link', 'image'],
+      ['link', 'code-block'],
+      [{ list: 'ordered' }, { list: 'bullet' }]
+    ],
+    cursors: {
+      hideDelay: 500
+    }
+  },
+  placeholder: 'Compose an epic...',
+  theme: 'snow' // or 'bubble'
+})
+
+let cursors = quill.getModule('cursors')
+
+function drawCursors () {
+  cursors.clearCursors()
+  users.map((user, userId) => {
+    if (user !== myUserInfo) {
+      let relativeRange = user.get('range')
+      let lastUpdated = new Date(user.get('last updated'))
+      if (lastUpdated != null && new Date() - lastUpdated < 20000 && relativeRange != null) {
+        let start = Y.utils.fromRelativePosition(y, relativeRange.start).offset
+        let end = Y.utils.fromRelativePosition(y, relativeRange.end).offset
+        let range = { index: start, length: end - start }
+        cursors.setCursor(userId + '', range, user.get('name'), user.get('color'))
+      }
+    }
+  })
+}
+
+users.observeDeep(drawCursors)
+drawCursors()
+
+quill.on('selection-change', function (range) {
+  if (range != null) {
+    myUserInfo.set('range', {
+      start: Y.utils.getRelativePosition(yText, range.index),
+      end: Y.utils.getRelativePosition(yText, range.index + range.length)
+    })
+  } else {
+    myUserInfo.delete('range')
+  }
+  myUserInfo.set('last updated', new Date().toString())
+})
+
+let yText = y.define('quill', Y.Text)
+let quillBinding = new Y.QuillBinding(yText, quill)
+
+window.quillBinding = quillBinding
+window.yText = yText
+window.y = y
+window.quill = quill
+window.users = users
+window.cursors = cursors
--- a/examples/quill/index.html
+++ b/examples/quill/index.html
@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!-- Main Quill library -->
+  <script src="../../node_modules/quill/dist/quill.min.js"></script>
+  <link href="../../node_modules/quill/dist/quill.snow.css" rel="stylesheet">
+  <!-- Yjs Library and connector -->
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+</head>
+<body>
+  <div id="quill-container">
+    <div id="quill">
+    </div>
+  </div>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/quill/index.js
+++ b/examples/quill/index.js
@ -0,0 +1,33 @@
+/* global Y, Quill */
+
+let y = new Y('quill-cursors-0', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+let quill = new Quill('#quill-container', {
+  modules: {
+    toolbar: [
+      [{ header: [1, 2, false] }],
+      ['bold', 'italic', 'underline'],
+      ['image', 'code-block'],
+      [{ color: [] }, { background: [] }], // Snow theme fills in values
+      [{ script: 'sub' }, { script: 'super' }],
+      ['link', 'image'],
+      ['link', 'code-block'],
+      [{ list: 'ordered' }, { list: 'bullet' }]
+    ]
+  },
+  placeholder: 'Compose an epic...',
+  theme: 'snow' // or 'bubble'
+})
+
+let yText = y.define('quill', Y.Text)
+
+let quillBinding = new Y.QuillBinding(yText, quill)
+window.quillBinding = quillBinding
+window.yText = yText
+window.y = y
+window.quill = quill
--- a/examples/rollup.config.js
+++ b/examples/rollup.config.js
@ -0,0 +1,29 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+
+var pkg = require('./package.json')
+
+export default {
+  input: 'yjs-dist.js',
+  name: 'Y',
+  output: {
+    file: 'yjs-dist.js',
+    format: 'umd'
+  },
+  plugins: [
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs()
+  ],
+  sourcemap: true,
+  banner: `
+/**
+ * ${pkg.name} - ${pkg.description}
+ * @version v${pkg.version}
+ * @license ${pkg.license}
+ */
+`
+}
--- a/examples/serviceworker/index.html
+++ b/examples/serviceworker/index.html
@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!-- quill does not include dist files! We are using the hosted version instead -->
+  <!--link rel="stylesheet" href="../bower_components/quill/dist/quill.snow.css" /-->
+  <link href="https://cdn.quilljs.com/1.0.4/quill.snow.css" rel="stylesheet">
+  <link href="//cdnjs.cloudflare.com/ajax/libs/KaTeX/0.5.1/katex.min.css" rel="stylesheet">
+  <link href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.2.0/styles/monokai-sublime.min.css" rel="stylesheet">
+  <style>
+    #quill-container {
+      border: 1px solid gray;
+      box-shadow: 0px 0px 10px gray;
+    }
+  </style>
+</head>
+<body>
+  <div id="quill-container">
+    <div id="quill">
+    </div>
+  </div>
+
+  <script src="//cdnjs.cloudflare.com/ajax/libs/KaTeX/0.5.1/katex.min.js" type="text/javascript"></script>
+  <script src="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.2.0/highlight.min.js" type="text/javascript"></script>
+  <script src="https://cdn.quilljs.com/1.0.4/quill.js"></script>
+  <!-- quill does not include dist files! We are using the hosted version instead (see above)
+  <script src="../bower_components/quill/dist/quill.js"></script>
+  -->
+  <script src="../bower_components/yjs/y.js"></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/serviceworker/index.js
+++ b/examples/serviceworker/index.js
@ -0,0 +1,49 @@
+/* global Y, Quill */
+
+// register yjs service worker
+if ('serviceWorker' in navigator) {
+  // Register service worker
+  // it is important to copy yjs-sw-template to the root directory!
+  navigator.serviceWorker.register('./yjs-sw-template.js').then(function (reg) {
+    console.log('Yjs service worker registration succeeded. Scope is ' + reg.scope)
+  }).catch(function (err) {
+    console.error('Yjs service worker registration failed with error ' + err)
+  })
+}
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'serviceworker',
+    room: 'ServiceWorkerExample2'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    richtext: 'Richtext' // y.share.richtext is of type Y.Richtext
+  }
+}).then(function (y) {
+  window.yServiceWorker = y
+
+  // create quill element
+  window.quill = new Quill('#quill', {
+    modules: {
+      formula: true,
+      syntax: true,
+      toolbar: [
+        [{ size: ['small', false, 'large', 'huge'] }],
+        ['bold', 'italic', 'underline'],
+        [{ color: [] }, { background: [] }], // Snow theme fills in values
+        [{ script: 'sub' }, { script: 'super' }],
+        ['link', 'image'],
+        ['link', 'code-block'],
+        [{ list: 'ordered' }]
+      ]
+    },
+    theme: 'snow'
+  })
+  // bind quill to richtext type
+  y.share.richtext.bind(window.quill)
+})
--- a/examples/serviceworker/yjs-sw-template.js
+++ b/examples/serviceworker/yjs-sw-template.js
@ -0,0 +1,22 @@
+/* eslint-env worker */
+
+// copy and modify this file
+
+self.DBConfig = {
+  name: 'indexeddb'
+}
+self.ConnectorConfig = {
+  name: 'websockets-client',
+  // url: '..',
+  options: {
+    jsonp: false
+  }
+}
+
+importScripts(
+  '/bower_components/yjs/y.js',
+  '/bower_components/y-memory/y-memory.js',
+  '/bower_components/y-indexeddb/y-indexeddb.js',
+  '/bower_components/y-websockets-client/y-websockets-client.js',
+  '/bower_components/y-serviceworker/yjs-sw-include.js'
+)
--- a/examples/textarea/index.html
+++ b/examples/textarea/index.html
@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<html>
+<body>
+  <textarea style="width:80%;" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+  <script type="module" src="./index.js"></script>
+</body>
+</html>
--- a/examples/textarea/index.js
+++ b/examples/textarea/index.js
@ -0,0 +1,13 @@
+/* eslint-env browser */
+import * as Y from '../../src/index.js'
+import WebsocketProvider from '../../provider/websocket/WebSocketProvider.js'
+
+const provider = new WebsocketProvider('ws://localhost:1234/')
+const ydocument = provider.get('textarea')
+const type = ydocument.define('textarea', Y.Text)
+const textarea = document.querySelector('textarea')
+const binding = new Y.TextareaBinding(type, textarea)
+
+window.textareaExample = {
+  provider, ydocument, type, textarea, binding
+}
--- a/examples/xml/index.html
+++ b/examples/xml/index.html
@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html>
+</head>
+  <!-- jquery is not required for YXml. It is just here for convenience, and to test batch operations. -->
+  <script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
+  <script src="../../y.js"></script>
+  <script src='../../../y-websockets-client/y-websockets-client.js'></script>
+  <script src="./index.js"></script>
+</head>
+<body>
+  <h1> Shared DOM Example </h1>
+  <p> Use native DOM function or jQuery to manipulate the shared DOM (window.sharedDom). </p>
+  <div class="command">
+    <button type="button">Execute</button>
+    <input type="text" value='$(sharedDom).append("<h3>Appended headline</h3>")' size="40"/>
+  </div>
+  <div class="command">
+    <button type="button">Execute</button>
+    <input type="text" value='$(sharedDom).attr("align","right")' size="40"/>
+  </div>
+  <div class="command">
+    <button type="button">Execute</button>
+    <input type="text" value='$(sharedDom).attr("style","color:blue;")' size="40"/>
+  </div>
+
+  <script>
+    /* global $ */
+    var commands = document.querySelectorAll('.command')
+    Array.prototype.forEach.call(commands, function (command) {
+      var execute = function () {
+        // eslint-disable-next-line no-eval
+        eval(command.querySelector('input').value)
+      }
+      command.querySelector('button').onclick = execute
+      $(command.querySelector('input')).keyup(function (e) {
+        if (e.keyCode === 13) {
+          execute()
+        }
+      })
+    })
+  </script>
+</body>
+</html>
--- a/examples/xml/index.js
+++ b/examples/xml/index.js
@ -0,0 +1,13 @@
+/* global Y */
+
+let y = new Y('xml-example', {
+  connector: {
+    name: 'websockets-client',
+    url: 'http://127.0.0.1:1234'
+  }
+})
+
+window.yXml = y
+// bind xml type to a dom, and put it in body
+window.sharedDom = y.define('xml', Y.XmlElement).toDom()
+document.body.appendChild(window.sharedDom)
--- a/funding.json
+++ b/funding.json
@ -1,142 +0,0 @@
-{
-  "version": "v1.0.0",
-  "entity": {
-    "type": "group",
-    "role": "steward",
-    "name": "Kevin Jahns",
-    "email": "kevin.jahns@protonmail.com",
-    "phone": "",
-    "description": "OSS Developer",
-    "webpageUrl": {
-      "url": "https://github.com/yjs"
-    }
-  },
-  "projects": [
-    {
-      "guid": "yjs",
-      "name": "Yjs",
-      "description": "A library for building collaborative applications. #p2p #local-first #CRDT Funding this project will also enable me to maintain the other Yjs-related technologies.",
-      "webpageUrl": {
-        "url": "https://github.com/yjs/yjs"
-      },
-      "repositoryUrl": {
-        "url": "https://github.com/yjs/yjs"
-      },
-      "licenses": [
-        "spdx:MIT"
-      ],
-      "tags": [
-        "collaboration",
-        "p2p",
-        "CRDT",
-        "rich-text",
-        "real-time"
-      ]
-    },
-    {
-      "guid": "Titanic",
-      "name": "Y/Titanic",
-      "description": "A provider for syncing millions of docs efficiently with other peers. This will become the foundation for building real local-first apps with Yjs.",
-      "webpageUrl": {
-        "url": "https://github.com/yjs/titanic",
-        "wellKnown": "https://github.com/yjs/titanic/blob/main/.well-known/funding-manifest-urls"
-      },
-      "repositoryUrl": {
-        "url": "https://github.com/yjs/titanic",
-        "wellKnown": "https://github.com/yjs/titanic/blob/main/.well-known/funding-manifest-urls"
-      },
-      "licenses": [
-        "spdx:MIT"
-      ],
-      "tags": [
-        "privacy",
-        "collaboration",
-        "p2p",
-        "CRDT",
-        "rich-text",
-        "real-time",
-        "web-development"
-      ]
-    }
-  ],
-  "funding": {
-    "channels": [
-      {
-        "guid": "github-sponsors",
-        "type": "payment-provider",
-        "address": "",
-        "description": "For funding of the Yjs project"
-      },
-      {
-        "guid": "y-collective",
-        "type": "payment-provider",
-        "address": "https://opencollective.com/y-collective",
-        "description": "For funding the Y-CRDT - the Rust implementation of Yjs and other listed projects."
-      }
-    ],
-    "plans": [
-      {
-        "guid": "supporter",
-        "status": "active",
-        "name": "Supporter",
-        "description": "",
-        "amount": 0,
-        "currency": "USD",
-        "frequency": "monthly",
-        "channels": [
-          "github-sponsors",
-          "y-collective"
-        ]
-      },
-      {
-        "guid": "titanic-funding",
-        "status": "active",
-        "name": "Titanic Funding",
-        "description": "Fund the next generation of local-first providers.",
-        "amount": 30000,
-        "currency": "USD",
-        "frequency": "one-time",
-        "channels": [
-          "github-sponsors"
-        ]
-      },
-      {
-        "guid": "bronze-sponsor",
-        "status": "active",
-        "name": "Bronze Sponsor",
-        "description": "This is the recommended plan for companies that use Yjs.",
-        "amount": 500,
-        "currency": "USD",
-        "frequency": "monthly",
-        "channels": [
-          "github-sponsors"
-        ]
-      },
-      {
-        "guid": "silver-sponsor",
-        "status": "active",
-        "name": "Silver Sponsor",
-        "description": "This is the recommended plan for large/successfull companies that use Yjs.",
-        "amount": 1000,
-        "currency": "USD",
-        "frequency": "monthly",
-        "channels": [
-          "github-sponsors"
-        ]
-      },
-      {
-        "guid": "gold-sponsor",
-        "status": "active",
-        "name": "Gold Sponsor",
-        "description": "This is the recommended plan for successful companies that build their entire product around Yjs-related technologies.",
-        "amount": 3000,
-        "currency": "USD",
-        "frequency": "monthly",
-        "channels": [
-          "github-sponsors"
-        ]
-      }
-    ],
-    "history": null
-  }
-}
--- a/lib/NamedEventHandler.js
+++ b/lib/NamedEventHandler.js
@ -0,0 +1,113 @@
+
+/**
+ * Handles named events.
+ */
+export default class NamedEventHandler {
+  constructor () {
+    this._eventListener = new Map()
+    this._stateListener = new Map()
+  }
+
+  /**
+   * @private
+   * Returns all listeners that listen to a specified name.
+   *
+   * @param {String} name The query event name.
+   */
+  _getListener (name) {
+    let listeners = this._eventListener.get(name)
+    if (listeners === undefined) {
+      listeners = {
+        once: new Set(),
+        on: new Set()
+      }
+      this._eventListener.set(name, listeners)
+    }
+    return listeners
+  }
+
+  /**
+   * Adds a named event listener. The listener is removed after it has been
+   * called once.
+   *
+   * @param {String} name The event name to listen to.
+   * @param {Function} f The function that is executed when the event is fired.
+   */
+  once (name, f) {
+    let listeners = this._getListener(name)
+    listeners.once.add(f)
+  }
+
+  /**
+   * Adds a named event listener.
+   *
+   * @param {String} name The event name to listen to.
+   * @param {Function} f The function that is executed when the event is fired.
+   */
+  on (name, f) {
+    let listeners = this._getListener(name)
+    listeners.on.add(f)
+  }
+
+  /**
+   * @private
+   * Init the saved state for an event name.
+   */
+  _initStateListener (name) {
+    let state = this._stateListener.get(name)
+    if (state === undefined) {
+      state = {}
+      state.promise = new Promise(function (resolve) {
+        state.resolve = resolve
+      })
+      this._stateListener.set(name, state)
+    }
+    return state
+  }
+
+  /**
+   * Returns a Promise that is resolved when the event name is called.
+   * The Promise is immediately resolved when the event name was called in the
+   * past.
+   */
+  when (name) {
+    return this._initStateListener(name).promise
+  }
+
+  /**
+   * Remove an event listener that was registered with either
+   * {@link EventHandler#on} or {@link EventHandler#once}.
+   */
+  off (name, f) {
+    if (name == null || f == null) {
+      throw new Error('You must specify event name and function!')
+    }
+    const listener = this._eventListener.get(name)
+    if (listener !== undefined) {
+      listener.on.delete(f)
+      listener.once.delete(f)
+    }
+  }
+
+  /**
+   * Emit a named event. All registered event listeners that listen to the
+   * specified name will receive the event.
+   *
+   * @param {String} name The event name.
+   * @param {Array} args The arguments that are applied to the event listener.
+   */
+  emit (name, ...args) {
+    this._initStateListener(name).resolve()
+    const listener = this._eventListener.get(name)
+    if (listener !== undefined) {
+      listener.on.forEach(f => f.apply(null, args))
+      listener.once.forEach(f => f.apply(null, args))
+      listener.once = new Set()
+    } else if (name === 'error') {
+      console.error(args[0])
+    }
+  }
+  destroy () {
+    this._eventListener = null
+  }
+}
--- a/lib/Tree.js
+++ b/lib/Tree.js
@ -0,0 +1,465 @@
+
+function rotate (tree, parent, newParent, n) {
+  if (parent === null) {
+    tree.root = newParent
+    newParent._parent = null
+  } else if (parent.left === n) {
+    parent.left = newParent
+  } else if (parent.right === n) {
+    parent.right = newParent
+  } else {
+    throw new Error('The elements are wrongly connected!')
+  }
+}
+
+class N {
+  // A created node is always red!
+  constructor (val) {
+    this.val = val
+    this.color = true
+    this._left = null
+    this._right = null
+    this._parent = null
+  }
+  isRed () { return this.color }
+  isBlack () { return !this.color }
+  redden () { this.color = true; return this }
+  blacken () { this.color = false; return this }
+  get grandparent () {
+    return this.parent.parent
+  }
+  get parent () {
+    return this._parent
+  }
+  get sibling () {
+    return (this === this.parent.left)
+      ? this.parent.right : this.parent.left
+  }
+  get left () {
+    return this._left
+  }
+  get right () {
+    return this._right
+  }
+  set left (n) {
+    if (n !== null) {
+      n._parent = this
+    }
+    this._left = n
+  }
+  set right (n) {
+    if (n !== null) {
+      n._parent = this
+    }
+    this._right = n
+  }
+  rotateLeft (tree) {
+    const parent = this.parent
+    const newParent = this.right
+    const newRight = this.right.left
+    newParent.left = this
+    this.right = newRight
+    rotate(tree, parent, newParent, this)
+  }
+  next () {
+    if (this.right !== null) {
+      // search the most left node in the right tree
+      var o = this.right
+      while (o.left !== null) {
+        o = o.left
+      }
+      return o
+    } else {
+      var p = this
+      while (p.parent !== null && p !== p.parent.left) {
+        p = p.parent
+      }
+      return p.parent
+    }
+  }
+  prev () {
+    if (this.left !== null) {
+      // search the most right node in the left tree
+      var o = this.left
+      while (o.right !== null) {
+        o = o.right
+      }
+      return o
+    } else {
+      var p = this
+      while (p.parent !== null && p !== p.parent.right) {
+        p = p.parent
+      }
+      return p.parent
+    }
+  }
+  rotateRight (tree) {
+    const parent = this.parent
+    const newParent = this.left
+    const newLeft = this.left.right
+    newParent.right = this
+    this.left = newLeft
+    rotate(tree, parent, newParent, this)
+  }
+  getUncle () {
+    // we can assume that grandparent exists when this is called!
+    if (this.parent === this.parent.parent.left) {
+      return this.parent.parent.right
+    } else {
+      return this.parent.parent.left
+    }
+  }
+}
+
+/*
+ * This is a Red Black Tree implementation
+ */
+export default class Tree {
+  constructor () {
+    this.root = null
+    this.length = 0
+  }
+  findNext (id) {
+    var nextID = id.clone()
+    nextID.clock += 1
+    return this.findWithLowerBound(nextID)
+  }
+  findPrev (id) {
+    let prevID = id.clone()
+    prevID.clock -= 1
+    return this.findWithUpperBound(prevID)
+  }
+  findNodeWithLowerBound (from) {
+    var o = this.root
+    if (o === null) {
+      return null
+    } else {
+      while (true) {
+        if (from === null || (from.lessThan(o.val._id) && o.left !== null)) {
+          // o is included in the bound
+          // try to find an element that is closer to the bound
+          o = o.left
+        } else if (from !== null && o.val._id.lessThan(from)) {
+          // o is not within the bound, maybe one of the right elements is..
+          if (o.right !== null) {
+            o = o.right
+          } else {
+            // there is no right element. Search for the next bigger element,
+            // this should be within the bounds
+            return o.next()
+          }
+        } else {
+          return o
+        }
+      }
+    }
+  }
+  findNodeWithUpperBound (to) {
+    if (to === void 0) {
+      throw new Error('You must define from!')
