v13.0.0-12 -- distribution files

2017-08-04 18:08:20 +02:00
113 changed files with 32415 additions and 15186 deletions
--- a/.babelrc
+++ b/.babelrc
@@ -0,0 +1,12 @@
+{
+  "presets": [
+    ["latest", {
+      "es2015": {
+        "modules": false
+      }
+    }]
+  ],
+  "plugins": [
+    "external-helpers"
+  ]
+}
--- a/.flowconfig
+++ b/.flowconfig
@@ -0,0 +1,12 @@
+[ignore]
+.*/node_modules/.*
+.*/dist/.*
+.*/build/.*
+
+[include]
+./src/
+
+[libs]
+./declarations/
+
+[options]
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
 node_modules
-dist
-.vscode
-docs
+bower_components
+/y.*
--- a/.jsdoc.json
+++ b/.jsdoc.json
@@ -1,50 +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": {
-      "y-js.org": "yjs.website"
-    },
-    "logo": {
-      "url": "https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png",
-      "width": "162px",
-      "height": "162px",
-      "link": "/"
-    },
-    "tabNames": {
-      "api": "API",
-      "tutorials": "Examples"
-    },
-    "footerText": "Shared Editing",
-    "css": [
-      "./style.css"
-    ],
-    "default": {
-      "staticFiles": {
-          "include": ["examples/"]
-      }
-    }
-  },
-  "opts": {
-    "destination": "./docs/",
-    "encoding": "utf8",
-    "private": false,
-    "recurse": true,
-    "template": "./node_modules/tui-jsdoc-template",
-    "tutorials": "./examples"
-  }
-}
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@

-# ![Yjs](https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png)
+# ![Yjs](http://y-js.org/images/yjs.png)

 Yjs is a framework for offline-first p2p shared editing on structured data like
 text, richtext, json, or XML. It is fairly easy to get started, as Yjs hides
@@ -64,18 +64,6 @@ missing modules.
 <script src="./bower_components/yjs/y.js"></script>
 ```

-### CDN
-```
-<script src="https://cdn.jsdelivr.net/npm/yjs@12/dist/y.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-array@10/dist/y-array.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-websockets-client@8/dist/y-websockets-client.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-memory@8/dist/y-memory.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-map@10/dist/y-map.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-text@9/dist/y-text.js"></script>
-// ..
-// do the same for all modules you want to use
-```
-
 ### Npm
 ```
 npm install --save yjs % add all y-* modules you want to use
@@ -88,6 +76,7 @@ var Y = require('yjs')
 require('y-array')(Y) // add the y-array type to Yjs
 require('y-websockets-client')(Y)
 require('y-memory')(Y)
+require('y-array')(Y)
 require('y-map')(Y)
 require('y-text')(Y)
 // ..
@@ -100,6 +89,7 @@ import Y from 'yjs'
 import yArray from 'y-array'
 import yWebsocketsClient from 'y-webrtc'
 import yMemory from 'y-memory'
+import yArray from 'y-array'
 import yMap from 'y-map'
 import yText from 'y-text'
 // ..
@@ -131,7 +121,7 @@ Here is a simple example of a shared textarea
            // name: 'xmpp'
            room: 'my-room' // clients connecting to the same room share data
          },
-          sourceDir: './bower_components', // location of the y-* modules (browser only)
+          sourceDir: '/bower_components', // location of the y-* modules (browser only)
          share: {
            textarea: 'Text' // y.share.textarea is of type y-text
          }
@@ -248,7 +238,7 @@ The promise returns an instance of Y. We denote it with a lower case `y`.
  * y-websockets-client aways waits to sync with the server
 * y.connector.disconnect()
  * Force to disconnect this instance from the other instances
-* y.connector.connect()
+* y.connector.reconnect()
  * Try to reconnect to the other instances (needs to be supported by the
    connector)
  * Not supported by y-xmpp
--- a/README.v13.md
+++ b/README.v13.md
@@ -1,370 +0,0 @@
-# ![Yjs](https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png)
-> The shared editing library
-
-Yjs is a library for automatic conflict resolution on shared state. It implements an operation-based CRDT and exposes its internal CRDT model as shared types. Shared types are common data types like `Map` or `Array` with superpowers - changes are automatically distributed to other peers and merged without merge conflicts.
-
-Yjs is **network agnostic** (p2p!), supports many existing **rich text editors**, **offline editing**, **version snapshots**, **shared cursors**, and encodes update messages using **binary protocol encoding**. 
-
-* Chat: [https://gitter.im/y-js/yjs](https://gitter.im/y-js/yjs)
-* Demos: [https://yjs.website/tutorial-prosemirror.html](https://yjs.website/tutorial-prosemirror.html)
-* API Docs: [https://yjs.website/](https://yjs.website/)
-
-### Supported Editors:
-
-| Name &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; | Cursors | Binding |  Demo |
-|---|:-:|---|---|
-| [ProseMirror](https://prosemirror.net/) | ✔ | [y-prosemirror](http://github.com/y-js/y-prosemirror) | [link](https://yjs.website/tutorial-prosemirror.html) |
-| [Quill](https://quilljs.com/) |  | [y-quill](http://github.com/y-js/y-quill) | [link](https://yjs.website/tutorial-quill.html) |
-| [CodeMirror](https://codemirror.net/) | ✔ | [y-codemirror](http://github.com/y-js/y-codemirror) | [link](https://yjs.website/tutorial-codemirror.html) |
-| [Ace](https://ace.c9.io/) | | [y-ace](http://github.com/y-js/y-ace) | [link]() |
-| [Monaco](https://microsoft.github.io/monaco-editor/) | | [y-monaco](http://github.com/y-js/y-monaco) | [link]() |
-
-### Providers
-
-Setting up the communication between clients, managing awareness information, and storing shared data for offline usage is quite a hassle. *Providers* manage all that for you and are a good off-the-shelf solution
-
-* [y-websockets](http://github.com/y-js/y-websockets)
-* [y-webrtc](http://github.com/y-js/y-webrtc)
-* [y-dat](http://github.com/y-js/y-dat)
-
-
-### Shared Types
-
-# Table of Contents
-
-* [Getting Started](#Getting-Started)
-  * [Tutorial](#Short-Tutorial)
-* [Providers](#Providers)
-  * [Websocket](#Websocket)
-  * [Ydb](#Ydb)
-  * [Create a Custom Provider](#Create-a-Custom-Provider)
-* [Shared Types](#Shared-Types)
-  * [YArray](#Yarray)
-  * [YMap](#YMap)
-  * [YText](#YText)
-  * [YXmlFragment and YXmlElement](#YXmlFragment-and-YXmlElement)
-  * [Create a Custom Type](#Create-a-Custom-Type)
-* [Bindings](#Bindings)
-  * [PromeMirror](#ProseMirror)
-  * [Quill](#Quill)
-  * [CodeMirror](#CodeMirror)
-  * [Ace](#Ace)
-  * [Monaco](#Monace)
-  * [DOM](#DOM)
-  * [Textarea](#Textarea)
-  * [Create a Custom Binding](#Create-a-Custom-Binding)
-* [Transaction](#Transaction)
-* [Offline Editing](#Offline-Editing)
-* [Awareness](#Awareness)
-* [Working with Yjs](#Working-with-Yjs)
-  * [Typescript Declarations](#Typescript-Declarations)
-* [Binary Protocols](#Binary-Protocols)
-  * [Sync Protocol](#Sync-Protocols)
-  * [Awareness Protocol](#Awareness-Protocols)
-  * [Auth Protocol](#Auth-Protocol)
-* [Yjs CRDT Algorithm](#Yjs-CRDT-Algorithm)
-* [Evaluation](#Evaluation)
-  * [Existing shared editing libraries](#Exisisting-Javascript-Products)
-  * [CRDT Algorithms](#CRDT-Algorithms)
-  * [Comparison of CRDT with OT](#Comparing-CRDT-with-OT)
-  * [Comparison of CRDT Algorithms](#Comparing-CRDT-Algorithms)
-  * [Comparison of Yjs with other Implementations](#Comparing-Yjs-with-other-Implementations)
-* [License and Author](#License-and-Author)
-
-## Getting Started
-
-Yjs does not hava any dependencies. Install this package with your favorite package manager, or just copy the files into your project.
-
-```sh
-npm i yjs
-```
-
-##### Quickstart
-
-Yjs itself only knows how to do conflict resolution. You need to choose a provider, that handles how document updates are distributed over the network.
-
-We will start by running a websocket server (part of the [websocket provider](#Websocket-Provider)):
-
-```sh
-PORT=1234 node ./node_modules/yjs/provider/websocket/server.js
-```
-
-The following client-side code connects to the websocket server and opens a shared document.
-
-```js
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-
-const provider = new WebsocketProvider('http://localhost:1234')
-const sharedDocument = provider.get('my-favourites')
-```
-
-All content created in a shared document is shared among all peers that request the same document. Now we define types on the shared document:
-
-```js
-sharedDocument.define('movie-ratings', Y.Map)
-sharedDocument.define('favourite-food', Y.Array)
-```
-
-All clients that define `'movie-ratings'` as `Y.Map` on the shared document named `'my-favourites'` have access to the same shared type. Example:
-
-**Client 1:**
-
-```js
-sharedDocument.define('movie-ratings', Y.Map)
-sharedDocument.define('favourite-food', Y.Array)
-
-const movies = sharedDocument.get('movie-ratings')
-const food = sharedDocument.get('fovourite-food')
-
-movies.set('deadpool', 10)
-food.insert(0, ['burger'])
-```
-
-**Client 2:**
-
-```js
-sharedDocument.define('movie-ratings', Y.Map)
-sharedDocument.define('favourite-food', Y.Map) // <- note that this definition differs from client1
-
-const movies = sharedDocument.get('movie-ratings')
-const food = sharedDocument.get('fovourite-food')
-
-movies.set('yt rewind', -10)
-food.set('pancake', 10)
-
-// after some time, when client1 and client2 synced, the movie list will be merged:
-movies.toJSON() // => { 'deadpool': 10, 'yt rewind': -10 }
-
-// But since client1 and client2 defined the types differently,
-// they do not have access to each others food list.
-food.toJSON() // => { pancake: 10 }
-```
-
-Now you understand how types are defined on a shared document. Next you can jump to one of the [tutorials on our website](https://yjs.website/tutorial-prosemirror.html) or continue reading about [Providers](#Providers), [Shared Types](#Shared-Types), and [Bindings](#Bindings).
-
-## API
-
-## Providers
-
-In Yjs, a provider handles the communication channel to *authenticate*, *authorize*, and *exchange document updates*. Yjs ships with some existing providers. 
-
-### Websocket Provider
-
-The websocket provider implements a classical client server model. Clients connect to a single endpoint over websocket. The server distributes awareness information and document updates among clients.
-
-The Websocket Provider is a solid choice if you want a central source that handles authentication and authorization. Websockets also send header information and cookies, so you can use existing authentication mechanisms with this server. I recommend that you slightly adapt the server in `./provider/websocket/server.js` to your needs.
-
-* Supports cross-tab communication. When you open the same document in the same browser, changes on the document are exchanged via cross-tab communication ([Broadcast Channel](https://developer.mozilla.org/en-US/docs/Web/API/Broadcast_Channel_API) and [localStorage](https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage) as fallback).
-* Supports exange of awareness information (e.g. cursors)
-
-##### Start a Websocket Server:
-
-```sh
-PORT=1234 node ./node_modules/yjs/provider/websocket/server.js
-```
-
-**Websocket Server with Persistence**
-
-Persist document updates in a LevelDB database.
-
-See [LevelDB Persistence](#LevelDB Persistence) for more info.
-
-```sh
-PORT=1234 YPERSISTENCE=./dbDir node ./node_modules/yjs/provider/websocket/server.js
-```
-
-##### Client Code:
-
-```js
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-
-const provider = new WebsocketProvider('http://localhost:1234')
-
-// open a websocket connection to http://localhost:1234/my-document-name
-const sharedDocument = provider.get('my-document-name')
-
-sharedDocument.on('status', event => {
-  console.log(event.status) // logs "connected" or "disconnected"
-})
-```
-
-#### Scaling
-
-These are mere suggestions how you could scale your server environment.
-
-**Option 1:** Websocket servers communicate with each other via a PubSub server. A room is represented by a PubSub channel. The downside of this approach is that the same shared document may be handled by many servers. But the upside is that this approach is fault tolerant, does not have a single point of failure, and is perfectly fit for route balancing.
-
-**Option 2:** Sharding with *consistent hashing*. Each document is handled by a unique server. This patterns requires an entity, like etcd, that performs regular health checks and manages servers. Based on the list of available servers (which is managed by etcd) a proxy calculates which server is responsible for each requested document. The disadvantage of this approach is that it is that load distribution may not be fair. Still, this approach may be the preferred solution if you want to store the shared document in a database - e.g. for indexing.
-
-### Ydb Provider
-
-TODO
-
-### Create Custom Provider
-
-A provider is only a concept. I encourage you to implement the same provider interface found above. This makes it easy to exchange communication protocols.
-
-Since providers handle the communication channel, they will necessarily interact with the [binary protocols](#Binary-Protocols). I suggest that you build upon the existing protocols. But you may also implement a custom communication protocol.
-
-Read section [Sync Protocol](#Sync-Protocol) to learn how syncing works.
-
-## Shared Types
-
-A shared type is just a normal data type like [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) or [Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array). But a shared type may also be modified by a remote client. Conflicts are automatically resolved by the rules described in this section - but please note that this is only a rough overview of how conflict resolution works. Please read the [Yjs CRDT Algorithm](#Yjs-CRDT-Algorithm) section for an in-depth description of the conflict resolution approach.
-
-As explained in [Tutorial](#Tutorial), a shared type is shared among all peers when they are defined with the same name on the same shared document. I.e.
-
-```js
-sharedDocument.define('my-array', Y.Array)
-
-const myArray = sharedDocument.get('my-array')
-```
-
-You may define a shared types several times, as long as you don't change the type definition.
-
-```js
-sharedDocument.define('my-array', Y.Array)
-
-const myArray = sharedDocument.get('my-array')
-
-const alsoMyArray = sharedDocument.define('my-array', Y.Array)
-
-console.log(myArray === alsoMyArray) // => true
-```
-
-All shared types have an `type.observe(event => ..)` method that allows you to observe any changes. You may also observe all changes on a type and any of its children with the `type.observeDeep(events => ..)` method. Here, `events` is the [Set](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set) of events that were fired on type, or any of its children.
-
-All Events inherit from [YEvent](https://yjs.website/module-utils.YEvent.html).
-
-### YMap
-> Complete API docs: [https://yjs.website/module-types.ymap](https://yjs.website/module-types.ymap)
-
-The YMap type is very similar to the JavaScript [Map](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map). 
-
-YMap fires [YMapEvents](https://yjs.website/module-types.YMapEvent.html).
-
-```js
-import * as Y from 'yjs'
-
-const ymap = new Y.Map()
-
-ymap.observe(event => {
-  console.log('ymap keys changed:', event.keysChanged, event.remote)
-})
-
-ymap.set('key', 'value') // => ymap keys changed: Set{ 'key' } false
-ymap.delete('key') // => ymap keys changed: Set{ 'key' }
-
-const ymap2 = new YMap()
-ymap2.set(1, 'two')
-
-ymap.set('type', ymap2) // => ymap keys changed: Set{ 'type' }
-```
-
-##### Concurrent YMap changes
-
-* Concurrent edits on different keys do not affect each other. E.g. if client1 does `ymap.set('a', 1)` and client2 does `ymap.set('b', 2)`, both clients will end up with `YMap{ a: 1, b: 2 }`
-* If client1 and client2 `set` the same property at the same time, the edit from the client with the smaller userID will prevail (`sharedDocument.userID`)
-* If client1 sets a property `ymap.set('a', 1)` and client2 deletes a property `ymap.delete('a')`, the set operation always prevails.
-
-### YArray
-> Complete API docs: [https://yjs.website/module-types.yarray](https://yjs.website/module-types.yarray)
-
-YArray fires [YArrayEvents](https://yjs.website/module-types.YMapEvent.html).
-
-
-```js
-import * as Y from 'yjs'
-
-const yarray = new Y.Array()
-
-yarray.observe(event => {
-  console.log('yarray changed:', event.addedElements, event.removedElements, event.remote)
-})
-
-// insert two elements at position 0
-yarray.insert(0, ['a', 1]) // => yarray changed: Set{Item{'a'}, Item{1}}, Set{}, false 
-console.log(yarray.toArray()) // => ['a', 1]
-yarray.delete(1, 1) // yarray changed: Set{}, Set{Item{1}}, false
-
-yarray.insert(1, new Y.Map()) // => yarray changed: Set{YMap{}}, Set{}, false
-
-// The difference between .toArray and .toJSON:
-console.log(yarray.toArray()) // => ['a', YMap{}]
-console.log(yarray.toJSON()) // => ['a', {}]
-```
-
-As you can see from the above example, primitive data is wrapped into an Item. This makes it possible to find the exact location of the change.
-
-##### Concurrent YArray changes
-
-* YArray internally represents the data as a doubly linked list. The Array `['a', YMap{}, 1]` is internally represented as `Item{'a'} <-> YMap{} <-> Item{1}`. Accordingly, the insert operation `yarray.insert(1, ['b'])` is internally transformed to `insert Item{'b'} between Item{'a'} and YMap{}`.
-* When an Item is deleted, it is only marked as deleted. Only its content is garbage collected and freed from memory.
-* Therefore, the remote operation `insert x between a and b` can still be fulfilled when item `a` or item `b` are deleted.
-* In case that two clients insert content between the same items (a concurrent insertion), the order of the insertions is decided based on the `sharedDocument.userID`.
-
-### YText
-> Complete API docs: [https://yjs.website/module-types.ytext](https://yjs.website/module-types.ytext)
-
-A YText is basically a [YArray](#YArray) that is optimized for text content. 
-
-### YXmlFragment and YXmlElement
-> Complete API docs: [https://yjs.website/module-types.yxmlfragment](https://yjs.website/module-types.yxmlfragment) and [https://yjs.website/module-types.yxmlelement](https://yjs.website/module-types.yxmlelement)
-
-### Custom Types
-
-## Bindings
-
-## Transaction
-
-
-
-## Binary Protocols
-
-### Sync Protocol
-
-Sync steps
-
-### Awareness Protocol
-
-### Auth Protocol
-
-## Offline Editing
-
-It is trivial with Yjs to persist the local state to indexeddb, so it is always available when working offline. But there are two non-trivial questions that need to answered when implementing a professional offline editing app:
-
-1. How does a client sync down all rooms that were modified while offline?
-2. How does a client sync up all rooms that were modified while offline?
-
-Assuming 5000 documents are stored on each client for offline usage. How do we sync up/down each of those documents after a client comes online? It would be inefficient to sync each of those rooms separately. The only provider that currently supports syncing many rooms efficiently is Ydb, because its database layer is optimized to sync many rooms with each client.
-
-If you do not care about 1. and 2. you can use `/persistences/indexeddb.js` to mirror the local state to indexeddb.
-
-## Working with Yjs
-
-### Typescript Declarations
-
-Until [this](https://github.com/Microsoft/TypeScript/issues/7546) is fixed, the only way to get type declarations is by adding Yjs to the list of checked files:
-
-```json
-{
-  "compilerOptions": {
-    "allowJs": true,
-    "checkJs": true,
-    ..
-  },
-  "maxNodeModuleJsDepth": 5
-}
-```
-
-## CRDT Algorithm
-
-## License and Author
-
-Yjs and all related projects are [**MIT licensed**](./LICENSE). Some files also contain an additional copyright notice that allows you to copy and modify the code without shipping the copyright notice (e.g. `./provider/websocket/WebsocketProvider.js` and `./provider/websocket/server.js`)
-
-Yjs is based on the research I did as a student at the RWTH i5. I am working on Yjs in my spare time. Please help me by donating or hiring me for consulting, so I can continue to work on this project.
-
-kevin.jahns@protonmail.com
--- a/examples/.gitignore
+++ b/examples/.gitignore
@@ -1 +0,0 @@
-build
--- a/examples/ace/index.html
+++ b/examples/ace/index.html
@@ -0,0 +1,32 @@
+<!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="../bower_components/yjs/y.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 +1,24 @@
+/* global Y, ace */
+
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'ace-example'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    ace: 'Text' // y.share.textarea is of type Y.Text
+  }
+}).then(function (y) {
+  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.share.ace.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 +1,23 @@
+<!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-array/y-array.js"></script>
+    <script src="../../../y-map/dist/y-map.js"></script>
+    <script src="../../../y-text/dist/y-text.js"></script>
+    <script src="../../../y-memory/y-memory.js"></script>
+    <script src="../../../y-websockets-client/dist/y-websockets-client.js"></script>
+    <script src="./index.js"></script>
+  </body>
+</html>
--- a/examples/chat/index.js
+++ b/examples/chat/index.js
@@ -0,0 +1,73 @@
+/* global Y, chat */
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'chat-example'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    chat: 'Array'
+  }
+}).then(function (y) {
+  window.yChat = y
+  // 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))
+    document.querySelector('#chat').insertBefore(p, chat.children[position] || null)
+  }
+  // This function makes sure that only 7 messages exist in the chat history.
+  // The rest is deleted
+  function cleanupChat () {
+    if (y.share.chat.length > 7) {
+      y.share.chat.delete(0, y.chat.length - 7)
+    }
+  }
+  // Insert the initial content
+  y.share.chat.toArray().forEach(appendMessage)
+  cleanupChat()
+
+  // whenever content changes, make sure to reflect the changes in the DOM
+  y.share.chat.observe(function (event) {
+    if (event.type === 'insert') {
+      for (let i = 0; i < event.length; i++) {
+        appendMessage(event.values[i], event.index + i)
+      }
+    } else if (event.type === 'delete') {
+      for (let i = 0; i < event.length; i++) {
+        chat.children[event.index].remove()
+      }
+    }
+    // concurrent insertions may result in a history > 7, so cleanup here
+    cleanupChat()
+  })
+  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 (y.share.chat.length > 6) {
+        // If we are goint to insert the 8th element, make sure to delete first.
+        y.share.chat.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
+      y.share.chat.push([message])
+      this.querySelector('[name=message]').value = ''
+    }
+    // Do not send this form!