+    }
+    var o = this.root
+    if (o === null) {
+      return null
+    } else {
+      while (true) {
+        if ((to === null || o.val._id.lessThan(to)) && o.right !== null) {
+          // o is included in the bound
+          // try to find an element that is closer to the bound
+          o = o.right
+        } else if (to !== null && to.lessThan(o.val._id)) {
+          // o is not within the bound, maybe one of the left elements is..
+          if (o.left !== null) {
+            o = o.left
+          } else {
+            // there is no left element. Search for the prev smaller element,
+            // this should be within the bounds
+            return o.prev()
+          }
+        } else {
+          return o
+        }
+      }
+    }
+  }
+  findSmallestNode () {
+    var o = this.root
+    while (o != null && o.left != null) {
+      o = o.left
+    }
+    return o
+  }
+  findWithLowerBound (from) {
+    var n = this.findNodeWithLowerBound(from)
+    return n == null ? null : n.val
+  }
+  findWithUpperBound (to) {
+    var n = this.findNodeWithUpperBound(to)
+    return n == null ? null : n.val
+  }
+  iterate (from, to, f) {
+    var o
+    if (from === null) {
+      o = this.findSmallestNode()
+    } else {
+      o = this.findNodeWithLowerBound(from)
+    }
+    while (
+      o !== null &&
+      (
+        to === null || // eslint-disable-line no-unmodified-loop-condition
+        o.val._id.lessThan(to) ||
+        o.val._id.equals(to)
+      )
+    ) {
+      f(o.val)
+      o = o.next()
+    }
+  }
+  find (id) {
+    let n = this.findNode(id)
+    if (n !== null) {
+      return n.val
+    } else {
+      return null
+    }
+  }
+  findNode (id) {
+    var o = this.root
+    if (o === null) {
+      return null
+    } else {
+      while (true) {
+        if (o === null) {
+          return null
+        }
+        if (id.lessThan(o.val._id)) {
+          o = o.left
+        } else if (o.val._id.lessThan(id)) {
+          o = o.right
+        } else {
+          return o
+        }
+      }
+    }
+  }
+  delete (id) {
+    var d = this.findNode(id)
+    if (d == null) {
+      // throw new Error('Element does not exist!')
+      return
+    }
+    this.length--
+    if (d.left !== null && d.right !== null) {
+      // switch d with the greates element in the left subtree.
+      // o should have at most one child.
+      var o = d.left
+      // find
+      while (o.right !== null) {
+        o = o.right
+      }
+      // switch
+      d.val = o.val
+      d = o
+    }
+    // d has at most one child
+    // let n be the node that replaces d
+    var isFakeChild
+    var child = d.left || d.right
+    if (child === null) {
+      isFakeChild = true
+      child = new N(null)
+      child.blacken()
+      d.right = child
+    } else {
+      isFakeChild = false
+    }
+
+    if (d.parent === null) {
+      if (!isFakeChild) {
+        this.root = child
+        child.blacken()
+        child._parent = null
+      } else {
+        this.root = null
+      }
+      return
+    } else if (d.parent.left === d) {
+      d.parent.left = child
+    } else if (d.parent.right === d) {
+      d.parent.right = child
+    } else {
+      throw new Error('Impossible!')
+    }
+    if (d.isBlack()) {
+      if (child.isRed()) {
+        child.blacken()
+      } else {
+        this._fixDelete(child)
+      }
+    }
+    this.root.blacken()
+    if (isFakeChild) {
+      if (child.parent.left === child) {
+        child.parent.left = null
+      } else if (child.parent.right === child) {
+        child.parent.right = null
+      } else {
+        throw new Error('Impossible #3')
+      }
+    }
+  }
+  _fixDelete (n) {
+    function isBlack (node) {
+      return node !== null ? node.isBlack() : true
+    }
+    function isRed (node) {
+      return node !== null ? node.isRed() : false
+    }
+    if (n.parent === null) {
+      // this can only be called after the first iteration of fixDelete.
+      return
+    }
+    // d was already replaced by the child
+    // d is not the root
+    // d and child are black
+    var sibling = n.sibling
+    if (isRed(sibling)) {
+      // make sibling the grandfather
+      n.parent.redden()
+      sibling.blacken()
+      if (n === n.parent.left) {
+        n.parent.rotateLeft(this)
+      } else if (n === n.parent.right) {
+        n.parent.rotateRight(this)
+      } else {
+        throw new Error('Impossible #2')
+      }
+      sibling = n.sibling
+    }
+    // parent, sibling, and children of n are black
+    if (n.parent.isBlack() &&
+      sibling.isBlack() &&
+      isBlack(sibling.left) &&
+      isBlack(sibling.right)
+    ) {
+      sibling.redden()
+      this._fixDelete(n.parent)
+    } else if (n.parent.isRed() &&
+      sibling.isBlack() &&
+      isBlack(sibling.left) &&
+      isBlack(sibling.right)
+    ) {
+      sibling.redden()
+      n.parent.blacken()
+    } else {
+      if (n === n.parent.left &&
+        sibling.isBlack() &&
+        isRed(sibling.left) &&
+        isBlack(sibling.right)
+      ) {
+        sibling.redden()
+        sibling.left.blacken()
+        sibling.rotateRight(this)
+        sibling = n.sibling
+      } else if (n === n.parent.right &&
+        sibling.isBlack() &&
+        isRed(sibling.right) &&
+        isBlack(sibling.left)
+      ) {
+        sibling.redden()
+        sibling.right.blacken()
+        sibling.rotateLeft(this)
+        sibling = n.sibling
+      }
+      sibling.color = n.parent.color
+      n.parent.blacken()
+      if (n === n.parent.left) {
+        sibling.right.blacken()
+        n.parent.rotateLeft(this)
+      } else {
+        sibling.left.blacken()
+        n.parent.rotateRight(this)
+      }
+    }
+  }
+  put (v) {
+    var node = new N(v)
+    if (this.root !== null) {
+      var p = this.root // p abbrev. parent
+      while (true) {
+        if (node.val._id.lessThan(p.val._id)) {
+          if (p.left === null) {
+            p.left = node
+            break
+          } else {
+            p = p.left
+          }
+        } else if (p.val._id.lessThan(node.val._id)) {
+          if (p.right === null) {
+            p.right = node
+            break
+          } else {
+            p = p.right
+          }
+        } else {
+          p.val = node.val
+          return p
+        }
+      }
+      this._fixInsert(node)
+    } else {
+      this.root = node
+    }
+    this.length++
+    this.root.blacken()
+    return node
+  }
+  _fixInsert (n) {
+    if (n.parent === null) {
+      n.blacken()
+      return
+    } else if (n.parent.isBlack()) {
+      return
+    }
+    var uncle = n.getUncle()
+    if (uncle !== null && uncle.isRed()) {
+      // Note: parent: red, uncle: red
+      n.parent.blacken()
+      uncle.blacken()
+      n.grandparent.redden()
+      this._fixInsert(n.grandparent)
+    } else {
+      // Note: parent: red, uncle: black or null
+      // Now we transform the tree in such a way that
+      // either of these holds:
+      //   1) grandparent.left.isRed
+      //     and grandparent.left.left.isRed
+      //   2) grandparent.right.isRed
+      //     and grandparent.right.right.isRed
+      if (n === n.parent.right && n.parent === n.grandparent.left) {
+        n.parent.rotateLeft(this)
+        // Since we rotated and want to use the previous
+        // cases, we need to set n in such a way that
+        // n.parent.isRed again
+        n = n.left
+      } else if (n === n.parent.left && n.parent === n.grandparent.right) {
+        n.parent.rotateRight(this)
+        // see above
+        n = n.right
+      }
+      // Case 1) or 2) hold from here on.
+      // Now traverse grandparent, make parent a black node
+      // on the highest level which holds two red nodes.
+      n.parent.blacken()
+      n.grandparent.redden()
+      if (n === n.parent.left) {
+        // Case 1
+        n.grandparent.rotateRight(this)
+      } else {
+        // Case 2
+        n.grandparent.rotateLeft(this)
+      }
+    }
+  }
+}
--- a/lib/binary.js
+++ b/lib/binary.js
@ -0,0 +1,7 @@
+
+export const BITS32 = 0xFFFFFFFF
+export const BITS21 = (1 << 21) - 1
+export const BITS16 = (1 << 16) - 1
+
+export const BIT26 = 1 << 26
+export const BIT32 = 1 << 32
--- a/lib/decoding.js
+++ b/lib/decoding.js
@ -0,0 +1,168 @@
+
+/* global Buffer */
+
+import * as globals from './globals.js'
+
+/**
+ * A Decoder handles the decoding of an ArrayBuffer.
+ */
+export class Decoder {
+  /**
+   * @param {ArrayBuffer} buffer Binary data to decode
+   */
+  constructor (buffer) {
+    this.arr = new Uint8Array(buffer)
+    this.pos = 0
+  }
+}
+
+/**
+ * @param {ArrayBuffer} buffer
+ * @return {Decoder}
+ */
+export const createDecoder = buffer => new Decoder(buffer)
+
+export const hasContent = decoder => decoder.pos !== decoder.arr.length
+
+/**
+ * Clone a decoder instance.
+ * Optionally set a new position parameter.
+ * @param {Decoder} decoder The decoder instance
+ * @return {Decoder} A clone of `decoder`
+ */
+export const clone = (decoder, newPos = decoder.pos) => {
+  let _decoder = createDecoder(decoder.arr.buffer)
+  _decoder.pos = newPos
+  return _decoder
+}
+
+/**
+ * Read `len` bytes as an ArrayBuffer.
+ * @param {Decoder} decoder The decoder instance
+ * @param {number} len The length of bytes to read
+ * @return {ArrayBuffer}
+ */
+export const readArrayBuffer = (decoder, len) => {
+  const arrayBuffer = globals.createUint8ArrayFromLen(len)
+  const view = globals.createUint8ArrayFromBuffer(decoder.arr.buffer, decoder.pos, len)
+  arrayBuffer.set(view)
+  decoder.pos += len
+  return arrayBuffer.buffer
+}
+
+/**
+ * Read variable length payload as ArrayBuffer
+ * @param {Decoder} decoder
+ * @return {ArrayBuffer}
+ */
+export const readPayload = decoder => readArrayBuffer(decoder, readVarUint(decoder))
+
+/**
+ * Read the rest of the content as an ArrayBuffer
+ * @param {Decoder} decoder
+ * @return {ArrayBuffer}
+ */
+export const readTail = decoder => readArrayBuffer(decoder, decoder.arr.length - decoder.pos)
+
+/**
+ * Skip one byte, jump to the next position.
+ * @param {Decoder} decoder The decoder instance
+ * @return {number} The next position
+ */
+export const skip8 = decoder => decoder.pos++
+
+/**
+ * Read one byte as unsigned integer.
+ * @param {Decoder} decoder The decoder instance
+ * @return {number} Unsigned 8-bit integer
+ */
+export const readUint8 = decoder => decoder.arr[decoder.pos++]
+
+/**
+ * Read 4 bytes as unsigned integer.
+ *
+ * @param {Decoder} decoder
+ * @return {number} An unsigned integer.
+ */
+export const readUint32 = decoder => {
+  let uint =
+    decoder.arr[decoder.pos] +
+    (decoder.arr[decoder.pos + 1] << 8) +
+    (decoder.arr[decoder.pos + 2] << 16) +
+    (decoder.arr[decoder.pos + 3] << 24)
+  decoder.pos += 4
+  return uint
+}
+
+/**
+ * Look ahead without incrementing position.
+ * to the next byte and read it as unsigned integer.
+ *
+ * @param {Decoder} decoder
+ * @return {number} An unsigned integer.
+ */
+export const peekUint8 = decoder => decoder.arr[decoder.pos]
+
+/**
+ * Read unsigned integer (32bit) with variable length.
+ * 1/8th of the storage is used as encoding overhead.
+ *  * numbers < 2^7 is stored in one bytlength
+ *  * numbers < 2^14 is stored in two bylength
+ *
+ * @param {Decoder} decoder
+ * @return {number} An unsigned integer.length
+ */
+export const readVarUint = decoder => {
+  let num = 0
+  let len = 0
+  while (true) {
+    let r = decoder.arr[decoder.pos++]
+    num = num | ((r & 0b1111111) << len)
+    len += 7
+    if (r < 1 << 7) {
+      return num >>> 0 // return unsigned number!
+    }
+    if (len > 35) {
+      throw new Error('Integer out of range!')
+    }
+  }
+}
+
+/**
+ * Read string of variable length
+ * * varUint is used to store the length of the string
+ *
+ * Transforming utf8 to a string is pretty expensive. The code performs 10x better
+ * when String.fromCodePoint is fed with all characters as arguments.
+ * But most environments have a maximum number of arguments per functions.
+ * For effiency reasons we apply a maximum of 10000 characters at once.
+ *
+ * @param {Decoder} decoder
+ * @return {String} The read String.
+ */
+export const readVarString = decoder => {
+  let remainingLen = readVarUint(decoder)
+  let encodedString = ''
+  while (remainingLen > 0) {
+    const nextLen = remainingLen < 10000 ? remainingLen : 10000
+    const bytes = new Array(nextLen)
+    for (let i = 0; i < nextLen; i++) {
+      bytes[i] = decoder.arr[decoder.pos++]
+    }
+    encodedString += String.fromCodePoint.apply(null, bytes)
+    remainingLen -= nextLen
+  }
+  return decodeURIComponent(escape(encodedString))
+}
+
+/**
+ * Look ahead and read varString without incrementing position
+ * @param {Decoder} decoder
+ * @return {string}
+ */
+export const peekVarString = decoder => {
+  let pos = decoder.pos
+  let s = readVarString(decoder)
+  decoder.pos = pos
+  return s
+}
--- a/lib/encoding.js
+++ b/lib/encoding.js
@ -0,0 +1,218 @@
+
+import * as globals from './globals.js'
+
+const bits7 = 0b1111111
+const bits8 = 0b11111111
+
+/**
+ * A BinaryEncoder handles the encoding to an ArrayBuffer.
+ */
+export class Encoder {
+  constructor () {
+    this.cpos = 0
+    this.cbuf = globals.createUint8ArrayFromLen(1000)
+    this.bufs = []
+  }
+}
+
+export const createEncoder = () => new Encoder()
+
+/**
+ * The current length of the encoded data.
+ */
+export const length = encoder => {
+  let len = encoder.cpos
+  for (let i = 0; i < encoder.bufs.length; i++) {
+    len += encoder.bufs[i].length
+  }
+  return len
+}
+
+/**
+ * Transform to ArrayBuffer. TODO: rename to .toArrayBuffer
+ * @param {Encoder} encoder
+ * @return {ArrayBuffer} The created ArrayBuffer.
+ */
+export const toBuffer = encoder => {
+  const uint8arr = globals.createUint8ArrayFromLen(length(encoder))
+  let curPos = 0
+  for (let i = 0; i < encoder.bufs.length; i++) {
+    let d = encoder.bufs[i]
+    uint8arr.set(d, curPos)
+    curPos += d.length
+  }
+  uint8arr.set(globals.createUint8ArrayFromBuffer(encoder.cbuf.buffer, 0, encoder.cpos), curPos)
+  return uint8arr.buffer
+}
+
+/**
+ * Write one byte to the encoder.
+ *
+ * @param {Encoder} encoder
+ * @param {number} num The byte that is to be encoded.
+ */
+export const write = (encoder, num) => {
+  if (encoder.cpos === encoder.cbuf.length) {
+    encoder.bufs.push(encoder.cbuf)
+    encoder.cbuf = globals.createUint8ArrayFromLen(encoder.cbuf.length * 2)
+    encoder.cpos = 0
+  }
+  encoder.cbuf[encoder.cpos++] = num
+}
+
+/**
+ * Write one byte at a specific position.
+ * Position must already be written (i.e. encoder.length > pos)
+ *
+ * @param {Encoder} encoder
+ * @param {number} pos Position to which to write data
+ * @param {number} num Unsigned 8-bit integer
+ */
+export const set = (encoder, pos, num) => {
+  let buffer = null
+  // iterate all buffers and adjust position
+  for (let i = 0; i < encoder.bufs.length && buffer === null; i++) {
+    const b = encoder.bufs[i]
+    if (pos < b.length) {
+      buffer = b // found buffer
+    } else {
+      pos -= b.length
+    }
+  }
+  if (buffer === null) {
+    // use current buffer
+    buffer = encoder.cbuf
+  }
+  buffer[pos] = num
+}
+
+/**
+ * Write one byte as an unsigned integer.
+ *
+ * @param {Encoder} encoder
+ * @param {number} num The number that is to be encoded.
+ */
+export const writeUint8 = (encoder, num) => write(encoder, num & bits8)
+
+/**
+ * Write one byte as an unsigned Integer at a specific location.
+ *
+ * @param {Encoder} encoder
+ * @param {number} pos The location where the data will be written.
+ * @param {number} num The number that is to be encoded.
+ */
+export const setUint8 = (encoder, pos, num) => set(encoder, pos, num & bits8)
+
+/**
+ * Write two bytes as an unsigned integer.
+ *
+ * @param {Encoder} encoder
+ * @param {number} num The number that is to be encoded.
+ */
+export const writeUint16 = (encoder, num) => {
+  write(encoder, num & bits8)
+  write(encoder, (num >>> 8) & bits8)
+}
+/**
+ * Write two bytes as an unsigned integer at a specific location.
+ *
+ * @param {Encoder} encoder
+ * @param {number} pos The location where the data will be written.
+ * @param {number} num The number that is to be encoded.
+ */
+export const setUint16 = (encoder, pos, num) => {
+  set(encoder, pos, num & bits8)
+  set(encoder, pos + 1, (num >>> 8) & bits8)
+}
+
+/**
+ * Write two bytes as an unsigned integer
+ *
+ * @param {Encoder} encoder
+ * @param {number} num The number that is to be encoded.
+ */
+export const writeUint32 = (encoder, num) => {
+  for (let i = 0; i < 4; i++) {
+    write(encoder, num & bits8)
+    num >>>= 8
+  }
+}
+
+/**
+ * Write two bytes as an unsigned integer at a specific location.
+ *
+ * @param {Encoder} encoder
+ * @param {number} pos The location where the data will be written.
+ * @param {number} num The number that is to be encoded.
+ */
+export const setUint32 = (encoder, pos, num) => {
+  for (let i = 0; i < 4; i++) {
+    set(encoder, pos + i, num & bits8)
+    num >>>= 8
+  }
+}
+
+/**
+ * Write a variable length unsigned integer.
+ *
+ * Encodes integers in the range from [0, 4294967295] / [0, 0xffffffff]. (max 32 bit unsigned integer)
+ *
+ * @param {Encoder} encoder
+ * @param {number} num The number that is to be encoded.
+ */
+export const writeVarUint = (encoder, num) => {
+  while (num >= 0b10000000) {
+    write(encoder, 0b10000000 | (bits7 & num))
+    num >>>= 7
+  }
+  write(encoder, bits7 & num)
+}
+
+/**
+ * Write a variable length string.
+ *
+ * @param {Encoder} encoder
+ * @param {String} str The string that is to be encoded.
+ */
+export const writeVarString = (encoder, str) => {
+  const encodedString = unescape(encodeURIComponent(str))
+  const len = encodedString.length
+  writeVarUint(encoder, len)
+  for (let i = 0; i < len; i++) {
+    write(encoder, encodedString.codePointAt(i))
+  }
+}
+
+/**
+ * Write the content of another Encoder.
+ *
+ * TODO: can be improved!
+ *
+ * @param {Encoder} encoder The enUint8Arr
+ * @param {Encoder} append The BinaryEncoder to be written.
+ */
+export const writeBinaryEncoder = (encoder, append) => writeArrayBuffer(encoder, toBuffer(append))
+
+/**
+ * Append an arrayBuffer to the encoder.
+ *
+ * @param {Encoder} encoder
+ * @param {ArrayBuffer} arrayBuffer
+ */
+export const writeArrayBuffer = (encoder, arrayBuffer) => {
+  const prevBufferLen = encoder.cbuf.length
+  // TODO: Append to cbuf if possible
+  encoder.bufs.push(globals.createUint8ArrayFromBuffer(encoder.cbuf.buffer, 0, encoder.cpos))
+  encoder.bufs.push(globals.createUint8ArrayFromArrayBuffer(arrayBuffer))
+  encoder.cbuf = globals.createUint8ArrayFromLen(prevBufferLen)
+  encoder.cpos = 0
+}
+
+/**
+ * @param {Encoder} encoder
+ * @param {ArrayBuffer} arrayBuffer
+ */
+export const writePayload = (encoder, arrayBuffer) => {
+  writeVarUint(encoder, arrayBuffer.byteLength)
+  writeArrayBuffer(encoder, arrayBuffer)
+}
--- a/lib/encoding.test.js
+++ b/lib/encoding.test.js
@ -0,0 +1,49 @@
+import * as encoding from './encoding.js'
+
+/**
+ * Check if binary encoding is compatible with golang binary encoding - binary.PutVarUint.
+ *
+ * Result: is compatible up to 32 bit: [0, 4294967295] / [0, 0xffffffff]. (max 32 bit unsigned integer)
+ */
+let err = null
+try {
+  const tests = [
+    { in: 0, out: [0] },
+    { in: 1, out: [1] },
+    { in: 128, out: [128, 1] },
+    { in: 200, out: [200, 1] },
+    { in: 32, out: [32] },
+    { in: 500, out: [244, 3] },
+    { in: 256, out: [128, 2] },
+    { in: 700, out: [188, 5] },
+    { in: 1024, out: [128, 8] },
+    { in: 1025, out: [129, 8] },
+    { in: 4048, out: [208, 31] },
+    { in: 5050, out: [186, 39] },
+    { in: 1000000, out: [192, 132, 61] },
+    { in: 34951959, out: [151, 166, 213, 16] },
+    { in: 2147483646, out: [254, 255, 255, 255, 7] },
+    { in: 2147483647, out: [255, 255, 255, 255, 7] },
+    { in: 2147483648, out: [128, 128, 128, 128, 8] },
+    { in: 2147483700, out: [180, 128, 128, 128, 8] },
+    { in: 4294967294, out: [254, 255, 255, 255, 15] },
+    { in: 4294967295, out: [255, 255, 255, 255, 15] }
+  ]
+  tests.forEach(test => {
+    const encoder = encoding.createEncoder()
+    encoding.writeVarUint(encoder, test.in)
+    const buffer = new Uint8Array(encoding.toBuffer(encoder))
+    if (buffer.byteLength !== test.out.length) {
+      throw new Error('Length don\'t match!')
+    }
+    for (let j = 0; j < buffer.length; j++) {
+      if (buffer[j] !== test[1][j]) {
+        throw new Error('values don\'t match!')
+      }
+    }
+  })
+} catch (error) {
+  err = error
+} finally {
+  console.log('YDB Client: Encoding varUint compatiblity test: ', err || 'success!')
+}
--- a/lib/globals.js
+++ b/lib/globals.js
@ -0,0 +1,63 @@
+/* eslint-env browser */
+
+export const Uint8Array_ = Uint8Array
+
+/**
+ * @param {Array<number>} arr
+ * @return {ArrayBuffer}
+ */
+export const createArrayBufferFromArray = arr => new Uint8Array_(arr).buffer
+
+export const createUint8ArrayFromLen = len => new Uint8Array_(len)
+
+/**
+ * Create Uint8Array with initial content from buffer
+ */
+export const createUint8ArrayFromBuffer = (buffer, byteOffset, length) => new Uint8Array_(buffer, byteOffset, length)
+
+/**
+ * Create Uint8Array with initial content from buffer
+ */
+export const createUint8ArrayFromArrayBuffer = arraybuffer => new Uint8Array_(arraybuffer)
+export const createArrayFromArrayBuffer = arraybuffer => Array.from(createUint8ArrayFromArrayBuffer(arraybuffer))
+
+export const createPromise = f => new Promise(f)
+
+export const createMap = () => new Map()
+export const createSet = () => new Set()
+
+/**
+ * `Promise.all` wait for all promises in the array to resolve and return the result
+ * @param {Array<Promise<any>>} arrp
+ * @return {any}
+ */
+export const pall = arrp => Promise.all(arrp)
+export const preject = reason => Promise.reject(reason)
+export const presolve = res => Promise.resolve(res)
+
+export const until = (timeout, check) => createPromise((resolve, reject) => {
+  const hasTimeout = timeout > 0
+  const untilInterval = () => {
+    if (check()) {
+      clearInterval(intervalHandle)
+      resolve()
+    } else if (hasTimeout) {
+      timeout -= 10
+      if (timeout < 0) {
+        clearInterval(intervalHandle)
+        reject(error('Timeout'))
+      }
+    }
+  }
+  const intervalHandle = setInterval(untilInterval, 10)
+})
+
+export const error = description => new Error(description)
+
+export const max = (a, b) => a > b ? a : b
+
+/**
+ * @param {number} t Time to wait
+ * @return {Promise} Promise that is resolved after t ms
+ */
+export const wait = t => createPromise(r => setTimeout(r, t))
--- a/lib/idb.js
+++ b/lib/idb.js
@ -0,0 +1,159 @@
+/* eslint-env browser */
+
+import * as globals from './globals.js'
+
+/*
+ * IDB Request to Promise transformer
+ */
+export const rtop = request => globals.createPromise((resolve, reject) => {
+  request.onerror = event => reject(new Error(event.target.error))
+  request.onblocked = () => location.reload()
+  request.onsuccess = event => resolve(event.target.result)
+})
+
+/**
+ * @return {Promise<IDBDatabase>}
+ */
+export const openDB = (name, initDB) => globals.createPromise((resolve, reject) => {
+  let request = indexedDB.open(name)
+  /**
+   * @param {any} event
+   */
+  request.onupgradeneeded = event => initDB(event.target.result)
+  /**
+   * @param {any} event
+   */
+  request.onerror = event => reject(new Error(event.target.error))
+  request.onblocked = () => location.reload()
+  /**
+   * @param {any} event
+   */
+  request.onsuccess = event => {
+    const db = event.target.result
+    db.onversionchange = () => { db.close() }
+    addEventListener('unload', () => db.close())
+    resolve(db)
+  }
+})
+
+export const deleteDB = name => rtop(indexedDB.deleteDatabase(name))
+
+export const createStores = (db, definitions) => definitions.forEach(d =>
+  db.createObjectStore.apply(db, d)
+)
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {String | number | ArrayBuffer | Date | Array } key
+ * @return {Promise<ArrayBuffer>}
+ */
+export const get = (store, key) =>
+  rtop(store.get(key))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {String | number | ArrayBuffer | Date | IDBKeyRange | Array } key
+ */
+export const del = (store, key) =>
+  rtop(store.delete(key))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {String | number | ArrayBuffer | Date | boolean} item
+ * @param {String | number | ArrayBuffer | Date | Array} [key]
+ */
+export const put = (store, item, key) =>
+  rtop(store.put(item, key))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {String | number | ArrayBuffer | Date | boolean}  item
+ * @param {String | number | ArrayBuffer | Date | Array}  [key]
+ * @return {Promise<ArrayBuffer>}
+ */
+export const add = (store, item, key) =>
+  rtop(store.add(item, key))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {String | number | ArrayBuffer | Date}  item
+ * @return {Promise<number>}
+ */
+export const addAutoKey = (store, item) =>
+  rtop(store.add(item))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {IDBKeyRange} [range]
+ */
+export const getAll = (store, range) =>
+  rtop(store.getAll(range))
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {IDBKeyRange} [range]
+ */
+export const getAllKeys = (store, range) =>
+  rtop(store.getAllKeys(range))
+
+/**
+ * @typedef KeyValuePair
+ * @type {Object}
+ * @property {any} k key
+ * @property {any} v Value
+ */
+
+/**
+ * @param {IDBObjectStore} store
+ * @param {IDBKeyRange} [range]
+ * @return {Promise<Array<KeyValuePair>>}
+ */
+export const getAllKeysValues = (store, range) =>
+  globals.pall([getAllKeys(store, range), getAll(store, range)]).then(([ks, vs]) => ks.map((k, i) => ({ k, v: vs[i] })))
+
+/**
+ * Iterate on keys and values
+ * @param {IDBObjectStore} store
+ * @param {IDBKeyRange?} keyrange
+ * @param {function(any, any)} f Return true in order to continue the cursor
+ */
+export const iterate = (store, keyrange, f) => globals.createPromise((resolve, reject) => {
+  const request = store.openCursor(keyrange)
+  request.onerror = reject
+  /**
+   * @param {any} event
+   */
+  request.onsuccess = event => {
+    const cursor = event.target.result
+    if (cursor === null) {
+      return resolve()
+    }
+    f(cursor.value, cursor.key)
+    cursor.continue()
+  }
+})
+
+/**
+ * Iterate on the keys (no values)
+ * @param {IDBObjectStore} store
+ * @param {IDBKeyRange} keyrange
+ * @param {function(IDBCursor)} f Call `idbcursor.continue()` to iterate further
+ */
+export const iterateKeys = (store, keyrange, f) => {
+  /**
+   * @param {any} event
+   */
+  store.openKeyCursor(keyrange).onsuccess = event => f(event.target.result)
+}
+
+/**
+ * Open store from transaction
+ * @param {IDBTransaction} t
+ * @param {String} store
+ * @returns {IDBObjectStore}
+ */
+export const getStore = (t, store) => t.objectStore(store)
+
+export const createIDBKeyRangeBound = (lower, upper, lowerOpen, upperOpen) => IDBKeyRange.bound(lower, upper, lowerOpen, upperOpen)
+export const createIDBKeyRangeUpperBound = (upper, upperOpen) => IDBKeyRange.upperBound(upper, upperOpen)
+export const createIDBKeyRangeLowerBound = (lower, lowerOpen) => IDBKeyRange.lowerBound(lower, lowerOpen)
--- a/lib/idb.test.js
+++ b/lib/idb.test.js
@ -0,0 +1,34 @@
+import * as test from './test.js'
+import * as idb from './idb.js'
+import * as logging from './logging.js'
+
+const initTestDB = db => idb.createStores(db, [['test']])
+const testDBName = 'idb-test'
+
+const createTransaction = db => db.transaction(['test'], 'readwrite')
+/**
+ * @param {IDBTransaction} t
+ * @return {IDBObjectStore}
+ */
+const getStore = t => idb.getStore(t, 'test')
+
+idb.deleteDB(testDBName).then(() => idb.openDB(testDBName, initTestDB)).then(db => {
+  test.run('idb iteration', async testname => {
+    const t = createTransaction(db)
+    await idb.put(getStore(t), 0, ['t', 0])
+    await idb.put(getStore(t), 1, ['t', 1])
+    const valsGetAll = await idb.getAll(getStore(t))
+    if (valsGetAll.length !== 2) {
+      logging.fail('getAll does not return two values')
+    }
+    const valsIterate = []
+    const keyrange = idb.createIDBKeyRangeBound(['t', 0], ['t', 1], false, false)
+    await idb.put(getStore(t), 2, ['t', 2])
+    await idb.iterate(getStore(t), keyrange, (val, key) => {
+      valsIterate.push(val)
+    })
+    if (valsIterate.length !== 2) {
+      logging.fail('iterate does not return two values')
+    }
+  })
+})
--- a/lib/logging.js
+++ b/lib/logging.js
@ -0,0 +1,23 @@
+
+import * as globals from './globals.js'
+
+let date = new Date().getTime()
+
+const writeDate = () => {
+  const oldDate = date
+  date = new Date().getTime()
+  return date - oldDate
+}
+
+export const print = (...args) => console.log(...args)
+export const log = m => print(`%cydb-client: %c${m} %c+${writeDate()}ms`, 'color: blue;', '', 'color: blue')
+
+export const fail = m => {
+  throw new Error(m)
+}
+
+/**
+ * @param {ArrayBuffer} buffer
+ * @return {string}
+ */
+export const arrayBufferToString = buffer => JSON.stringify(Array.from(globals.createUint8ArrayFromBuffer(buffer)))
--- a/lib/math.js
+++ b/lib/math.js
@ -0,0 +1,2 @@
+
+export const floor = Math.floor
--- a/lib/mutex.js
+++ b/lib/mutex.js
@ -0,0 +1,32 @@
+
+/**
+ * Creates a mutual exclude function with the following property:
+ *
+ * @example
+ * const mutex = createMutex()
+ * mutex(function () {
+ *   // This function is immediately executed
+ *   mutex(function () {
+ *     // This function is never executed, as it is called with the same
+ *     // mutex function
+ *   })
+ * })
+ *
+ * @return {Function} A mutual exclude function
+ * @public
+ */
+export const createMutex = () => {
+  let token = true
+  return (f, g) => {
+    if (token) {
+      token = false
+      try {
+        f()
+      } finally {
+        token = true
+      }
+    } else if (g !== undefined) {
+      g()
+    }
+  }
+}
--- a/lib/number.js
+++ b/lib/number.js
@ -0,0 +1,2 @@
+export const MAX_SAFE_INTEGER = Number.MAX_SAFE_INTEGER
+export const MIN_SAFE_INTEGER = Number.MIN_SAFE_INTEGER
--- a/lib/random/PRNG/Mt19937.js
+++ b/lib/random/PRNG/Mt19937.js
@ -0,0 +1,66 @@
+const N = 624
+const M = 397
+
+function twist (u, v) {
+  return ((((u & 0x80000000) | (v & 0x7fffffff)) >>> 1) ^ ((v & 1) ? 0x9908b0df : 0))
+}
+
+function nextState (state) {
+  let p = 0
+  let j
+  for (j = N - M + 1; --j; p++) {
+    state[p] = state[p + M] ^ twist(state[p], state[p + 1])
+  }
+  for (j = M; --j; p++) {
+    state[p] = state[p + M - N] ^ twist(state[p], state[p + 1])
+  }
+  state[p] = state[p + M - N] ^ twist(state[p], state[0])
+}
+
+/**
+ * This is a port of Shawn Cokus's implementation of the original Mersenne Twister algorithm (http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/CODES/MTARCOK/mt19937ar-cok.c).
+ * MT has a very high period of 2^19937. Though the authors of xorshift describe that a high period is not
+ * very relevant (http://vigna.di.unimi.it/xorshift/). It is four times slower than xoroshiro128plus and
+ * needs to recompute its state after generating 624 numbers.
+ *
+ * @example
+ * const gen = new Mt19937(new Date().getTime())
+ * console.log(gen.next())
+ *
+ * @public
+ */
+export default class Mt19937 {
+  /**
+   * @param {Number} seed The starting point for the random number generation. If you use the same seed, the generator will return the same sequence of random numbers.
+   */
+  constructor (seed) {
+    this.seed = seed
+    const state = new Uint32Array(N)
+    state[0] = seed
+    for (let i = 1; i < N; i++) {
+      state[i] = (Math.imul(1812433253, (state[i - 1] ^ (state[i - 1] >>> 30))) + i) & 0xFFFFFFFF
+    }
+    this._state = state
+    this._i = 0
+    nextState(this._state)
+  }
+
+  /**
+   * Generate a random signed integer.
+   *
+   * @return {Number} A 32 bit signed integer.
+   */
+  next () {
+    if (this._i === N) {
+      // need to compute a new state
+      nextState(this._state)
+      this._i = 0
+    }
+    let y = this._state[this._i++]
+    y ^= (y >>> 11)
+    y ^= (y << 7) & 0x9d2c5680
+    y ^= (y << 15) & 0xefc60000
+    y ^= (y >>> 18)
+    return y
+  }
+}
--- a/lib/random/PRNG/PRNG.tests.js
+++ b/lib/random/PRNG/PRNG.tests.js
@ -0,0 +1,48 @@
+
+import Mt19937 from './Mt19937.js'
+import Xoroshiro128plus from './Xoroshiro128plus.js'
+import Xorshift32 from './Xorshift32.js'
+import * as time from '../../time.js'
+
+const DIAMETER = 300
+const NUMBERS = 10000
+
+function runPRNG (name, Gen) {
+  console.log('== ' + name + ' ==')
+  const gen = new Gen(1234)
+  let head = 0
+  let tails = 0
+  const date = time.getUnixTime()
+  const canvas = document.createElement('canvas')
+  canvas.height = DIAMETER
+  canvas.width = DIAMETER
+  const ctx = canvas.getContext('2d')
+  const vals = new Set()
+  ctx.fillStyle = 'blue'
+  for (let i = 0; i < NUMBERS; i++) {
+    const n = gen.next() & 0xFFFFFF
+    const x = (gen.next() >>> 0) % DIAMETER
+    const y = (gen.next() >>> 0) % DIAMETER
+    ctx.fillRect(x, y, 1, 2)
+    if ((n & 1) === 1) {
+      head++
+    } else {
+      tails++
+    }
+    if (vals.has(n)) {
+      console.warn(`The generator generated a duplicate`)
+    }
+    vals.add(n)
+  }
+  console.log('time: ', time.getUnixTime() - date)
+  console.log('head:', head, 'tails:', tails)
+  console.log('%c       ', `font-size: 200px; background: url(${canvas.toDataURL()}) no-repeat;`)
+  const h1 = document.createElement('h1')
+  h1.insertBefore(document.createTextNode(name), null)
+  document.body.insertBefore(h1, null)
+  document.body.appendChild(canvas)
+}
+
+runPRNG('mt19937', Mt19937)
+runPRNG('xoroshiro128plus', Xoroshiro128plus)
+runPRNG('xorshift32', Xorshift32)
--- a/lib/random/PRNG/README.md
+++ b/lib/random/PRNG/README.md
@ -0,0 +1,5 @@
+# Pseudo Random Number Generators (PRNG)
+
+Given a seed a PRNG generates a sequence of numbers that cannot be reasonably predicted. Two PRNGs must generate the same random sequence of numbers if  given the same seed.
+
+TODO: explain what POINT is
--- a/lib/random/PRNG/Xoroshiro128plus.js
+++ b/lib/random/PRNG/Xoroshiro128plus.js
@ -0,0 +1,98 @@
+
+import Xorshift32 from './Xorshift32.js'
+
+/**
+ * This is a variant of xoroshiro128plus - the fastest full-period generator passing BigCrush without systematic failures.
+ *
+ * This implementation follows the idea of the original xoroshiro128plus implementation,
+ * but is optimized for the JavaScript runtime. I.e.
+ * * The operations are performed on 32bit integers (the original implementation works with 64bit values).
+ * * The initial 128bit state is computed based on a 32bit seed and Xorshift32.
+ * * This implementation returns two 32bit values based on the 64bit value that is computed by xoroshiro128plus.
+ *   Caution: The last addition step works slightly different than in the original implementation - the add carry of the
+ *   first 32bit addition is not carried over to the last 32bit.
+ *
+ * [Reference implementation](http://vigna.di.unimi.it/xorshift/xoroshiro128plus.c)
+ */
+export default class Xoroshiro128plus {
+  constructor (seed) {
+    this.seed = seed
+    // This is a variant of Xoroshiro128plus to fill the initial state
+    const xorshift32 = new Xorshift32(seed)
+    this.state = new Uint32Array(4)
+    for (let i = 0; i < 4; i++) {
+      this.state[i] = xorshift32.next()
+    }
+    this._fresh = true
+  }
+  next () {
+    const state = this.state
+    if (this._fresh) {
+      this._fresh = false
+      return (state[0] + state[2]) & 0xFFFFFFFF
+    } else {
+      this._fresh = true
+      const s0 = state[0]
+      const s1 = state[1]
+      const s2 = state[2] ^ s0
+      const s3 = state[3] ^ s1
+      // function js_rotl (x, k) {
+      //   k = k - 32
+      //   const x1 = x[0]
+      //   const x2 = x[1]
+      //   x[0] = x2 << k | x1 >>> (32 - k)
+      //   x[1] = x1 << k | x2 >>> (32 - k)
+      // }
+      // rotl(s0, 55) // k = 23 = 55 - 32; j = 9 =  32 - 23
+      state[0] = (s1 << 23 | s0 >>> 9) ^ s2 ^ (s2 << 14 | s3 >>> 18)
+      state[1] = (s0 << 23 | s1 >>> 9) ^ s3 ^ (s3 << 14)
+      // rol(s1, 36) // k = 4 = 36 - 32; j = 23 = 32 - 9
+      state[2] = s3 << 4 | s2 >>> 28
+      state[3] = s2 << 4 | s3 >>> 28
+      return (state[1] + state[3]) & 0xFFFFFFFF
+    }
+  }
+}
+
+/*
+
+// reference implementation
+#include <stdint.h>
+#include <stdio.h>
+
+uint64_t s[2];
+
+static inline uint64_t rotl(const uint64_t x, int k) {
+    return (x << k) | (x >> (64 - k));
+}
+
+uint64_t next(void) {
+    const uint64_t s0 = s[0];
+    uint64_t s1 = s[1];
+    s1 ^= s0;
+    s[0] = rotl(s0, 55) ^ s1 ^ (s1 << 14); // a, b
+    s[1] = rotl(s1, 36); // c
+    return (s[0] + s[1]) & 0xFFFFFFFF;
+}
+
+int main(void)
+{
+    int i;
+    s[0] = 1111 | (1337ul << 32);
+    s[1] = 1234 | (9999ul << 32);
+
+    printf("1000 outputs of genrand_int31()\n");
+    for (i=0; i<100; i++) {
+        printf("%10lu ", i);
+        printf("%10lu ", next());
+        printf("- %10lu ", s[0] >> 32);
+        printf("%10lu ", (s[0] << 32) >> 32);
+        printf("%10lu ", s[1] >> 32);
+        printf("%10lu ", (s[1] << 32) >> 32);
+        printf("\n");
+        // if (i%5==4) printf("\n");
+    }
+    return 0;
+}
+
+*/
--- a/lib/random/PRNG/Xorshift32.js
+++ b/lib/random/PRNG/Xorshift32.js
@ -0,0 +1,26 @@
+
+/**
+ * Xorshift32 is a very simple but elegang PRNG with a period of `2^32-1`.