+    event.preventDefault()
+    return false
+  }
+})
--- a/examples/codemirror.html
+++ b/examples/codemirror.html
@@ -1,70 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-    <title>Yjs CodeMirror Example</title>
-    <link rel=stylesheet href="https://codemirror.net/lib/codemirror.css">
-    <style>
-      #container {
-        border: grey;
-        border-style: solid;
-        border-width: thin;
-      }
-    </style>
-  </head>
-<body>
-  <p>This example shows how to bind a YText type to <a href="https://codemirror.net/">CodeMirror</a> editor.</p>
-  <p>The content of this editor is shared with every client who visits this domain.</p>
-  <div class="code-html">
-<style>
-.remote-caret {
-  position: absolute;
-  border-left: black;
-  border-left-style: solid;
-  border-left-width: 2px;
-  height: 1em;
-}
-.remote-caret > div {
-  position: relative;
-  top: -1.05em;
-  font-size: 13px;
-  background-color: rgb(250, 129, 0);
-  font-family: serif;
-  font-style: normal;
-  font-weight: normal;
-  line-height: normal;
-  user-select: none;
-  color: white;
-  padding-left: 2px;
-  padding-right: 2px;
-}
-</style>
-<div id="container"></div>
-  </div>
-  <!-- The actual source file for the following code is found in ./codemirror.js. Run `npm run watch` to compile the files -->
-  <script class="code-js" src="./build/codemirror.js" type="module">
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-import { CodeMirrorBinding } from 'yjs/bindings/codemirror.js'
-
-import * as conf from './exampleConfig.js'
-
-import CodeMirror from 'codemirror'
-import 'codemirror/mode/javascript/javascript.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('codemirror')
-const ytext = ydocument.define('codemirror', Y.Text)
-
-const editor = new CodeMirror(document.querySelector('#container'), {
-    mode: 'javascript',
-    lineNumbers: true
-})
-
-const binding = new CodeMirrorBinding(ytext, editor)
-
-window.codemirrorExample = {
-  binding, editor, ytext, ydocument
-}
-  </script>
-</body>
-</html>
--- a/examples/codemirror.js
+++ b/examples/codemirror.js
@@ -1,22 +0,0 @@
-import { WebsocketProvider } from 'y-websocket'
-import { CodeMirrorBinding } from 'y-codemirror'
-
-import * as conf from './exampleConfig.js'
-
-import CodeMirror from 'codemirror'
-import 'codemirror/mode/javascript/javascript.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('codemirror')
-const ytext = ydocument.getText('codemirror')
-
-const editor = new CodeMirror(document.querySelector('#container'), {
-  mode: 'javascript',
-  lineNumbers: true
-})
-
-const binding = new CodeMirrorBinding(ytext, editor)
-
-window.codemirrorExample = {
-  binding, editor, ytext, ydocument
-}
--- a/examples/codemirror/index.html
+++ b/examples/codemirror/index.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+  <head>
+  </head>
+  <body>
+    <div id="codeMirrorContainer"></div>
+
+    <script src="../bower_components/yjs/y.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 +1,24 @@
+/* global Y, CodeMirror */
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'codemirror-example'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    codemirror: 'Text' // y.share.codemirror is of type Y.Text
+  }
+}).then(function (y) {
+  window.yCodeMirror = y
+
+  var editor = CodeMirror(document.querySelector('#codeMirrorContainer'), {
+    mode: 'javascript',
+    lineNumbers: true
+  })
+  y.share.codemirror.bindCodeMirror(editor)
+})
--- a/examples/dom.html
+++ b/examples/dom.html
@@ -1,37 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-    <title>Yjs Prosemirror Example</title>
-    <link rel=stylesheet href="https://prosemirror.net/css/editor.css">
-    <style>
-      #content {
-        min-height: 500px;
-      }
-    </style>
-</head>
-<body>
-  <p>This example shows how to bind a YXmlFragment type to an arbitrary DOM element. We set the DOM element to contenteditable so it basically behaves like a very powerful rich-text editor.</p>
-  <p>The content of this editor is shared with every client who visits this domain.</p>
-  <hr>
-  <div class="code-html">
-
-<div id="content" contenteditable=""></div>
-  </div>
-  <!-- The actual source file for the following code is found in ./dom.js. Run `npm run watch` to compile the files -->
-  <script class="code-js" src="./build/dom.js" type="module">
-    import * as Y from 'yjs/index.js'
-    import { WebsocketProvider } from 'yjs/provider/websocket.js'
-    import { DomBinding } from 'yjs/bindings/dom.js'
-    import * as conf from './exampleConfig.js'
-
-    const provider = new WebsocketProvider(conf.serverAddress)
-    const ydocument = provider.get('dom')
-    const type = ydocument.define('xml', Y.XmlFragment)
-    const binding = new DomBinding(type, document.querySelector('#content'), { scrollingElement: document.scrollingElement })
-
-    window.example = {
-      provider, ydocument, type, binding
-    }
-  </script>
-</body>
-</html>
--- a/examples/dom.js
+++ b/examples/dom.js
@@ -1,13 +0,0 @@
-import * as Y from '../src/index.js'
-import { WebsocketProvider } from 'y-websocket'
-import { DomBinding } from 'y-dom'
-import * as conf from './exampleConfig.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('dom')
-const type = ydocument.define('xml', Y.XmlFragment)
-const binding = new DomBinding(type, document.querySelector('#content'), { scrollingElement: document.scrollingElement })
-
-window.example = {
-  provider, ydocument, type, binding
-}
--- a/examples/drawing/index.html
+++ b/examples/drawing/index.html
@@ -0,0 +1,23 @@
+<!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-array/y-array.js"></script>
+  <script src="../../../y-map/dist/y-map.js"></script>
+  <script src="../../../y-memory/y-memory.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/drawing/index.js
+++ b/examples/drawing/index.js
@@ -0,0 +1,84 @@
+/* globals Y, d3 */
+'strict mode'
+
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'drawing-example',
+    url: 'localhost:1234'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    drawing: 'Array'
+  }
+}).then(function (y) {
+  window.yDrawing = y
+  var drawing = y.share.drawing
+  var renderPath = d3.svg.line()
+    .x(function (d) { return d[0] })
+    .y(function (d) { return d[1] })
+    .interpolate('basis')
+
+  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) {
+      // we only implement insert events that are appended to the end of the array
+      event.values.forEach(function (value) {
+        line.datum().push(value)
+      })
+      line.attr('d', renderPath)
+    })
+  }
+  // call drawLine every time an array is appended
+  y.share.drawing.observe(function (event) {
+    if (event.type === 'insert') {
+      event.values.forEach(drawLine)
+    } else {
+      // just remove all elements (thats what we do anyway)
+      svg.selectAll('path').remove()
+    }
+  })
+  // 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
+      }, 33)
+      sharedLine.push([d3.mouse(this)])
+    }
+  }
+
+  function dragend () {
+    sharedLine = null
+    window.clearTimeout(ignoreDrag)
+    ignoreDrag = null
+  }
+})
--- a/examples/exampleConfig.js
+++ b/examples/exampleConfig.js
@@ -1,9 +0,0 @@
-/* eslint-env browser */
-
-const isDeployed = location.hostname === 'yjs.website'
-
-if (!isDeployed) {
-  console.log('%cYjs: Start your local websocket server by running %c`npm run websocket-server`', 'color:blue', 'color: grey; font-weight: bold')
-}
-
-export const serverAddress = isDeployed ? 'wss://api.yjs.website' : 'ws://localhost:1234'
--- a/examples/examples.json
+++ b/examples/examples.json
@@ -1,17 +0,0 @@
-{
-  "codemirror": {
-    "title": "CodeMirror Binding"
-  },
-  "prosemirror": {
-    "title": "ProseMirror Binding"
-  },
-  "textarea": {
-    "title": "Textarea Binding"
-  },
-  "quill": {
-    "title": "Quill Binding"
-  },
-  "dom": {
-    "title": "Dom Binding"
-  }
-}
--- a/examples/jigsaw/index.html
+++ b/examples/jigsaw/index.html
@@ -0,0 +1,26 @@
+<!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-map/dist/y-map.js"></script>
+  <script src="../../../y-memory/y-memory.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 +1,74 @@
+/* @flow */
+/* global Y, d3 */
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'Puzzle-example',
+    url: 'http://localhost:1234'
+  },
+  share: {
+    piece1: 'Map',
+    piece2: 'Map',
+    piece3: 'Map',
+    piece4: 'Map'
+  }
+}).then(function (y) {
+  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
+      piece.set('translation', {x: x, y: y})
+    })
+
+  var data = [y.share.piece1, y.share.piece2, y.share.piece3, y.share.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) {
+    piece.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('translation') || {x: 0, y: 0}
+          return 'translate(' + translation.x + ',' + translation.y + ')'
+        })
+    })
+  })
+})
--- a/examples/monaco/index.html
+++ b/examples/monaco/index.html
@@ -0,0 +1,24 @@
+<!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="../bower_components/yjs/y.js"></script>
+    <script src="../bower_components/y-array/y-array.js"></script>
+    <script src="../bower_components/y-text/y-text.js"></script>
+    <script src="../bower_components/y-websockets-client/y-websockets-client.js"></script>
+    <script src="../bower_components/y-memory/y-memory.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 +1,30 @@
+/* global Y, monaco */
+
+require.config({ paths: { 'vs': '../node_modules/monaco-editor/min/vs' } })
+
+require(['vs/editor/editor.main'], function () {
+  // Initialize a shared object. This function call returns a promise!
+  Y({
+    db: {
+      name: 'memory'
+    },
+    connector: {
+      name: 'websockets-client',
+      room: 'monaco-example'
+    },
+    sourceDir: '/bower_components',
+    share: {
+      monaco: 'Text' // y.share.monaco is of type Y.Text
+    }
+  }).then(function (y) {
+    window.yMonaco = y
+
+    // Create Monaco editor
+    var editor = monaco.editor.create(document.getElementById('monacoContainer'), {
+      language: 'javascript'
+    })
+
+    // Bind to y.share.monaco
+    y.share.monaco.bindMonaco(editor)
+  })
+})
--- a/examples/package-lock.json
+++ b/examples/package-lock.json
--- a/examples/package.json
+++ b/examples/package.json
@@ -0,0 +1,16 @@
+{
+  "name": "examples",
+  "version": "0.0.0",
+  "description": "",
+  "author": "Kevin Jahns",
+  "license": "MIT",
+  "dependencies": {
+    "monaco-editor": "^0.8.3"
+  },
+  "devDependencies": {
+    "standard": "^10.0.2"
+  },
+  "standard": {
+    "ignore": ["bower_components"]
+  }
+}
--- a/examples/prosemirror-history.js
+++ b/examples/prosemirror-history.js
@@ -1,159 +0,0 @@
-
-import { Plugin } from 'prosemirror-state'
-import crel from 'crel'
-import * as Y from '../src/index.js'
-import { prosemirrorPluginKey } from 'y-prosemirror'
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-import * as historyProtocol from 'y-protocols/history.js'
-
-const niceColors = ['#3cb44b', '#4363d8', '#f58231', '#911eb4', '#46f0f0', '#f032e6', '#bcf60c', '#008080', '#9a6324', '#800000', '#808000', '#000075', '#808080']
-
-const createUserCSS = (userid, username, color = 'rgb(250, 129, 0)', color2 = 'rgba(250, 129, 0, .41)') => `
-  [ychange_state][ychange_user="${userid}"]:hover::before {
-    content: "${username}" !important;
-    background-color: ${color} !important;
-  }
-  [ychange_state="added"][ychange_user="${userid}"] {
-    background-color: ${color2} !important;
-  }
-  [ychange_state="removed"][ychange_user="${userid}"] {
-    color: ${color} !important;
-  }
-`
-
-export const noteHistoryPlugin = new Plugin({
-  state: {
-    init (initargs, state) {
-      return new NoteHistoryPlugin()
-    },
-    apply (tr, pluginState) {
-      return pluginState
-    }
-  },
-  view (editorView) {
-    const hstate = noteHistoryPlugin.getState(editorView.state)
-    hstate.init(editorView)
-    return {
-      destroy: hstate.destroy.bind(hstate)
-    }
-  }
-})
-
-const createWrapper = () => {
-  const wrapper = crel('div', { style: 'display: flex;' })
-  const historyContainer = crel('div', { style: 'align-self: baseline; flex-basis: 250px;', class: 'shared-history' })
-  wrapper.insertBefore(historyContainer, null)
-  const userStyleContainer = crel('style')
-  wrapper.insertBefore(userStyleContainer, null)
-  return { wrapper, historyContainer, userStyleContainer }
-}
-
-class NoteHistoryPlugin {
-  init (editorView) {
-    this.editorView = editorView
-    const { historyContainer, wrapper, userStyleContainer } = createWrapper()
-    this.userStyleContainer = userStyleContainer
-    this.wrapper = wrapper
-    this.historyContainer = historyContainer
-    const n = editorView.dom.parentNode.parentNode
-    n.parentNode.replaceChild(this.wrapper, n)
-    n.style['flex-grow'] = '1'
-    wrapper.insertBefore(n, this.wrapper.firstChild)
-    this.render()
-    const y = prosemirrorPluginKey.getState(this.editorView.state).y
-    const history = y.define('history', Y.Array)
-    history.observe(this.render.bind(this))
-  }
-  destroy () {
-    this.wrapper.parentNode.replaceChild(this.wrapper.firstChild, this.wrapper)
-    const y = prosemirrorPluginKey.getState(this.editorView.state).y
-    const history = y.define('history', Y.Array)
-    history.unobserve(this.render)
-  }
-  render () {
-    const y = prosemirrorPluginKey.getState(this.editorView.state).y
-    const history = y.define('history', Y.Array).toArray()
-    const fragment = document.createDocumentFragment()
-    const snapshotBtn = crel('button', { type: 'button' }, ['snapshot'])
-    fragment.insertBefore(snapshotBtn, null)
-    let _prevSnap = null // empty
-    snapshotBtn.addEventListener('click', () => {
-      const awareness = y.getAwarenessInfo()
-      const userMap = new Map()
-      const aw = y.getLocalAwarenessInfo()
-      userMap.set(y.userID, aw.name || 'unknown')
-      awareness.forEach((a, userID) => {
-        userMap.set(userID, a.name || 'Unknown')
-      })
-      this.snapshot(userMap)
-    })
-    history.forEach(buf => {
-      const decoder = decoding.createDecoder(buf)
-      const snapshot = historyProtocol.readHistorySnapshot(decoder)
-      const date = new Date(decoding.readUint32(decoder) * 1000)
-      const restoreBtn = crel('button', { type: 'button' }, ['restore'])
-      const a = crel('a', [
-        '• ' + date.toUTCString(), restoreBtn
-      ])
-      const el = crel('div', [ a ])
-      let prevSnapshot = _prevSnap // rebind to new variable
-      restoreBtn.addEventListener('click', event => {
-        if (prevSnapshot === null) {
-          prevSnapshot = { ds: snapshot.ds, sm: new Map() }
-        }
-        this.editorView.dispatch(this.editorView.state.tr.setMeta(prosemirrorPluginKey, { snapshot, prevSnapshot, restore: true }))
-        event.stopPropagation()
-      })
-      a.addEventListener('click', () => {
-        console.log('setting snapshot')
-        if (prevSnapshot === null) {
-          prevSnapshot = { ds: snapshot.ds, sm: new Map() }
-        }
-        this.renderSnapshot(snapshot, prevSnapshot)
-      })
-      fragment.insertBefore(el, null)
-      _prevSnap = snapshot
-    })
-    this.historyContainer.innerHTML = ''
-    this.historyContainer.insertBefore(fragment, null)
-  }
-  renderSnapshot (snapshot, prevSnapshot) {
-    this.editorView.dispatch(this.editorView.state.tr.setMeta(prosemirrorPluginKey, { snapshot, prevSnapshot }))
-    /**
-     * @type {Array<string|null>}
-     */
-    let colors = niceColors.slice()
-    let style = ''
-    snapshot.userMap.forEach((name, userid) => {
-      /**
-       * @type {any}
-       */
-      const randInt = name.split('').map(s => s.charCodeAt(0)).reduce((a, b) => a + b)
-      let color = null
-      let i = 0
-      for (; i < colors.length && color === null; i++) {
-        color = colors[(randInt + i) % colors.length]
-      }
-      if (color === null) {
-        colors = niceColors.slice()
-        i = 0
-        color = colors[randInt % colors.length]
-      }
-      colors[randInt % colors.length] = null
-      style += createUserCSS(userid, name, color, color + '69')
-    })
-    this.userStyleContainer.innerHTML = style
-  }
-  /**
-   * @param {Map<number, string>} [updatedUserMap] Maps from userid (yjs model) to account name (e.g. mail address)
-   */
-  snapshot (updatedUserMap = new Map()) {
-    const y = prosemirrorPluginKey.getState(this.editorView.state).y
-    const history = y.define('history', Y.Array)
-    const encoder = encoding.createEncoder()
-    historyProtocol.writeHistorySnapshot(encoder, y, updatedUserMap)
-    encoding.writeUint32(encoder, Math.floor(Date.now() / 1000))
-    history.push([encoding.toBuffer(encoder)])
-  }
-}
--- a/examples/prosemirror-schema.js
+++ b/examples/prosemirror-schema.js
@@ -1,197 +0,0 @@
-import { Schema } from 'prosemirror-model'
-
-const brDOM = ['br']
-
-const calcYchangeDomAttrs = (attrs, domAttrs = {}) => {
-  domAttrs = Object.assign({}, domAttrs)
-  if (attrs.ychange !== null) {
-    domAttrs.ychange_user = attrs.ychange.user
-    domAttrs.ychange_state = attrs.ychange.state
-  }
-  return domAttrs
-}
-
-// :: Object
-// [Specs](#model.NodeSpec) for the nodes defined in this schema.
-export const nodes = {
-  // :: NodeSpec The top level document node.
-  doc: {
-    content: 'block+'
-  },
-
-  // :: NodeSpec A plain paragraph textblock. Represented in the DOM
-  // as a `<p>` element.
-  paragraph: {
-    attrs: { ychange: { default: null } },
-    content: 'inline*',
-    group: 'block',
-    parseDOM: [{ tag: 'p' }],
-    toDOM (node) { return ['p', calcYchangeDomAttrs(node.attrs), 0] }
-  },
-
-  // :: NodeSpec A blockquote (`<blockquote>`) wrapping one or more blocks.
-  blockquote: {
-    attrs: { ychange: { default: null } },
-    content: 'block+',
-    group: 'block',
-    defining: true,
-    parseDOM: [{ tag: 'blockquote' }],
-    toDOM (node) { return ['blockquote', calcYchangeDomAttrs(node.attrs), 0] }
-  },
-
-  // :: NodeSpec A horizontal rule (`<hr>`).
-  horizontal_rule: {
-    attrs: { ychange: { default: null } },
-    group: 'block',
-    parseDOM: [{ tag: 'hr' }],
-    toDOM (node) {
-      return ['hr', calcYchangeDomAttrs(node.attrs)]
-    }
-  },
-
-  // :: NodeSpec A heading textblock, with a `level` attribute that
-  // should hold the number 1 to 6. Parsed and serialized as `<h1>` to
-  // `<h6>` elements.
-  heading: {
-    attrs: {
-      level: { default: 1 },
-      ychange: { default: null }
-    },
-    content: 'inline*',
-    group: 'block',
-    defining: true,
-    parseDOM: [{ tag: 'h1', attrs: { level: 1 } },
-      { tag: 'h2', attrs: { level: 2 } },
-      { tag: 'h3', attrs: { level: 3 } },
-      { tag: 'h4', attrs: { level: 4 } },
-      { tag: 'h5', attrs: { level: 5 } },
-      { tag: 'h6', attrs: { level: 6 } }],
-    toDOM (node) { return ['h' + node.attrs.level, calcYchangeDomAttrs(node.attrs), 0] }
-  },
-
-  // :: NodeSpec A code listing. Disallows marks or non-text inline
-  // nodes by default. Represented as a `<pre>` element with a
-  // `<code>` element inside of it.
-  code_block: {
-    attrs: { ychange: { default: null } },
-    content: 'text*',
-    marks: '',
-    group: 'block',
-    code: true,
-    defining: true,
-    parseDOM: [{ tag: 'pre', preserveWhitespace: 'full' }],
-    toDOM (node) { return ['pre', calcYchangeDomAttrs(node.attrs), ['code', 0]] }
-  },
-
-  // :: NodeSpec The text node.
-  text: {
-    group: 'inline'
-  },
-
-  // :: NodeSpec An inline image (`<img>`) node. Supports `src`,
-  // `alt`, and `href` attributes. The latter two default to the empty
-  // string.
-  image: {
-    inline: true,
-    attrs: {
-      ychange: { default: null },
-      src: {},
-      alt: { default: null },
-      title: { default: null }
-    },
-    group: 'inline',
-    draggable: true,
-    parseDOM: [{ tag: 'img[src]',
-      getAttrs (dom) {
-        return {
-          src: dom.getAttribute('src'),
-          title: dom.getAttribute('title'),
-          alt: dom.getAttribute('alt')
-        }
-      } }],
-    toDOM (node) {
-      const domAttrs = {
-        src: node.attrs.src,
-        title: node.attrs.title,
-        alt: node.attrs.alt
-      }
-      return ['img', calcYchangeDomAttrs(node.attrs, domAttrs)]
-    }
-  },
-
-  // :: NodeSpec A hard line break, represented in the DOM as `<br>`.
-  hard_break: {
-    inline: true,
-    group: 'inline',
-    selectable: false,
-    parseDOM: [{ tag: 'br' }],
-    toDOM () { return brDOM }
-  }
-}
-
-const emDOM = ['em', 0]; const strongDOM = ['strong', 0]; const codeDOM = ['code', 0]
-
-// :: Object [Specs](#model.MarkSpec) for the marks in the schema.
-export const marks = {
-  // :: MarkSpec A link. Has `href` and `title` attributes. `title`
-  // defaults to the empty string. Rendered and parsed as an `<a>`
-  // element.
-  link: {
-    attrs: {
-      href: {},
-      title: { default: null }
-    },
-    inclusive: false,
-    parseDOM: [{ tag: 'a[href]',
-      getAttrs (dom) {
-        return { href: dom.getAttribute('href'), title: dom.getAttribute('title') }
-      } }],
-    toDOM (node) { return ['a', node.attrs, 0] }
-  },
-
-  // :: MarkSpec An emphasis mark. Rendered as an `<em>` element.
-  // Has parse rules that also match `<i>` and `font-style: italic`.
-  em: {
-    parseDOM: [{ tag: 'i' }, { tag: 'em' }, { style: 'font-style=italic' }],
-    toDOM () { return emDOM }
-  },
-
-  // :: MarkSpec A strong mark. Rendered as `<strong>`, parse rules
-  // also match `<b>` and `font-weight: bold`.
-  strong: {
-    parseDOM: [{ tag: 'strong' },
-      // This works around a Google Docs misbehavior where
-      // pasted content will be inexplicably wrapped in `<b>`
-      // tags with a font-weight normal.
-      { tag: 'b', getAttrs: node => node.style.fontWeight !== 'normal' && null },
-      { style: 'font-weight', getAttrs: value => /^(bold(er)?|[5-9]\d{2,})$/.test(value) && null }],
-    toDOM () { return strongDOM }
-  },
-
-  // :: MarkSpec Code font mark. Represented as a `<code>` element.
-  code: {
-    parseDOM: [{ tag: 'code' }],
-    toDOM () { return codeDOM }
-  },
-  ychange: {
-    attrs: {
-      user: { default: null },
-      state: { default: null }
-    },
-    inclusive: false,
-    parseDOM: [{ tag: 'ychange' }],
-    toDOM (node) {
-      return ['ychange', { ychange_user: node.attrs.user, ychange_state: node.attrs.state }, 0]
-    }
-  }
-}
-
-// :: Schema
-// This schema rougly corresponds to the document schema used by
-// [CommonMark](http://commonmark.org/), minus the list elements,
-// which are defined in the [`prosemirror-schema-list`](#schema-list)
-// module.
-//
-// To reuse elements from this schema, extend or read from its
-// `spec.nodes` and `spec.marks` [properties](#model.Schema.spec).
-export const schema = new Schema({ nodes, marks })
--- a/examples/prosemirror.css
+++ b/examples/prosemirror.css
@@ -1,330 +0,0 @@
-.ProseMirror {
-  position: relative;
-}
-
-.ProseMirror {
-  word-wrap: break-word;
-  white-space: pre-wrap;
-  -webkit-font-variant-ligatures: none;
-  font-variant-ligatures: none;
-}
-
-.ProseMirror pre {
-  white-space: pre-wrap;
-}
-
-.ProseMirror li {
-  position: relative;
-}
-
-.ProseMirror-hideselection *::selection { background: transparent; }
-.ProseMirror-hideselection *::-moz-selection { background: transparent; }
-.ProseMirror-hideselection { caret-color: transparent; }
-
-.ProseMirror-selectednode {
-  outline: 2px solid #8cf;
-}
-
-/* Make sure li selections wrap around markers */
-
-li.ProseMirror-selectednode {
-  outline: none;
-}
-
-li.ProseMirror-selectednode:after {
-  content: "";
-  position: absolute;
-  left: -32px;
-  right: -2px; top: -2px; bottom: -2px;
-  border: 2px solid #8cf;
-  pointer-events: none;
-}
-.ProseMirror-textblock-dropdown {
-  min-width: 3em;
-}
-
-.ProseMirror-menu {
-  margin: 0 -4px;
-  line-height: 1;
-}
-
-.ProseMirror-tooltip .ProseMirror-menu {
-  width: -webkit-fit-content;
-  width: fit-content;
-  white-space: pre;
-}
-
-.ProseMirror-menuitem {
-  margin-right: 3px;
-  display: inline-block;
-}
-
-.ProseMirror-menuseparator {
-  border-right: 1px solid #ddd;
-  margin-right: 3px;
-}
-
-.ProseMirror-menu-dropdown, .ProseMirror-menu-dropdown-menu {
-  font-size: 90%;
-  white-space: nowrap;
-}
-
-.ProseMirror-menu-dropdown {
-  vertical-align: 1px;
-  cursor: pointer;
-  position: relative;
-  padding-right: 15px;
-}
-
-.ProseMirror-menu-dropdown-wrap {
-  padding: 1px 0 1px 4px;
-  display: inline-block;
-  position: relative;
-}
-
-.ProseMirror-menu-dropdown:after {
-  content: "";
-  border-left: 4px solid transparent;
-  border-right: 4px solid transparent;
-  border-top: 4px solid currentColor;
-  opacity: .6;
-  position: absolute;
-  right: 4px;
-  top: calc(50% - 2px);
-}
-
-.ProseMirror-menu-dropdown-menu, .ProseMirror-menu-submenu {
-  position: absolute;
-  background: white;
-  color: #666;
-  border: 1px solid #aaa;
-  padding: 2px;
-}
-
-.ProseMirror-menu-dropdown-menu {
-  z-index: 15;
-  min-width: 6em;
-}
-
-.ProseMirror-menu-dropdown-item {
-  cursor: pointer;
-  padding: 2px 8px 2px 4px;
-}
-
-.ProseMirror-menu-dropdown-item:hover {
-  background: #f2f2f2;
-}
-
-.ProseMirror-menu-submenu-wrap {
-  position: relative;
-  margin-right: -4px;
-}
-
-.ProseMirror-menu-submenu-label:after {
-  content: "";
-  border-top: 4px solid transparent;
-  border-bottom: 4px solid transparent;
-  border-left: 4px solid currentColor;
-  opacity: .6;
-  position: absolute;
-  right: 4px;
-  top: calc(50% - 4px);
-}
-
-.ProseMirror-menu-submenu {
-  display: none;
-  min-width: 4em;
-  left: 100%;
-  top: -3px;
-}
-
-.ProseMirror-menu-active {
-  background: #eee;
-  border-radius: 4px;
-}
-
-.ProseMirror-menu-active {
-  background: #eee;
-  border-radius: 4px;
-}
-
-.ProseMirror-menu-disabled {
-  opacity: .3;
-}
-
-.ProseMirror-menu-submenu-wrap:hover .ProseMirror-menu-submenu, .ProseMirror-menu-submenu-wrap-active .ProseMirror-menu-submenu {
-  display: block;
-}
-
-.ProseMirror-menubar {
-  border-top-left-radius: inherit;
-  border-top-right-radius: inherit;
-  position: relative;
-  min-height: 1em;
-  color: #666;
-  padding: 1px 6px;
-  top: 0; left: 0; right: 0;
-  border-bottom: 1px solid silver;
-  background: white;
-  z-index: 10;
-  -moz-box-sizing: border-box;
-  box-sizing: border-box;
-  overflow: visible;
-}
-
-.ProseMirror-icon {
-  display: inline-block;
-  line-height: .8;
-  vertical-align: -2px; /* Compensate for padding */
-  padding: 2px 8px;
-  cursor: pointer;
-}
-
-.ProseMirror-menu-disabled.ProseMirror-icon {
-  cursor: default;
-}
-
-.ProseMirror-icon svg {
-  fill: currentColor;
-  height: 1em;
-}
-
-.ProseMirror-icon span {
-  vertical-align: text-top;
-}
-.ProseMirror-gapcursor {
-  display: none;
-  pointer-events: none;
-  position: absolute;
-}
-
-.ProseMirror-gapcursor:after {
-  content: "";
-  display: block;
-  position: absolute;
-  top: -2px;
-  width: 20px;
-  border-top: 1px solid black;
-  animation: ProseMirror-cursor-blink 1.1s steps(2, start) infinite;
-}
-
-@keyframes ProseMirror-cursor-blink {
-  to {
-    visibility: hidden;
-  }
-}
-
-.ProseMirror-focused .ProseMirror-gapcursor {
-  display: block;
-}
-/* Add space around the hr to make clicking it easier */
-
-.ProseMirror-example-setup-style hr {
-  padding: 2px 10px;
-  border: none;
-  margin: 1em 0;
-}
-
-.ProseMirror-example-setup-style hr:after {
-  content: "";
-  display: block;
-  height: 1px;
-  background-color: silver;
-  line-height: 2px;
-}
-
-.ProseMirror ul, .ProseMirror ol {
-  padding-left: 30px;
-}
-
-.ProseMirror blockquote {
-  padding-left: 1em;
-  border-left: 3px solid #eee;
-  margin-left: 0; margin-right: 0;
-}
-
-.ProseMirror-example-setup-style img {
-  cursor: default;
-}
-
-.ProseMirror-prompt {
-  background: white;
-  padding: 5px 10px 5px 15px;
-  border: 1px solid silver;
-  position: fixed;
-  border-radius: 3px;
-  z-index: 11;
-  box-shadow: -.5px 2px 5px rgba(0, 0, 0, .2);
-}
-
-.ProseMirror-prompt h5 {
-  margin: 0;
-  font-weight: normal;
-  font-size: 100%;
-  color: #444;
-}
-
-.ProseMirror-prompt input[type="text"],
-.ProseMirror-prompt textarea {
-  background: #eee;
-  border: none;
-  outline: none;
-}
-
-.ProseMirror-prompt input[type="text"] {
-  padding: 0 4px;
-}
-
-.ProseMirror-prompt-close {
-  position: absolute;
-  left: 2px; top: 1px;
-  color: #666;
-  border: none; background: transparent; padding: 0;
-}
-
-.ProseMirror-prompt-close:after {
-  content: "✕";
-  font-size: 12px;
-}
-
-.ProseMirror-invalid {
-  background: #ffc;
-  border: 1px solid #cc7;
-  border-radius: 4px;
-  padding: 5px 10px;
-  position: absolute;
-  min-width: 10em;
-}
-
-.ProseMirror-prompt-buttons {
-  margin-top: 5px;
-  display: none;
-}
-#editor, .editor {
-  background: white;
-  color: black;
-  background-clip: padding-box;
-  border-radius: 4px;
-  border: 2px solid rgba(0, 0, 0, 0.2);
-  padding: 5px 0;
-  margin-bottom: 23px;
-}
-
-.ProseMirror p:first-child,
-.ProseMirror h1:first-child,
-.ProseMirror h2:first-child,
-.ProseMirror h3:first-child,
-.ProseMirror h4:first-child,
-.ProseMirror h5:first-child,
-.ProseMirror h6:first-child {
-  margin-top: 10px;
-}
-
-.ProseMirror {
-  padding: 4px 8px 4px 14px;
-  line-height: 1.2;
-  outline: none;
-}
-
-.ProseMirror p { margin-bottom: 1em }
-
--- a/examples/prosemirror.html
+++ b/examples/prosemirror.html
@@ -1,117 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-    <title>Yjs Prosemirror Example</title>
-    <link rel=stylesheet href="./prosemirror.css">
-    <style>
-      placeholder {
-        display: inline;
-        border: 1px solid #ccc;
-        color: #ccc;
-      }
-      placeholder:after {
-        content: "☁";
-        font-size: 200%;
-        line-height: 0.1;
-        font-weight: bold;
-      }
-      .ProseMirror img { max-width: 100px }
-      /* this is a rough fix for the first cursor position when the first paragraph is empty */
-      .ProseMirror > .ProseMirror-yjs-cursor:first-child {
-        margin-top: 16px;
-      }
-      .ProseMirror p:first-child, .ProseMirror h1:first-child, .ProseMirror h2:first-child, .ProseMirror h3:first-child, .ProseMirror h4:first-child, .ProseMirror h5:first-child, .ProseMirror h6:first-child {
-        margin-top: 16px
-      }
-      .ProseMirror-yjs-cursor {
-        position: absolute;
-        border-left: black;
-        border-left-style: solid;
-        border-left-width: 2px;
-        border-color: orange;
-        height: 1em;
-        word-break: normal;
-      }
-      .ProseMirror-yjs-cursor > div {
-        position: relative;
-        top: -1.05em;
-        font-size: 13px;
-        background-color: rgb(250, 129, 0);
-        font-family: serif;
-        font-style: normal;
-        font-weight: normal;
-        line-height: normal;
-        user-select: none;
-        color: white;
-        padding-left: 2px;
-        padding-right: 2px;
-      }
-      [ychange_state] {
-        position: relative;
-      }
-      [ychange_state]:hover::before {
-        content: attr(ychange_user);
-        background-color: #fa8100;
-        position: absolute;
-        top: -14px;
-        right: 0;
-        font-size: 12px;
-        padding: 0 2px;
-        border-radius: 3px 3px 0 0;
-        color: #fdfdfe;
-        user-select: none;
-        word-break: normal;
-      }
-      *[ychange_state='added'] {
-        background-color: #fa810069;
-      }
-      ychange[ychange_state='removed'] {
-        color: rgb(250, 129, 0);
-        text-decoration: line-through;
-      }
-      *:not(ychange)[ychange_state='removed'] {
-        background-color: #ff9494c9;
-        text-decoration: line-through;
-      }
-      img[ychange_state='removed'] {
-        padding: 2px;
-      }
-    </style>
-</head>
-<body>
-  <p>This example shows how to bind a YXmlFragment type to a <a href="http://prosemirror.net">Prosemirror</a> editor.</p>
-  <p>The content of this editor is shared with every client who visits this domain.</p>
-  <div class="code-html">
-
-<div id="editor" style="margin-bottom: 23px"></div>
-<div style="display: none" id="content"></div>
-  </div>
-  <!-- The actual source file for the following code is found in ./prosemirror.js. Run `npm run watch` to compile the files -->
-  <script class="code-js" src="./build/prosemirror.js" type="module">
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-import { prosemirrorPlugin, cursorPlugin } from 'yjs/bindings/prosemirror'
-
-import * as conf from './exampleConfig.js'
-
-import { EditorState } from 'prosemirror-state'
-import { EditorView } from 'prosemirror-view'
-import { DOMParser } from 'prosemirror-model'
-import { schema } from 'prosemirror-schema-basic'
-import { exampleSetup } from 'prosemirror-example-setup'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('prosemirror')
-const type = ydocument.define('prosemirror', Y.XmlFragment)
-
-const prosemirrorView = new EditorView(document.querySelector('#editor'), {
-  state: EditorState.create({
-    doc: DOMParser.fromSchema(schema).parse(document.querySelector('#content')),
-    plugins: exampleSetup({schema}).concat([prosemirrorPlugin(type), cursorPlugin])
-  })
-})
-
-window.example = { provider, ydocument, type, prosemirrorView }
-  </script>
-</body>
-</html>
--- a/examples/prosemirror.js
+++ b/examples/prosemirror.js
@@ -1,25 +0,0 @@
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'y-websocket'
-import { prosemirrorPlugin, cursorPlugin } from 'y-prosemirror'
-
-import * as conf from './exampleConfig.js'
-
-import { EditorState } from 'prosemirror-state'
-import { EditorView } from 'prosemirror-view'
-import { DOMParser } from 'prosemirror-model'
-import { schema } from './prosemirror-schema.js'
-import { exampleSetup } from 'prosemirror-example-setup'
-// import { noteHistoryPlugin } from './prosemirror-history.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('prosemirror', { gc: false })
-const type = ydocument.define('prosemirror', Y.XmlFragment)
-
-const prosemirrorView = new EditorView(document.querySelector('#editor'), {
-  state: EditorState.create({
-    doc: DOMParser.fromSchema(schema).parse(document.querySelector('#content')),
-    plugins: exampleSetup({ schema }).concat([prosemirrorPlugin(type), cursorPlugin])
-  })
-})
-
-window.example = { provider, ydocument, type, prosemirrorView }
--- a/examples/quill.html
+++ b/examples/quill.html
@@ -1,51 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-    <title>Yjs Quill Example</title>
-    <link rel="stylesheet" href="https://cdn.quilljs.com/1.3.6/quill.snow.css">
-  </head>
-<body>
-  <p>This example shows how to bind a YText type to <a href="https://quilljs.com">Quill</a> editor.</p>
-  <p>The content of this editor is shared with every client who visits this domain.</p>
-  <div class="code-html">
-<div id="quill-container">
-  <div id="quill">
-  </div>
-</div>
-  </div>
-  <!-- The actual source file for the following code is found in ./quill.js. Run `npm run watch` to compile the files -->
-  <script class="code-js" src="./build/quill.js" type="module">
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-import { QuillBinding } from 'yjs/bindings/quill.js'
-
-import * as conf from './exampleConfig.js'
-
-import Quill from 'quill'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('quill')
-const ytext = ydocument.define('quill', Y.Text)
-
-const 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'
-})
-
-window.quillBinding = new QuillBinding(ytext, quill)
-
-  </script>
-</body>
-</html>
--- a/examples/quill.js
+++ b/examples/quill.js
@@ -1,30 +0,0 @@
-import * as Y from '../src/index.js'
-import { WebsocketProvider } from 'y-websocket'
-import { QuillBinding } from 'y-quill'
-
-import * as conf from './exampleConfig.js'
-
-import Quill from 'quill'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('quill')
-const ytext = ydocument.define('quill', Y.Text)
-
-const 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'
-})
-
-window.quillBinding = new QuillBinding(ytext, quill)
--- a/examples/quill/index.html
+++ b/examples/quill/index.html
@@ -0,0 +1,35 @@
+<!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="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.5.1/katex.min.css" rel="stylesheet">
+  <link href="https://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="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.5.1/katex.min.js" type="text/javascript"></script>
+  <script src="https://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="../../y.js"></script>
+  <script src="../../../y-array/y-array.js"></script>
+  <script src="../../../y-richtext/dist/y-richtext.js"></script>
+  <script src="../../../y-memory/y-memory.js"></script>
+  <script src="../../../y-websockets-client/y-websockets-client.js"></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/quill/index.js
+++ b/examples/quill/index.js
@@ -0,0 +1,40 @@
+/* global Y, Quill */
+
+// initialize a shared object. This function call returns a promise!
+
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'richtext-example-quill-1.0-test',
+    url: 'http://localhost:1234'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    richtext: 'Richtext' // y.share.richtext is of type Y.Richtext
+  }
+}).then(function (y) {
+  window.yQuill = 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/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/style.css
+++ b/examples/style.css
@@ -1,29 +0,0 @@
-footer img {
-  display: none;
-}
-
-nav .title h1 a {
-  display: none;
-}
-
-footer {
-  background-color: #b93c1d;
-}
-
-#resizer {
-  background-color: #b93c1d;
-}
-
-.main section article.readme h1:first-child img {
-  display: none;
-}
-
-.main section article.readme h1:first-child {
-  margin-bottom: 16px;
-  margin-top: 30px;
-}
-
-.main section article.readme h1:first-child::before {
-  content: "Yjs";
-  font-size: 2em;
-}
--- a/examples/textarea.html
+++ b/examples/textarea.html
@@ -1,32 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-    <title>Yjs Textarea Example</title>
-</head>
-<body>
-  <p>This example shows how to bind a YText type to a DOM Textarea.</p>
-  <p>The content of this textarea is shared with every client who visits this domain.</p>
-  <div class="code-html">
-
-<textarea style="width:80%;" rows=40 autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
-  </div>
-  <!-- The actual source file for the following code is found in ./textarea.js. Run `npm run watch` to compile the files -->
-  <script class="code-js" src="./build/textarea.js" type="module">
-import * as Y from 'yjs'
-import { WebsocketProvider } from 'yjs/provider/websocket.js'
-import { TextareaBinding } from 'yjs/bindings/textarea.js'
-
-import * as conf from './exampleConfig.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('textarea')
-const type = ydocument.define('textarea', Y.Text)
-const textarea = document.querySelector('textarea')
-const binding = new TextareaBinding(type, textarea)
-
-window.textareaExample = {
-  provider, ydocument, type, textarea, binding
-}
-  </script>
-</body>
-</html>
--- a/examples/textarea.js
+++ b/examples/textarea.js
@@ -1,14 +0,0 @@
-import { WebsocketProvider } from 'y-websocket'
-import { TextareaBinding } from 'y-textarea'
-
-import * as conf from './exampleConfig.js'
-
-const provider = new WebsocketProvider(conf.serverAddress)
-const ydocument = provider.get('textarea')
-const type = ydocument.getText('textarea')
-const textarea = document.querySelector('textarea')
-const binding = new TextareaBinding(type, textarea)
-
-window.textareaExample = {
-  provider, ydocument, type, textarea, binding
-}
--- a/examples/textarea/index.html
+++ b/examples/textarea/index.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<body>
+  <textarea style="width:80%;" rows=40 id="textfield" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>
+  <script src="../../y.js"></script>
+  <script src="../../../y-array/y-array.js"></script>
+  <script src="../../../y-text/dist/y-text.js"></script>
+  <script src="../../../y-memory/y-memory.js"></script>
+  <script src="../../../y-websockets-client/y-websockets-client.js"></script>
+  <script src="./index.js"></script>
+</body>
+</html>
--- a/examples/textarea/index.js
+++ b/examples/textarea/index.js
@@ -0,0 +1,24 @@
+/* global Y */
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'Textarea-example',
+    url: 'http://127.0.0.1:1234'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    textarea: 'Text', // y.share.textarea is of type Y.Text
+    test: 'Array'
+  }
+}).then(function (y) {
+  window.yTextarea = y
+
+  // bind the textarea to a shared text element
+  y.share.textarea.bind(document.getElementById('textfield'))
+  // thats it..
+})
--- a/examples/xml/index.html
+++ b/examples/xml/index.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+</head>
+  <script src="../bower_components/yjs/y.js"></script>
+  <script src="../bower_components/jquery/dist/jquery.min.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>
+    var commands = document.querySelectorAll(".command");
+    Array.prototype.forEach.call(document.querySelectorAll('.command'), function (command) {
+      var execute = function(){
+        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 +1,21 @@
+/* global Y */
+
+// initialize a shared object. This function call returns a promise!
+Y({
+  db: {
+    name: 'memory'
+  },
+  connector: {
+    name: 'websockets-client',
+    room: 'Xml-example'
+  },
+  sourceDir: '/bower_components',
+  share: {
+    xml: 'Xml("p")' // y.share.xml is of type Y.Xml with tagname "p"
+  }
+}).then(function (y) {
+  window.yXml = y
+  // bind xml type to a dom, and put it in body
+  window.sharedDom = y.share.xml.getDom()
+  document.body.appendChild(window.sharedDom)
+})
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,41 +1,25 @@
 {
  "name": "yjs",
-  "version": "13.0.0-78",
-  "description": "A ",
-  "main": "./dist/yjs.js",
-  "module": "./dist/yjs.mjs'",
-  "sideEffects": false,
+  "version": "13.0.0-12",
+  "description": "A framework for real-time p2p shared editing on any data",
+  "main": "./y.node.js",
+  "browser": "./y.js",
+  "module": "./src/y.js",
  "scripts": {
-    "test": "npm run dist && PRODUCTION=1 node ./dist/tests.js --repitition-time 50 --production",
-    "test-exhaustive": "npm run lint && npm run dist && node ./dist/tests.js --repitition-time 10000",
-    "dist": "rm -rf dist examples/build && rollup -c",
-    "watch": "rollup -wc",
-    "lint": "standard && tsc",
-    "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.v13.md --package ./package.json || true",
-    "serve-docs": "npm run docs && serve ./docs/",
-    "postversion": "npm run lint && PRODUCTION=1 npm run dist && node ./dist/tests.js --repitition-time 1000",
-    "debug": "concurrently 'live-server --port=3443 --entry-file=test.html' 'npm run watch'",
-    "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.js",
-    "trace-opt": "clear && rollup -c  && node --trace-opt dist/test.js"
+    "test": "npm run lint",
+    "debug": "concurrently 'rollup -wc rollup.test.js' 'cutest-serve y.test.js -o'",
+    "lint": "standard",
+    "dist": "rollup -c rollup.browser.js; rollup -c rollup.node.js",
+    "postversion": "npm run dist",
+    "postpublish": "tag-dist-files --overwrite-existing-tag"
  },
  "files": [
-    "dist/*",
-    "examples/*",
-    "docs/*",
-    "README.md",
-    "LICENSE"
+    "y.*"
  ],
-  "dictionaries": {
-    "doc": "docs",
-    "example": "examples",
-    "test": "tests"
-  },
  "standard": {
    "ignore": [
-      "/dist",
-      "/node_modules",
-      "/docs",
-      "/examples/build"
+      "/y.js",
+      "/y.js.map"
    ]
  },
  "repository": {
@@ -43,7 +27,13 @@
    "url": "https://github.com/y-js/yjs.git"
  },
  "keywords": [
-    "crdt"
+    "Yjs",
+    "OT",
+    "Collaboration",
+    "Synchronization",
+    "ShareJS",
+    "Coweb",
+    "Concurrency"
  ],
  "author": "Kevin Jahns",
  "email": "kevin.jahns@rwth-aachen.de",
@@ -52,29 +42,28 @@
    "url": "https://github.com/y-js/yjs/issues"
  },
  "homepage": "http://y-js.org",
-  "dependencies": {
-    "lib0": "0.0.0"
-  },
  "devDependencies": {
-    "codemirror": "^5.42.0",
-    "concurrently": "^3.6.1",
-    "esdoc": "^1.1.0",
-    "esdoc-standard-plugin": "^1.0.0",
-    "jsdoc": "^3.5.5",
-    "live-server": "^1.2.1",
-    "prosemirror-example-setup": "^1.0.1",
-    "prosemirror-schema-basic": "^1.0.0",
-    "prosemirror-state": "^1.2.2",
-    "prosemirror-view": "^1.6.5",
-    "quill": "^1.3.6",
-    "quill-cursors": "^1.0.3",
-    "rollup": "^1.1.2",
-    "rollup-cli": "^1.0.9",
-    "rollup-plugin-commonjs": "^9.2.0",
-    "rollup-plugin-node-resolve": "^4.0.0",
-    "rollup-plugin-terser": "^4.0.4",
-    "standard": "^11.0.1",
-    "tui-jsdoc-template": "^1.2.2",
-    "typescript": "^3.3.3333"
+    "babel-cli": "^6.24.1",
+    "babel-plugin-external-helpers": "^6.22.0",
+    "babel-plugin-transform-regenerator": "^6.24.1",
+    "babel-plugin-transform-runtime": "^6.23.0",
+    "babel-preset-latest": "^6.24.1",
+    "chance": "^1.0.9",
+    "concurrently": "^3.4.0",
+    "cutest": "^0.1.9",
+    "rollup-plugin-babel": "^2.7.1",
+    "rollup-plugin-commonjs": "^8.0.2",
+    "rollup-plugin-inject": "^2.0.0",
+    "rollup-plugin-multi-entry": "^2.0.1",
+    "rollup-plugin-node-resolve": "^3.0.0",
+    "rollup-plugin-uglify": "^1.0.2",
+    "rollup-regenerator-runtime": "^6.23.1",
+    "rollup-watch": "^3.2.2",
+    "standard": "^10.0.2",
+    "tag-dist-files": "^0.1.6"
+  },
+  "dependencies": {
+    "debug": "^2.6.8",
+    "utf-8": "^1.0.0"
  }
 }
--- a/rollup.browser.js
+++ b/rollup.browser.js
@@ -0,0 +1,47 @@
+import inject from 'rollup-plugin-inject'
+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 {
+  entry: 'src/y.js',
+  moduleName: 'Y',
+  format: 'umd',
+  plugins: [
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs(),
+    babel({
+      runtimeHelpers: true
+    }),
+    inject({
+      regeneratorRuntime: 'regenerator-runtime'
+    }),
+    uglify({
+      output: {
+        comments: function (node, comment) {
+          var text = comment.value
+          var type = comment.type
+          if (type === 'comment2') {
+            // multiline comment
+            return /@license/i.test(text)
+          }
+        }
+      }
+    })
+  ],
+  dest: 'y.js',
+  sourceMap: true,
+  banner: `
+/**
+ * ${pkg.name} - ${pkg.description}
+ * @version v${pkg.version}
+ * @license ${pkg.license}
+ */
+`
+}
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -1,105 +0,0 @@
-import nodeResolve from 'rollup-plugin-node-resolve'
-import commonjs from 'rollup-plugin-commonjs'
-import { terser } from 'rollup-plugin-terser'
-
-const customModules = new Set([
-  'y-websocket',
-  'y-codemirror',
-  'y-ace',
-  'y-textarea',
-  'y-quill',
-  'y-dom',
-  'y-prosemirror'
-])
-/**
- * @type {Set<any>}
- */
-const customLibModules = new Set([
-  'lib0',
-  'y-protocols'
-])
-const debugResolve = {
-  resolveId (importee) {
-    if (importee === 'yjs') {
-      return `${process.cwd()}/src/index.js`
-    }
-    if (customModules.has(importee.split('/')[0])) {
-      return `${process.cwd()}/../${importee}/src/${importee}.js`
-    }
-    if (customLibModules.has(importee.split('/')[0])) {
-      return `${process.cwd()}/../${importee}`
-    }
-    return null
-  }
-}
-
-const minificationPlugins = process.env.PRODUCTION ? [terser({
-  module: true,
-  compress: {
-    hoist_vars: true,
-    module: true,
-    passes: 5,
-    pure_getters: true,
-    unsafe_comps: true,
-    unsafe_undefined: true
-  },
-  mangle: {
-    toplevel: true
-  }
-})] : []
-
-export default [{
-  input: './src/index.js',
-  output: [{
-    name: 'Y',
-    file: 'dist/yjs.js',
-    format: 'cjs',
-    sourcemap: true,
-    paths: path => {
-      if (/^lib0\//.test(path)) {
-        return `lib0/dist/${path.slice(5)}`
-      }
-      return path
-    }
-  }, {
-    name: 'Y',
-    file: 'dist/yjs.mjs',
-    format: 'es',
-    sourcemap: true
-  }],
-  external: id => /^lib0\//.test(id)
-}, {
-  input: './tests/index.js',
-  output: {
-    name: 'test',
-    file: 'dist/tests.js',
-    format: 'iife',
-    sourcemap: true
-  },
-  plugins: [
-    debugResolve,
-    nodeResolve({
-      sourcemap: true,
-      module: true,
-      browser: true
-    }),
-    commonjs()
-  ]
-}, {
-  input: ['./examples/codemirror.js', './examples/textarea.js'], // './examples/quill.js', './examples/dom.js', './examples/prosemirror.js'
-  output: {
-    dir: 'examples/build',
-    format: 'esm',
-    sourcemap: true
-  },
-  plugins: [
-    debugResolve,
-    nodeResolve({
-      sourcemap: true,
-      module: true,
-      browser: true
-    }),
-    commonjs(),
-    ...minificationPlugins
-  ]
-}]
--- a/rollup.node.js
+++ b/rollup.node.js
@@ -0,0 +1,26 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+var pkg = require('./package.json')
+
+export default {
+  entry: 'src/y.js',
+  moduleName: 'Y',
+  format: 'umd',
+  plugins: [
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs()
+  ],
+  dest: 'y.node.js',
+  sourceMap: true,
+  banner: `
+/**
+ * ${pkg.name} - ${pkg.description}
+ * @version v${pkg.version}
+ * @license ${pkg.license}
+ */
+`
+}
--- a/rollup.test.js
+++ b/rollup.test.js
@@ -0,0 +1,20 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import commonjs from 'rollup-plugin-commonjs'
+import multiEntry from 'rollup-plugin-multi-entry'
+
+export default {
+  entry: 'test/*',
+  moduleName: 'y-tests',
+  format: 'umd',
+  plugins: [
+    nodeResolve({
+      main: true,
+      module: true,
+      browser: true
+    }),
+    commonjs(),
+    multiEntry()
+  ],
+  dest: 'y.test.js',
+  sourceMap: true
+}
--- a/src/Connector.js
+++ b/src/Connector.js
@@ -0,0 +1,379 @@
+import { BinaryEncoder, BinaryDecoder } from './Encoding.js'
+import { sendSyncStep1, computeMessageSyncStep1, computeMessageSyncStep2, computeMessageUpdate } from './MessageHandler.js'
+
+export default function extendConnector (Y/* :any */) {
+  class AbstractConnector {
+    /*
+      opts contains the following information:
+       role : String Role of this client ("master" or "slave")
+    */
+    constructor (y, opts) {
+      this.y = y
+      if (opts == null) {
+        opts = {}
+      }
+      this.opts = opts
+      // Prefer to receive untransformed operations. This does only work if
+      // this client receives operations from only one other client.