+ */
+export default class Xorshift32 {
+  /**
+   * @param {number} seed The starting point for the random number generation. If you use the same seed, the generator will return the same sequence of random numbers.
+   */
+  constructor (seed) {
+    this.seed = seed
+    this._state = seed
+  }
+  /**
+   * Generate a random signed integer.
+   *
+   * @return {Number} A 32 bit signed integer.
+   */
+  next () {
+    let x = this._state
+    x ^= x << 13
+    x ^= x >> 17
+    x ^= x << 5
+    this._state = x
+    return x
+  }
+}
--- a/lib/random/random.js
+++ b/lib/random/random.js
@ -0,0 +1,131 @@
+
+import * as binary from '../binary.js'
+import { fromCharCode, fromCodePoint } from '../string.js'
+import { MAX_SAFE_INTEGER, MIN_SAFE_INTEGER } from '../number.js'
+import * as math from '../math.js'
+
+import DefaultPRNG from './PRNG/Xoroshiro128plus.js'
+
+/**
+ * Description of the function
+ *  @callback generatorNext
+ *  @return {number} A 32bit integer
+ */
+
+/**
+ * A random type generator.
+ *
+ * @typedef {Object} PRNG
+ * @property {generatorNext} next Generate new number
+ */
+
+/**
+ * Create a Xoroshiro128plus Pseudo-Random-Number-Generator.
+ * This is the fastest full-period generator passing BigCrush without systematic failures.
+ * But there are more PRNGs available in ./PRNG/.
+ *
+ * @param {number} seed A positive 32bit integer. Do not use negative numbers.
+ * @return {PRNG}
+ */
+export const createPRNG = seed => new DefaultPRNG(Math.floor(seed < 1 ? seed * binary.BITS32 : seed))
+
+/**
+ * Generates a single random bool.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @return {Boolean} A random boolean
+ */
+export const bool = gen => (gen.next() & 2) === 2 // brackets are non-optional!
+
+/**
+ * Generates a random integer with 53 bit resolution.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @param {Number} [min = MIN_SAFE_INTEGER] The lower bound of the allowed return values (inclusive).
+ * @param {Number} [max = MAX_SAFE_INTEGER] The upper bound of the allowed return values (inclusive).
+ * @return {Number} A random integer on [min, max]
+ */
+export const int53 = (gen, min = MIN_SAFE_INTEGER, max = MAX_SAFE_INTEGER) => math.floor(real53(gen) * (max + 1 - min) + min)
+
+/**
+ * Generates a random integer with 32 bit resolution.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @param {Number} [min = MIN_SAFE_INTEGER] The lower bound of the allowed return values (inclusive).
+ * @param {Number} [max = MAX_SAFE_INTEGER] The upper bound of the allowed return values (inclusive).
+ * @return {Number} A random integer on [min, max]
+ */
+export const int32 = (gen, min = MIN_SAFE_INTEGER, max = MAX_SAFE_INTEGER) => min + ((gen.next() >>> 0) % (max + 1 - min))
+
+/**
+ * Generates a random real on [0, 1) with 32 bit resolution.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @return {Number} A random real number on [0, 1).
+ */
+export const real32 = gen => (gen.next() >>> 0) / binary.BITS32
+
+/**
+ * Generates a random real on [0, 1) with 53 bit resolution.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @return {Number} A random real number on [0, 1).
+ */
+export const real53 = gen => (((gen.next() >>> 5) * binary.BIT26) + (gen.next() >>> 6)) / MAX_SAFE_INTEGER
+
+/**
+ * Generates a random character from char code 32 - 126. I.e. Characters, Numbers, special characters, and Space:
+ *
+ * (Space)!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[/]^_`abcdefghijklmnopqrstuvwxyz{|}~
+ */
+export const char = gen => fromCharCode(int32(gen, 32, 126))
+
+/**
+ * @param {PRNG} gen
+ * @return {string} A single letter (a-z)
+ */
+export const letter = gen => fromCharCode(int32(gen, 97, 122))
+
+/**
+ * @param {PRNG} gen
+ * @return {string} A random word without spaces consisting of letters (a-z)
+ */
+export const word = gen => {
+  const len = int32(gen, 0, 20)
+  let str = ''
+  for (let i = 0; i < len; i++) {
+    str += letter(gen)
+  }
+  return str
+}
+
+/**
+ * TODO: this function produces invalid runes. Does not cover all of utf16!!
+ */
+export const utf16Rune = gen => {
+  const codepoint = int32(gen, 0, 256)
+  return fromCodePoint(codepoint)
+}
+
+/**
+ * @param {PRNG} gen
+ * @param {number} [maxlen = 20]
+ */
+export const utf16String = (gen, maxlen = 20) => {
+  const len = int32(gen, 0, maxlen)
+  let str = ''
+  for (let i = 0; i < len; i++) {
+    str += utf16Rune(gen)
+  }
+  return str
+}
+
+/**
+ * Returns one element of a given array.
+ *
+ * @param {PRNG} gen A random number generator.
+ * @param {Array<T>} array Non empty Array of possible values.
+ * @return {T} One of the values of the supplied Array.
+ * @template T
+ */
+export const oneOf = (gen, array) => array[int32(gen, 0, array.length - 1)]
--- a/lib/random/random.test.js
+++ b/lib/random/random.test.js
@ -0,0 +1,110 @@
+/**
+ *TODO: enable tests
+import * as rt from '../rich-text/formatters.mjs'
+import { test } from '../test/test.mjs'
+import Xoroshiro128plus from './PRNG/Xoroshiro128plus.mjs'
+import Xorshift32 from './PRNG/Xorshift32.mjs'
+import MT19937 from './PRNG/Mt19937.mjs'
+import { generateBool, generateInt, generateInt32, generateReal, generateChar } from './random.mjs'
+import { MAX_SAFE_INTEGER } from '../number/constants.mjs'
+import { BIT32 } from '../binary/constants.mjs'
+
+function init (Gen) {
+  return {
+    gen: new Gen(1234)
+  }
+}
+
+const PRNGs = [
+  { name: 'Xoroshiro128plus', Gen: Xoroshiro128plus },
+  { name: 'Xorshift32', Gen: Xorshift32 },
+  { name: 'MT19937', Gen: MT19937 }
+]
+
+const ITERATONS = 1000000
+
+for (const PRNG of PRNGs) {
+  const prefix = rt.orange`${PRNG.name}:`
+
+  test(rt.plain`${prefix} generateBool`, function generateBoolTest (t) {
+    const { gen } = init(PRNG.Gen)
+    let head = 0
+    let tail = 0
+    let b
+    let i
+
+    for (i = 0; i < ITERATONS; i++) {
+      b = generateBool(gen)
+      if (b) {
+        head++
+      } else {
+        tail++
+      }
+    }
+    t.log(`Generated ${head} heads and ${tail} tails.`)
+    t.assert(tail >= Math.floor(ITERATONS * 0.49), 'Generated enough tails.')
+    t.assert(head >= Math.floor(ITERATONS * 0.49), 'Generated enough heads.')
+  })
+
+  test(rt.plain`${prefix} generateInt integers average correctly`, function averageIntTest (t) {
+    const { gen } = init(PRNG.Gen)
+    let count = 0
+    let i
+
+    for (i = 0; i < ITERATONS; i++) {
+      count += generateInt(gen, 0, 100)
+    }
+    const average = count / ITERATONS
+    const expectedAverage = 100 / 2
+    t.log(`Average is: ${average}. Expected average is ${expectedAverage}.`)
+    t.assert(Math.abs(average - expectedAverage) <= 1, 'Expected average is at most 1 off.')
+  })
+
+  test(rt.plain`${prefix} generateInt32 generates integer with 32 bits`, function generateLargeIntegers (t) {
+    const { gen } = init(PRNG.Gen)
+    let num = 0
+    let i
+    let newNum
+    for (i = 0; i < ITERATONS; i++) {
+      newNum = generateInt32(gen, 0, MAX_SAFE_INTEGER)
+      if (newNum > num) {
+        num = newNum
+      }
+    }
+    t.log(`Largest number generated is ${num} (0b${num.toString(2)})`)
+    t.assert(num > (BIT32 >>> 0), 'Largest number is 32 bits long.')
+  })
+
+  test(rt.plain`${prefix} generateReal has 53 bit resolution`, function real53bitResolution (t) {
+    const { gen } = init(PRNG.Gen)
+    let num = 0
+    let i
+    let newNum
+    for (i = 0; i < ITERATONS; i++) {
+      newNum = generateReal(gen) * MAX_SAFE_INTEGER
+      if (newNum > num) {
+        num = newNum
+      }
+    }
+    t.log(`Largest number generated is ${num}.`)
+    t.assert((MAX_SAFE_INTEGER - num) / MAX_SAFE_INTEGER < 0.01, 'Largest number is close to MAX_SAFE_INTEGER (at most 1% off).')
+  })
+
+  test(rt.plain`${prefix} generateChar generates all described characters`, function real53bitResolution (t) {
+    const { gen } = init(PRNG.Gen)
+    const charSet = new Set()
+    const chars = ' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[/]^_`abcdefghijklmnopqrstuvwxyz{|}~"'
+    let i
+    let char
+    for (i = chars.length - 1; i >= 0; i--) {
+      charSet.add(chars[i])
+    }
+    for (i = 0; i < ITERATONS; i++) {
+      char = generateChar(gen)
+      charSet.delete(char)
+    }
+    t.log(`Charactes missing: ${charSet.size} - generating all of "${chars}"`)
+    t.assert(charSet.size === 0, 'Generated all documented characters.')
+  })
+}
+*/
--- a/lib/simpleDiff.js
+++ b/lib/simpleDiff.js
@ -0,0 +1,47 @@
+
+/**
+ * A SimpleDiff describes a change on a String.
+ *
+ * @example
+ * console.log(a) // the old value
+ * console.log(b) // the updated value
+ * // Apply changes of diff (pseudocode)
+ * a.remove(diff.pos, diff.remove) // Remove `diff.remove` characters
+ * a.insert(diff.pos, diff.insert) // Insert `diff.insert`
+ * a === b // values match
+ *
+ * @typedef {Object} SimpleDiff
+ * @property {Number} pos The index where changes were applied
+ * @property {Number} remove The number of characters to delete starting
+ *                                  at `index`.
+ * @property {String} insert The new text to insert at `index` after applying
+ *                           `delete`
+ */
+
+/**
+ * Create a diff between two strings. This diff implementation is highly
+ * efficient, but not very sophisticated.
+ *
+ * @public
+ * @param {String} a The old version of the string
+ * @param {String} b The updated version of the string
+ * @return {SimpleDiff} The diff description.
+ */
+export default function simpleDiff (a, b) {
+  let left = 0 // number of same characters counting from left
+  let right = 0 // number of same characters counting from right
+  while (left < a.length && left < b.length && a[left] === b[left]) {
+    left++
+  }
+  if (left !== a.length || left !== b.length) {
+    // Only check right if a !== b
+    while (right + left < a.length && right + left < b.length && a[a.length - right - 1] === b[b.length - right - 1]) {
+      right++
+    }
+  }
+  return {
+    pos: left, // TODO: rename to index (also in type above)
+    remove: a.length - left - right,
+    insert: b.slice(left, b.length - right)
+  }
+}
--- a/lib/string.js
+++ b/lib/string.js
@ -0,0 +1,2 @@
+export const fromCharCode = String.fromCharCode
+export const fromCodePoint = String.fromCodePoint
--- a/lib/test.js
+++ b/lib/test.js
@ -0,0 +1,33 @@
+import * as logging from './logging.js'
+import simpleDiff from './simpleDiff.js'
+
+export const run = async (name, f) => {
+  console.log(`%cStart:%c   ${name}`, 'color:blue;', '')
+  const start = new Date()
+  try {
+    await f(name)
+  } catch (e) {
+    logging.print(`%cFailure:%c ${name} in %c${new Date().getTime() - start.getTime()}ms`, 'color:red;font-weight:bold', '', 'color:grey')
+    throw e
+  }
+  logging.print(`%cSuccess:%c ${name} in %c${new Date().getTime() - start.getTime()}ms`, 'color:green;font-weight:bold', '', 'color:grey')
+}
+
+export const compareArrays = (as, bs) => {
+  if (as.length !== bs.length) {
+    return false
+  }
+  for (let i = 0; i < as.length; i++) {
+    if (as[i] !== bs[i]) {
+      return false
+    }
+  }
+  return true
+}
+
+export const compareStrings = (a, b) => {
+  if (a !== b) {
+    const diff = simpleDiff(a, b)
+    logging.print(`%c${a.slice(0, diff.pos)}%c${a.slice(diff.pos, diff.remove)}%c${diff.insert}%c${a.slice(diff.pos + diff.remove)}`, 'color:grey', 'color:red', 'color:green', 'color:grey')
+  }
+}
--- a/lib/time.js
+++ b/lib/time.js
@ -0,0 +1,3 @@
+
+export const getDate = () => new Date()
+export const getUnixTime = () => getDate().getTime()
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@ -1,99 +1,76 @@
 {
  "name": "yjs",
-  "version": "13.6.24",
-  "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"
-  },
+  "version": "13.0.0-66",
+  "description": "A framework for real-time p2p shared editing on any data",
+  "main": "./y.node.js",
+  "browser": "./y.js",
+  "module": "./src/index.js",
  "scripts": {
-    "clean": "rm -rf dist docs",
-    "test": "npm run dist && NODE_ENV=development node ./dist/tests.cjs --repetition-time 50",
-    "test-extensive": "npm run lint && npm run dist && node ./dist/tests.cjs --production --repetition-time 10000",
-    "dist": "npm run clean && 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 && node ./dist/tests.cjs --repetition-time 1000 && 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"
-  },
-  "exports": {
-    ".": {
-      "types": "./dist/src/index.d.ts",
-      "module": "./dist/yjs.mjs",
-      "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"
+    "test": "npm run lint",
+    "debug": "concurrently 'rollup -wc rollup.test.js' 'cutest-serve y.test.js -o'",
+    "lint": "standard src/**/*.js test/**/*.js tests-lib/**/*.js",
+    "docs": "esdoc",
+    "serve-docs": "npm run docs && serve ./docs/",
+    "dist": "rollup -c rollup.browser.js; rollup -c rollup.node.js",
+    "watch": "concurrently 'rollup -wc rollup.browser.js' 'rollup -wc rollup.node.js'",
+    "postversion": "npm run dist"
  },
  "files": [
-    "dist/yjs.*",
-    "dist/src",
-    "src",
-    "tests/testHelper.js",
-    "dist/testHelper.mjs",
-    "sponsor-y.js"
+    "y.*",
+    "src/*",
+    ".esdoc.json",
+    "docs/*"
  ],
-  "dictionaries": {
-    "test": "tests"
-  },
  "standard": {
    "ignore": [
-      "/dist",
-      "/node_modules",
-      "/docs"
+      "/y.js",
+      "/y.js.map"
    ]
  },
  "repository": {
    "type": "git",
-    "url": "https://github.com/yjs/yjs.git"
+    "url": "https://github.com/y-js/yjs.git"
  },
  "keywords": [
    "Yjs",
-    "CRDT",
-    "offline",
-    "offline-first",
-    "shared-editing",
-    "concurrency",
-    "collaboration"
+    "OT",
+    "Collaboration",
+    "Synchronization",
+    "ShareJS",
+    "Coweb",
+    "Concurrency"
  ],
  "author": "Kevin Jahns",
-  "email": "kevin.jahns@protonmail.com",
+  "email": "kevin.jahns@rwth-aachen.de",
  "license": "MIT",
  "bugs": {
-    "url": "https://github.com/yjs/yjs/issues"
-  },
-  "homepage": "https://docs.yjs.dev",
-  "dependencies": {
-    "lib0": "^0.2.99"
+    "url": "https://github.com/y-js/yjs/issues"
  },
+  "homepage": "http://y-js.org",
  "devDependencies": {
-    "@rollup/plugin-commonjs": "^24.0.1",
-    "@rollup/plugin-node-resolve": "^15.0.1",
-    "@types/node": "^18.15.5",
+    "babel-cli": "^6.26.0",
+    "babel-plugin-external-helpers": "^6.22.0",
+    "babel-plugin-transform-regenerator": "^6.26.0",
+    "babel-plugin-transform-runtime": "^6.23.0",
+    "babel-preset-latest": "^6.24.1",
    "concurrently": "^3.6.1",
-    "http-server": "^0.12.3",
-    "jsdoc": "^3.6.7",
-    "markdownlint-cli": "^0.41.0",
-    "rollup": "^3.20.0",
-    "standard": "^16.0.4",
-    "tui-jsdoc-template": "^1.2.2",
-    "typescript": "^4.9.5",
-    "y-protocols": "^1.0.5"
+    "cutest": "^0.1.9",
+    "esdoc": "^1.1.0",
+    "esdoc-standard-plugin": "^1.0.0",
+    "quill": "^1.3.6",
+    "quill-cursors": "^1.0.3",
+    "rollup": "^0.58.2",
+    "rollup-plugin-babel": "^2.7.1",
+    "rollup-plugin-commonjs": "^8.4.1",
+    "rollup-plugin-inject": "^2.2.0",
+    "rollup-plugin-multi-entry": "^2.0.2",
+    "rollup-plugin-node-resolve": "^3.4.0",
+    "rollup-plugin-uglify": "^1.0.2",
+    "rollup-regenerator-runtime": "^6.23.1",
+    "rollup-watch": "^3.2.2",
+    "standard": "^11.0.1"
  },
-  "engines": {
-    "npm": ">=8.0.0",
-    "node": ">=16.0.0"
+  "dependencies": {
+    "ws": "^6.1.0"
  }
 }
--- a/provider/websocket/WebSocketProvider.js
+++ b/provider/websocket/WebSocketProvider.js
@ -0,0 +1,85 @@
+/* eslint-env browser */
+
+import * as Y from '../../src/index.js'
+export * from '../../src/index.js'
+
+const reconnectTimeout = 100
+
+const setupWS = (doc, url) => {
+  const websocket = new WebSocket(url)
+  websocket.binaryType = 'arraybuffer'
+  doc.ws = websocket
+  websocket.onmessage = event => {
+    const decoder = Y.createDecoder(event.data)
+    const encoder = Y.createEncoder()
+    doc.mux(() =>
+      Y.readMessage(decoder, encoder, doc)
+    )
+    if (Y.length(encoder) > 0) {
+      websocket.send(Y.toBuffer(encoder))
+    }
+  }
+  websocket.onclose = () => {
+    doc.ws = null
+    doc.wsconnected = false
+    doc.emit('status', {
+      status: 'connected'
+    })
+    setTimeout(setupWS, reconnectTimeout, doc, url)
+  }
+  websocket.onopen = () => {
+    doc.wsconnected = true
+    doc.emit('status', {
+      status: 'disconnected'
+    })
+    // always send sync step 1 when connected
+    const encoder = Y.createEncoder()
+    Y.writeSyncStep1(encoder, doc)
+    websocket.send(Y.toBuffer(encoder))
+  }
+}
+
+const broadcastUpdate = (y, transaction) => {
+  if (y.wsconnected && transaction.encodedStructsLen > 0) {
+    y.mux(() => {
+      const encoder = Y.createEncoder()
+      Y.writeUpdate(encoder, transaction.encodedStructsLen, transaction.encodedStructs)
+      y.ws.send(Y.toBuffer(encoder))
+    })
+  }
+}
+
+class WebsocketsSharedDocument extends Y.Y {
+  constructor (url) {
+    super()
+    this.wsconnected = false
+    this.mux = Y.createMutex()
+    setupWS(this, url)
+    this.on('afterTransaction', broadcastUpdate)
+  }
+}
+
+export default class WebsocketProvider {
+  constructor (url) {
+    // ensure that url is always ends with /
+    while (url[url.length - 1] === '/') {
+      url = url.slice(0, url.length - 1)
+    }
+    this.url = url + '/'
+    /**
+     * @type {Map<string, WebsocketsSharedDocument>}
+     */
+    this.docs = new Map()
+  }
+  /**
+   * @param {string} name
+   * @return {WebsocketsSharedDocument}
+   */
+  get (name) {
+    let doc = this.docs.get(name)
+    if (doc === undefined) {
+      doc = new WebsocketsSharedDocument(this.url + name)
+    }
+    return doc
+  }
+}
--- a/provider/websocket/server.js
+++ b/provider/websocket/server.js
@ -0,0 +1,53 @@
+const Y = require('../../build/node/index.js')
+const WebSocket = require('ws')
+const wss = new WebSocket.Server({ port: 1234 })
+const docs = new Map()
+
+const afterTransaction = (doc, transaction) => {
+  if (transaction.encodedStructsLen > 0) {
+    const encoder = Y.createEncoder()
+    Y.writeUpdate(encoder, transaction.encodedStructsLen, transaction.encodedStructs)
+    const message = Y.toBuffer(encoder)
+    doc.conns.forEach(conn => conn.send(message))
+  }
+}
+
+class WSSharedDoc extends Y.Y {
+  constructor () {
+    super()
+    this.mux = Y.createMutex()
+    this.conns = new Set()
+    this.on('afterTransaction', afterTransaction)
+  }
+}
+
+const messageListener = (conn, doc, message) => {
+  const encoder = Y.createEncoder()
+  const decoder = Y.createDecoder(message)
+  Y.readMessage(decoder, encoder, doc)
+  if (Y.length(encoder) > 0) {
+    conn.send(Y.toBuffer(encoder))
+  }
+}
+
+const setupConnection = (conn, req) => {
+  conn.binaryType = 'arraybuffer'
+  // get doc, create if it does not exist yet
+  let doc = docs.get(req.url.slice(1))
+  if (doc === undefined) {
+    doc = new WSSharedDoc()
+    docs.set(req.url.slice(1), doc)
+  }
+  doc.conns.add(conn)
+  // listen and reply to events
+  conn.on('message', message => messageListener(conn, doc, message))
+  conn.on('close', () =>
+    doc.conns.delete(conn)
+  )
+  // send sync step 1
+  const encoder = Y.createEncoder()
+  Y.writeSyncStep1(encoder, doc)
+  conn.send(Y.toBuffer(encoder))
+}
+
+wss.on('connection', setupConnection)
--- a/rollup.browser.js
+++ b/rollup.browser.js
@ -0,0 +1,46 @@
+import babel from 'rollup-plugin-babel'
+import uglify from 'rollup-plugin-uglify'
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+var pkg = require('./package.json')
+
+export default {
+  input: 'src/Y.dist.js',
+  name: 'Y',
+  sourcemap: true,
+  output: {
+    file: 'y.js',
+    format: 'umd'
+  },
+  plugins: [
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs(),
+    babel(),
+    uglify({
+      mangle: {
+        except: ['YMap', 'Y', 'YArray', 'YText', 'YXmlHook', 'YXmlFragment', 'YXmlElement', 'YXmlEvent', 'YXmlText', 'YEvent', 'YArrayEvent', 'YMapEvent', 'Type', 'Delete', 'ItemJSON', 'ItemString', 'Item']
+      },
+      output: {
+        comments: function (node, comment) {
+          var text = comment.value
+          var type = comment.type
+          if (type === 'comment2') {
+            // multiline comment
+            return /@license/i.test(text)
+          }
+        }
+      }
+    })
+  ],
+  banner: `
+/**
+ * ${pkg.name} - ${pkg.description}
+ * @version v${pkg.version}
+ * @license ${pkg.license}
+ */
+`
+}
--- a/rollup.config.js
+++ b/rollup.config.js
@ -1,106 +0,0 @@
-import nodeResolve from '@rollup/plugin-node-resolve'
-import commonjs from '@rollup/plugin-commonjs'
-
-const localImports = process.env.LOCALIMPORTS
-
-const customModules = new Set([
-  'y-websocket',
-  'y-codemirror',
-  'y-ace',
-  'y-textarea',
-  'y-quill',
-  'y-dom',
-  'y-prosemirror'
-])
-/**
- * @type {Set<any>}
- */
-const customLibModules = new Set([
-  'lib0',
-  'y-protocols'
-])
-const debugResolve = {
-  resolveId (importee) {
-    if (importee === 'yjs') {
-      return `${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
-  },
-  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: ['browser', 'module', 'main']
-    }),
-    commonjs()
-  ]
-}, {
-  input: './tests/index.js',
-  output: {
-    name: 'test',
-    file: 'dist/tests.cjs',
-    format: 'cjs',
-    sourcemap: true
-  },
-  plugins: [
-    debugResolve,
-    nodeResolve({
-      mainFields: ['node', 'module', 'main'],
-      exportConditions: ['node', 'module', 'import', 'default']
-    }),
-    commonjs()
-  ],
-  external: id => /^lib0\//.test(id)
-}]
--- a/rollup.node.js
+++ b/rollup.node.js
@ -0,0 +1,18 @@
+const pkg = require('./package.json')
+
+export default {
+  input: 'src/index.js',
+  output: {
+    name: 'Y',
+    file: 'build/node/index.js',
+    format: 'cjs',
+    sourcemap: true,
+    banner: `
+/**
+ * ${pkg.name} - ${pkg.description}
+ * @version v${pkg.version}
+ * @license ${pkg.license}
+ */
+`
+  }
+}
--- a/rollup.test.js
+++ b/rollup.test.js
@ -0,0 +1,22 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+import multiEntry from 'rollup-plugin-multi-entry'
+
+export default {
+  input: 'test/index.js',
+  name: 'y-tests',
+  sourcemap: true,
+  output: {
+    file: 'y.test.js',
+    format: 'umd'
+  },
+  plugins: [
+    multiEntry(),
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs()
+  ]
+}
--- a/src/Bindings/Binding.js
+++ b/src/Bindings/Binding.js
@ -0,0 +1,47 @@
+
+import { createMutex } from '../../lib/mutex.js'
+
+/**
+ * Abstract class for bindings.