+      // In particular, this does not work with y-webrtc.
+      // It will work with y-websockets-client
+      this.preferUntransformed = opts.preferUntransformed || false
+      if (opts.role == null || opts.role === 'master') {
+        this.role = 'master'
+      } else if (opts.role === 'slave') {
+        this.role = 'slave'
+      } else {
+        throw new Error("Role must be either 'master' or 'slave'!")
+      }
+      this.log = Y.debug('y:connector')
+      this.logMessage = Y.debug('y:connector-message')
+      this.y.db.forwardAppliedOperations = opts.forwardAppliedOperations || false
+      this.role = opts.role
+      this.connections = new Map()
+      this.isSynced = false
+      this.userEventListeners = []
+      this.whenSyncedListeners = []
+      this.currentSyncTarget = null
+      this.debug = opts.debug === true
+      this.broadcastOpBuffer = []
+      this.protocolVersion = 11
+      this.authInfo = opts.auth || null
+      this.checkAuth = opts.checkAuth || function () { return Promise.resolve('write') } // default is everyone has write access
+      if (opts.generateUserId !== false) {
+        this.setUserId(Y.utils.generateUserId())
+      }
+    }
+
+    reconnect () {
+      this.log('reconnecting..')
+      return this.y.db.startGarbageCollector()
+    }
+
+    disconnect () {
+      this.log('discronnecting..')
+      this.connections = new Map()
+      this.isSynced = false
+      this.currentSyncTarget = null
+      this.whenSyncedListeners = []
+      this.y.db.stopGarbageCollector()
+      return this.y.db.whenTransactionsFinished()
+    }
+
+    repair () {
+      this.log('Repairing the state of Yjs. This can happen if messages get lost, and Yjs detects that something is wrong. If this happens often, please report an issue here: https://github.com/y-js/yjs/issues')
+      this.isSynced = false
+      this.connections.forEach((user, userId) => {
+        user.isSynced = false
+        this._syncWithUser(userId)
+      })
+    }
+
+    setUserId (userId) {
+      if (this.userId == null) {
+        if (!Number.isInteger(userId)) {
+          let err = new Error('UserId must be an integer!')
+          this.y.emit('error', err)
+          throw err
+        }
+        this.log('Set userId to "%s"', userId)
+        this.userId = userId
+        return this.y.db.setUserId(userId)
+      } else {
+        return null
+      }
+    }
+
+    onUserEvent (f) {
+      this.userEventListeners.push(f)
+    }
+
+    removeUserEventListener (f) {
+      this.userEventListeners = this.userEventListeners.filter(g => f !== g)
+    }
+
+    userLeft (user) {
+      if (this.connections.has(user)) {
+        this.log('%s: User left %s', this.userId, user)
+        this.connections.delete(user)
+        // check if isSynced event can be sent now
+        this._setSyncedWith(null)
+        for (var f of this.userEventListeners) {
+          f({
+            action: 'userLeft',
+            user: user
+          })
+        }
+      }
+    }
+    userJoined (user, role, auth) {
+      if (role == null) {
+        throw new Error('You must specify the role of the joined user!')
+      }
+      if (this.connections.has(user)) {
+        throw new Error('This user already joined!')
+      }
+      this.log('%s: User joined %s', this.userId, user)
+      this.connections.set(user, {
+        uid: user,
+        isSynced: false,
+        role: role,
+        processAfterAuth: [],
+        auth: auth || null,
+        receivedSyncStep2: false
+      })
+      let defer = {}
+      defer.promise = new Promise(function (resolve) { defer.resolve = resolve })
+      this.connections.get(user).syncStep2 = defer
+      for (var f of this.userEventListeners) {
+        f({
+          action: 'userJoined',
+          user: user,
+          role: role
+        })
+      }
+      this._syncWithUser(user)
+    }
+    // Execute a function _when_ we are connected.
+    // If not connected, wait until connected
+    whenSynced (f) {
+      if (this.isSynced) {
+        f()
+      } else {
+        this.whenSyncedListeners.push(f)
+      }
+    }
+    _syncWithUser (userid) {
+      if (this.role === 'slave') {
+        return // "The current sync has not finished or this is controlled by a master!"
+      }
+      sendSyncStep1(this, userid)
+    }
+    _fireIsSyncedListeners () {
+      this.y.db.whenTransactionsFinished().then(() => {
+        if (!this.isSynced) {
+          this.isSynced = true
+          // It is safer to remove this!
+          // TODO: remove: yield * this.garbageCollectAfterSync()
+          // call whensynced listeners
+          for (var f of this.whenSyncedListeners) {
+            f()
+          }
+          this.whenSyncedListeners = []
+        }
+      })
+    }
+    send (uid, buffer) {
+      if (!(buffer instanceof ArrayBuffer || buffer instanceof Uint8Array)) {
+        throw new Error('Expected Message to be an ArrayBuffer or Uint8Array - please don\'t use this method to send custom messages')
+      }
+      this.log('%s: Send \'%y\' to %s', this.userId, buffer, uid)
+      this.logMessage('Message: %Y', buffer)
+    }
+    broadcast (buffer) {
+      if (!(buffer instanceof ArrayBuffer || buffer instanceof Uint8Array)) {
+        throw new Error('Expected Message to be an ArrayBuffer or Uint8Array - please don\'t use this method to send custom messages')
+      }
+      this.log('%s: Broadcast \'%y\'', this.userId, buffer)
+      this.logMessage('Message: %Y', buffer)
+    }
+    /*
+      Buffer operations, and broadcast them when ready.
+    */
+    broadcastOps (ops) {
+      ops = ops.map(function (op) {
+        return Y.Struct[op.struct].encode(op)
+      })
+      var self = this
+      function broadcastOperations () {
+        if (self.broadcastOpBuffer.length > 0) {
+          let encoder = new BinaryEncoder()
+          encoder.writeVarString(self.opts.room)
+          encoder.writeVarString('update')
+          let ops = self.broadcastOpBuffer
+          self.broadcastOpBuffer = []
+          let length = ops.length
+          encoder.writeUint32(length)
+          for (var i = 0; i < length; i++) {
+            let op = ops[i]
+            Y.Struct[op.struct].binaryEncode(encoder, op)
+          }
+          self.broadcast(encoder.createBuffer())
+        }
+      }
+      if (this.broadcastOpBuffer.length === 0) {
+        this.broadcastOpBuffer = ops
+        this.y.db.whenTransactionsFinished().then(broadcastOperations)
+      } else {
+        this.broadcastOpBuffer = this.broadcastOpBuffer.concat(ops)
+      }
+    }
+    /*
+      You received a raw message, and you know that it is intended for Yjs. Then call this function.
+    */
+    receiveMessage (sender, buffer) {
+      if (!(buffer instanceof ArrayBuffer || buffer instanceof Uint8Array)) {
+        return Promise.reject(new Error('Expected Message to be an ArrayBuffer or Uint8Array!'))
+      }
+      if (sender === this.userId) {
+        return Promise.resolve()
+      }
+      let decoder = new BinaryDecoder(buffer)
+      let encoder = new BinaryEncoder()
+      let roomname = decoder.readVarString() // read room name
+      encoder.writeVarString(roomname)
+      let messageType = decoder.readVarString()
+      let senderConn = this.connections.get(sender)
+
+      this.log('%s: Receive \'%s\' from %s', this.userId, messageType, sender)
+      this.logMessage('Message: %Y', buffer)
+
+      if (senderConn == null) {
+        throw new Error('Received message from unknown peer!')
+      }
+
+      if (messageType === 'sync step 1' || messageType === 'sync step 2') {
+        let auth = decoder.readVarUint()
+        if (senderConn.auth == null) {
+          senderConn.processAfterAuth.push([messageType, senderConn, decoder, encoder, sender])
+          // check auth
+          return this.checkAuth(auth, this.y, sender).then(authPermissions => {
+            if (senderConn.auth == null) {
+              senderConn.auth = authPermissions
+              this.y.emit('userAuthenticated', {
+                user: senderConn.uid,
+                auth: authPermissions
+              })
+            }
+            let messages = senderConn.processAfterAuth
+            senderConn.processAfterAuth = []
+
+            return messages.reduce((p, m) =>
+              p.then(() => this.computeMessage(m[0], m[1], m[2], m[3], m[4]))
+            , Promise.resolve())
+          })
+        }
+      }
+      if (senderConn.auth != null) {
+        return this.computeMessage(messageType, senderConn, decoder, encoder, sender)
+      } else {
+        senderConn.processAfterAuth.push([messageType, senderConn, decoder, encoder, sender])
+      }
+    }
+
+    computeMessage (messageType, senderConn, decoder, encoder, sender) {
+      if (messageType === 'sync step 1' && (senderConn.auth === 'write' || senderConn.auth === 'read')) {
+        // cannot wait for sync step 1 to finish, because we may wait for sync step 2 in sync step 1 (->lock)
+        computeMessageSyncStep1(decoder, encoder, this, senderConn, sender)
+        return this.y.db.whenTransactionsFinished()
+      } else if (messageType === 'sync step 2' && senderConn.auth === 'write') {
+        return computeMessageSyncStep2(decoder, encoder, this, senderConn, sender)
+      } else if (messageType === 'update' && senderConn.auth === 'write') {
+        return computeMessageUpdate(decoder, encoder, this, senderConn, sender)
+      } else {
+        return Promise.reject(new Error('Unable to receive message'))
+      }
+    }
+
+    _setSyncedWith (user) {
+      if (user != null) {
+        this.connections.get(user).isSynced = true
+      }
+      let conns = Array.from(this.connections.values())
+      if (conns.length > 0 && conns.every(u => u.isSynced)) {
+        this._fireIsSyncedListeners()
+      }
+    }
+
+    /*
+      Currently, the HB encodes operations as JSON. For the moment I want to keep it
+      that way. Maybe we support encoding in the HB as XML in the future, but for now I don't want
+      too much overhead. Y is very likely to get changed a lot in the future
+
+      Because we don't want to encode JSON as string (with character escaping, wich makes it pretty much unreadable)
+      we encode the JSON as XML.
+
+      When the HB support encoding as XML, the format should look pretty much like this.
+
+      does not support primitive values as array elements
+      expects an ltx (less than xml) object
+    */
+    parseMessageFromXml (m/* :any */) {
+      function parseArray (node) {
+        for (var n of node.children) {
+          if (n.getAttribute('isArray') === 'true') {
+            return parseArray(n)
+          } else {
+            return parseObject(n)
+          }
+        }
+      }
+      function parseObject (node/* :any */) {
+        var json = {}
+        for (var attrName in node.attrs) {
+          var value = node.attrs[attrName]
+          var int = parseInt(value, 10)
+          if (isNaN(int) || ('' + int) !== value) {
+            json[attrName] = value
+          } else {
+            json[attrName] = int
+          }
+        }
+        for (var n/* :any */ in node.children) {
+          var name = n.name
+          if (n.getAttribute('isArray') === 'true') {
+            json[name] = parseArray(n)
+          } else {
+            json[name] = parseObject(n)
+          }
+        }
+        return json
+      }
+      parseObject(m)
+    }
+    /*
+      encode message in xml
+      we use string because Strophe only accepts an "xml-string"..
+      So {a:4,b:{c:5}} will look like
+      <y a="4">
+        <b c="5"></b>
+      </y>
+      m - ltx element
+      json - Object
+    */
+    encodeMessageToXml (msg, obj) {
+      // attributes is optional
+      function encodeObject (m, json) {
+        for (var name in json) {
+          var value = json[name]
+          if (name == null) {
+            // nop
+          } else if (value.constructor === Object) {
+            encodeObject(m.c(name), value)
+          } else if (value.constructor === Array) {
+            encodeArray(m.c(name), value)
+          } else {
+            m.setAttribute(name, value)
+          }
+        }
+      }
+      function encodeArray (m, array) {
+        m.setAttribute('isArray', 'true')
+        for (var e of array) {
+          if (e.constructor === Object) {
+            encodeObject(m.c('array-element'), e)
+          } else {
+            encodeArray(m.c('array-element'), e)
+          }
+        }
+      }
+      if (obj.constructor === Object) {
+        encodeObject(msg.c('y', { xmlns: 'http://y.ninja/connector-stanza' }), obj)
+      } else if (obj.constructor === Array) {
+        encodeArray(msg.c('y', { xmlns: 'http://y.ninja/connector-stanza' }), obj)
+      } else {
+        throw new Error("I can't encode this json!")
+      }
+    }
+  }
+  Y.AbstractConnector = AbstractConnector
+}
--- a/src/Database.js
+++ b/src/Database.js
@@ -0,0 +1,607 @@
+/* @flow */
+'use strict'
+
+export default function extendDatabase (Y /* :any */) {
+  /*
+    Partial definition of an OperationStore.
+    TODO: name it Database, operation store only holds operations.
+
+    A database definition must alse define the following methods:
+    * logTable() (optional)
+      - show relevant information information in a table
+    * requestTransaction(makeGen)
+      - request a transaction
+    * destroy()
+      - destroy the database
+  */
+  class AbstractDatabase {
+    /* ::
+    y: YConfig;
+    forwardAppliedOperations: boolean;
+    listenersById: Object;
+    listenersByIdExecuteNow: Array<Object>;
+    listenersByIdRequestPending: boolean;
+    initializedTypes: Object;
+    whenUserIdSetListener: ?Function;
+    waitingTransactions: Array<Transaction>;
+    transactionInProgress: boolean;
+    executeOrder: Array<Object>;
+    gc1: Array<Struct>;
+    gc2: Array<Struct>;
+    gcTimeout: number;
+    gcInterval: any;
+    garbageCollect: Function;
+    executeOrder: Array<any>; // for debugging only
+    userId: UserId;
+    opClock: number;
+    transactionsFinished: ?{promise: Promise, resolve: any};
+    transact: (x: ?Generator) => any;
+    */
+    constructor (y, opts) {
+      this.y = y
+      opts.gc = opts.gc === true
+      this.dbOpts = opts
+      var os = this
+      this.userId = null
+      var resolve_
+      this.userIdPromise = new Promise(function (resolve) {
+        resolve_ = resolve
+      })
+      this.userIdPromise.resolve = resolve_
+      // whether to broadcast all applied operations (insert & delete hook)
+      this.forwardAppliedOperations = false
+      // E.g. this.listenersById[id] : Array<Listener>
+      this.listenersById = {}
+      // Execute the next time a transaction is requested
+      this.listenersByIdExecuteNow = []
+      // A transaction is requested
+      this.listenersByIdRequestPending = false
+      /* To make things more clear, the following naming conventions:
+         * ls : we put this.listenersById on ls
+         * l : Array<Listener>
+         * id : Id (can't use as property name)
+         * sid : String (converted from id via JSON.stringify
+                         so we can use it as a property name)
+
+        Always remember to first overwrite
+        a property before you iterate over it!
+      */
+      // TODO: Use ES7 Weak Maps. This way types that are no longer user,
+      // wont be kept in memory.
+      this.initializedTypes = {}
+      this.waitingTransactions = []
+      this.transactionInProgress = false
+      this.transactionIsFlushed = false
+      if (typeof YConcurrencyTestingMode !== 'undefined') {
+        this.executeOrder = []
+      }
+      this.gc1 = [] // first stage
+      this.gc2 = [] // second stage -> after that, remove the op
+
+      function garbageCollect () {
+        return os.whenTransactionsFinished().then(function () {
+          if (os.gcTimeout > 0 && (os.gc1.length > 0 || os.gc2.length > 0)) {
+            if (!os.y.connector.isSynced) {
+              console.warn('gc should be empty when not synced!')
+            }
+            return new Promise((resolve) => {
+              os.requestTransaction(function * () {
+                if (os.y.connector != null && os.y.connector.isSynced) {
+                  for (var i = 0; i < os.gc2.length; i++) {
+                    var oid = os.gc2[i]
+                    yield * this.garbageCollectOperation(oid)
+                  }
+                  os.gc2 = os.gc1
+                  os.gc1 = []
+                }
+                // TODO: Use setInterval here instead (when garbageCollect is called several times there will be several timeouts..)
+                if (os.gcTimeout > 0) {
+                  os.gcInterval = setTimeout(garbageCollect, os.gcTimeout)
+                }
+                resolve()
+              })
+            })
+          } else {
+            // TODO: see above
+            if (os.gcTimeout > 0) {
+              os.gcInterval = setTimeout(garbageCollect, os.gcTimeout)
+            }
+            return Promise.resolve()
+          }
+        })
+      }
+      this.garbageCollect = garbageCollect
+      this.startGarbageCollector()
+
+      this.repairCheckInterval = !opts.repairCheckInterval ? 6000 : opts.repairCheckInterval
+      this.opsReceivedTimestamp = new Date()
+      this.startRepairCheck()
+    }
+    startGarbageCollector () {
+      this.gc = this.dbOpts.gc
+      if (this.gc) {
+        this.gcTimeout = !this.dbOpts.gcTimeout ? 100000 : this.dbOpts.gcTimeout
+      } else {
+        this.gcTimeout = -1
+      }
+      if (this.gcTimeout > 0) {
+        this.garbageCollect()
+      }
+    }
+    startRepairCheck () {
+      var os = this
+      if (this.repairCheckInterval > 0) {
+        this.repairCheckIntervalHandler = setInterval(function repairOnMissingOperations () {
+          /*
+            Case 1. No ops have been received in a while (new Date() - os.opsReceivedTimestamp > os.repairCheckInterval)
+              - 1.1 os.listenersById is empty. Then the state was correct the whole time. -> Nothing to do (nor to update)
+              - 1.2 os.listenersById is not empty.
+                      * Then the state was incorrect for at least {os.repairCheckInterval} seconds.
+                      * -> Remove everything in os.listenersById and sync again (connector.repair())
+            Case 2. An op has been received in the last {os.repairCheckInterval } seconds.
+                    It is not yet necessary to check for faulty behavior. Everything can still resolve itself. Wait for more messages.
+                    If nothing was received for a while and os.listenersById is still not emty, we are in case 1.2
+                    -> Do nothing
+
+            Baseline here is: we really only have to catch case 1.2..