+ *
+ * A binding handles data binding from a Yjs type to a data object. For example,
+ * you can bind a Quill editor instance to a YText instance with the `QuillBinding` class.
+ *
+ * It is expected that a concrete implementation accepts two parameters
+ * (type and binding target).
+ *
+ * @example
+ *   const quill = new Quill(document.createElement('div'))
+ *   const type = y.define('quill', Y.Text)
+ *   const binding = new Y.QuillBinding(quill, type)
+ *
+ */
+export default class Binding {
+  /**
+   * @param {YType} type Yjs type.
+   * @param {any} target Binding Target.
+   */
+  constructor (type, target) {
+    /**
+     * The Yjs type that is bound to `target`
+     * @type {YType}
+     */
+    this.type = type
+    /**
+     * The target that `type` is bound to.
+     * @type {*}
+     */
+    this.target = target
+    /**
+     * @private
+     */
+    this._mutualExclude = createMutex()
+  }
+  /**
+   * Remove all data observers (both from the type and the target).
+   */
+  destroy () {
+    this.type = null
+    this.target = null
+  }
+}
--- a/src/Bindings/CodeMirrorBinding/CodeMirrorBinding.js
+++ b/src/Bindings/CodeMirrorBinding/CodeMirrorBinding.js
@ -0,0 +1,56 @@
+
+import Binding from '../Binding.js'
+import simpleDiff from '../../Util/simpleDiff.js'
+import { getRelativePosition, fromRelativePosition } from '../../Util/relativePosition.js'
+
+function typeObserver () {
+  this._mutualExclude(() => {
+    const textarea = this.target
+    const textType = this.type
+    const relativeStart = getRelativePosition(textType, textarea.selectionStart)
+    const relativeEnd = getRelativePosition(textType, textarea.selectionEnd)
+    textarea.value = textType.toString()
+    const start = fromRelativePosition(textType._y, relativeStart)
+    const end = fromRelativePosition(textType._y, relativeEnd)
+    textarea.setSelectionRange(start, end)
+  })
+}
+
+function domObserver () {
+  this._mutualExclude(() => {
+    let diff = simpleDiff(this.type.toString(), this.target.value)
+    this.type.delete(diff.pos, diff.remove)
+    this.type.insert(diff.pos, diff.insert)
+  })
+}
+
+/**
+ * A binding that binds a YText to a dom textarea.
+ *
+ * This binding is automatically destroyed when its parent is deleted.
+ *
+ * @example
+ *   const textare = document.createElement('textarea')
+ *   const type = y.define('textarea', Y.Text)
+ *   const binding = new Y.QuillBinding(type, textarea)
+ *
+ */
+export default class TextareaBinding extends Binding {
+  constructor (textType, domTextarea) {
+    // Binding handles textType as this.type and domTextarea as this.target
+    super(textType, domTextarea)
+    // set initial value
+    domTextarea.value = textType.toString()
+    // Observers are handled by this class
+    this._typeObserver = typeObserver.bind(this)
+    this._domObserver = domObserver.bind(this)
+    textType.observe(this._typeObserver)
+    domTextarea.addEventListener('input', this._domObserver)
+  }
+  destroy () {
+    // Remove everything that is handled by this class
+    this.type.unobserve(this._typeObserver)
+    this.target.unobserve(this._domObserver)
+    super.destroy()
+  }
+}
--- a/src/Bindings/DomBinding/DomBinding.js
+++ b/src/Bindings/DomBinding/DomBinding.js
@ -0,0 +1,211 @@
+/* global MutationObserver, getSelection */
+
+import { fromRelativePosition } from '../../Util/relativePosition.js'
+import Binding from '../Binding.js'
+import { createAssociation, removeAssociation } from './util.js'
+import { beforeTransactionSelectionFixer, afterTransactionSelectionFixer, getCurrentRelativeSelection } from './selection.js'
+import { defaultFilter, applyFilterOnType } from './filter.js'
+import typeObserver from './typeObserver.js'
+import domObserver from './domObserver.js'
+
+/**
+ * @typedef {import('./filter.js').DomFilter} DomFilter
+ */
+
+/**
+ * A binding that binds the children of a YXmlFragment to a DOM element.
+ *
+ * This binding is automatically destroyed when its parent is deleted.
+ *
+ * @example
+ * const div = document.createElement('div')
+ * const type = y.define('xml', Y.XmlFragment)
+ * const binding = new Y.QuillBinding(type, div)
+ *
+ */
+export default class DomBinding extends Binding {
+  /**
+   * @param {YXmlFragment} type The bind source. This is the ultimate source of
+   *                            truth.
+   * @param {Element} target The bind target. Mirrors the target.
+   * @param {Object} [opts] Optional configurations
+
+   * @param {DomFilter} [opts.filter=defaultFilter] The filter function to use.
+   */
+  constructor (type, target, opts = {}) {
+    // Binding handles textType as this.type and domTextarea as this.target
+    super(type, target)
+    this.opts = opts
+    opts.document = opts.document || document
+    opts.hooks = opts.hooks || {}
+    this.scrollingElement = opts.scrollingElement || null
+    /**
+     * Maps each DOM element to the type that it is associated with.
+     * @type {Map}
+     */
+    this.domToType = new Map()
+    /**
+     * Maps each YXml type to the DOM element that it is associated with.
+     * @type {Map}
+     */
+    this.typeToDom = new Map()
+    /**
+     * Defines which DOM attributes and elements to filter out.
+     * Also filters remote changes.
+     * @type {DomFilter}
+     */
+    this.filter = opts.filter || defaultFilter
+    // set initial value
+    target.innerHTML = ''
+    type.forEach(child => {
+      target.insertBefore(child.toDom(opts.document, opts.hooks, this), null)
+    })
+    this._typeObserver = typeObserver.bind(this)
+    this._domObserver = mutations => {
+      domObserver.call(this, mutations, opts.document)
+    }
+    type.observeDeep(this._typeObserver)
+    this._mutationObserver = new MutationObserver(this._domObserver)
+    this._mutationObserver.observe(target, {
+      childList: true,
+      attributes: true,
+      characterData: true,
+      subtree: true
+    })
+    this._currentSel = null
+    this._selectionchange = () => {
+      this._currentSel = getCurrentRelativeSelection(this)
+    }
+    document.addEventListener('selectionchange', this._selectionchange)
+    const y = type._y
+    this.y = y
+    // Force flush dom changes before Type changes are applied (they might
+    // modify the dom)
+    this._beforeTransactionHandler = (y, transaction, remote) => {
+      this._domObserver(this._mutationObserver.takeRecords())
+      this._mutualExclude(() => {
+        beforeTransactionSelectionFixer(this, remote)
+      })
+    }
+    y.on('beforeTransaction', this._beforeTransactionHandler)
+    this._afterTransactionHandler = (y, transaction, remote) => {
+      this._mutualExclude(() => {
+        afterTransactionSelectionFixer(this, remote)
+      })
+      // remove associations
+      // TODO: this could be done more efficiently
+      // e.g. Always delete using the following approach, or removeAssociation
+      // in dom/type-observer..
+      transaction.deletedStructs.forEach(type => {
+        const dom = this.typeToDom.get(type)
+        if (dom !== undefined) {
+          removeAssociation(this, dom, type)
+        }
+      })
+    }
+    y.on('afterTransaction', this._afterTransactionHandler)
+    // Before calling observers, apply dom filter to all changed and new types.
+    this._beforeObserverCallsHandler = (y, transaction) => {
+      // Apply dom filter to new and changed types
+      transaction.changedTypes.forEach((subs, type) => {
+        // Only check attributes. New types are filtered below.
+        if ((subs.size > 1 || (subs.size === 1 && subs.has(null) === false))) {
+          applyFilterOnType(y, this, type)
+        }
+      })
+      transaction.newTypes.forEach(type => {
+        applyFilterOnType(y, this, type)
+      })
+    }
+    y.on('beforeObserverCalls', this._beforeObserverCallsHandler)
+    createAssociation(this, target, type)
+  }
+
+  /**
+   * NOTE: currently does not apply filter to existing elements!
+   * @param {DomFilter} filter The filter function to use from now on.
+   */
+  setFilter (filter) {
+    this.filter = filter
+    // TODO: apply filter to all elements
+  }
+
+  _getUndoStackInfo () {
+    return this.getSelection()
+  }
+
+  _restoreUndoStackInfo (info) {
+    this.restoreSelection(info)
+  }
+
+  getSelection () {
+    return this._currentSel
+  }
+
+  restoreSelection (selection) {
+    if (selection !== null) {
+      const { to, from } = selection
+      /**
+       * There is little information on the difference between anchor/focus and base/extent.
+       * MDN doesn't even mention base/extent anymore.. though you still have to call
+       * setBaseAndExtent to change the selection..
+       * I can observe that base/extend refer to notes higher up in the xml hierachy.
+       * Espesially for undo/redo this is preferred. If this becomes a problem in the future,
+       * we should probably go back to anchor/focus.
+       */
+      const browserSelection = getSelection()
+      let { baseNode, baseOffset, extentNode, extentOffset } = browserSelection
+      if (from !== null) {
+        let sel = fromRelativePosition(this.y, from)
+        if (sel !== null) {
+          let node = this.typeToDom.get(sel.type)
+          let offset = sel.offset
+          if (node !== baseNode || offset !== baseOffset) {
+            baseNode = node
+            baseOffset = offset
+          }
+        }
+      }
+      if (to !== null) {
+        let sel = fromRelativePosition(this.y, to)
+        if (sel !== null) {
+          let node = this.typeToDom.get(sel.type)
+          let offset = sel.offset
+          if (node !== extentNode || offset !== extentOffset) {
+            extentNode = node
+            extentOffset = offset
+          }
+        }
+      }
+      browserSelection.setBaseAndExtent(
+        baseNode,
+        baseOffset,
+        extentNode,
+        extentOffset
+      )
+    }
+  }
+
+  /**
+   * Remove all properties that are handled by this class.
+   */
+  destroy () {
+    this.domToType = null
+    this.typeToDom = null
+    this.type.unobserveDeep(this._typeObserver)
+    this._mutationObserver.disconnect()
+    const y = this.type._y
+    y.off('beforeTransaction', this._beforeTransactionHandler)
+    y.off('beforeObserverCalls', this._beforeObserverCallsHandler)
+    y.off('afterTransaction', this._afterTransactionHandler)
+    document.removeEventListener('selectionchange', this._selectionchange)
+    super.destroy()
+  }
+}
+/**
+ * A filter defines which elements and attributes to share.
+ * Return null if the node should be filtered. Otherwise return the Map of
+ * accepted attributes.
+ *
+ * @typedef {function(nodeName: String, attrs: Map): Map|null} FilterFunction
+ */
--- a/src/Bindings/DomBinding/domObserver.js
+++ b/src/Bindings/DomBinding/domObserver.js
@ -0,0 +1,144 @@
+
+import YXmlHook from '../../Types/YXml/YXmlHook.js'
+import {
+  iterateUntilUndeleted,
+  removeAssociation,
+  insertNodeHelper } from './util.js'
+import diff from '../../../lib/simpleDiff.js'
+import YXmlFragment from '../../Types/YXml/YXmlFragment.js'
+
+/**
+ * 1. Check if any of the nodes was deleted
+ * 2. Iterate over the children.
+ *    2.1 If a node exists that is not yet bound to a type, insert a new node
+ *    2.2 If _contents.length < dom.childNodes.length, fill the
+ *        rest of _content with childNodes
+ *    2.3 If a node was moved, delete it and
+ *       recreate a new yxml element that is bound to that node.
+ *       You can detect that a node was moved because expectedId
+ *       !== actualId in the list
+ * @private
+ */
+function applyChangesFromDom (binding, dom, yxml, _document) {
+  if (yxml == null || yxml === false || yxml.constructor === YXmlHook) {
+    return
+  }
+  const y = yxml._y
+  const knownChildren = new Set()
+  for (let i = dom.childNodes.length - 1; i >= 0; i--) {
+    const type = binding.domToType.get(dom.childNodes[i])
+    if (type !== undefined && type !== false) {
+      knownChildren.add(type)
+    }
+  }
+  // 1. Check if any of the nodes was deleted
+  yxml.forEach(function (childType) {
+    if (knownChildren.has(childType) === false) {
+      childType._delete(y)
+      removeAssociation(binding, binding.typeToDom.get(childType), childType)
+    }
+  })
+  // 2. iterate
+  const childNodes = dom.childNodes
+  const len = childNodes.length
+  let prevExpectedType = null
+  let expectedType = iterateUntilUndeleted(yxml._start)
+  for (let domCnt = 0; domCnt < len; domCnt++) {
+    const childNode = childNodes[domCnt]
+    const childType = binding.domToType.get(childNode)
+    if (childType !== undefined) {
+      if (childType === false) {
+        // should be ignored or is going to be deleted
+        continue
+      }
+      if (expectedType !== null) {
+        if (expectedType !== childType) {
+          // 2.3 Not expected node
+          if (childType._parent !== yxml) {
+            // child was moved from another parent
+            // childType is going to be deleted by its previous parent
+            removeAssociation(binding, childNode, childType)
+          } else {
+            // child was moved to a different position.
+            removeAssociation(binding, childNode, childType)
+            childType._delete(y)
+          }
+          prevExpectedType = insertNodeHelper(yxml, prevExpectedType, childNode, _document, binding)
+        } else {
+          // Found expected node. Continue.
+          prevExpectedType = expectedType
+          expectedType = iterateUntilUndeleted(expectedType._right)
+        }
+      } else {
+        // 2.2 Fill _content with child nodes
+        prevExpectedType = insertNodeHelper(yxml, prevExpectedType, childNode, _document, binding)
+      }
+    } else {
+      // 2.1 A new node was found
+      prevExpectedType = insertNodeHelper(yxml, prevExpectedType, childNode, _document, binding)
+    }
+  }
+}
+
+/**
+ * @private
+ */
+export default function domObserver (mutations, _document) {
+  this._mutualExclude(() => {
+    this.type._y.transact(() => {
+      let diffChildren = new Set()
+      mutations.forEach(mutation => {
+        const dom = mutation.target
+        const yxml = this.domToType.get(dom)
+        if (yxml === undefined) { // In case yxml is undefined, we double check if we forgot to bind the dom
+          let parent = dom
+          let yParent
+          do {
+            parent = parent.parentElement
+            yParent = this.domToType.get(parent)
+          } while (yParent === undefined && parent !== null)
+          if (yParent !== false && yParent !== undefined && yParent.constructor !== YXmlHook) {
+            diffChildren.add(parent)
+          }
+          return
+        } else if (yxml === false || yxml.constructor === YXmlHook) {
+          // dom element is filtered / a dom hook
+          return
+        }
+        switch (mutation.type) {
+          case 'characterData':
+            var change = diff(yxml.toString(), dom.nodeValue)
+            yxml.delete(change.pos, change.remove)
+            yxml.insert(change.pos, change.insert)
+            break
+          case 'attributes':
+            if (yxml.constructor === YXmlFragment) {
+              break
+            }
+            let name = mutation.attributeName
+            let val = dom.getAttribute(name)
+            // check if filter accepts attribute
+            let attributes = new Map()
+            attributes.set(name, val)
+            if (yxml.constructor !== YXmlFragment && this.filter(dom.nodeName, attributes).size > 0) {
+              if (yxml.getAttribute(name) !== val) {
+                if (val == null) {
+                  yxml.removeAttribute(name)
+                } else {
+                  yxml.setAttribute(name, val)
+                }
+              }
+            }
+            break
+          case 'childList':
+            diffChildren.add(mutation.target)
+            break
+        }
+      })
+      for (let dom of diffChildren) {
+        const yxml = this.domToType.get(dom)
+        applyChangesFromDom(this, dom, yxml, _document)
+      }
+    })
+  })
+}
--- a/src/Bindings/DomBinding/domToType.js
+++ b/src/Bindings/DomBinding/domToType.js
@ -0,0 +1,66 @@
+/* eslint-env browser */
+import YXmlText from '../../Types/YXml/YXmlText.js'
+import YXmlHook from '../../Types/YXml/YXmlHook.js'
+import YXmlElement from '../../Types/YXml/YXmlElement.js'
+import { createAssociation, domsToTypes } from './util.js'
+import { filterDomAttributes, defaultFilter } from './filter.js'
+
+/**
+ * @typedef {import('./filter.js').DomFilter} DomFilter
+ * @typedef {import('./DomBinding.js').default} DomBinding
+ */
+
+/**
+ * Creates a Yjs type (YXml) based on the contents of a DOM Element.