+          */
+          if (
+            new Date() - os.opsReceivedTimestamp > os.repairCheckInterval &&
+            Object.keys(os.listenersById).length > 0 // os.listenersById is not empty
+          ) {
+            // haven't received operations for over {os.repairCheckInterval} seconds, resend state vector
+            os.listenersById = {}
+            os.opsReceivedTimestamp = new Date() // update so you don't send repair several times in a row
+            os.y.connector.repair()
+          }
+        }, this.repairCheckInterval)
+      }
+    }
+    stopRepairCheck () {
+      clearInterval(this.repairCheckIntervalHandler)
+    }
+    queueGarbageCollector (id) {
+      if (this.y.connector.isSynced && this.gc) {
+        this.gc1.push(id)
+      }
+    }
+    emptyGarbageCollector () {
+      return new Promise(resolve => {
+        var check = () => {
+          if (this.gc1.length > 0 || this.gc2.length > 0) {
+            this.garbageCollect().then(check)
+          } else {
+            resolve()
+          }
+        }
+        setTimeout(check, 0)
+      })
+    }
+    addToDebug () {
+      if (typeof YConcurrencyTestingMode !== 'undefined') {
+        var command /* :string */ = Array.prototype.map.call(arguments, function (s) {
+          if (typeof s === 'string') {
+            return s
+          } else {
+            return JSON.stringify(s)
+          }
+        }).join('').replace(/"/g, "'").replace(/,/g, ', ').replace(/:/g, ': ')
+        this.executeOrder.push(command)
+      }
+    }
+    getDebugData () {
+      console.log(this.executeOrder.join('\n'))
+    }
+    stopGarbageCollector () {
+      var self = this
+      this.gc = false
+      this.gcTimeout = -1
+      return new Promise(function (resolve) {
+        self.requestTransaction(function * () {
+          var ungc /* :Array<Struct> */ = self.gc1.concat(self.gc2)
+          self.gc1 = []
+          self.gc2 = []
+          for (var i = 0; i < ungc.length; i++) {
+            var op = yield * this.getOperation(ungc[i])
+            if (op != null) {
+              delete op.gc
+              yield * this.setOperation(op)
+            }
+          }
+          resolve()
+        })
+      })
+    }
+    /*
+      Try to add to GC.
+
+      TODO: rename this function
+
+      Rulez:
+      * Only gc if this user is online & gc turned on
+      * The most left element in a list must not be gc'd.
+        => There is at least one element in the list
+
+      returns true iff op was added to GC
+    */
+    * addToGarbageCollector (op, left) {
+      if (
+        op.gc == null &&
+        op.deleted === true &&
+        this.store.gc &&
+        this.store.y.connector.isSynced
+      ) {
+        var gc = false
+        if (left != null && left.deleted === true) {
+          gc = true
+        } else if (op.content != null && op.content.length > 1) {
+          op = yield * this.getInsertionCleanStart([op.id[0], op.id[1] + 1])
+          gc = true
+        }
+        if (gc) {
+          op.gc = true
+          yield * this.setOperation(op)
+          this.store.queueGarbageCollector(op.id)
+          return true
+        }
+      }
+      return false
+    }
+    removeFromGarbageCollector (op) {
+      function filter (o) {
+        return !Y.utils.compareIds(o, op.id)
+      }
+      this.gc1 = this.gc1.filter(filter)
+      this.gc2 = this.gc2.filter(filter)
+      delete op.gc
+    }
+    destroyTypes () {
+      for (var key in this.initializedTypes) {
+        var type = this.initializedTypes[key]
+        if (type._destroy != null) {
+          type._destroy()
+        } else {
+          console.error('The type you included does not provide destroy functionality, it will remain in memory (updating your packages will help).')
+        }
+      }
+    }
+    * destroy () {
+      clearTimeout(this.gcInterval)
+      this.gcInterval = null
+      this.stopRepairCheck()
+    }
+    setUserId (userId) {
+      if (!this.userIdPromise.inProgress) {
+        this.userIdPromise.inProgress = true
+        var self = this
+        self.requestTransaction(function * () {
+          self.userId = userId
+          var state = yield * this.getState(userId)
+          self.opClock = state.clock
+          self.userIdPromise.resolve(userId)
+        })
+      }
+      return this.userIdPromise
+    }
+    whenUserIdSet (f) {
+      this.userIdPromise.then(f)
+    }
+    getNextOpId (numberOfIds) {
+      if (numberOfIds == null) {
+        throw new Error('getNextOpId expects the number of created ids to create!')
+      } else if (this.userId == null) {
+        throw new Error('OperationStore not yet initialized!')
+      } else {
+        var id = [this.userId, this.opClock]
+        this.opClock += numberOfIds
+        return id
+      }
+    }
+    /*
+      Apply a list of operations.
+
+      * we save a timestamp, because we received new operations that could resolve ops in this.listenersById (see this.startRepairCheck)
+      * get a transaction
+      * check whether all Struct.*.requiredOps are in the OS
+      * check if it is an expected op (otherwise wait for it)
+      * check if was deleted, apply a delete operation after op was applied
+    */
+    applyOperations (decoder) {
+      this.opsReceivedTimestamp = new Date()
+      let length = decoder.readUint32()
+
+      for (var i = 0; i < length; i++) {
+        let o = Y.Struct.binaryDecodeOperation(decoder)
+        if (o.id == null || o.id[0] !== this.y.connector.userId) {
+          var required = Y.Struct[o.struct].requiredOps(o)
+          if (o.requires != null) {
+            required = required.concat(o.requires)
+          }
+          this.whenOperationsExist(required, o)
+        }
+      }
+    }
+    /*
+      op is executed as soon as every operation requested is available.
+      Note that Transaction can (and should) buffer requests.
+    */
+    whenOperationsExist (ids, op) {
+      if (ids.length > 0) {
+        let listener = {
+          op: op,
+          missing: ids.length
+        }
+
+        for (let i = 0; i < ids.length; i++) {
+          let id = ids[i]
+          let sid = JSON.stringify(id)
+          let l = this.listenersById[sid]
+          if (l == null) {
+            l = []
+            this.listenersById[sid] = l
+          }
+          l.push(listener)
+        }
+      } else {
+        this.listenersByIdExecuteNow.push({
+          op: op
+        })
+      }
+
+      if (this.listenersByIdRequestPending) {
+        return
+      }
+
+      this.listenersByIdRequestPending = true
+      var store = this
+
+      this.requestTransaction(function * () {
+        var exeNow = store.listenersByIdExecuteNow
+        store.listenersByIdExecuteNow = []
+
+        var ls = store.listenersById
+        store.listenersById = {}
+
+        store.listenersByIdRequestPending = false
+
+        for (let key = 0; key < exeNow.length; key++) {
+          let o = exeNow[key].op
+          yield * store.tryExecute.call(this, o)
+        }
+
+        for (var sid in ls) {
+          var l = ls[sid]
+          var id = JSON.parse(sid)
+          var op
+          if (typeof id[1] === 'string') {
+            op = yield * this.getOperation(id)
+          } else {
+            op = yield * this.getInsertion(id)
+          }
+          if (op == null) {
+            store.listenersById[sid] = l
+          } else {
+            for (let i = 0; i < l.length; i++) {
+              let listener = l[i]
+              let o = listener.op
+              if (--listener.missing === 0) {
+                yield * store.tryExecute.call(this, o)
+              }
+            }
+          }
+        }
+      })
+    }
+    /*
+      Actually execute an operation, when all expected operations are available.
+    */
+    /* :: // TODO: this belongs somehow to transaction
+    store: Object;
+    getOperation: any;
+    isGarbageCollected: any;
+    addOperation: any;
+    whenOperationsExist: any;
+    */
+    * tryExecute (op) {
+      this.store.addToDebug('yield * this.store.tryExecute.call(this, ', JSON.stringify(op), ')')
+      if (op.struct === 'Delete') {
+        yield * Y.Struct.Delete.execute.call(this, op)
+        // this is now called in Transaction.deleteOperation!
+        // yield * this.store.operationAdded(this, op)
+      } else {
+        // check if this op was defined
+        var defined = yield * this.getInsertion(op.id)
+        while (defined != null && defined.content != null) {
+          // check if this op has a longer content in the case it is defined
+          if (defined.id[1] + defined.content.length < op.id[1] + op.content.length) {
+            var overlapSize = defined.content.length - (op.id[1] - defined.id[1])
+            op.content.splice(0, overlapSize)
+            op.id = [op.id[0], op.id[1] + overlapSize]
+            op.left = Y.utils.getLastId(defined)
+            op.origin = op.left
+            defined = yield * this.getOperation(op.id) // getOperation suffices here
+          } else {
+            break
+          }
+        }
+        if (defined == null) {
+          var opid = op.id
+          var isGarbageCollected = yield * this.isGarbageCollected(opid)
+          if (!isGarbageCollected) {
+            // TODO: reduce number of get / put calls for op ..
+            yield * Y.Struct[op.struct].execute.call(this, op)
+            yield * this.addOperation(op)
+            yield * this.store.operationAdded(this, op)
+            // operationAdded can change op..
+            op = yield * this.getOperation(opid)
+            // if insertion, try to combine with left
+            yield * this.tryCombineWithLeft(op)
+          }
+        }
+      }
+    }
+    /*
+     * Called by a transaction when an operation is added.
+     * This function is especially important for y-indexeddb, where several instances may share a single database.
+     * Every time an operation is created by one instance, it is send to all other instances and operationAdded is called
+     *
+     * If it's not a Delete operation:
+     *   * Checks if another operation is executable (listenersById)
+     *   * Update state, if possible
+     *
+     * Always:
+     *   * Call type
+     */
+    * operationAdded (transaction, op) {
+      if (op.struct === 'Delete') {
+        var type = this.initializedTypes[JSON.stringify(op.targetParent)]
+        if (type != null) {
+          yield * type._changed(transaction, op)
+        }
+      } else {
+        // increase SS
+        yield * transaction.updateState(op.id[0])
+        var opLen = op.content != null ? op.content.length : 1
+        for (let i = 0; i < opLen; i++) {
+          // notify whenOperation listeners (by id)
+          var sid = JSON.stringify([op.id[0], op.id[1] + i])
+          var l = this.listenersById[sid]
+          delete this.listenersById[sid]
+          if (l != null) {
+            for (var key in l) {
+              var listener = l[key]
+              if (--listener.missing === 0) {
+                this.whenOperationsExist([], listener.op)
+              }
+            }
+          }
+        }
+        var t = this.initializedTypes[JSON.stringify(op.parent)]
+
+        // if parent is deleted, mark as gc'd and return
+        if (op.parent != null) {
+          var parentIsDeleted = yield * transaction.isDeleted(op.parent)
+          if (parentIsDeleted) {
+            yield * transaction.deleteList(op.id)
+            return
+          }
+        }
+
+        // notify parent, if it was instanciated as a custom type
+        if (t != null) {
+          let o = Y.utils.copyOperation(op)
+          yield * t._changed(transaction, o)
+        }
+        if (!op.deleted) {
+          // Delete if DS says this is actually deleted
+          var len = op.content != null ? op.content.length : 1
+          var startId = op.id // You must not use op.id in the following loop, because op will change when deleted
+            // TODO: !! console.log('TODO: change this before commiting')
+          for (let i = 0; i < len; i++) {
+            var id = [startId[0], startId[1] + i]
+            var opIsDeleted = yield * transaction.isDeleted(id)
+            if (opIsDeleted) {
+              var delop = {
+                struct: 'Delete',
+                target: id
+              }
+              yield * this.tryExecute.call(transaction, delop)
+            }
+          }
+        }
+      }
+    }
+    whenTransactionsFinished () {
+      if (this.transactionInProgress) {
+        if (this.transactionsFinished == null) {
+          var resolve_
+          var promise = new Promise(function (resolve) {
+            resolve_ = resolve
+          })
+          this.transactionsFinished = {
+            resolve: resolve_,
+            promise: promise
+          }
+        }
+        return this.transactionsFinished.promise
+      } else {
+        return Promise.resolve()
+      }
+    }
+    // Check if there is another transaction request.
+    // * the last transaction is always a flush :)
+    getNextRequest () {
+      if (this.waitingTransactions.length === 0) {
+        if (this.transactionIsFlushed) {
+          this.transactionInProgress = false
+          this.transactionIsFlushed = false
+          if (this.transactionsFinished != null) {
+            this.transactionsFinished.resolve()
+            this.transactionsFinished = null
+          }
+          return null
+        } else {
+          this.transactionIsFlushed = true
+          return function * () {
+            yield * this.flush()
+          }
+        }
+      } else {
+        this.transactionIsFlushed = false
+        return this.waitingTransactions.shift()
+      }
+    }
+    requestTransaction (makeGen/* :any */, callImmediately) {
+      this.waitingTransactions.push(makeGen)
+      if (!this.transactionInProgress) {
+        this.transactionInProgress = true
+        setTimeout(() => {
+          this.transact(this.getNextRequest())
+        }, 0)
+      }
+    }
+    /*
+      Get a created/initialized type.
+    */
+    getType (id) {
+      return this.initializedTypes[JSON.stringify(id)]
+    }
+    /*
+      Init type. This is called when a remote operation is retrieved, and transformed to a type
+      TODO: delete type from store.initializedTypes[id] when corresponding id was deleted!
+    */
+    * initType (id, args) {
+      var sid = JSON.stringify(id)
+      var t = this.store.initializedTypes[sid]
+      if (t == null) {
+        var op/* :MapStruct | ListStruct */ = yield * this.getOperation(id)
+        if (op != null) {
+          t = yield * Y[op.type].typeDefinition.initType.call(this, this.store, op, args)
+          this.store.initializedTypes[sid] = t
+        }
+      }
+      return t
+    }
+    /*
+     Create type. This is called when the local user creates a type (which is a synchronous action)
+    */
+    createType (typedefinition, id) {
+      var structname = typedefinition[0].struct
+      id = id || this.getNextOpId(1)
+      var op = Y.Struct[structname].create(id)
+      op.type = typedefinition[0].name
+
+      this.requestTransaction(function * () {
+        if (op.id[0] === 0xFFFFFF) {
+          yield * this.setOperation(op)
+        } else {
+          yield * this.applyCreatedOperations([op])
+        }
+      })
+      var t = Y[op.type].typeDefinition.createType(this, op, typedefinition[1])
+      this.initializedTypes[JSON.stringify(op.id)] = t
+      return t
+    }
+  }
+  Y.AbstractDatabase = AbstractDatabase
+}
--- a/src/Database.spec.js
+++ b/src/Database.spec.js
@@ -0,0 +1,354 @@
+/* global async, databases, describe, beforeEach, afterEach */
+/* eslint-env browser,jasmine,console */
+'use strict'
+
+var Y = require('./SpecHelper.js')
+
+for (let database of databases) {
+  describe(`Database (${database})`, function () {
+    var store
+    describe('DeleteStore', function () {
+      describe('Basic', function () {
+        beforeEach(function () {
+          store = new Y[database](null, {
+            gcTimeout: -1,
+            namespace: 'testing'
+          })
+        })
+        afterEach(function (done) {
+          store.requestTransaction(function * () {
+            yield * this.store.destroy()
+            done()
+          })
+        })
+        it('Deleted operation is deleted', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['u1', 10], 1)
+            expect(yield * this.isDeleted(['u1', 10])).toBeTruthy()
+            expect(yield * this.getDeleteSet()).toEqual({'u1': [[10, 1, false]]})
+            done()
+          })
+        }))
+        it('Deleted operation extends other deleted operation', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['u1', 10], 1)
+            yield * this.markDeleted(['u1', 11], 1)
+            expect(yield * this.isDeleted(['u1', 10])).toBeTruthy()
+            expect(yield * this.isDeleted(['u1', 11])).toBeTruthy()
+            expect(yield * this.getDeleteSet()).toEqual({'u1': [[10, 2, false]]})
+            done()
+          })
+        }))
+        it('Deleted operation extends other deleted operation', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['0', 3], 1)
+            yield * this.markDeleted(['0', 4], 1)
+            yield * this.markDeleted(['0', 2], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'0': [[2, 3, false]]})
+            done()
+          })
+        }))
+        it('Debug #1', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['166', 0], 1)
+            yield * this.markDeleted(['166', 2], 1)
+            yield * this.markDeleted(['166', 0], 1)
+            yield * this.markDeleted(['166', 2], 1)
+            yield * this.markGarbageCollected(['166', 2], 1)
+            yield * this.markDeleted(['166', 1], 1)
+            yield * this.markDeleted(['166', 3], 1)
+            yield * this.markGarbageCollected(['166', 3], 1)
+            yield * this.markDeleted(['166', 0], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'166': [[0, 2, false], [2, 2, true]]})
+            done()
+          })
+        }))
+        it('Debug #2', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['293', 0], 1)
+            yield * this.markDeleted(['291', 2], 1)
+            yield * this.markDeleted(['291', 2], 1)
+            yield * this.markGarbageCollected(['293', 0], 1)
+            yield * this.markDeleted(['293', 1], 1)
+            yield * this.markGarbageCollected(['291', 2], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'291': [[2, 1, true]], '293': [[0, 1, true], [1, 1, false]]})
+            done()
+          })
+        }))
+        it('Debug #3', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['581', 0], 1)
+            yield * this.markDeleted(['581', 1], 1)
+            yield * this.markDeleted(['580', 0], 1)
+            yield * this.markDeleted(['580', 0], 1)
+            yield * this.markGarbageCollected(['581', 0], 1)
+            yield * this.markDeleted(['581', 2], 1)
+            yield * this.markDeleted(['580', 1], 1)
+            yield * this.markDeleted(['580', 2], 1)
+            yield * this.markDeleted(['580', 1], 1)
+            yield * this.markDeleted(['580', 2], 1)
+            yield * this.markGarbageCollected(['581', 2], 1)
+            yield * this.markGarbageCollected(['581', 1], 1)
+            yield * this.markGarbageCollected(['580', 1], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'580': [[0, 1, false], [1, 1, true], [2, 1, false]], '581': [[0, 3, true]]})
+            done()
+          })
+        }))
+        it('Debug #4', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['544', 0], 1)
+            yield * this.markDeleted(['543', 2], 1)
+            yield * this.markDeleted(['544', 0], 1)
+            yield * this.markDeleted(['543', 2], 1)
+            yield * this.markGarbageCollected(['544', 0], 1)
+            yield * this.markDeleted(['545', 1], 1)
+            yield * this.markDeleted(['543', 4], 1)
+            yield * this.markDeleted(['543', 3], 1)
+            yield * this.markDeleted(['544', 1], 1)
+            yield * this.markDeleted(['544', 2], 1)
+            yield * this.markDeleted(['544', 1], 1)
+            yield * this.markDeleted(['544', 2], 1)
+            yield * this.markGarbageCollected(['543', 2], 1)
+            yield * this.markGarbageCollected(['543', 4], 1)
+            yield * this.markGarbageCollected(['544', 2], 1)
+            yield * this.markGarbageCollected(['543', 3], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'543': [[2, 3, true]], '544': [[0, 1, true], [1, 1, false], [2, 1, true]], '545': [[1, 1, false]]})
+            done()
+          })
+        }))
+        it('Debug #5', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.applyDeleteSet({'16': [[1, 2, false]], '17': [[0, 1, true], [1, 3, false]]})
+            expect(yield * this.getDeleteSet()).toEqual({'16': [[1, 2, false]], '17': [[0, 1, true], [1, 3, false]]})
+            yield * this.applyDeleteSet({'16': [[1, 2, false]], '17': [[0, 4, true]]})
+            expect(yield * this.getDeleteSet()).toEqual({'16': [[1, 2, false]], '17': [[0, 4, true]]})
+            done()
+          })
+        }))
+        it('Debug #6', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.applyDeleteSet({'40': [[0, 3, false]]})
+            expect(yield * this.getDeleteSet()).toEqual({'40': [[0, 3, false]]})
+            yield * this.applyDeleteSet({'39': [[2, 2, false]], '40': [[0, 1, true], [1, 2, false]], '41': [[2, 1, false]]})
+            expect(yield * this.getDeleteSet()).toEqual({'39': [[2, 2, false]], '40': [[0, 1, true], [1, 2, false]], '41': [[2, 1, false]]})
+            done()
+          })
+        }))
+        it('Debug #7', async(function * (done) {
+          store.requestTransaction(function * () {
+            yield * this.markDeleted(['9', 2], 1)
+            yield * this.markDeleted(['11', 2], 1)
+            yield * this.markDeleted(['11', 4], 1)
+            yield * this.markDeleted(['11', 1], 1)
+            yield * this.markDeleted(['9', 4], 1)
+            yield * this.markDeleted(['10', 0], 1)
+            yield * this.markGarbageCollected(['11', 2], 1)
+            yield * this.markDeleted(['11', 2], 1)
+            yield * this.markGarbageCollected(['11', 3], 1)
+            yield * this.markDeleted(['11', 3], 1)
+            yield * this.markDeleted(['11', 3], 1)
+            yield * this.markDeleted(['9', 4], 1)
+            yield * this.markDeleted(['10', 0], 1)
+            yield * this.markGarbageCollected(['11', 1], 1)
+            yield * this.markDeleted(['11', 1], 1)
+            expect(yield * this.getDeleteSet()).toEqual({'9': [[2, 1, false], [4, 1, false]], '10': [[0, 1, false]], '11': [[1, 3, true], [4, 1, false]]})
+            done()
+          })
+        }))
+      })
+    })
+    describe('OperationStore', function () {
+      describe('Basic Tests', function () {
+        beforeEach(function () {
+          store = new Y[database](null, {
+            gcTimeout: -1,
+            namespace: 'testing'
+          })
+        })
+        afterEach(function (done) {
+          store.requestTransaction(function * () {
+            yield * this.store.destroy()
+            done()
+          })
+        })
+        it('debug #1', function (done) {
+          store.requestTransaction(function * () {
+            yield * this.os.put({id: [2]})
+            yield * this.os.put({id: [0]})
+            yield * this.os.delete([2])
+            yield * this.os.put({id: [1]})
+            expect(yield * this.os.find([0])).toBeTruthy()
+            expect(yield * this.os.find([1])).toBeTruthy()
+            expect(yield * this.os.find([2])).toBeFalsy()
+            done()
+          })
+        })
+        it('can add&retrieve 5 elements', function (done) {
+          store.requestTransaction(function * () {
+            yield * this.os.put({val: 'four', id: [4]})
+            yield * this.os.put({val: 'one', id: [1]})
+            yield * this.os.put({val: 'three', id: [3]})
+            yield * this.os.put({val: 'two', id: [2]})
+            yield * this.os.put({val: 'five', id: [5]})
+            expect((yield * this.os.find([1])).val).toEqual('one')
+            expect((yield * this.os.find([2])).val).toEqual('two')
+            expect((yield * this.os.find([3])).val).toEqual('three')
+            expect((yield * this.os.find([4])).val).toEqual('four')
+            expect((yield * this.os.find([5])).val).toEqual('five')
+            done()
+          })
+        })
+        it('5 elements do not exist anymore after deleting them', function (done) {
+          store.requestTransaction(function * () {
+            yield * this.os.put({val: 'four', id: [4]})
+            yield * this.os.put({val: 'one', id: [1]})
+            yield * this.os.put({val: 'three', id: [3]})
+            yield * this.os.put({val: 'two', id: [2]})
+            yield * this.os.put({val: 'five', id: [5]})
+            yield * this.os.delete([4])
+            expect(yield * this.os.find([4])).not.toBeTruthy()
+            yield * this.os.delete([3])
+            expect(yield * this.os.find([3])).not.toBeTruthy()
+            yield * this.os.delete([2])
+            expect(yield * this.os.find([2])).not.toBeTruthy()
+            yield * this.os.delete([1])
+            expect(yield * this.os.find([1])).not.toBeTruthy()
+            yield * this.os.delete([5])
+            expect(yield * this.os.find([5])).not.toBeTruthy()
+            done()
+          })
+        })
+      })
+      var numberOfOSTests = 1000
+      describe(`Random Tests - after adding&deleting (0.8/0.2) ${numberOfOSTests} times`, function () {
+        var elements = []
+        beforeAll(function (done) {
+          store = new Y[database](null, {
+            gcTimeout: -1,
+            namespace: 'testing'
+          })
+          store.requestTransaction(function * () {
+            for (var i = 0; i < numberOfOSTests; i++) {
+              var r = Math.random()
+              if (r < 0.8) {
+                var obj = [Math.floor(Math.random() * numberOfOSTests * 10000)]
+                if (!(yield * this.os.find(obj))) {
+                  elements.push(obj)
+                  yield * this.os.put({id: obj})
+                }
+              } else if (elements.length > 0) {
+                var elemid = Math.floor(Math.random() * elements.length)
+                var elem = elements[elemid]
+                elements = elements.filter(function (e) {
+                  return !Y.utils.compareIds(e, elem)
+                })
+                yield * this.os.delete(elem)
+              }
+            }
+            done()
+          })
+        })
+        afterAll(function (done) {
+          store.requestTransaction(function * () {
+            yield * this.store.destroy()
+            done()
+          })
+        })
+        it('can find every object', function (done) {
+          store.requestTransaction(function * () {
+            for (var id of elements) {
+              expect((yield * this.os.find(id)).id).toEqual(id)
+            }
+            done()
+          })
+        })
+
+        it('can find every object with lower bound search', function (done) {
+          store.requestTransaction(function * () {
+            for (var id of elements) {
+              var e = yield * this.os.findWithLowerBound(id)
+              expect(e.id).toEqual(id)
+            }
+            done()
+          })
+        })
+
+        it('iterating over a tree with lower bound yields the right amount of results', function (done) {
+          var lowerBound = elements[Math.floor(Math.random() * elements.length)]
+          var expectedResults = elements.filter(function (e, pos) {
+            return (Y.utils.smaller(lowerBound, e) || Y.utils.compareIds(e, lowerBound)) && elements.indexOf(e) === pos
+          }).length
+
+          var actualResults = 0
+          store.requestTransaction(function * () {
+            yield * this.os.iterate(this, lowerBound, null, function * (val) {
+              expect(val).toBeDefined()
+              actualResults++
+            })
+            expect(expectedResults).toEqual(actualResults)
+            done()
+          })
+        })
+
+        it('iterating over a tree without bounds yield the right amount of results', function (done) {
+          var lowerBound = null
+          var expectedResults = elements.filter(function (e, pos) {
+            return elements.indexOf(e) === pos
+          }).length
+          var actualResults = 0
+          store.requestTransaction(function * () {
+            yield * this.os.iterate(this, lowerBound, null, function * (val) {
+              expect(val).toBeDefined()
+              actualResults++
+            })
+            expect(expectedResults).toEqual(actualResults)
+            done()
+          })
+        })
+
+        it('iterating over a tree with upper bound yields the right amount of results', function (done) {
+          var upperBound = elements[Math.floor(Math.random() * elements.length)]
+          var expectedResults = elements.filter(function (e, pos) {
+            return (Y.utils.smaller(e, upperBound) || Y.utils.compareIds(e, upperBound)) && elements.indexOf(e) === pos
+          }).length
+
+          var actualResults = 0
+          store.requestTransaction(function * () {
+            yield * this.os.iterate(this, null, upperBound, function * (val) {
+              expect(val).toBeDefined()
+              actualResults++
+            })
+            expect(expectedResults).toEqual(actualResults)
+            done()
+          })
+        })
+
+        it('iterating over a tree with upper and lower bounds yield the right amount of results', function (done) {
+          var b1 = elements[Math.floor(Math.random() * elements.length)]
+          var b2 = elements[Math.floor(Math.random() * elements.length)]
+          var upperBound, lowerBound
+          if (Y.utils.smaller(b1, b2)) {
+            lowerBound = b1
+            upperBound = b2
+          } else {
+            lowerBound = b2
+            upperBound = b1
+          }
+          var expectedResults = elements.filter(function (e, pos) {
+            return (Y.utils.smaller(lowerBound, e) || Y.utils.compareIds(e, lowerBound)) &&
+              (Y.utils.smaller(e, upperBound) || Y.utils.compareIds(e, upperBound)) && elements.indexOf(e) === pos
+          }).length
+          var actualResults = 0
+          store.requestTransaction(function * () {
+            yield * this.os.iterate(this, lowerBound, upperBound, function * (val) {
+              expect(val).toBeDefined()
+              actualResults++
+            })
+            expect(expectedResults).toEqual(actualResults)
+            done()
+          })
+        })
+      })
+    })
+  })
+}
--- a/src/Encoding.js
+++ b/src/Encoding.js
@@ -0,0 +1,133 @@
+import utf8 from 'utf-8'
+
+const bits7 = 0b1111111
+const bits8 = 0b11111111
+
+export class BinaryEncoder {
+  constructor () {
+    this.data = []
+  }
+  get pos () {
+    return this.data.length
+  }
+  createBuffer () {
+    return Uint8Array.from(this.data).buffer
+  }
+  writeUint8 (num) {
+    this.data.push(num & bits8)
+  }
+  setUint8 (pos, num) {
+    this.data[pos] = num & bits8
+  }
+  writeUint16 (num) {
+    this.data.push(num & bits8, (num >>> 8) & bits8)
+  }
+  setUint16 (pos, num) {
+    this.data[pos] = num & bits8
+    this.data[pos + 1] = (num >>> 8) & bits8
+  }
+  writeUint32 (num) {
+    for (let i = 0; i < 4; i++) {
+      this.data.push(num & bits8)
+      num >>>= 8
+    }
+  }
+  setUint32 (pos, num) {
+    for (let i = 0; i < 4; i++) {
+      this.data[pos + i] = num & bits8
+      num >>>= 8
+    }
+  }
+  writeVarUint (num) {
+    while (num >= 0b10000000) {
+      this.data.push(0b10000000 | (bits7 & num))
+      num >>>= 7
+    }
+    this.data.push(bits7 & num)
+  }
+  writeVarString (str) {
+    let bytes = utf8.setBytesFromString(str)
+    let len = bytes.length
+    this.writeVarUint(len)
+    for (let i = 0; i < len; i++) {
+      this.data.push(bytes[i])
+    }
+  }
+  writeOpID (id) {
+    let user = id[0]
+    this.writeVarUint(user)
+    if (user !== 0xFFFFFF) {
+      this.writeVarUint(id[1])
+    } else {
+      this.writeVarString(id[1])
+    }
+  }
+}
+
+export class BinaryDecoder {
+  constructor (buffer) {
+    if (buffer instanceof ArrayBuffer) {
+      this.uint8arr = new Uint8Array(buffer)
+    } else if (buffer instanceof Uint8Array) {
+      this.uint8arr = buffer
+    } else {
+      throw new Error('Expected an ArrayBuffer or Uint8Array!')