+ *
+ * @param {Element|Text} element The DOM Element
+ * @param {?Document} _document Optional. Provide the global document object
+ * @param {Object<string, any>} [hooks = {}] Optional. Set of Yjs Hooks
+ * @param {DomFilter} [filter=defaultFilter] Optional. Dom element filter
+ * @param {?DomBinding} binding Warning: This property is for internal use only!
+ * @return {YXmlElement | YXmlText | false}
+ */
+export default function domToType (element, _document = document, hooks = {}, filter = defaultFilter, binding) {
+  /**
+   * @type {any}
+   */
+  let type = null
+  if (element instanceof Element) {
+    let hookName = null
+    let hook
+    // configure `hookName !== undefined` if element is a hook.
+    if (element.hasAttribute('data-yjs-hook')) {
+      hookName = element.getAttribute('data-yjs-hook')
+      hook = hooks[hookName]
+      if (hook === undefined) {
+        console.error(`Unknown hook "${hookName}". Deleting yjsHook dataset property.`)
+        element.removeAttribute('data-yjs-hook')
+        hookName = null
+      }
+    }
+    if (hookName === null) {
+      // Not a hook
+      const attrs = filterDomAttributes(element, filter)
+      if (attrs === null) {
+        type = false
+      } else {
+        type = new YXmlElement(element.nodeName)
+        attrs.forEach((val, key) => {
+          type.setAttribute(key, val)
+        })
+        type.insert(0, domsToTypes(element.childNodes, document, hooks, filter, binding))
+      }
+    } else {
+      // Is a hook
+      type = new YXmlHook(hookName)
+      hook.fillType(element, type)
+    }
+  } else if (element instanceof Text) {
+    type = new YXmlText()
+    type.insert(0, element.nodeValue)
+  } else {
+    throw new Error('Can\'t transform this node type to a YXml type!')
+  }
+  createAssociation(binding, element, type)
+  return type
+}
--- a/src/Bindings/DomBinding/filter.js
+++ b/src/Bindings/DomBinding/filter.js
@ -0,0 +1,67 @@
+import isParentOf from '../../Util/isParentOf.js'
+
+/**
+ * @callback DomFilter
+ * @param {string} nodeName
+ * @param {Map<string, string>} attrs
+ * @return {Map | null}
+ */
+
+/**
+ * Default filter method (does nothing).
+ *
+ * @param {String} nodeName The nodeName of the element
+ * @param {Map} attrs Map of key-value pairs that are attributes of the node.
+ * @return {Map | null} The allowed attributes or null, if the element should be
+ *                      filtered.
+ */
+export function defaultFilter (nodeName, attrs) {
+  // TODO: implement basic filter that filters out dangerous properties!
+  return attrs
+}
+
+/**
+ *
+ */
+export function filterDomAttributes (dom, filter) {
+  const attrs = new Map()
+  for (let i = dom.attributes.length - 1; i >= 0; i--) {
+    const attr = dom.attributes[i]
+    attrs.set(attr.name, attr.value)
+  }
+  return filter(dom.nodeName, attrs)
+}
+
+/**
+ * Applies a filter on a type.
+ *
+ * @param {Y} y The Yjs instance.
+ * @param {DomBinding} binding The DOM binding instance that has the dom filter.
+ * @param {YXmlElement | YXmlFragment } type The type to apply the filter to.
+ *
+ * @private
+ */
+export function applyFilterOnType (y, binding, type) {
+  if (isParentOf(binding.type, type)) {
+    const nodeName = type.nodeName
+    let attributes = new Map()
+    if (type.getAttributes !== undefined) {
+      let attrs = type.getAttributes()
+      for (let key in attrs) {
+        attributes.set(key, attrs[key])
+      }
+    }
+    const filteredAttributes = binding.filter(nodeName, new Map(attributes))
+    if (filteredAttributes === null) {
+      type._delete(y)
+    } else {
+      // iterate original attributes
+      attributes.forEach((value, key) => {
+        // delete all attributes that are not in filteredAttributes
+        if (filteredAttributes.has(key) === false) {
+          type.removeAttribute(key)
+        }
+      })
+    }
+  }
+}
--- a/src/Bindings/DomBinding/selection.js
+++ b/src/Bindings/DomBinding/selection.js
@ -0,0 +1,35 @@
+/* globals getSelection */
+
+import { getRelativePosition } from '../../Util/relativePosition.js'
+
+let relativeSelection = null
+
+function _getCurrentRelativeSelection (domBinding) {
+  const { baseNode, baseOffset, extentNode, extentOffset } = getSelection()
+  const baseNodeType = domBinding.domToType.get(baseNode)
+  const extentNodeType = domBinding.domToType.get(extentNode)
+  if (baseNodeType !== undefined && extentNodeType !== undefined) {
+    return {
+      from: getRelativePosition(baseNodeType, baseOffset),
+      to: getRelativePosition(extentNodeType, extentOffset)
+    }
+  }
+  return null
+}
+
+export const getCurrentRelativeSelection = typeof getSelection !== 'undefined' ? _getCurrentRelativeSelection : domBinding => null
+
+export function beforeTransactionSelectionFixer (domBinding) {
+  relativeSelection = getCurrentRelativeSelection(domBinding)
+}
+
+/**
+ * Reset the browser range after every transaction.
+ * This prevents any collapsing issues with the local selection.
+ * @private
+ */
+export function afterTransactionSelectionFixer (domBinding) {
+  if (relativeSelection !== null) {
+    domBinding.restoreSelection(relativeSelection)
+  }
+}
--- a/src/Bindings/DomBinding/typeObserver.js
+++ b/src/Bindings/DomBinding/typeObserver.js
@ -0,0 +1,106 @@
+/* eslint-env browser */
+/* global getSelection */
+
+import YXmlText from '../../Types/YXml/YXmlText.js'
+import YXmlHook from '../../Types/YXml/YXmlHook.js'
+import { removeDomChildrenUntilElementFound } from './util.js'
+
+function findScrollReference (scrollingElement) {
+  if (scrollingElement !== null) {
+    let anchor = getSelection().anchorNode
+    if (anchor == null) {
+      let children = scrollingElement.children // only iterate through non-text nodes
+      for (let i = 0; i < children.length; i++) {
+        const elem = children[i]
+        const rect = elem.getBoundingClientRect()
+        if (rect.top >= 0) {
+          return { elem, top: rect.top }
+        }
+      }
+    } else {
+      /**
+       * @type {Element}
+       */
+      let elem = anchor.parentElement
+      if (anchor instanceof Element) {
+        elem = anchor
+      }
+      return {
+        elem,
+        top: elem.getBoundingClientRect().top
+      }
+    }
+  }
+  return null
+}
+
+function fixScroll (scrollingElement, ref) {
+  if (ref !== null) {
+    const { elem, top } = ref
+    const currentTop = elem.getBoundingClientRect().top
+    const newScroll = scrollingElement.scrollTop + currentTop - top
+    if (newScroll >= 0) {
+      scrollingElement.scrollTop = newScroll
+    }
+  }
+}
+
+/**
+ * @private
+ */
+export default function typeObserver (events) {
+  this._mutualExclude(() => {
+    const scrollRef = findScrollReference(this.scrollingElement)
+    events.forEach(event => {
+      const yxml = event.target
+      const dom = this.typeToDom.get(yxml)
+      if (dom !== undefined && dom !== false) {
+        if (yxml.constructor === YXmlText) {
+          dom.nodeValue = yxml.toString()
+        } else if (event.attributesChanged !== undefined) {
+          // update attributes
+          event.attributesChanged.forEach(attributeName => {
+            const value = yxml.getAttribute(attributeName)
+            if (value === undefined) {
+              dom.removeAttribute(attributeName)
+            } else {
+              dom.setAttribute(attributeName, value)
+            }
+          })
+          /*
+           * TODO: instead of hard-checking the types, it would be best to
+           *       specify the type's features. E.g.
+           *         - _yxmlHasAttributes
+           *         - _yxmlHasChildren
+           *       Furthermore, the features shouldn't be encoded in the types,
+           *       only in the attributes (above)
+           */
+          if (event.childListChanged && yxml.constructor !== YXmlHook) {
+            let currentChild = dom.firstChild
+            yxml.forEach(childType => {
+              const childNode = this.typeToDom.get(childType)
+              switch (childNode) {
+                case undefined:
+                  // Does not exist. Create it.
+                  const node = childType.toDom(this.opts.document, this.opts.hooks, this)
+                  dom.insertBefore(node, currentChild)
+                  break
+                case false:
+                  // nop
+                  break
+                default:
+                  // Is already attached to the dom.
+                  // Find it and remove all dom nodes in-between.
+                  removeDomChildrenUntilElementFound(dom, currentChild, childNode)
+                  currentChild = childNode.nextSibling
+                  break
+              }
+            })
+            removeDomChildrenUntilElementFound(dom, currentChild, null)
+          }
+        }
+      }
+    })
+    fixScroll(this.scrollingElement, scrollRef)
+  })
+}
--- a/src/Bindings/DomBinding/util.js
+++ b/src/Bindings/DomBinding/util.js
@ -0,0 +1,131 @@
+
+import domToType from './domToType.js'
+
+/**
+ * @typedef {import('../../Types/YXml/YXmlText.js').default} YXmlText
+ * @typedef {import('../../Types/YXml/YXmlElement.js').default} YXmlElement
+ * @typedef {import('../../Types/YXml/YXmlHook.js').default} YXmlHook
+ * @typedef {import('./DomBinding.js').default} DomBinding
+ */
+
+/**
+ * Iterates items until an undeleted item is found.
+ *
+ * @private
+ */
+export function iterateUntilUndeleted (item) {
+  while (item !== null && item._deleted) {
+    item = item._right
+  }
+  return item
+}
+
+/**
+ * Removes an association (the information that a DOM element belongs to a
+ * type).
+ *
+ * @param {DomBinding} domBinding The binding object
+ * @param {Element} dom The dom that is to be associated with type
+ * @param {YXmlElement|YXmlHook} type The type that is to be associated with dom
+ *
+ */
+export function removeAssociation (domBinding, dom, type) {
+  domBinding.domToType.delete(dom)
+  domBinding.typeToDom.delete(type)
+}
+
+/**
+ * Creates an association (the information that a DOM element belongs to a
+ * type).
+ *
+ * @param {DomBinding} domBinding The binding object
+ * @param {DocumentFragment|Element|Text} dom The dom that is to be associated with type
+ * @param {YXmlElement|YXmlHook|YXmlText} type The type that is to be associated with dom
+ *
+ */
+export function createAssociation (domBinding, dom, type) {
+  if (domBinding !== undefined) {
+    domBinding.domToType.set(dom, type)
+    domBinding.typeToDom.set(type, dom)
+  }
+}
+
+/**
+ * If oldDom is associated with a type, associate newDom with the type and
+ * forget about oldDom. If oldDom is not associated with any type, nothing happens.
+ *
+ * @param {DomBinding} domBinding The binding object
+ * @param {Element} oldDom The existing dom
+ * @param {Element} newDom The new dom object
+ */
+export function switchAssociation (domBinding, oldDom, newDom) {
+  if (domBinding !== undefined) {
+    const type = domBinding.domToType.get(oldDom)
+    if (type !== undefined) {
+      removeAssociation(domBinding, oldDom, type)
+      createAssociation(domBinding, newDom, type)
+    }
+  }
+}
+
+/**
+ * Insert Dom Elements after one of the children of this YXmlFragment.
+ * The Dom elements will be bound to a new YXmlElement and inserted at the
+ * specified position.
+ *
+ * @param {YXmlElement} type The type in which to insert DOM elements.
+ * @param {YXmlElement|null} prev The reference node. New YxmlElements are
+ *                           inserted after this node. Set null to insert at
+ *                           the beginning.
+ * @param {Array<Element>} doms The Dom elements to insert.
+ * @param {?Document} _document Optional. Provide the global document object.
+ * @param {DomBinding} binding The dom binding
+ * @return {Array<YXmlElement>} The YxmlElements that are inserted.
+ *
+ * @private
+ */
+export function insertDomElementsAfter (type, prev, doms, _document, binding) {
+  const types = domsToTypes(doms, _document, binding.opts.hooks, binding.filter, binding)
+  return type.insertAfter(prev, types)
+}
+
+export function domsToTypes (doms, _document, hooks, filter, binding) {
+  const types = []
+  for (let dom of doms) {
+    const t = domToType(dom, _document, hooks, filter, binding)
+    if (t !== false) {
+      types.push(t)
+    }
+  }
+  return types
+}
+
+/**
+ * @private
+ */
+export function insertNodeHelper (yxml, prevExpectedNode, child, _document, binding) {
+  let insertedNodes = insertDomElementsAfter(yxml, prevExpectedNode, [child], _document, binding)
+  if (insertedNodes.length > 0) {
+    return insertedNodes[0]
+  } else {
+    return prevExpectedNode
+  }
+}
+
+/**
+ * Remove children until `elem` is found.
+ *
+ * @param {Element} parent The parent of `elem` and `currentChild`.
+ * @param {Element} currentChild Start removing elements with `currentChild`. If
+ *                               `currentChild` is `elem` it won't be removed.
+ * @param {Element|null} elem The elemnt to look for.
+ *
+ * @private
+ */
+export function removeDomChildrenUntilElementFound (parent, currentChild, elem) {
+  while (currentChild !== elem) {
+    const del = currentChild
+    currentChild = currentChild.nextSibling
+    parent.removeChild(del)
+  }
+}
--- a/src/Bindings/QuillBinding/QuillBinding.js
+++ b/src/Bindings/QuillBinding/QuillBinding.js
@ -0,0 +1,53 @@
+import Binding from '../Binding.js'
+
+function typeObserver (event) {
+  const quill = this.target
+  // Force flush Quill changes.
+  quill.update('yjs')
+  this._mutualExclude(function () {
+    // Apply computed delta.
+    quill.updateContents(event.delta, 'yjs')
+    // Force flush Quill changes. Ignore applied changes.
+    quill.update('yjs')
+  })
+}
+
+function quillObserver (delta) {
+  this._mutualExclude(() => {
+    this.type.applyDelta(delta.ops)
+  })
+}
+
+/**
+ * A Binding that binds a YText type to a Quill editor.
+ *
+ * @example
+ * const quill = new Quill(document.createElement('div'))
+ * const type = y.define('quill', Y.Text)
+ * const binding = new Y.QuillBinding(quill, type)
+ * // Now modifications on the DOM will be reflected in the Type, and the other
+ * // way around!
+ */
+export default class QuillBinding extends Binding {
+  /**
+   * @param {YText} textType
+   * @param {Quill} quill
+   */
+  constructor (textType, quill) {
+    // Binding handles textType as this.type and quill as this.target.
+    super(textType, quill)
+    // Set initial value.
+    quill.setContents(textType.toDelta(), 'yjs')
+    // Observers are handled by this class.
+    this._typeObserver = typeObserver.bind(this)
+    this._quillObserver = quillObserver.bind(this)
+    textType.observe(this._typeObserver)
+    quill.on('text-change', this._quillObserver)
+  }
+  destroy () {
+    // Remove everything that is handled by this class.
+    this.type.unobserve(this._typeObserver)
+    this.target.off('text-change', this._quillObserver)
+    super.destroy()
+  }
+}
--- a/src/Bindings/TextareaBinding/TextareaBinding.js
+++ b/src/Bindings/TextareaBinding/TextareaBinding.js
@ -0,0 +1,56 @@
+
+import Binding from '../Binding.js'
+import simpleDiff from '../../../lib/simpleDiff.js'
+import { getRelativePosition, fromRelativePosition } from '../../Util/relativePosition.js'
+
+function typeObserver () {
+  this._mutualExclude(() => {
+    const textarea = this.target
+    const textType = this.type
+    const relativeStart = getRelativePosition(textType, textarea.selectionStart)
+    const relativeEnd = getRelativePosition(textType, textarea.selectionEnd)
+    textarea.value = textType.toString()
+    const start = fromRelativePosition(textType._y, relativeStart)
+    const end = fromRelativePosition(textType._y, relativeEnd)
+    textarea.setSelectionRange(start, end)
+  })
+}
+
+function domObserver () {
+  this._mutualExclude(() => {
+    let diff = simpleDiff(this.type.toString(), this.target.value)
+    this.type.delete(diff.pos, diff.remove)
+    this.type.insert(diff.pos, diff.insert)
+  })
+}
+
+/**
+ * A binding that binds a YText to a dom textarea.
+ *
+ * This binding is automatically destroyed when its parent is deleted.
+ *
+ * @example
+ *   const textare = document.createElement('textarea')
+ *   const type = y.define('textarea', Y.Text)
+ *   const binding = new Y.QuillBinding(type, textarea)
+ *
+ */
+export default class TextareaBinding extends Binding {
+  constructor (textType, domTextarea) {
+    // Binding handles textType as this.type and domTextarea as this.target
+    super(textType, domTextarea)
+    // set initial value
+    domTextarea.value = textType.toString()
+    // Observers are handled by this class
+    this._typeObserver = typeObserver.bind(this)
+    this._domObserver = domObserver.bind(this)
+    textType.observe(this._typeObserver)
+    domTextarea.addEventListener('input', this._domObserver)
+  }
+  destroy () {
+    // Remove everything that is handled by this class
+    this.type.unobserve(this._typeObserver)
+    this.target.unobserve(this._domObserver)
+    super.destroy()
+  }
+}
--- a/src/Persistences/AbstractPersistence.js
+++ b/src/Persistences/AbstractPersistence.js
@ -0,0 +1,2 @@
+
+export default class AbstractPersistence {}
--- a/src/Persistences/FilePersistence.js
+++ b/src/Persistences/FilePersistence.js
@ -0,0 +1,72 @@
+import fs from 'fs'
+import path from 'path'
+import * as encoding from '../../lib/encoding.js'
+import * as decoding from '../../lib/decoding.js'
+import { createMutualExclude } from '../../lib/mutualExclude.js'
+import { encodeUpdate, encodeStructsDS, decodePersisted } from './decodePersisted.js'
+
+function createFilePath (persistence, roomName) {
+  // TODO: filename checking!
+  return path.join(persistence.dir, roomName)
+}
+
+export default class FilePersistence {
+  constructor (dir) {
+    this.dir = dir
+    this._mutex = createMutualExclude()
+  }
+  setRemoteUpdateCounter (roomName, remoteUpdateCounter) {
+    // TODO: implement
+    // nop
+  }
+  saveUpdate (room, y, encodedStructs) {
+    return new Promise((resolve, reject) => {
+      this._mutex(() => {
+        const filePath = createFilePath(this, room)
+        const updateMessage = encoding.createEncoder()
+        encodeUpdate(y, encodedStructs, updateMessage)
+        fs.appendFile(filePath, Buffer.from(encoding.toBuffer(updateMessage)), (err) => {
+          if (err !== null) {
+            reject(err)
+          } else {
+            resolve()
+          }
+        })
+      }, resolve)
+    })
+  }
+  saveState (roomName, y) {
+    return new Promise((resolve, reject) => {
+      const encoder = encoding.createEncoder()
+      encodeStructsDS(y, encoder)
+      const filePath = createFilePath(this, roomName)
+      fs.writeFile(filePath, Buffer.from(encoding.toBuffer(encoder)), (err) => {
+        if (err !== null) {
+          reject(err)
+        } else {
+          resolve()
+        }
+      })
+    })
+  }
+  readState (roomName, y) {
+    // Check if the file exists in the current directory.