+    }
+    this.pos = 0
+  }
+  skip8 () {
+    this.pos++
+  }
+  readUint8 () {
+    return this.uint8arr[this.pos++]
+  }
+  readUint32 () {
+    let uint =
+      this.uint8arr[this.pos] +
+      (this.uint8arr[this.pos + 1] << 8) +
+      (this.uint8arr[this.pos + 2] << 16) +
+      (this.uint8arr[this.pos + 3] << 24)
+    this.pos += 4
+    return uint
+  }
+  peekUint8 () {
+    return this.uint8arr[this.pos]
+  }
+  readVarUint () {
+    let num = 0
+    let len = 0
+    while (true) {
+      let r = this.uint8arr[this.pos++]
+      num = num | ((r & bits7) << len)
+      len += 7
+      if (r < 1 << 7) {
+        return num >>> 0 // return unsigned number!
+      }
+      if (len > 35) {
+        throw new Error('Integer out of range!')
+      }
+    }
+  }
+  readVarString () {
+    let len = this.readVarUint()
+    let bytes = new Array(len)
+    for (let i = 0; i < len; i++) {
+      bytes[i] = this.uint8arr[this.pos++]
+    }
+    return utf8.getStringFromBytes(bytes)
+  }
+  peekVarString () {
+    let pos = this.pos
+    let s = this.readVarString()
+    this.pos = pos
+    return s
+  }
+  readOpID () {
+    let user = this.readVarUint()
+    if (user !== 0xFFFFFF) {
+      return [user, this.readVarUint()]
+    } else {
+      return [user, this.readVarString()]
+    }
+  }
+}
--- a/src/MessageHandler.js
+++ b/src/MessageHandler.js
@@ -0,0 +1,188 @@
+
+import Y from './y.js'
+import { BinaryDecoder, BinaryEncoder } from './Encoding.js'
+
+export function formatYjsMessage (buffer) {
+  let decoder = new BinaryDecoder(buffer)
+  decoder.readVarString() // read roomname
+  let type = decoder.readVarString()
+  let strBuilder = []
+  strBuilder.push('\n === ' + type + ' ===\n')
+  if (type === 'update') {
+    logMessageUpdate(decoder, strBuilder)
+  } else if (type === 'sync step 1') {
+    logMessageSyncStep1(decoder, strBuilder)
+  } else if (type === 'sync step 2') {
+    logMessageSyncStep2(decoder, strBuilder)
+  } else {
+    strBuilder.push('-- Unknown message type - probably an encoding issue!!!')
+  }
+  return strBuilder.join('')
+}
+
+export function formatYjsMessageType (buffer) {
+  let decoder = new BinaryDecoder(buffer)
+  decoder.readVarString() // roomname
+  return decoder.readVarString()
+}
+
+export function logMessageUpdate (decoder, strBuilder) {
+  let len = decoder.readUint32()
+  for (let i = 0; i < len; i++) {
+    strBuilder.push(JSON.stringify(Y.Struct.binaryDecodeOperation(decoder)) + '\n')
+  }
+}
+
+export function computeMessageUpdate (decoder, encoder, conn) {
+  if (conn.y.db.forwardAppliedOperations) {
+    let messagePosition = decoder.pos
+    let len = decoder.readUint32()
+    let delops = []
+    for (let i = 0; i < len; i++) {
+      let op = Y.Struct.binaryDecodeOperation(decoder)
+      if (op.struct === 'Delete') {
+        delops.push(op)
+      }
+    }
+    if (delops.length > 0) {
+      conn.broadcastOps(delops)
+    }
+    decoder.pos = messagePosition
+  }
+  conn.y.db.applyOperations(decoder)
+}
+
+export function sendSyncStep1 (conn, syncUser) {
+  conn.y.db.requestTransaction(function * () {
+    let encoder = new BinaryEncoder()
+    encoder.writeVarString(conn.opts.room || '')
+    encoder.writeVarString('sync step 1')
+    encoder.writeVarString(conn.authInfo || '')
+    encoder.writeVarUint(conn.protocolVersion)
+    let preferUntransformed = conn.preferUntransformed && this.os.length === 0 // TODO: length may not be defined
+    encoder.writeUint8(preferUntransformed ? 1 : 0)
+    yield * this.writeStateSet(encoder)
+    conn.send(syncUser, encoder.createBuffer())
+  })
+}
+
+export function logMessageSyncStep1 (decoder, strBuilder) {
+  let auth = decoder.readVarString()
+  let protocolVersion = decoder.readVarUint()
+  let preferUntransformed = decoder.readUint8() === 1
+  strBuilder.push(`
+  - auth: "${auth}"
+  - protocolVersion: ${protocolVersion}
+  - preferUntransformed: ${preferUntransformed}
+`)
+  logSS(decoder, strBuilder)
+}
+
+export function computeMessageSyncStep1 (decoder, encoder, conn, senderConn, sender) {
+  let protocolVersion = decoder.readVarUint()
+  let preferUntransformed = decoder.readUint8() === 1
+
+  // check protocol version
+  if (protocolVersion !== conn.protocolVersion) {
+    console.warn(
+      `You tried to sync with a yjs instance that has a different protocol version
+      (You: ${protocolVersion}, Client: ${protocolVersion}).
+      The sync was stopped. You need to upgrade your dependencies (especially Yjs & the Connector)!
+      `)
+    conn.y.destroy()
+  }
+
+  return conn.y.db.whenTransactionsFinished().then(() => {
+    // send sync step 2
+    conn.y.db.requestTransaction(function * () {
+      encoder.writeVarString('sync step 2')
+      encoder.writeVarString(conn.authInfo || '')
+
+      if (preferUntransformed) {
+        encoder.writeUint8(1)
+        yield * this.writeOperationsUntransformed(encoder)
+      } else {
+        encoder.writeUint8(0)
+        yield * this.writeOperations(encoder, decoder)
+      }
+
+      yield * this.writeDeleteSet(encoder)
+      conn.send(senderConn.uid, encoder.createBuffer())
+      senderConn.receivedSyncStep2 = true
+    })
+    return conn.y.db.whenTransactionsFinished().then(() => {
+      if (conn.role === 'slave') {
+        sendSyncStep1(conn, sender)
+      }
+    })
+  })
+}
+
+export function logSS (decoder, strBuilder) {
+  strBuilder.push('  == SS: \n')
+  let len = decoder.readUint32()
+  for (let i = 0; i < len; i++) {
+    let user = decoder.readVarUint()
+    let clock = decoder.readVarUint()
+    strBuilder.push(`     ${user}: ${clock}\n`)
+  }
+}
+
+export function logOS (decoder, strBuilder) {
+  strBuilder.push('  == OS: \n')
+  let len = decoder.readUint32()
+  for (let i = 0; i < len; i++) {
+    let op = Y.Struct.binaryDecodeOperation(decoder)
+    strBuilder.push(JSON.stringify(op) + '\n')
+  }
+}
+
+export function logDS (decoder, strBuilder) {
+  strBuilder.push('  == DS: \n')
+  let len = decoder.readUint32()
+  for (let i = 0; i < len; i++) {
+    let user = decoder.readVarUint()
+    strBuilder.push(`    User: ${user}: `)
+    let len2 = decoder.readVarUint()
+    for (let j = 0; j < len2; j++) {
+      let from = decoder.readVarUint()
+      let to = decoder.readVarUint()
+      let gc = decoder.readUint8() === 1
+      strBuilder.push(`[${from}, ${to}, ${gc}]`)
+    }
+  }
+}
+
+export function logMessageSyncStep2 (decoder, strBuilder) {
+  strBuilder.push('     - auth: ' + decoder.readVarString() + '\n')
+  let osTransformed = decoder.readUint8() === 1
+  strBuilder.push('     - osUntransformed: ' + osTransformed + '\n')
+  logOS(decoder, strBuilder)
+  if (osTransformed) {
+    logSS(decoder, strBuilder)
+  }
+  logDS(decoder, strBuilder)
+}
+
+export function computeMessageSyncStep2 (decoder, encoder, conn, senderConn, sender) {
+  var db = conn.y.db
+  let defer = senderConn.syncStep2
+
+  // apply operations first
+  db.requestTransaction(function * () {
+    let osUntransformed = decoder.readUint8()
+    if (osUntransformed === 1) {
+      yield * this.applyOperationsUntransformed(decoder)
+    } else {
+      this.store.applyOperations(decoder)
+    }
+  })
+  // then apply ds
+  db.requestTransaction(function * () {
+    yield * this.applyDeleteSet(decoder)
+  })
+  return db.whenTransactionsFinished().then(() => {
+    conn._setSyncedWith(sender)
+    defer.resolve()
+  })
+}
--- a/src/Notes.md
+++ b/src/Notes.md
@@ -0,0 +1,12 @@
+
+# Notes
+
+### Terminology
+
+* DB: DataBase that holds all the information of the shared object. It is devided into the OS, DS, and SS. This can be a persistent database or an in-memory database. Depending on the type of database, it could make sense to store OS, DS, and SS in different tables, or maybe different databases.
+* OS: OperationStore holds all the operations. An operation is a js object with a fixed number of name fields.
+* DS: DeleteStore holds the information about which operations are deleted and which operations were garbage collected (no longer available in the OS).
+* SS: StateSet holds the current state of the OS. SS.getState(username) refers to the amount of operations that were received by that respective user.
+* Op: Operation defines an action on a shared type. But it is also the format in which we store the model of a type. This is why it is also called a Struct/Structure.
+* Type and Structure: We crearly distinguish between type and structure. Short explanation: A type (e.g. Strings, Numbers) have a number of functions that you can apply on them. (+) is well defined on both of them. They are *modeled* by a structure - the functions really change the structure of a type. Types can be implemented differently but still provide the same functionality. In Yjs, almost all types are realized as a doubly linked list (on which Yjs can provide eventual convergence)
+*
--- a/src/Struct.js
+++ b/src/Struct.js
@@ -0,0 +1,568 @@
+const CDELETE = 0
+const CINSERT = 1
+const CLIST = 2
+const CMAP = 3
+
+/*
+ An operation also defines the structure of a type. This is why operation and
+ structure are used interchangeably here.
+
+ It must be of the type Object. I hope to achieve some performance
+ improvements when working on databases that support the json format.
+
+ An operation must have the following properties:
+
+ * encode
+     - Encode the structure in a readable format (preferably string- todo)
+ * decode (todo)
+     - decode structure to json
+ * execute
+     - Execute the semantics of an operation.
+ * requiredOps
+     - Operations that are required to execute this operation.
+*/
+export default function extendStruct (Y) {
+  var Struct = {
+    binaryDecodeOperation: function (decoder) {
+      let code = decoder.peekUint8()
+      if (code === CDELETE) {
+        return Y.Struct.Delete.binaryDecode(decoder)
+      } else if (code === CINSERT) {
+        return Y.Struct.Insert.binaryDecode(decoder)
+      } else if (code === CLIST) {
+        return Y.Struct.List.binaryDecode(decoder)
+      } else if (code === CMAP) {
+        return Y.Struct.Map.binaryDecode(decoder)
+      } else {
+        throw new Error('Unable to decode operation!')
+      }
+    },
+    /* This is the only operation that is actually not a structure, because
+    it is not stored in the OS. This is why it _does not_ have an id
+
+    op = {
+      target: Id
+    }
+    */
+    Delete: {
+      encode: function (op) {
+        return {
+          target: op.target,
+          length: op.length || 0,
+          struct: 'Delete'
+        }
+      },
+      binaryEncode: function (encoder, op) {
+        encoder.writeUint8(CDELETE)
+        encoder.writeOpID(op.target)
+        encoder.writeVarUint(op.length || 0)
+      },
+      binaryDecode: function (decoder) {
+        decoder.skip8()
+        return {
+          target: decoder.readOpID(),
+          length: decoder.readVarUint(),
+          struct: 'Delete'
+        }
+      },
+      requiredOps: function (op) {
+        return [] // [op.target]
+      },
+      execute: function * (op) {
+        return yield * this.deleteOperation(op.target, op.length || 1)
+      }
+    },
+    Insert: {
+      /* {
+          content: [any],
+          opContent: Id,
+          id: Id,
+          left: Id,
+          origin: Id,
+          right: Id,
+          parent: Id,
+          parentSub: string (optional), // child of Map type
+        }
+      */
+      encode: function (op/* :Insertion */) /* :Insertion */ {
+        // TODO: you could not send the "left" property, then you also have to
+        // "op.left = null" in $execute or $decode
+        var e/* :any */ = {
+          id: op.id,
+          left: op.left,
+          right: op.right,
+          origin: op.origin,
+          parent: op.parent,
+          struct: op.struct
+        }
+        if (op.parentSub != null) {
+          e.parentSub = op.parentSub
+        }
+        if (op.hasOwnProperty('opContent')) {
+          e.opContent = op.opContent
+        } else {
+          e.content = op.content.slice()
+        }
+
+        return e
+      },
+      binaryEncode: function (encoder, op) {
+        encoder.writeUint8(CINSERT)
+        // compute info property
+        let contentIsText = op.content != null && op.content.every(c => typeof c === 'string' && c.length === 1)
+        let originIsLeft = Y.utils.compareIds(op.left, op.origin)
+        let info =
+          (op.parentSub != null ? 1 : 0) |
+          (op.opContent != null ? 2 : 0) |
+          (contentIsText ? 4 : 0) |
+          (originIsLeft ? 8 : 0) |
+          (op.left != null ? 16 : 0) |
+          (op.right != null ? 32 : 0) |
+          (op.origin != null ? 64 : 0)
+        encoder.writeUint8(info)
+        encoder.writeOpID(op.id)
+        encoder.writeOpID(op.parent)
+        if (info & 16) {
+          encoder.writeOpID(op.left)
+        }
+        if (info & 32) {
+          encoder.writeOpID(op.right)
+        }
+        if (!originIsLeft && info & 64) {
+          encoder.writeOpID(op.origin)
+        }
+        if (info & 1) {
+          // write parentSub
+          encoder.writeVarString(op.parentSub)
+        }
+        if (info & 2) {
+          // write opContent
+          encoder.writeOpID(op.opContent)
+        } else if (info & 4) {
+          // write text
+          encoder.writeVarString(op.content.join(''))
+        } else {
+          // convert to JSON and write
+          encoder.writeVarString(JSON.stringify(op.content))
+        }
+      },
+      binaryDecode: function (decoder) {
+        let op = {
+          struct: 'Insert'
+        }
+        decoder.skip8()
+        // get info property
+        let info = decoder.readUint8()
+
+        op.id = decoder.readOpID()
+        op.parent = decoder.readOpID()
+        if (info & 16) {
+          op.left = decoder.readOpID()
+        } else {
+          op.left = null
+        }
+        if (info & 32) {
+          op.right = decoder.readOpID()
+        } else {
+          op.right = null
+        }
+        if (info & 8) {
+          // origin is left
+          op.origin = op.left
+        } else if (info & 64) {
+          op.origin = decoder.readOpID()
+        } else {
+          op.origin = null
+        }
+        if (info & 1) {
+          // has parentSub
+          op.parentSub = decoder.readVarString()
+        }
+        if (info & 2) {
+          // has opContent
+          op.opContent = decoder.readOpID()
+        } else if (info & 4) {
+          // has pure text content
+          op.content = decoder.readVarString().split('')
+        } else {
+          // has mixed content
+          let s = decoder.readVarString()
+          op.content = JSON.parse(s)
+        }
+        return op
+      },
+      requiredOps: function (op) {
+        var ids = []
+        if (op.left != null) {
+          ids.push(op.left)
+        }
+        if (op.right != null) {
+          ids.push(op.right)
+        }
+        if (op.origin != null && !Y.utils.compareIds(op.left, op.origin)) {
+          ids.push(op.origin)
+        }
+        // if (op.right == null && op.left == null) {
+        ids.push(op.parent)
+
+        if (op.opContent != null) {
+          ids.push(op.opContent)
+        }
+        return ids
+      },
+      getDistanceToOrigin: function * (op) {
+        if (op.left == null) {
+          return 0
+        } else {
+          var d = 0
+          var o = yield * this.getInsertion(op.left)
+          while (!Y.utils.matchesId(o, op.origin)) {
+            d++
+            if (o.left == null) {
+              break
+            } else {
+              o = yield * this.getInsertion(o.left)
+            }
+          }
+          return d
+        }
+      },
+      /*
+      # $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!)
+      */
+      execute: function * (op) {
+        var i // loop counter
+
+        // during this function some ops may get split into two pieces (e.g. with getInsertionCleanEnd)
+        // We try to merge them later, if possible
+        var tryToRemergeLater = []
+
+        if (op.origin != null) { // TODO: !== instead of !=
+          // we save in origin that op originates in it
+          // we need that later when we eventually garbage collect origin (see transaction)
+          var origin = yield * this.getInsertionCleanEnd(op.origin)
+          if (origin.originOf == null) {
+            origin.originOf = []
+          }
+          origin.originOf.push(op.id)
+          yield * this.setOperation(origin)
+          if (origin.right != null) {
+            tryToRemergeLater.push(origin.right)
+          }
+        }
+        var distanceToOrigin = i = yield * Struct.Insert.getDistanceToOrigin.call(this, op) // most cases: 0 (starts from 0)
+
+        // now we begin to insert op in the list of insertions..
+        var o
+        var parent
+        var start
+
+        // find o. o is the first conflicting operation
+        if (op.left != null) {
+          o = yield * this.getInsertionCleanEnd(op.left)
+          if (!Y.utils.compareIds(op.left, op.origin) && o.right != null) {
+            // only if not added previously
+            tryToRemergeLater.push(o.right)
+          }
+          o = (o.right == null) ? null : yield * this.getOperation(o.right)
+        } else { // left == null
+          parent = yield * this.getOperation(op.parent)
+          let startId = op.parentSub ? parent.map[op.parentSub] : parent.start
+          start = startId == null ? null : yield * this.getOperation(startId)
+          o = start
+        }
+
+        // make sure to split op.right if necessary (also add to tryCombineWithLeft)
+        if (op.right != null) {
+          tryToRemergeLater.push(op.right)
+          yield * this.getInsertionCleanStart(op.right)
+        }
+
+        // handle conflicts
+        while (true) {
+          if (o != null && !Y.utils.compareIds(o.id, op.right)) {
+            var oOriginDistance = yield * Struct.Insert.getDistanceToOrigin.call(this, o)
+            if (oOriginDistance === i) {
+              // case 1
+              if (o.id[0] < op.id[0]) {
+                op.left = Y.utils.getLastId(o)
+                distanceToOrigin = i + 1 // just ignore o.content.length, doesn't make a difference
+              }
+            } else if (oOriginDistance < i) {
+              // case 2
+              if (i - distanceToOrigin <= oOriginDistance) {
+                op.left = Y.utils.getLastId(o)
+                distanceToOrigin = i + 1 // just ignore o.content.length, doesn't make a difference
+              }
+            } else {
+              break
+            }
+            i++
+            if (o.right != null) {
+              o = yield * this.getInsertion(o.right)
+            } else {
+              o = null
+            }
+          } else {
+            break
+          }
+        }
+
+        // reconnect..
+        var left = null
+        var right = null
+        if (parent == null) {
+          parent = yield * this.getOperation(op.parent)
+        }
+
+        // reconnect left and set right of op
+        if (op.left != null) {
+          left = yield * this.getInsertion(op.left)
+          // link left
+          op.right = left.right
+          left.right = op.id
+
+          yield * this.setOperation(left)
+        } else {
+          // set op.right from parent, if necessary
+          op.right = op.parentSub ? parent.map[op.parentSub] || null : parent.start
+        }
+        // reconnect right
+        if (op.right != null) {
+          // TODO: wanna connect right too?
+          right = yield * this.getOperation(op.right)
+          right.left = Y.utils.getLastId(op)
+
+          // if right exists, and it is supposed to be gc'd. Remove it from the gc
+          if (right.gc != null) {
+            if (right.content != null && right.content.length > 1) {
+              right = yield * this.getInsertionCleanEnd(right.id)
+            }
+            this.store.removeFromGarbageCollector(right)
+          }
+          yield * this.setOperation(right)
+        }
+
+        // update parents .map/start/end properties
+        if (op.parentSub != null) {
+          if (left == null) {
+            parent.map[op.parentSub] = op.id
+            yield * this.setOperation(parent)
+          }
+          // is a child of a map struct.
+          // Then also make sure that only the most left element is not deleted
+          // We do not call the type in this case (this is what the third parameter is for)
+          if (op.right != null) {
+            yield * this.deleteOperation(op.right, 1, true)
+          }
+          if (op.left != null) {
+            yield * this.deleteOperation(op.id, 1, true)
+          }
+        } else {
+          if (right == null || left == null) {
+            if (right == null) {
+              parent.end = Y.utils.getLastId(op)
+            }
+            if (left == null) {
+              parent.start = op.id
+            }
+            yield * this.setOperation(parent)
+          }
+        }
+
+        // try to merge original op.left and op.origin
+        for (i = 0; i < tryToRemergeLater.length; i++) {
+          var m = yield * this.getOperation(tryToRemergeLater[i])
+          yield * this.tryCombineWithLeft(m)
+        }
+      }
+    },
+    List: {
+      /*
+      {
+        start: null,
+        end: null,
+        struct: "List",
+        type: "",
+        id: this.os.getNextOpId(1)
+      }
+      */
+      create: function (id) {
+        return {
+          start: null,
+          end: null,
+          struct: 'List',
+          id: id
+        }
+      },
+      encode: function (op) {
+        var e = {
+          struct: 'List',
+          id: op.id,
+          type: op.type
+        }
+        if (op.info != null) {
+          e.info = op.info
+        }
+        return e
+      },
+      binaryEncode: function (encoder, op) {
+        encoder.writeUint8(CLIST)
+        encoder.writeOpID(op.id)
+        encoder.writeVarString(op.type)
+        let info = op.info != null ? JSON.stringify(op.info) : ''
+        encoder.writeVarString(info)
+      },
+      binaryDecode: function (decoder) {
+        decoder.skip8()
+        let op = {
+          id: decoder.readOpID(),
+          type: decoder.readVarString(),
+          struct: 'List'
+        }
+        let info = decoder.readVarString()
+        if (info.length > 0) {
+          op.info = JSON.parse(info)
+        }
+        return op
+      },
+      requiredOps: function () {
+        /*
+        var ids = []
+        if (op.start != null) {
+          ids.push(op.start)
+        }
+        if (op.end != null){
+          ids.push(op.end)
+        }
+        return ids
+        */
+        return []
+      },
+      execute: function * (op) {
+        op.start = null
+        op.end = null
+      },
+      ref: function * (op, pos) {
+        if (op.start == null) {
+          return null
+        }
+        var res = null
+        var o = yield * this.getOperation(op.start)
+
+        while (true) {
+          if (!o.deleted) {
+            res = o
+            pos--
+          }
+          if (pos >= 0 && o.right != null) {
+            o = yield * this.getOperation(o.right)
+          } else {
+            break
+          }
+        }
+        return res
+      },
+      map: function * (o, f) {
+        o = o.start
+        var res = []
+        while (o != null) { // TODO: change to != (at least some convention)
+          var operation = yield * this.getOperation(o)
+          if (!operation.deleted) {
+            res.push(f(operation))
+          }
+          o = operation.right
+        }
+        return res
+      }
+    },
+    Map: {
+      /*
+        {
+          map: {},
+          struct: "Map",
+          type: "",
+          id: this.os.getNextOpId(1)
+        }
+      */
+      create: function (id) {
+        return {
+          id: id,
+          map: {},
+          struct: 'Map'
+        }
+      },
+      encode: function (op) {
+        var e = {
+          struct: 'Map',
+          type: op.type,
+          id: op.id,
+          map: {} // overwrite map!!
+        }
+        if (op.requires != null) {
+          e.requires = op.require
+          // TODO: !!
+          console.warn('requires is used! see same note above for List')
+        }
+        if (op.info != null) {
+          e.info = op.info
+        }
+        return e
+      },
+      binaryEncode: function (encoder, op) {
+        encoder.writeUint8(CMAP)
+        encoder.writeOpID(op.id)
+        encoder.writeVarString(op.type)
+        let info = op.info != null ? JSON.stringify(op.info) : ''
+        encoder.writeVarString(info)
+      },
+      binaryDecode: function (decoder) {
+        decoder.skip8()
+        let op = {
+          id: decoder.readOpID(),
+          type: decoder.readVarString(),
+          struct: 'Map',
+          map: {}
+        }
+        let info = decoder.readVarString()
+        if (info.length > 0) {
+          op.info = JSON.parse(info)
+        }
+        return op
+      },
+      requiredOps: function () {
+        return []
+      },
+      execute: function * () {},
+      /*
+        Get a property by name
+      */
+      get: function * (op, name) {
+        var oid = op.map[name]
+        if (oid != null) {
+          var res = yield * this.getOperation(oid)
+          if (res == null || res.deleted) {
+            return void 0
+          } else if (res.opContent == null) {
+            return res.content[0]
+          } else {
+            return yield * this.getType(res.opContent)
+          }
+        }
+      }
+    }
+  }
+  Y.Struct = Struct
+}
--- a/src/Transaction.js
+++ b/src/Transaction.js
--- a/src/Utils.js
+++ b/src/Utils.js
@@ -0,0 +1,843 @@
+/* globals crypto */
+
+import { BinaryDecoder, BinaryEncoder } from './Encoding.js'
+
+/*
+  EventHandler is an helper class for constructing custom types.
+
+  Why: When constructing custom types, you sometimes want your types to work
+  synchronous: E.g.
+  ``` Synchronous
+    mytype.setSomething("yay")
+    mytype.getSomething() === "yay"
+  ```
+  versus
+  ``` Asynchronous
+    mytype.setSomething("yay")
+    mytype.getSomething() === undefined
+    mytype.waitForSomething().then(function(){
+      mytype.getSomething() === "yay"
+    })
+  ```
+
+  The structures usually work asynchronously (you have to wait for the
+  database request to finish). EventHandler helps you to make your type
+  synchronous.
+*/
+
+export default function Utils (Y) {
+  Y.utils = {
+    BinaryDecoder: BinaryDecoder,
+    BinaryEncoder: BinaryEncoder
+  }
+
+  Y.utils.bubbleEvent = function (type, event) {
+    type.eventHandler.callEventListeners(event)
+    event.path = []
+    while (type != null && type._deepEventHandler != null) {
+      type._deepEventHandler.callEventListeners(event)
+      var parent = null
+      if (type._parent != null) {
+        parent = type.os.getType(type._parent)
+      }
+      if (parent != null && parent._getPathToChild != null) {
+        event.path = [parent._getPathToChild(type._model)].concat(event.path)
+        type = parent
+      } else {
+        type = null
+      }
+    }
+  }
+
+  class NamedEventHandler {
+    constructor () {
+      this._eventListener = {}
+    }
+    on (name, f) {
+      if (this._eventListener[name] == null) {
+        this._eventListener[name] = []
+      }
+      this._eventListener[name].push(f)
+    }
+    off (name, f) {
+      if (name == null || f == null) {
+        throw new Error('You must specify event name and function!')
+      }
+      let listener = this._eventListener[name] || []
+      this._eventListener[name] = listener.filter(e => e !== f)
+    }
+    emit (name, value) {
+      (this._eventListener[name] || []).forEach(l => l(value))
+    }
+    destroy () {
+      this._eventListener = null
+    }
+  }
+  Y.utils.NamedEventHandler = NamedEventHandler
+
+  class EventListenerHandler {
+    constructor () {
+      this.eventListeners = []
+    }
+    destroy () {
+      this.eventListeners = null
+    }
+     /*
+      Basic event listener boilerplate...
+    */
+    addEventListener (f) {
+      this.eventListeners.push(f)
+    }
+    removeEventListener (f) {
+      this.eventListeners = this.eventListeners.filter(function (g) {
+        return f !== g
+      })
+    }
+    removeAllEventListeners () {
+      this.eventListeners = []
+    }
+    callEventListeners (event) {
+      for (var i = 0; i < this.eventListeners.length; i++) {
+        try {
+          var _event = {}
+          for (var name in event) {
+            _event[name] = event[name]
+          }
+          this.eventListeners[i](_event)
+        } catch (e) {
+          /*
+            Your observer threw an error. This error was caught so that Yjs
+            can ensure data consistency! In order to debug this error you
+            have to check "Pause On Caught Exceptions" in developer tools.
+          */
+          console.error(e)
+        }
+      }
+    }
+  }
+  Y.utils.EventListenerHandler = EventListenerHandler
+
+  class EventHandler extends EventListenerHandler {
+    /* ::
+    waiting: Array<Insertion | Deletion>;
+    awaiting: number;
+    onevent: Function;
+    eventListeners: Array<Function>;
+    */
+    /*
+      onevent: is called when the structure changes.
+
+      Note: "awaiting opertations" is used to denote operations that were
+      prematurely called. Events for received operations can not be executed until
+      all prematurely called operations were executed ("waiting operations")
+    */
+    constructor (onevent /* : Function */) {
+      super()
+      this.waiting = []
+      this.awaiting = 0
+      this.onevent = onevent
+    }
+    destroy () {
+      super.destroy()
+      this.waiting = null
+      this.onevent = null
+    }
+    /*
+      Call this when a new operation arrives. It will be executed right away if
+      there are no waiting operations, that you prematurely executed
+    */
+    receivedOp (op) {
+      if (this.awaiting <= 0) {
+        this.onevent(op)
+      } else if (op.struct === 'Delete') {
+        var self = this
+        var checkDelete = function checkDelete (d) {
+          if (d.length == null) {
+            throw new Error('This shouldn\'t happen! d.length must be defined!')
+          }
+          // we check if o deletes something in self.waiting
+          // if so, we remove the deleted operation
+          for (var w = 0; w < self.waiting.length; w++) {
+            var i = self.waiting[w]
+            if (i.struct === 'Insert' && i.id[0] === d.target[0]) {
+              var iLength = i.hasOwnProperty('content') ? i.content.length : 1
+              var dStart = d.target[1]
+              var dEnd = d.target[1] + (d.length || 1)
+              var iStart = i.id[1]
+              var iEnd = i.id[1] + iLength
+              // Check if they don't overlap
+              if (iEnd <= dStart || dEnd <= iStart) {
+                // no overlapping
+                continue
+              }
+              // we check all overlapping cases. All cases:
+              /*
+                1)  iiiii
+                      ddddd
+                    --> modify i and d
+                2)  iiiiiii
+                      ddddd
+                    --> modify i, remove d
+                3)  iiiiiii
+                      ddd
+                    --> remove d, modify i, and create another i (for the right hand side)
+                4)  iiiii
+                    ddddddd
+                    --> remove i, modify d
+                5)  iiiiiii
+                    ddddddd
+                    --> remove both i and d (**)
+                6)  iiiiiii
+                    ddddd
+                    --> modify i, remove d
+                7)    iii
+                    ddddddd
+                    --> remove i, create and apply two d with checkDelete(d) (**)
+                8)    iiiii
+                    ddddddd
+                    --> remove i, modify d (**)
+                9)    iiiii
+                    ddddd
+                    --> modify i and d
+                (**) (also check if i contains content or type)
+              */
+              // TODO: I left some debugger statements, because I want to debug all cases once in production. REMEMBER END TODO
+              if (iStart < dStart) {
+                if (dStart < iEnd) {
+                  if (iEnd < dEnd) {
+                    // Case 1
+                    // remove the right part of i's content
+                    i.content.splice(dStart - iStart)
+                    // remove the start of d's deletion
+                    d.length = dEnd - iEnd
+                    d.target = [d.target[0], iEnd]
+                    continue
+                  } else if (iEnd === dEnd) {
+                    // Case 2
+                    i.content.splice(dStart - iStart)
+                    // remove d, we do that by simply ending this function
+                    return
+                  } else { // (dEnd < iEnd)
+                    // Case 3
+                    var newI = {
+                      id: [i.id[0], dEnd],
+                      content: i.content.slice(dEnd - iStart),
+                      struct: 'Insert'
+                    }
+                    self.waiting.push(newI)
+                    i.content.splice(dStart - iStart)
+                    return
+                  }
+                }
+              } else if (dStart === iStart) {
+                if (iEnd < dEnd) {
+                  // Case 4
+                  d.length = dEnd - iEnd
+                  d.target = [d.target[0], iEnd]
+                  i.content = []
+                  continue
+                } else if (iEnd === dEnd) {
+                  // Case 5
+                  self.waiting.splice(w, 1)
+                  return
+                } else { // (dEnd < iEnd)
+                  // Case 6
+                  i.content = i.content.slice(dEnd - iStart)
+                  i.id = [i.id[0], dEnd]
+                  return
+                }
+              } else { // (dStart < iStart)
+                if (iStart < dEnd) {
+                  // they overlap
+                  /*
+                  7)    iii
+                      ddddddd
+                      --> remove i, create and apply two d with checkDelete(d) (**)
+                  8)    iiiii
+                      ddddddd
+                      --> remove i, modify d (**)
+                  9)    iiiii
+                      ddddd
+                      --> modify i and d
+                  */
+                  if (iEnd < dEnd) {
+                    // Case 7
+                    // debugger // TODO: You did not test this case yet!!!! (add the debugger here)
+                    self.waiting.splice(w, 1)
+                    checkDelete({
+                      target: [d.target[0], dStart],
+                      length: iStart - dStart,
+                      struct: 'Delete'
+                    })
+                    checkDelete({
+                      target: [d.target[0], iEnd],
+                      length: iEnd - dEnd,
+                      struct: 'Delete'
+                    })
+                    return
+                  } else if (iEnd === dEnd) {
+                    // Case 8
+                    self.waiting.splice(w, 1)
+                    w--
+                    d.length -= iLength
+                    continue
+                  } else { // dEnd < iEnd
+                    // Case 9
+                    d.length = iStart - dStart
+                    i.content.splice(0, dEnd - iStart)
+                    i.id = [i.id[0], dEnd]
+                    continue
+                  }
+                }
+              }
+            }
+          }
+          // finished with remaining operations
+          self.waiting.push(d)
+        }
+        if (op.key == null) {
+          // deletes in list
+          checkDelete(op)
+        } else {
+          // deletes in map
+          this.waiting.push(op)
+        }
+      } else {
+        this.waiting.push(op)
+      }
+    }
+    /*
+      You created some operations, and you want the `onevent` function to be
+      called right away. Received operations will not be executed untill all
+      prematurely called operations are executed
+    */
+    awaitAndPrematurelyCall (ops) {
+      this.awaiting++
+      ops.map(Y.utils.copyOperation).forEach(this.onevent)
+    }
+    * awaitOps (transaction, f, args) {
+      function notSoSmartSort (array) {
+        // this function sorts insertions in a executable order
+        var result = []
+        while (array.length > 0) {
+          for (var i = 0; i < array.length; i++) {
+            var independent = true
+            for (var j = 0; j < array.length; j++) {
+              if (Y.utils.matchesId(array[j], array[i].left)) {
+                // array[i] depends on array[j]
+                independent = false
+                break
+              }
+            }
+            if (independent) {
+              result.push(array.splice(i, 1)[0])
+              i--
+            }
+          }
+        }
+        return result
+      }
+      var before = this.waiting.length
+      // somehow create new operations
+      yield * f.apply(transaction, args)
+      // remove all appended ops / awaited ops
+      this.waiting.splice(before)
+      if (this.awaiting > 0) this.awaiting--
+      // if there are no awaited ops anymore, we can update all waiting ops, and send execute them (if there are still no awaited ops)
+      if (this.awaiting === 0 && this.waiting.length > 0) {
+        // update all waiting ops
+        for (let i = 0; i < this.waiting.length; i++) {
+          var o = this.waiting[i]
+          if (o.struct === 'Insert') {
+            var _o = yield * transaction.getInsertion(o.id)
+            if (_o.parentSub != null && _o.left != null) {
+              // if o is an insertion of a map struc (parentSub is defined), then it shouldn't be necessary to compute left
+              this.waiting.splice(i, 1)
+              i-- // update index
+            } else if (!Y.utils.compareIds(_o.id, o.id)) {
+              // o got extended
+              o.left = [o.id[0], o.id[1] - 1]
+            } else if (_o.left == null) {
+              o.left = null
+            } else {
+              // find next undeleted op
+              var left = yield * transaction.getInsertion(_o.left)
+              while (left.deleted != null) {
+                if (left.left != null) {
+                  left = yield * transaction.getInsertion(left.left)
+                } else {
+                  left = null
+                  break
+                }
+              }
+              o.left = left != null ? Y.utils.getLastId(left) : null
+            }
+          }
+        }
+        // the previous stuff was async, so we have to check again!
+        // We also pull changes from the bindings, if there exists such a method, this could increase awaiting too
+        if (this._pullChanges != null) {
+          this._pullChanges()
+        }
+        if (this.awaiting === 0) {
+          // sort by type, execute inserts first
+          var ins = []
+          var dels = []
+          this.waiting.forEach(function (o) {
+            if (o.struct === 'Delete') {
+              dels.push(o)
+            } else {
+              ins.push(o)
+            }
+          })
+          this.waiting = []
+          // put in executable order
+          ins = notSoSmartSort(ins)
+          // this.onevent can trigger the creation of another operation
+          // -> check if this.awaiting increased & stop computation if it does
+          for (var i = 0; i < ins.length; i++) {
+            if (this.awaiting === 0) {
+              this.onevent(ins[i])
+            } else {
+              this.waiting = this.waiting.concat(ins.slice(i))
+              break
+            }
+          }
+          for (i = 0; i < dels.length; i++) {
+            if (this.awaiting === 0) {
+              this.onevent(dels[i])
+            } else {
+              this.waiting = this.waiting.concat(dels.slice(i))
+              break
+            }
+          }
+        }
+      }
+    }
+    // TODO: Remove awaitedInserts and awaitedDeletes in favor of awaitedOps, as they are deprecated and do not always work
+    // Do this in one of the coming releases that are breaking anyway
+    /*
+      Call this when you successfully awaited the execution of n Insert operations
+    */
+    awaitedInserts (n) {
+      var ops = this.waiting.splice(this.waiting.length - n)
+      for (var oid = 0; oid < ops.length; oid++) {
+        var op = ops[oid]
+        if (op.struct === 'Insert') {
+          for (var i = this.waiting.length - 1; i >= 0; i--) {
+            let w = this.waiting[i]
+            // TODO: do I handle split operations correctly here? Super unlikely, but yeah..
+            // Also: can this case happen? Can op be inserted in the middle of a larger op that is in $waiting?
+            if (w.struct === 'Insert') {
+              if (Y.utils.matchesId(w, op.left)) {
+                // include the effect of op in w
+                w.right = op.id
+                // exclude the effect of w in op
+                op.left = w.left
+              } else if (Y.utils.compareIds(w.id, op.right)) {
+                // similar..
+                w.left = Y.utils.getLastId(op)
+                op.right = w.right
+              }
+            }
+          }
+        } else {
+          throw new Error('Expected Insert Operation!')
+        }
+      }
+      this._tryCallEvents(n)
+    }
+    /*
+      Call this when you successfully awaited the execution of n Delete operations
+    */
+    awaitedDeletes (n, newLeft) {
+      var ops = this.waiting.splice(this.waiting.length - n)
+      for (var j = 0; j < ops.length; j++) {
+        var del = ops[j]
+        if (del.struct === 'Delete') {
+          if (newLeft != null) {
+            for (var i = 0; i < this.waiting.length; i++) {
+              let w = this.waiting[i]
+              // We will just care about w.left
+              if (w.struct === 'Insert' && Y.utils.compareIds(del.target, w.left)) {
+                w.left = newLeft
+              }
+            }
+          }
+        } else {
+          throw new Error('Expected Delete Operation!')
+        }
+      }
+      this._tryCallEvents(n)
+    }
+    /* (private)
+      Try to execute the events for the waiting operations
+    */
+    _tryCallEvents () {
+      function notSoSmartSort (array) {
+        var result = []
+        while (array.length > 0) {
+          for (var i = 0; i < array.length; i++) {
+            var independent = true
+            for (var j = 0; j < array.length; j++) {
+              if (Y.utils.matchesId(array[j], array[i].left)) {
+                // array[i] depends on array[j]
+                independent = false
+                break
+              }
+            }
+            if (independent) {
+              result.push(array.splice(i, 1)[0])
+              i--
+            }
+          }
+        }
+        return result
+      }
+      if (this.awaiting > 0) this.awaiting--
+      if (this.awaiting === 0 && this.waiting.length > 0) {
+        var ins = []
+        var dels = []
+        this.waiting.forEach(function (o) {
+          if (o.struct === 'Delete') {
+            dels.push(o)
+          } else {
+            ins.push(o)
+          }
+        })
+        ins = notSoSmartSort(ins)
+        ins.forEach(this.onevent)
+        dels.forEach(this.onevent)
+        this.waiting = []
+      }
+    }
+  }
+  Y.utils.EventHandler = EventHandler
+
+  /*
+    Default class of custom types!