+    return new Promise((resolve, reject) => {
+      const filePath = path.join(this.dir, roomName)
+      fs.readFile(filePath, (err, data) => {
+        if (err !== null) {
+          resolve()
+          // reject(err)
+        } else {
+          this._mutex(() => {
+            console.info(`unpacking data (${data.length})`)
+            console.time('unpacking')
+            decodePersisted(y, decoding.createDecoder(data.buffer))
+            console.timeEnd('unpacking')
+          })
+          resolve()
+        }
+      })
+    })
+  }
+}
--- a/src/Persistences/IndexedDBPersistence.js
+++ b/src/Persistences/IndexedDBPersistence.js
@ -0,0 +1,281 @@
+/* global indexedDB, location, BroadcastChannel */
+
+import Y from '../Y.js'
+import { createMutualExclude } from '../../lib/mutualExclude.js'
+import { decodePersisted, encodeStructsDS, encodeUpdate, PERSIST_STRUCTS_DS, PERSIST_UPDATE } from './decodePersisted.js'
+import * as decoding from '../../lib/decoding.js'
+import * as encoding from '../../lib/encoding.js'
+/*
+ * Request to Promise transformer
+ */
+function rtop (request) {
+  return new Promise(function (resolve, reject) {
+    request.onerror = function (event) {
+      reject(new Error(event.target.error))
+    }
+    request.onblocked = function () {
+      location.reload()
+    }
+    request.onsuccess = function (event) {
+      resolve(event.target.result)
+    }
+  })
+}
+
+function openDB (room) {
+  return new Promise(function (resolve, reject) {
+    let request = indexedDB.open(room)
+    request.onupgradeneeded = function (event) {
+      const db = event.target.result
+      if (db.objectStoreNames.contains('updates')) {
+        db.deleteObjectStore('updates')
+      }
+      db.createObjectStore('updates', {autoIncrement: true})
+    }
+    request.onerror = function (event) {
+      reject(new Error(event.target.error))
+    }
+    request.onblocked = function () {
+      location.reload()
+    }
+    request.onsuccess = function (event) {
+      const db = event.target.result
+      db.onversionchange = function () { db.close() }
+      resolve(db)
+    }
+  })
+}
+
+function persist (room) {
+  let t = room.db.transaction(['updates'], 'readwrite')
+  let updatesStore = t.objectStore('updates')
+  return rtop(updatesStore.getAll())
+  .then(updates => {
+    // apply all previous updates before deleting them
+    room.mutex(() => {
+      updates.forEach(update => {
+        decodePersisted(y, new BinaryDecoder(update))
+      })
+    })
+    const encoder = new BinaryEncoder()
+    encodeStructsDS(y, encoder)
+    // delete all pending updates
+    rtop(updatesStore.clear()).then(() => {
+      // write current model
+      updatesStore.put(encoder.createBuffer())
+    })
+  })
+}
+
+function saveUpdate (room, updateBuffer) {
+  const db = room.db
+  if (db !== null) {
+    const t = db.transaction(['updates'], 'readwrite')
+    const updatesStore = t.objectStore('updates')
+    const updatePut = rtop(updatesStore.put(updateBuffer))
+    rtop(updatesStore.count()).then(cnt => {
+      if (cnt >= PREFERRED_TRIM_SIZE) {
+        persist(room)
+      }
+    })
+    return updatePut
+  }
+}
+
+function registerRoomInPersistence (documentsDB, roomName) {
+  return documentsDB.then(
+    db => Promise.all([
+      db,
+      rtop(db.transaction(['documents'], 'readonly').objectStore('documents').get(roomName))
+    ])
+  ).then(
+    ([db, doc]) => {
+      if (doc === undefined) {
+        return rtop(db.transaction(['documents'], 'readwrite').objectStore('documents').add({ roomName, serverUpdateCounter: 0 }))
+      }
+    }
+  )
+}
+
+const PREFERRED_TRIM_SIZE = 400
+
+export default class IndexedDBPersistence {
+  constructor () {
+    this._rooms = new Map()
+    this._documentsDB = new Promise(function (resolve, reject) {
+      let request = indexedDB.open('_yjs_documents')
+      request.onupgradeneeded = function (event) {
+        const db = event.target.result
+        if (db.objectStoreNames.contains('documents')) {
+          db.deleteObjectStore('documents')
+        }
+        db.createObjectStore('documents', { keyPath: "roomName" })
+      }
+      request.onerror = function (event) {
+        reject(new Error(event.target.error))
+      }
+      request.onblocked = function () {
+        location.reload()
+      }
+      request.onsuccess = function (event) {
+        const db = event.target.result
+        db.onversionchange = function () { db.close() }
+        resolve(db)
+      }
+    })
+    addEventListener('unload', () => {
+      // close everything when page unloads
+      this._rooms.forEach(room => {
+        if (room.db !== null) {
+          room.db.close()
+        } else {
+          room.dbPromise.then(db => db.close())
+        }
+      })
+      this._documentsDB.then(db => db.close())
+    })
+  }
+  getAllDocuments () {
+    return this._documentsDB.then(
+      db => rtop(db.transaction(['documents'], 'readonly').objectStore('documents').getAll())
+    )
+  }
+  setRemoteUpdateCounter (roomName, remoteUpdateCounter) {
+    this._documentsDB.then(
+      db => rtop(db.transaction(['documents'], 'readwrite').objectStore('documents').put({ roomName, remoteUpdateCounter }))
+    )
+  }
+
+  _createYInstance (roomName) {
+    const room = this._rooms.get(roomName)
+    if (room !== undefined) {
+      return room.y
+    }
+    const y = new Y()
+    return openDB(roomName).then(
+      db => rtop(db.transaction(['updates'], 'readonly').objectStore('updates').getAll())
+    ).then(
+      updates =>
+        y.transact(() => {
+          updates.forEach(update => {
+            decodePersisted(y, new BinaryDecoder(update))
+          })
+        }, true)
+    ).then(() => Promise.resolve(y))
+  }
+
+  _persistStructsDS (roomName, structsDS) {
+    const encoder = new BinaryEncoder()
+    encoder.writeVarUint(PERSIST_STRUCTS_DS)
+    encoder.writeArrayBuffer(structsDS)
+    return openDB(roomName).then(db => {
+      const t = db.transaction(['updates'], 'readwrite')
+      const updatesStore = t.objectStore('updates')
+      return rtop(updatesStore.put(encoder.createBuffer()))
+    })
+  }
+
+  _persistStructs (roomName, structs) {
+    const encoder = new BinaryEncoder()
+    encoder.writeVarUint(PERSIST_UPDATE)
+    encoder.writeArrayBuffer(structs)
+    return openDB(roomName).then(db => {
+      const t = db.transaction(['updates'], 'readwrite')
+      const updatesStore = t.objectStore('updates')
+      return rtop(updatesStore.put(encoder.createBuffer()))
+    })
+  }
+
+  connectY (roomName, y) {
+    if (this._rooms.has(roomName)) {
+      throw new Error('A Y instance is already bound to this room!')
+    }
+    let room = {
+      db: null,
+      dbPromise: null,
+      channel: null,
+      mutex: createMutualExclude(),
+      y
+    }
+    if (typeof BroadcastChannel !== 'undefined') {
+      room.channel = new BroadcastChannel('__yjs__' + roomName)
+      room.channel.addEventListener('message', e => {
+        room.mutex(function () {
+          decodePersisted(y, new BinaryDecoder(e.data))
+        })
+      })
+    }
+    y.on('destroyed', () => {
+      this.disconnectY(roomName, y)
+    })
+    y.on('afterTransaction', (y, transaction) => {
+      room.mutex(() => {
+        if (transaction.encodedStructsLen > 0) {
+          const encoder = new BinaryEncoder()
+          const update = new BinaryEncoder()
+          encodeUpdate(y, transaction.encodedStructs, update)
+          const updateBuffer = update.createBuffer()
+          if (room.channel !== null) {
+            room.channel.postMessage(updateBuffer)
+          }
+          if (transaction.encodedStructsLen > 0) {
+            if (room.db !== null) {
+              saveUpdate(room, updateBuffer)
+            }
+          }
+        }
+      })
+    })
+    // register document in documentsDB
+    this._documentsDB.then(
+      db => 
+        rtop(db.transaction(['documents'], 'readonly').objectStore('documents').get(roomName))
+          .then(
+            doc => doc === undefined && rtop(db.transaction(['documents'], 'readwrite').objectStore('documents').add({ roomName, serverUpdateCounter: -1 }))
+          )
+    )
+    // open room db and read existing data
+    return room.dbPromise = openDB(roomName)
+      .then(db => {
+        room.db = db
+        const t = room.db.transaction(['updates'], 'readwrite')
+        const updatesStore = t.objectStore('updates')
+        // write current state as update
+        const encoder = new BinaryEncoder()
+        encodeStructsDS(y, encoder)
+        return rtop(updatesStore.put(encoder.createBuffer())).then(() => {
+          // read persisted state
+          return rtop(updatesStore.getAll()).then(updates => {
+            room.mutex(() => {
+              y.transact(() => {
+                updates.forEach(update => {
+                  decodePersisted(y, new BinaryDecoder(update))
+                })
+              }, true)
+            })
+          })
+        })
+      })
+  }
+  disconnectY (roomName) {
+    const {
+      db, channel
+    } = this._rooms.get(roomName)
+    db.close()
+    if (channel !== null) {
+      channel.close()
+    }
+    this._rooms.delete(roomName)
+  }
+
+  /**
+   * Remove all persisted data that belongs to a room.
+   * Automatically destroys all Yjs all Yjs instances that persist to
+   * the room. If `destroyYjsInstances = false` the persistence functionality
+   * will be removed from the Yjs instances.
+   */
+  removePersistedData (roomName, destroyYjsInstances = true) {
+    this.disconnectY(roomName)
+    return rtop(indexedDB.deleteDatabase(roomName))
+  }
+}
--- a/src/Persistences/decodePersisted.js
+++ b/src/Persistences/decodePersisted.js
@ -0,0 +1,51 @@
+import { integrateRemoteStructs } from '../MessageHandler/integrateRemoteStructs.js'
+import { writeStructs } from '../MessageHandler/syncStep1.js'
+import { writeDeleteSet, readDeleteSet } from '../MessageHandler/deleteSet.js'
+
+export const PERSIST_UPDATE = 0
+/**
+ * Write an update to an encoder.
+ *
+ * @param {Yjs} y A Yjs instance
+ * @param {BinaryEncoder} updateEncoder I.e. transaction.encodedStructs
+ */
+export function encodeUpdate (y, updateEncoder, encoder) {
+  encoder.writeVarUint(PERSIST_UPDATE)
+  encoder.writeBinaryEncoder(updateEncoder)
+}
+
+export const PERSIST_STRUCTS_DS = 1
+
+/**
+ * Write the current Yjs data model to an encoder.
+ *
+ * @param {Yjs} y A Yjs instance
+ * @param {BinaryEncoder} encoder An encoder to write to
+ */
+export function encodeStructsDS (y, encoder) {
+  encoder.writeVarUint(PERSIST_STRUCTS_DS)
+  writeStructs(y, encoder, new Map())
+  writeDeleteSet(y, encoder)
+}
+
+/**
+ * Feed the Yjs instance with the persisted state
+ * @param {Yjs} y A Yjs instance.
+ * @param {BinaryDecoder} decoder A Decoder instance that holds the file content.
+ */
+export function decodePersisted (y, decoder) {
+  y.transact(() => {
+    while (decoder.hasContent()) {
+      const contentType = decoder.readVarUint()
+      switch (contentType) {
+        case PERSIST_UPDATE:
+          integrateRemoteStructs(decoder, y)
+          break
+        case PERSIST_STRUCTS_DS:
+          integrateRemoteStructs(decoder, y)
+          readDeleteSet(y, decoder)
+          break
+      }
+    }
+  }, true)
+}
--- a/src/Store/DeleteStore.js
+++ b/src/Store/DeleteStore.js
@ -0,0 +1,90 @@
+
+import Tree from '../../lib/Tree.js'
+import * as ID from '../Util/ID.js'
+
+class DSNode {
+  constructor (id, len, gc) {
+    this._id = id
+    this.len = len
+    this.gc = gc
+  }
+  clone () {
+    return new DSNode(this._id, this.len, this.gc)
+  }
+}
+
+export default class DeleteStore extends Tree {
+  logTable () {
+    const deletes = []
+    this.iterate(null, null, function (n) {
+      deletes.push({
+        user: n._id.user,
+        clock: n._id.clock,
+        len: n.len,
+        gc: n.gc
+      })
+    })
+    console.table(deletes)
+  }
+  isDeleted (id) {
+    var n = this.findWithUpperBound(id)
+    return n !== null && n._id.user === id.user && id.clock < n._id.clock + n.len
+  }
+  mark (id, length, gc) {
+    if (length === 0) return
+    // Step 1. Unmark range
+    const leftD = this.findWithUpperBound(ID.createID(id.user, id.clock - 1))
+    // Resize left DSNode if necessary
+    if (leftD !== null && leftD._id.user === id.user) {
+      if (leftD._id.clock < id.clock && id.clock < leftD._id.clock + leftD.len) {
+        // node is overlapping. need to resize
+        if (id.clock + length < leftD._id.clock + leftD.len) {
+          // overlaps new mark range and some more
+          // create another DSNode to the right of new mark
+          this.put(new DSNode(ID.createID(id.user, id.clock + length), leftD._id.clock + leftD.len - id.clock - length, leftD.gc))
+        }
+        // resize left DSNode
+        leftD.len = id.clock - leftD._id.clock
+      } // Otherwise there is no overlapping
+    }
+    // Resize right DSNode if necessary
+    const upper = ID.createID(id.user, id.clock + length - 1)
+    const rightD = this.findWithUpperBound(upper)
+    if (rightD !== null && rightD._id.user === id.user) {
+      if (rightD._id.clock < id.clock + length && id.clock <= rightD._id.clock && id.clock + length < rightD._id.clock + rightD.len) { // we only consider the case where we resize the node
+        const d = id.clock + length - rightD._id.clock
+        rightD._id = ID.createID(rightD._id.user, rightD._id.clock + d)
+        rightD.len -= d
+      }
+    }
+    // Now we only have to delete all inner marks
+    const deleteNodeIds = []
+    this.iterate(id, upper, m => {
+      deleteNodeIds.push(m._id)
+    })
+    for (let i = deleteNodeIds.length - 1; i >= 0; i--) {
+      this.delete(deleteNodeIds[i])
+    }
+    let newMark = new DSNode(id, length, gc)
+    // Step 2. Check if we can extend left or right
+    if (leftD !== null && leftD._id.user === id.user && leftD._id.clock + leftD.len === id.clock && leftD.gc === gc) {
+      // We can extend left
+      leftD.len += length
+      newMark = leftD
+    }
+    const rightNext = this.find(ID.createID(id.user, id.clock + length))
+    if (rightNext !== null && rightNext._id.user === id.user && id.clock + length === rightNext._id.clock && gc === rightNext.gc) {
+      // We can merge newMark and rightNext
+      newMark.len += rightNext.len
+      this.delete(rightNext._id)
+    }
+    if (leftD !== newMark) {
+      // only put if we didn't extend left
+      this.put(newMark)
+    }
+  }
+  // TODO: exchange markDeleted for mark()
+  markDeleted (id, length) {
+    this.mark(id, length, false)
+  }
+}
--- a/src/Store/OperationStore.js
+++ b/src/Store/OperationStore.js
@ -0,0 +1,94 @@
+import Tree from '../../lib/Tree.js'
+import * as ID from '../Util/ID.js'
+import { getStruct } from '../Util/structReferences.js'
+import { stringifyID, stringifyItemID } from '../message.js'
+import GC from '../Struct/GC.js'
+
+export default class OperationStore extends Tree {
+  constructor (y) {
+    super()
+    this.y = y
+  }
+  logTable () {
+    const items = []
+    this.iterate(null, null, function (item) {
+      if (item.constructor === GC) {
+        items.push({
+          id: stringifyItemID(item),
+          content: item._length,
+          deleted: 'GC'
+        })
+      } else {
+        items.push({
+          id: stringifyItemID(item),
+          origin: item._origin === null ? '()' : stringifyID(item._origin._lastId),
+          left: item._left === null ? '()' : stringifyID(item._left._lastId),
+          right: stringifyItemID(item._right),
+          right_origin: stringifyItemID(item._right_origin),
+          parent: stringifyItemID(item._parent),
+          parentSub: item._parentSub,
+          deleted: item._deleted,
+          content: JSON.stringify(item._content)
+        })
+      }
+    })
+    console.table(items)
+  }
+  get (id) {
+    let struct = this.find(id)
+    if (struct === null && id instanceof ID.RootID) {
+      const Constr = getStruct(id.type)
+      const y = this.y
+      struct = new Constr()
+      struct._id = id
+      struct._parent = y
+      y.transact(() => {
+        struct._integrate(y)
+      })
+      this.put(struct)
+    }
+    return struct
+  }
+  // Use getItem for structs with _length > 1
+  getItem (id) {
+    var item = this.findWithUpperBound(id)
+    if (item === null) {
+      return null
+    }
+    const itemID = item._id
+    if (id.user === itemID.user && id.clock < itemID.clock + item._length) {
+      return item
+    } else {
+      return null
+    }
+  }
+  // Return an insertion such that id is the first element of content
+  // This function manipulates an item, if necessary
+  getItemCleanStart (id) {
+    var ins = this.getItem(id)
+    if (ins === null || ins._length === 1) {
+      return ins
+    }
+    const insID = ins._id
+    if (insID.clock === id.clock) {
+      return ins
+    } else {
+      return ins._splitAt(this.y, id.clock - insID.clock)
+    }
+  }
+  // Return an insertion such that id is the last element of content
+  // This function manipulates an operation, if necessary
+  getItemCleanEnd (id) {
+    var ins = this.getItem(id)
+    if (ins === null || ins._length === 1) {
+      return ins
+    }
+    const insID = ins._id
+    if (insID.clock + ins._length - 1 === id.clock) {
+      return ins
+    } else {
+      ins._splitAt(this.y, id.clock - insID.clock + 1)
+      return ins
+    }
+  }
+}
--- a/src/Store/StateStore.js
+++ b/src/Store/StateStore.js
@ -0,0 +1,51 @@
+import * as ID from '../Util/ID.js'
+
+/**
+ * @typedef {Map<number, number>} StateSet
+ */
+
+export default class StateStore {
+  constructor (y) {
+    this.y = y
+    this.state = new Map()
+  }
+  logTable () {
+    const entries = []
+    for (let [user, state] of this.state) {
+      entries.push({
+        user, state
+      })
+    }
+    console.table(entries)
+  }
+  getNextID (len) {
+    const user = this.y.userID
+    const state = this.getState(user)
+    this.setState(user, state + len)
+    return ID.createID(user, state)
+  }
+  updateRemoteState (struct) {
+    let user = struct._id.user
+    let userState = this.state.get(user)
+    while (struct !== null && struct._id.clock === userState) {
+      userState += struct._length
+      struct = this.y.os.get(ID.createID(user, userState))
+    }
+    this.state.set(user, userState)
+  }
+  getState (user) {
+    let state = this.state.get(user)
+    if (state == null) {
+      return 0
+    }
+    return state
+  }
+  setState (user, state) {
+    // TODO: modify missingi structs here
+    const beforeState = this.y._transaction.beforeState
+    if (!beforeState.has(user)) {
+      beforeState.set(user, this.getState(user))
+    }
+    this.state.set(user, state)
+  }
+}
--- a/src/Struct/Delete.js
+++ b/src/Struct/Delete.js
@ -0,0 +1,130 @@
+import { getStructReference } from '../Util/structReferences.js'
+import * as ID from '../Util/ID.js'
+import { stringifyID } from '../message.js'
+import { writeStructToTransaction } from '../Util/Transaction.js'
+import * as decoding from '../../lib/decoding.js'
+import * as encoding from '../../lib/encoding.js'
+
+/**
+ * @private
+ * Delete all items in an ID-range.
+ * Does not create delete operations!
+ * TODO: implement getItemCleanStartNode for better performance (only one lookup).
+ */
+export function deleteItemRange (y, user, clock, range, gcChildren) {
+  let item = y.os.getItemCleanStart(ID.createID(user, clock))
+  if (item !== null) {
+    if (!item._deleted) {
+      item._splitAt(y, range)
+      item._delete(y, false, true)
+    }
+    let itemLen = item._length
+    range -= itemLen
+    clock += itemLen
+    if (range > 0) {
+      let node = y.os.findNode(ID.createID(user, clock))
+      while (node !== null && node.val !== null && range > 0 && node.val._id.equals(ID.createID(user, clock))) {
+        const nodeVal = node.val
+        if (!nodeVal._deleted) {
+          nodeVal._splitAt(y, range)
+          nodeVal._delete(y, false, gcChildren)
+        }
+        const nodeLen = nodeVal._length
+        range -= nodeLen
+        clock += nodeLen
+        node = node.next()
+      }
+    }
+  }
+}
+
+/**
+ * @private
+ * A Delete change is not a real Item, but it provides the same interface as an
+ * Item. The only difference is that it will not be saved in the ItemStore
+ * (OperationStore), but instead it is safed in the DeleteStore.
+ */
+export default class Delete {
+  constructor () {
+    /**
+     * @type {ID.ID}
+     */
+    this._targetID = null
+    /**
+     * @type {import('./Item.js').default}
+     */
+    this._target = null
+    this._length = null
+  }
+
+  /**
+   * @private
+   * Read the next Item in a Decoder and fill this Item with the read data.
+   *
+   * This is called when data is received from a remote peer.
+   *
+   * @param {import('../Y.js').default} y The Yjs instance that this Item belongs to.
+   * @param {decoding.Decoder} decoder The decoder object to read data from.
+   */
+  _fromBinary (y, decoder) {
+    // TODO: set target, and add it to missing if not found
+    // There is an edge case in p2p networks!
+    /**
+     * @type {any}
+     */
+    const targetID = ID.decode(decoder)
+    this._targetID = targetID
+    this._length = decoding.readVarUint(decoder)
+    if (y.os.getItem(targetID) === null) {
+      return [targetID]
+    } else {
+      return []
+    }
+  }
+
+  /**
+   * @private
+   * 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 {encoding.Encoder} encoder The encoder to write data to.
+   */
+  _toBinary (encoder) {
+    encoding.writeUint8(encoder, getStructReference(this.constructor))
+    this._targetID.encode(encoder)
+    encoding.writeVarUint(encoder, this._length)
+  }
+
+  /**
+   * @private
+   * Integrates this Item into the shared structure.
+   *
+   * This method actually applies the change to the Yjs instance. In the case of
+   * Delete it marks the delete target as deleted.
+   *
+   * * If created remotely (a remote user deleted something),
+   *   this Delete is applied to all structs in id-range.
+   * * If created lokally (e.g. when y-array deletes a range of elements),
+   *   this struct is broadcasted only (it is already executed)
+   */
+  _integrate (y, locallyCreated = false) {
+    if (!locallyCreated) {
+      // from remote
+      const id = this._targetID
+      deleteItemRange(y, id.user, id.clock, this._length, false)
+    }
+    writeStructToTransaction(y._transaction, this)
+  }
+
+  /**
+   * Transform this YXml Type to a readable format.
+   * Useful for logging as all Items and Delete implement this method.
+   *
+   * @private
+   */
+  _logString () {
+    return `Delete - target: ${stringifyID(this._targetID)}, len: ${this._length}`
+  }
+}
--- a/src/Struct/GC.js
+++ b/src/Struct/GC.js
@ -0,0 +1,97 @@
+import { getStructReference } from '../Util/structReferences.js'
+import * as ID from '../Util/ID.js'
+import { writeStructToTransaction } from '../Util/Transaction.js'
+import * as decoding from '../../lib/decoding.js'
+import * as encoding from '../../lib/encoding.js'
+
+// TODO should have the same base class as Item
+export default class GC {
+  constructor () {
+    /**
+     * @type {ID.ID}
+     */
+    this._id = null
+    this._length = 0
+  }
+
+  get _deleted () {
+    return true
+  }
+
+  _integrate (y) {
+    const id = this._id
+    const userState = y.ss.getState(id.user)
+    if (id.clock === userState) {
+      y.ss.setState(id.user, id.clock + this._length)
+    }
+    y.ds.mark(this._id, this._length, true)
+    let n = y.os.put(this)
+    const prev = n.prev().val
+    if (prev !== null && prev.constructor === GC && prev._id.user === n.val._id.user && prev._id.clock + prev._length === n.val._id.clock) {
+      // TODO: do merging for all items!
+      prev._length += n.val._length
+      y.os.delete(n.val._id)
+      n = prev
+    }
+    if (n.val) {
+      n = n.val
+    }
+    const next = y.os.findNext(n._id)
+    if (next !== null && next.constructor === GC && next._id.user === n._id.user && next._id.clock === n._id.clock + n._length) {
+      n._length += next._length
+      y.os.delete(next._id)
+    }
+    if (id.user !== ID.RootFakeUserID) {
+      writeStructToTransaction(y._transaction, 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 {encoding.Encoder} encoder The encoder to write data to.
+   * @private
+   */
+  _toBinary (encoder) {
+    encoding.writeUint8(encoder, getStructReference(this.constructor))
+    this._id.encode(encoder)
+    encoding.writeVarUint(encoder, this._length)
+  }
+
+  /**
+   * Read the next Item in a Decoder and fill this Item with the read data.
+   *
+   * This is called when data is received from a remote peer.
+   *
+   * @param {import('../Y.js').default} y The Yjs instance that this Item belongs to.
+   * @param {decoding.Decoder} decoder The decoder object to read data from.
+   * @private
+   */
+  _fromBinary (y, decoder) {
+    /**
+     * @type {any}
+     */
+    const id = ID.decode(decoder)
+    this._id = id
+    this._length = decoding.readVarUint(decoder)
+    const missing = []
+    if (y.ss.getState(id.user) < id.clock) {
+      missing.push(ID.createID(id.user, id.clock - 1))
+    }
+    return missing
+  }
+
+  _splitAt () {
+    return this
+  }
+
+  _clonePartial (diff) {
+    const gc = new GC()
+    gc._id = ID.createID(this._id.user, this._id.clock + diff)
+    gc._length = this._length - diff
+    return gc
+  }
+}
--- a/src/Struct/Item.js
+++ b/src/Struct/Item.js
@ -0,0 +1,545 @@
+import { getStructReference } from '../Util/structReferences.js'
+import * as ID from '../Util/ID.js'
+import Delete from './Delete.js'
+import { transactionTypeChanged, writeStructToTransaction } from '../Util/Transaction.js'
+import GC from './GC.js'
+import * as encoding from '../../lib/encoding.js'
+import * as decoding from '../../lib/decoding.js'
+import Y from '../Y.js'
+
+/**
+ * @typedef {import('./Type.js').default} YType
+ */
+
+/**
+ * @private
+ * Helper utility to split an Item (see {@link Item#_splitAt})
+ * - copies all properties from a to b
+ * - connects a to b
+ * - assigns the correct _id
+ * - saves b to os
+ */
+export function splitHelper (y, a, b, diff) {
+  const aID = a._id
+  b._id = ID.createID(aID.user, aID.clock + diff)
+  b._origin = a
+  b._left = a
+  b._right = a._right
+  if (b._right !== null) {
+    b._right._left = b
+  }
+  b._right_origin = a._right_origin
+  // do not set a._right_origin, as this will lead to problems when syncing
+  a._right = b
+  b._parent = a._parent
+  b._parentSub = a._parentSub
+  b._deleted = a._deleted
+  // now search all relevant items to the right and update origin
+  // if origin is not it foundOrigins, we don't have to search any longer
+  let foundOrigins = new Set()
+  foundOrigins.add(a)
+  let o = b._right
+  while (o !== null && foundOrigins.has(o._origin)) {
+    if (o._origin === a) {
+      o._origin = b
+    }
+    foundOrigins.add(o)
+    o = o._right
+  }
+  y.os.put(b)
+  if (y._transaction.newTypes.has(a)) {
+    y._transaction.newTypes.add(b)
+  } else if (y._transaction.deletedStructs.has(a)) {
+    y._transaction.deletedStructs.add(b)
+  }
+}
+
+/**
+ * Abstract class that represents any content.
+ */
+export default class Item {
+  constructor () {
+    /**
+     * The uniqe identifier of this type.
+     * @type {ID.ID | ID.RootID}
+     */
+    this._id = null
+    /**
+     * The item that was originally to the left of this item.
+     * @type {Item}
+     */
+    this._origin = null
+    /**
+     * The item that is currently to the left of this item.
+     * @type {Item}
+     */
+    this._left = null
+    /**
+     * The item that is currently to the right of this item.
+     * @type {Item}
+     */
+    this._right = null
+    /**
+     * The item that was originally to the right of this item.
+     * @type {Item}
+     */
+    this._right_origin = null
+    /**
+     * The parent type.
+     * @type {Y|YType}
+     */
+    this._parent = null
+    /**
+     * 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}
+     */
+    this._parentSub = null
+    /**
+     * Whether this item was deleted or not.
+     * @type {Boolean}
+     */
+    this._deleted = false
+    /**
+     * If this type's effect is reundone this type refers to the type that undid
+     * this operation.
+     * @type {YType}
+     */
+    this._redone = null
+  }
+
+  /**
+   * Creates an Item with the same effect as this Item (without position effect)
+   *
+   * @private
+   */
+  _copy () {
+    const C = this.constructor
+    return C()
+  }
+
+  /**
+   * Redoes the effect of this operation.
+   *
+   * @param {Y} y The Yjs instance.
+   *
+   * @private
+   */
+  _redo (y, redoitems) {
+    if (this._redone !== null) {
+      return this._redone
+    }
+    if (this._parent instanceof Y) {
+      return
+    }
+    let struct = this._copy()
+    let left, right
+    if (this._parentSub === null) {
+      // Is an array item. Insert at the old position
+      left = this._left
+      right = this
+    } else {
+      // Is a map item. Insert at the start
+      left = null
+      right = this._parent._map.get(this._parentSub)
+      right._delete(y)
+    }
+    let parent = this._parent
+    // make sure that parent is redone
+    if (parent._deleted === true && parent._redone === null) {
+      // try to undo parent if it will be undone anyway
+      if (!redoitems.has(parent) || !parent._redo(y, redoitems)) {
+        return false
+      }
+    }
+    if (parent._redone !== null) {
+      parent = parent._redone
+      // find next cloned_redo items
+      while (left !== null) {
+        if (left._redone !== null && left._redone._parent === parent) {
+          left = left._redone
+          break
+        }
+        left = left._left
+      }
+      while (right !== null) {
+        if (right._redone !== null && right._redone._parent === parent) {
+          right = right._redone
+        }
+        right = right._right
+      }
+    }
+    struct._origin = left
+    struct._left = left
+    struct._right = right
+    struct._right_origin = right
+    struct._parent = parent
+    struct._parentSub = this._parentSub
+    struct._integrate(y)
+    this._redone = struct
+    return true
+  }
+
+  /**
+   * Computes the last content address of this Item.
+   *
+   * @private
+   */
+  get _lastId () {
+    /**
+     * @type {any}
+     */
+    const id = this._id
+    return ID.createID(id.user, id.clock + this._length - 1)
+  }
+
+  /**
+   * Computes the length of this Item.
+   *
+   * @private
+   */
+  get _length () {
+    return 1
+  }
+
+  /**
+   * 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
+   *
+   * @private
+   */
+  get _countable () {
+    return true
+  }
+
+  /**
+   * Splits this Item so that another Items can be inserted in-between.
+   * This must be overwritten if _length > 1
+   * Returns right part after split
+   * * diff === 0 => this
+   * * diff === length => this._right
+   * * otherwise => split _content and return right part of split
+   * (see {@link ItemJSON}/{@link ItemString} for implementation)
+   *
+   * @private
+   */
+  _splitAt (y, diff) {
+    if (diff === 0) {
+      return this
+    }
+    return this._right
+  }
+
+  /**
+   * Mark this Item as deleted.
+   *
+   * @param {Y} y The Yjs instance
+   * @param {boolean} createDelete Whether to propagate a message that this
+   *                               Type was deleted.
+   * @param {boolean} gcChildren
+   *
+   * @private
+   */
+  _delete (y, createDelete = true, gcChildren) {
+    if (!this._deleted) {
+      this._deleted = true
+      y.ds.mark(this._id, this._length, false)
+      let del = new Delete()
+      del._targetID = this._id
+      del._length = this._length
+      if (createDelete) {
+        // broadcast and persists Delete
+        del._integrate(y, true)
+      }
+      transactionTypeChanged(y, this._parent, this._parentSub)
+      y._transaction.deletedStructs.add(this)
+    }
+  }
+
+  _gcChildren (y) {}
+
+  _gc (y) {
+    const gc = new GC()
+    gc._id = this._id
+    gc._length = this._length
+    y.os.delete(this._id)
+    gc._integrate(y)
+  }
+
+  /**
+   * This is called right before this Item receives any children.
+   * It can be overwritten to apply pending changes before applying remote changes
+   *
+   * @private
+   */
+  _beforeChange () {
+    // nop
+  }
+
+  /**
+   * Integrates this Item into the shared structure.
+   *
+   * This method actually applies the change to the Yjs instance. In case of
+   * Item it connects _left and _right to this Item and calls the
+   * {@link Item#beforeChange} method.
+   *
+   * * Integrate the struct so that other types/structs can see it
+   * * Add this struct to y.os
+   * * Check if this is struct deleted
+   *
+   * @param {Y} y
+   *
+   * @private
+   */
+  _integrate (y) {
+    y._transaction.newTypes.add(this)
+    /**
+     * @type {any}
+     */
+    const parent = this._parent
+    /**
+     * @type {any}
+     */
+    const selfID = this._id
+    const user = selfID === null ? y.userID : selfID.user
+    const userState = y.ss.getState(user)
+    if (selfID === null) {
+      this._id = y.ss.getNextID(this._length)
+    } else if (selfID.user === ID.RootFakeUserID) {
+      // is parent
+      return
+    } else if (selfID.clock < userState) {
+      // already applied..
+      return
+    } else if (selfID.clock === userState) {
+      y.ss.setState(selfID.user, userState + this._length)
+    } else {
+      // missing content from user
+      throw new Error('Can not apply yet!')
+    }
+    if (!parent._deleted && !y._transaction.changedTypes.has(parent) && !y._transaction.newTypes.has(parent)) {
+      // this is the first time parent is updated
+      // or this types is new
+      parent._beforeChange()
+    }
+
+    /*
+    # $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!)
+    */
+    // handle conflicts
+    let o
+    // set o to the first conflicting item
+    if (this._left !== null) {
+      o = this._left._right
+    } else if (this._parentSub !== null) {
+      o = parent._map.get(this._parentSub) || null
+    } else {
+      o = parent._start
+    }
+    let conflictingItems = new Set()
+    let 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 (this._origin === o._origin) {
+        // case 1
+        if (o._id.user < this._id.user) {
+          this._left = o
+          conflictingItems.clear()
+        }
+      } else if (itemsBeforeOrigin.has(o._origin)) {
+        // case 2
+        if (!conflictingItems.has(o._origin)) {
+          this._left = o
+          conflictingItems.clear()
+        }
+      } else {
+        break
+      }
+      // TODO: try to use right_origin instead.
+      // Then you could basically omit conflictingItems!
+      // Note: you probably can't use right_origin in every case.. only when setting _left
+      o = o._right
+    }
+    // reconnect left/right + update parent map/start if necessary
+    const parentSub = this._parentSub
+    if (this._left === null) {
+      let right
+      if (parentSub !== null) {
+        const pmap = parent._map
+        right = pmap.get(parentSub) || null
+        pmap.set(parentSub, this)
+      } else {
+        right = parent._start
+        parent._start = this
+      }
+      this._right = right
+      if (right !== null) {
+        right._left = this
+      }
+    } else {
+      const left = this._left
+      const right = left._right
+      this._right = right
+      left._right = this
+      if (right !== null) {
+        right._left = this
+      }
+    }
+    if (parent._deleted) {
+      this._delete(y, false, true)
+    }
+    y.os.put(this)
+    transactionTypeChanged(y, parent, parentSub)
+    if (this._id.user !== ID.RootFakeUserID) {
+      writeStructToTransaction(y._transaction, 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 {encoding.Encoder} encoder The encoder to write data to.
+   *
+   * @private
+   */
+  _toBinary (encoder) {
+    encoding.writeUint8(encoder, getStructReference(this.constructor))
+    let info = 0
+    if (this._origin !== null) {
+      info += 0b1 // origin is defined
+    }
+    // TODO: remove
+    /* no longer send _left
+    if (this._left !== this._origin) {
+      info += 0b10 // do not copy origin to left
+    }
+    */
+    if (this._right_origin !== null) {
+      info += 0b100
+    }
+    if (this._parentSub !== null) {
+      info += 0b1000
+    }
+    encoding.writeUint8(encoder, info)
+    this._id.encode(encoder)
+    if (info & 0b1) {
+      this._origin._lastId.encode(encoder)
+    }
+    // TODO: remove
+    /* see above
+    if (info & 0b10) {
+      encoder.writeID(this._left._lastId)
+    }
+    */
+    if (info & 0b100) {
+      this._right_origin._id.encode(encoder)
+    }
+    if ((info & 0b101) === 0) {
+      // neither origin nor right is defined
+      this._parent._id.encode(encoder)
+    }
+    if (info & 0b1000) {
+      encoding.writeVarString(encoder, JSON.stringify(this._parentSub))
+    }
+  }
+
+  /**
+   * Read the next Item in a Decoder and fill this Item with the read data.
+   *
+   * This is called when data is received from a remote peer.
+   *
+   * @param {Y} y The Yjs instance that this Item belongs to.
+   * @param {decoding.Decoder} decoder The decoder object to read data from.
+   *
+   * @private
+   */
+  _fromBinary (y, decoder) {
+    let missing = []
+    const info = decoding.readUint8(decoder)
+    const id = ID.decode(decoder)
+    this._id = id
+    // read origin
+    if (info & 0b1) {
+      // origin != null
+      const originID = ID.decode(decoder)
+      // we have to query for left again because it might have been split/merged..
+      const origin = y.os.getItemCleanEnd(originID)
+      if (origin === null) {
+        missing.push(originID)
+      } else {
+        this._origin = origin
+        this._left = this._origin
+      }
+    }
+    // read right
+    if (info & 0b100) {
+      // right != null
+      const rightID = ID.decode(decoder)
+      // we have to query for right again because it might have been split/merged..
+      const right = y.os.getItemCleanStart(rightID)
+      if (right === null) {
+        missing.push(rightID)
+      } else {
+        this._right = right
+        this._right_origin = right
+      }
+    }
+    // read parent
+    if ((info & 0b101) === 0) {
+      // neither origin nor right is defined
+      const parentID = ID.decode(decoder)
+      // parent does not change, so we don't have to search for it again
+      if (this._parent === null) {
+        let parent
+        if (parentID.constructor === ID.RootID) {
+          parent = y.os.get(parentID)
+        } else {
+          parent = y.os.getItem(parentID)
+        }
+        if (parent === null) {
+          missing.push(parentID)
+        } else {
+          this._parent = parent
+        }
+      }
+    } else if (this._parent === null) {
+      if (this._origin !== null) {
+        this._parent = this._origin._parent
+      } else if (this._right_origin !== null) {
+        this._parent = this._right_origin._parent
+      }
+    }
+    if (info & 0b1000) {
+      // TODO: maybe put this in read parent condition (you can also read parentsub from left/right)
+      this._parentSub = JSON.parse(decoding.readVarString(decoder))
+    }
+    if (id instanceof ID.ID && y.ss.getState(id.user) < id.clock) {
+      missing.push(ID.createID(id.user, id.clock - 1))
+    }
+    return missing
+  }
+}
--- a/src/Struct/ItemEmbed.js
+++ b/src/Struct/ItemEmbed.js
@ -0,0 +1,48 @@
+import Item from './Item.js'
+import { logItemHelper } from '../message.js'
+import * as encoding from '../../lib/encoding.js'
+import * as decoding from '../../lib/decoding.js'
+
+/**
+ * @typedef {import('../index.js').Y} Y
+ */
+
+export default class ItemEmbed extends Item {
+  constructor () {
+    super()
+    this.embed = null
+  }
+  _copy (undeleteChildren, copyPosition) {
+    let struct = super._copy()
+    struct.embed = this.embed
+    return struct
+  }
+  get _length () {
+    return 1
+  }
+  /**
+   * @param {Y} y
+   * @param {decoding.Decoder} decoder
+   */
+  _fromBinary (y, decoder) {
+    const missing = super._fromBinary(y, decoder)
+    this.embed = JSON.parse(decoding.readVarString(decoder))
+    return missing
+  }
+  /**
+   * @param {encoding.Encoder} encoder
+   */
+  _toBinary (encoder) {
+    super._toBinary(encoder)
+    encoding.writeVarString(encoder, JSON.stringify(this.embed))
+  }
+  /**
+   * Transform this YXml Type to a readable format.
+   * Useful for logging as all Items and Delete implement this method.
+   *
+   * @private
+   */
+  _logString () {
+    return logItemHelper('ItemEmbed', this, `embed:${JSON.stringify(this.embed)}`)
+  }
+}
--- a/Show More
+++ b/Show More
				`@ -0,0 +1,2 @@`

				`export default class AbstractPersistence {}`