+  */
+  class CustomType {
+    getPath () {
+      var parent = null
+      if (this._parent != null) {
+        parent = this.os.getType(this._parent)
+      }
+      if (parent != null && parent._getPathToChild != null) {
+        var firstKey = parent._getPathToChild(this._model)
+        var parentKeys = parent.getPath()
+        parentKeys.push(firstKey)
+        return parentKeys
+      } else {
+        return []
+      }
+    }
+  }
+  Y.utils.CustomType = CustomType
+
+  /*
+    A wrapper for the definition of a custom type.
+    Every custom type must have three properties:
+
+    * struct
+      - Structname of this type
+    * initType
+      - Given a model, creates a custom type
+    * class
+      - the constructor of the custom type (e.g. in order to inherit from a type)
+  */
+  class CustomTypeDefinition { // eslint-disable-line
+    /* ::
+    struct: any;
+    initType: any;
+    class: Function;
+    name: String;
+    */
+    constructor (def) {
+      if (def.struct == null ||
+        def.initType == null ||
+        def.class == null ||
+        def.name == null ||
+        def.createType == null
+      ) {
+        throw new Error('Custom type was not initialized correctly!')
+      }
+      this.struct = def.struct
+      this.initType = def.initType
+      this.createType = def.createType
+      this.class = def.class
+      this.name = def.name
+      if (def.appendAdditionalInfo != null) {
+        this.appendAdditionalInfo = def.appendAdditionalInfo
+      }
+      this.parseArguments = (def.parseArguments || function () {
+        return [this]
+      }).bind(this)
+      this.parseArguments.typeDefinition = this
+    }
+  }
+  Y.utils.CustomTypeDefinition = CustomTypeDefinition
+
+  Y.utils.isTypeDefinition = function isTypeDefinition (v) {
+    if (v != null) {
+      if (v instanceof Y.utils.CustomTypeDefinition) return [v]
+      else if (v.constructor === Array && v[0] instanceof Y.utils.CustomTypeDefinition) return v
+      else if (v instanceof Function && v.typeDefinition instanceof Y.utils.CustomTypeDefinition) return [v.typeDefinition]
+    }
+    return false
+  }
+
+  /*
+    Make a flat copy of an object
+    (just copy properties)
+  */
+  function copyObject (o) {
+    var c = {}
+    for (var key in o) {
+      c[key] = o[key]
+    }
+    return c
+  }
+  Y.utils.copyObject = copyObject
+
+  /*
+    Copy an operation, so that it can be manipulated.
+    Note: You must not change subproperties (except o.content)!
+  */
+  function copyOperation (o) {
+    o = copyObject(o)
+    if (o.content != null) {
+      o.content = o.content.map(function (c) { return c })
+    }
+    return o
+  }
+
+  Y.utils.copyOperation = copyOperation
+
+  /*
+    Defines a smaller relation on Id's
+  */
+  function smaller (a, b) {
+    return a[0] < b[0] || (a[0] === b[0] && (a[1] < b[1] || typeof a[1] < typeof b[1]))
+  }
+  Y.utils.smaller = smaller
+
+  function inDeletionRange (del, ins) {
+    return del.target[0] === ins[0] && del.target[1] <= ins[1] && ins[1] < del.target[1] + (del.length || 1)
+  }
+  Y.utils.inDeletionRange = inDeletionRange
+
+  function compareIds (id1, id2) {
+    if (id1 == null || id2 == null) {
+      return id1 === id2
+    } else {
+      return id1[0] === id2[0] && id1[1] === id2[1]
+    }
+  }
+  Y.utils.compareIds = compareIds
+
+  function matchesId (op, id) {
+    if (id == null || op == null) {
+      return id === op
+    } else {
+      if (id[0] === op.id[0]) {
+        if (op.content == null) {
+          return id[1] === op.id[1]
+        } else {
+          return id[1] >= op.id[1] && id[1] < op.id[1] + op.content.length
+        }
+      }
+    }
+    return false
+  }
+  Y.utils.matchesId = matchesId
+
+  function getLastId (op) {
+    if (op.content == null || op.content.length === 1) {
+      return op.id
+    } else {
+      return [op.id[0], op.id[1] + op.content.length - 1]
+    }
+  }
+  Y.utils.getLastId = getLastId
+
+  function createEmptyOpsArray (n) {
+    var a = new Array(n)
+    for (var i = 0; i < a.length; i++) {
+      a[i] = {
+        id: [null, null]
+      }
+    }
+    return a
+  }
+
+  function createSmallLookupBuffer (Store) {
+    /*
+      This buffer implements a very small buffer that temporarily stores operations
+      after they are read / before they are written.
+      The buffer basically implements FIFO. Often requested lookups will be re-queued every time they are looked up / written.
+
+      It can speed up lookups on Operation Stores and State Stores. But it does not require notable use of memory or processing power.
+
+      Good for os and ss, bot not for ds (because it often uses methods that require a flush)
+
+      I tried to optimize this for performance, therefore no highlevel operations.
+    */
+    class SmallLookupBuffer extends Store {
+      constructor (arg1, arg2) {
+        // super(...arguments) -- do this when this is supported by stable nodejs
+        super(arg1, arg2)
+        this.writeBuffer = createEmptyOpsArray(5)
+        this.readBuffer = createEmptyOpsArray(10)
+      }
+      * find (id, noSuperCall) {
+        var i, r
+        for (i = this.readBuffer.length - 1; i >= 0; i--) {
+          r = this.readBuffer[i]
+          // we don't have to use compareids, because id is always defined!
+          if (r.id[1] === id[1] && r.id[0] === id[0]) {
+            // found r
+            // move r to the end of readBuffer
+            for (; i < this.readBuffer.length - 1; i++) {
+              this.readBuffer[i] = this.readBuffer[i + 1]
+            }
+            this.readBuffer[this.readBuffer.length - 1] = r
+            return r
+          }
+        }
+        var o
+        for (i = this.writeBuffer.length - 1; i >= 0; i--) {
+          r = this.writeBuffer[i]
+          if (r.id[1] === id[1] && r.id[0] === id[0]) {
+            o = r
+            break
+          }
+        }
+        if (i < 0 && noSuperCall === undefined) {
+          // did not reach break in last loop
+          // read id and put it to the end of readBuffer
+          o = yield * super.find(id)
+        }
+        if (o != null) {
+          for (i = 0; i < this.readBuffer.length - 1; i++) {
+            this.readBuffer[i] = this.readBuffer[i + 1]
+          }
+          this.readBuffer[this.readBuffer.length - 1] = o
+        }
+        return o
+      }
+      * put (o) {
+        var id = o.id
+        var i, r // helper variables
+        for (i = this.writeBuffer.length - 1; i >= 0; i--) {
+          r = this.writeBuffer[i]
+          if (r.id[1] === id[1] && r.id[0] === id[0]) {
+            // is already in buffer
+            // forget r, and move o to the end of writeBuffer
+            for (; i < this.writeBuffer.length - 1; i++) {
+              this.writeBuffer[i] = this.writeBuffer[i + 1]
+            }
+            this.writeBuffer[this.writeBuffer.length - 1] = o
+            break
+          }
+        }
+        if (i < 0) {
+          // did not reach break in last loop
+          // write writeBuffer[0]
+          var write = this.writeBuffer[0]
+          if (write.id[0] !== null) {
+            yield * super.put(write)
+          }
+          // put o to the end of writeBuffer
+          for (i = 0; i < this.writeBuffer.length - 1; i++) {
+            this.writeBuffer[i] = this.writeBuffer[i + 1]
+          }
+          this.writeBuffer[this.writeBuffer.length - 1] = o
+        }
+        // check readBuffer for every occurence of o.id, overwrite if found
+        // whether found or not, we'll append o to the readbuffer
+        for (i = 0; i < this.readBuffer.length - 1; i++) {
+          r = this.readBuffer[i + 1]
+          if (r.id[1] === id[1] && r.id[0] === id[0]) {
+            this.readBuffer[i] = o
+          } else {
+            this.readBuffer[i] = r
+          }
+        }
+        this.readBuffer[this.readBuffer.length - 1] = o
+      }
+      * delete (id) {
+        var i, r
+        for (i = 0; i < this.readBuffer.length; i++) {
+          r = this.readBuffer[i]
+          if (r.id[1] === id[1] && r.id[0] === id[0]) {
+            this.readBuffer[i] = {
+              id: [null, null]
+            }
+          }
+        }
+        yield * this.flush()
+        yield * super.delete(id)
+      }
+      * findWithLowerBound (id) {
+        var o = yield * this.find(id, true)
+        if (o != null) {
+          return o
+        } else {
+          yield * this.flush()
+          return yield * super.findWithLowerBound.apply(this, arguments)
+        }
+      }
+      * findWithUpperBound (id) {
+        var o = yield * this.find(id, true)
+        if (o != null) {
+          return o
+        } else {
+          yield * this.flush()
+          return yield * super.findWithUpperBound.apply(this, arguments)
+        }
+      }
+      * findNext () {
+        yield * this.flush()
+        return yield * super.findNext.apply(this, arguments)
+      }
+      * findPrev () {
+        yield * this.flush()
+        return yield * super.findPrev.apply(this, arguments)
+      }
+      * iterate () {
+        yield * this.flush()
+        yield * super.iterate.apply(this, arguments)
+      }
+      * flush () {
+        for (var i = 0; i < this.writeBuffer.length; i++) {
+          var write = this.writeBuffer[i]
+          if (write.id[0] !== null) {
+            yield * super.put(write)
+            this.writeBuffer[i] = {
+              id: [null, null]
+            }
+          }
+        }
+      }
+    }
+    return SmallLookupBuffer
+  }
+  Y.utils.createSmallLookupBuffer = createSmallLookupBuffer
+
+  function generateUserId () {
+    if (typeof crypto !== 'undefined' && crypto.getRandomValue != null) {
+      // browser
+      let arr = new Uint32Array(1)
+      crypto.getRandomValues(arr)
+      return arr[0]
+    } else if (typeof crypto !== 'undefined' && crypto.randomBytes != null) {
+      // node
+      let buf = crypto.randomBytes(4)
+      return new Uint32Array(buf.buffer)[0]
+    } else {
+      return Math.ceil(Math.random() * 0xFFFFFFFF)
+    }
+  }
+  Y.utils.generateUserId = generateUserId
+}
--- a/src/index.js
+++ b/src/index.js
@@ -1,26 +0,0 @@
-
-export {
-  Y,
-  Transaction,
-  YArray as Array,
-  YMap as Map,
-  YText as Text,
-  YXmlText as XmlText,
-  YXmlHook as XmlHook,
-  YXmlElement as XmlElement,
-  YXmlFragment as XmlFragment,
-  createCursorFromTypeOffset,
-  createCursorFromJSON,
-  createAbsolutePositionFromCursor,
-  writeCursor,
-  readCursor,
-  ID,
-  createID,
-  compareIDs,
-  getState,
-  getStates,
-  readStatesAsMap,
-  writeStates,
-  writeModel,
-  readModel
-} from './internals.js'
--- a/src/internals.js
+++ b/src/internals.js
@@ -1,33 +0,0 @@
-export * from './utils/DeleteSet.js'
-export * from './utils/EventHandler.js'
-export * from './utils/ID.js'
-export * from './utils/isParentOf.js'
-export * from './utils/cursor.js'
-export * from './utils/Snapshot.js'
-export * from './utils/StructStore.js'
-export * from './utils/Transaction.js'
-// export * from './utils/UndoManager.js'
-export * from './utils/Y.js'
-export * from './utils/YEvent.js'
-
-export * from './types/AbstractType.js'
-export * from './types/YArray.js'
-export * from './types/YMap.js'
-export * from './types/YText.js'
-export * from './types/YXmlElement.js'
-export * from './types/YXmlEvent.js'
-export * from './types/YXmlHook.js'
-export * from './types/YXmlText.js'
-
-export * from './structs/AbstractStruct.js'
-export * from './structs/AbstractItem.js'
-export * from './structs/GC.js'
-export * from './structs/ItemBinary.js'
-export * from './structs/ItemDeleted.js'
-export * from './structs/ItemEmbed.js'
-export * from './structs/ItemFormat.js'
-export * from './structs/ItemJSON.js'
-export * from './structs/ItemString.js'
-export * from './structs/ItemType.js'
-
-export * from './utils/encoding.js'
--- a/src/structs/AbstractItem.js
+++ b/src/structs/AbstractItem.js
@@ -1,631 +0,0 @@
-
-import {
-  readID,
-  createID,
-  writeID,
-  GC,
-  nextID,
-  AbstractStructRef,
-  AbstractStruct,
-  replaceStruct,
-  addStruct,
-  addToDeleteSet,
-  ItemDeleted,
-  findRootTypeKey,
-  compareIDs,
-  getItem,
-  getItemType,
-  getItemCleanEnd,
-  getItemCleanStart,
-  YEvent, StructStore, ID, AbstractType, Y, Transaction // eslint-disable-line
-} from '../internals.js'
-
-import * as error from 'lib0/error.js'
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-import * as maplib from 'lib0/map.js'
-import * as set from 'lib0/set.js'
-import * as binary from 'lib0/binary.js'
-
-/**
- * Split leftItem into two items
- * @param {Transaction} transaction
- * @param {AbstractItem} leftItem
- * @param {number} diff
- * @return {AbstractItem}
- *
- * @function
- * @private
- */
-export const splitItem = (transaction, leftItem, diff) => {
-  const id = leftItem.id
-  // create rightItem
-  const rightItem = leftItem.copy(
-    createID(id.client, id.clock + diff),
-    leftItem,
-    createID(id.client, id.clock + diff - 1),
-    leftItem.right,
-    leftItem.rightOrigin,
-    leftItem.parent,
-    leftItem.parentSub
-  )
-  if (leftItem.deleted) {
-    rightItem.deleted = true
-  }
-  // update left (do not set leftItem.rightOrigin as it will lead to problems when syncing)
-  leftItem.right = rightItem
-  // update right
-  if (rightItem.right !== null) {
-    rightItem.right.left = rightItem
-  }
-  // right is more specific.
-  transaction._mergeStructs.add(rightItem.id)
-  return rightItem
-}
-
-/**
- * Abstract class that represents any content.
- */
-export class AbstractItem extends AbstractStruct {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub) {
-    super(id)
-    /**
-     * The item that was originally to the left of this item.
-     * @type {ID | null}
-     * @readonly
-     */
-    this.origin = origin
-    /**
-     * The item that is currently to the left of this item.
-     * @type {AbstractItem | null}
-     */
-    this.left = left
-    /**
-     * The item that is currently to the right of this item.
-     * @type {AbstractItem | null}
-     */
-    this.right = right
-    /**
-     * The item that was originally to the right of this item.
-     * @readonly
-     * @type {ID | null}
-     */
-    this.rightOrigin = rightOrigin
-    /**
-     * The parent type.
-     * @type {AbstractType<any>}
-     * @readonly
-     */
-    this.parent = parent
-    /**
-     * If the parent refers to this item with some kind of key (e.g. YMap, the
-     * key is specified here. The key is then used to refer to the list in which
-     * to insert this item. If `parentSub = null` type._start is the list in
-     * which to insert to. Otherwise it is `parent._map`.
-     * @type {String | null}
-     * @readonly
-     */
-    this.parentSub = parentSub
-    /**
-     * 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 {AbstractItem | null}
-     */
-    this.redone = null
-  }
-
-  /**
-   * @param {Transaction} transaction
-   * @private
-   */
-  integrate (transaction) {
-    const store = transaction.y.store
-    const id = this.id
-    const parent = this.parent
-    const parentSub = this.parentSub
-    const length = this.length
-    /**
-     * @type {AbstractItem|null}
-     */
-    let o
-    // set o to the first conflicting item
-    if (this.left !== null) {
-      o = this.left.right
-    } else if (parentSub !== null) {
-      o = parent._map.get(parentSub) || null
-      while (o !== null && o.left !== null) {
-        o = o.left
-      }
-    } else {
-      o = parent._start
-    }
-    // TODO: use something like DeleteSet here (a tree implementation would be best)
-    /**
-     * @type {Set<AbstractItem>}
-     */
-    const conflictingItems = new Set()
-    /**
-     * @type {Set<AbstractItem>}
-     */
-    const itemsBeforeOrigin = new Set()
-    // Let c in conflictingItems, b in itemsBeforeOrigin
-    // ***{origin}bbbb{this}{c,b}{c,b}{o}***
-    // Note that conflictingItems is a subset of itemsBeforeOrigin
-    while (o !== null && o !== this.right) {
-      itemsBeforeOrigin.add(o)
-      conflictingItems.add(o)
-      if (compareIDs(this.origin, o.origin)) {
-        // case 1
-        if (o.id.client < id.client) {
-          this.left = o
-          conflictingItems.clear()
-        }
-      } else if (o.origin !== null && itemsBeforeOrigin.has(getItem(store, o.origin))) {
-        // case 2
-        if (o.origin === null || !conflictingItems.has(getItem(store, o.origin))) {
-          this.left = o
-          conflictingItems.clear()
-        }
-      } else {
-        break
-      }
-      o = o.right
-    }
-    // reconnect left/right + update parent map/start if necessary
-    if (this.left !== null) {
-      const right = this.left.right
-      this.right = right
-      this.left.right = this
-    } else {
-      let r
-      if (parentSub !== null) {
-        r = parent._map.get(parentSub) || null
-        while (r !== null && r.left !== null) {
-          r = r.left
-        }
-      } else {
-        r = parent._start
-        parent._start = this
-      }
-      this.right = r
-    }
-    if (this.right !== null) {
-      this.right.left = this
-    } else if (parentSub !== null) {
-      // set as current parent value if right === null and this is parentSub
-      parent._map.set(parentSub, this)
-      if (this.left !== null) {
-        // this is the current attribute value of parent. delete right
-        this.left.delete(transaction)
-      }
-    }
-    // adjust length of parent
-    if (parentSub === null && this.countable && !this.deleted) {
-      parent._length += length
-    }
-    addStruct(store, this)
-    maplib.setIfUndefined(transaction.changed, parent, set.create).add(parentSub)
-    // @ts-ignore
-    if ((parent._item !== null && parent._item.deleted) || (this.right !== null && parentSub !== null)) {
-      // delete if parent is deleted or if this is not the current attribute value of parent
-      this.delete(transaction)
-    }
-  }
-
-  /**
-   * Returns the next non-deleted item
-   * @private
-   */
-  get next () {
-    let n = this.right
-    while (n !== null && n.deleted) {
-      n = n.right
-    }
-    return n
-  }
-
-  /**
-   * Returns the previous non-deleted item
-   * @private
-   */
-  get prev () {
-    let n = this.left
-    while (n !== null && n.deleted) {
-      n = n.left
-    }
-    return n
-  }
-
-  /**
-   * Creates an Item with the same effect as this Item (without position effect)
-   *
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @return {AbstractItem}
-   *
-   * @private
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    throw new Error('unimplemented')
-  }
-
-  /**
-   * Redoes the effect of this operation.
-   *
-   * @param {Transaction} transaction The Yjs instance.
-   * @param {Set<AbstractItem>} redoitems
-   *
-   * @private
-   */
-  redo (transaction, redoitems) {
-    if (this.redone !== null) {
-      return this.redone
-    }
-    /**
-     * @type {any}
-     */
-    let parent = this.parent
-    if (parent === null) {
-      return
-    }
-    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 as current value
-      left = parent.type._map.get(this.parentSub)
-      right = null
-    }
-    // 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(transaction, redoitems)) {
-        return false
-      }
-    }
-    if (parent.redone !== null) {
-      while (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
-      }
-    }
-    this.redone = this.copy(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, this.parentSub)
-    this.redone.integrate(transaction)
-    return true
-  }
-
-  /**
-   * Computes the last content address of this Item.
-   */
-  get lastId () {
-    return createID(this.id.client, this.id.clock + this.length - 1)
-  }
-
-  /**
-   * Computes the length of this Item.
-   */
-  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
-   */
-  get countable () {
-    return true
-  }
-
-  /**
-   * Do not call directly. Always split via StructStore!
-   *
-   * Splits this Item so that another Item can be inserted in-between.
-   * This must be overwritten if _length > 1
-   * Returns right part after split
-   *
-   * (see {@link ItemJSON}/{@link ItemString} for implementation)
-   *
-   * Does not integrate the struct, nor store it in struct store.
-   *
-   * This method should only be cally by StructStore.
-   *
-   * @param {Transaction} transaction
-   * @param {number} diff
-   * @return {AbstractItem}
-   *
-   * @private
-   */
-  splitAt (transaction, diff) {
-    throw new Error('unimplemented')
-  }
-
-  /**
-   * @param {AbstractItem} right
-   * @return {boolean}
-   *
-   * @private
-   */
-  mergeWith (right) {
-    if (compareIDs(right.origin, this.lastId) && this.right === right && compareIDs(this.rightOrigin, right.rightOrigin)) {
-      this.right = right.right
-      if (this.right !== null) {
-        this.right.left = this
-      }
-      return true
-    }
-    return false
-  }
-  /**
-   * Mark this Item as deleted.
-   *
-   * @param {Transaction} transaction
-   */
-  delete (transaction) {
-    if (!this.deleted) {
-      const parent = this.parent
-      // adjust the length of parent
-      if (this.countable && this.parentSub === null) {
-        parent._length -= this.length
-      }
-      this.deleted = true
-      addToDeleteSet(transaction.deleteSet, this.id, this.length)
-      maplib.setIfUndefined(transaction.changed, parent, set.create).add(this.parentSub)
-    }
-  }
-
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   *
-   * @private
-   */
-  gcChildren (transaction, store) { }
-
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   *
-   * @private
-   */
-  gc (transaction, store) {
-    let r
-    if (this.parent._item !== null && this.parent._item.deleted) {
-      r = new GC(this.id, this.length)
-    } else {
-      r = new ItemDeleted(this.id, this.left, this.origin, this.right, this.rightOrigin, this.parent, this.parentSub, this.length)
-      if (r.right !== null) {
-        r.right.left = r
-      } else if (r.parentSub !== null) {
-        r.parent._map.set(r.parentSub, r)
-      }
-      if (r.left !== null) {
-        r.left.right = r
-      } else if (r.parentSub === null) {
-        r.parent._start = r
-      }
-    }
-    replaceStruct(store, this, r)
-    transaction._mergeStructs.add(r.id)
-  }
-
-  /**
-   * @return {Array<any>}
-   */
-  getContent () {
-    throw error.methodUnimplemented()
-  }
-
-  /**
-   * 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.
-   * @param {number} offset
-   * @param {number} encodingRef
-   *
-   * @private
-   */
-  write (encoder, offset, encodingRef) {
-    const origin = offset > 0 ? createID(this.id.client, this.id.clock + offset - 1) : this.origin
-    const rightOrigin = this.rightOrigin
-    const parentSub = this.parentSub
-    const info = (encodingRef & binary.BITS5) |
-      (origin === null ? 0 : binary.BIT8) | // origin is defined
-      (rightOrigin === null ? 0 : binary.BIT7) | // right origin is defined
-      (parentSub === null ? 0 : binary.BIT6) // parentSub is non-null
-    encoding.writeUint8(encoder, info)
-    if (origin !== null) {
-      writeID(encoder, origin)
-    }
-    if (rightOrigin !== null) {
-      writeID(encoder, rightOrigin)
-    }
-    if (origin === null && rightOrigin === null) {
-      const parent = this.parent
-      if (parent._item === null) {
-        // parent type on y._map
-        // find the correct key
-        // @ts-ignore we know that y exists
-        const ykey = findRootTypeKey(parent)
-        encoding.writeVarUint(encoder, 1) // write parentYKey
-        encoding.writeVarString(encoder, ykey)
-      } else {
-        encoding.writeVarUint(encoder, 0) // write parent id
-        // @ts-ignore _item is defined because parent is integrated
-        writeID(encoder, parent._item.id)
-      }
-      if (parentSub !== null) {
-        encoding.writeVarString(encoder, parentSub)
-      }
-    }
-  }
-}
-
-/**
- * @private
- */
-export class AbstractItemRef extends AbstractStructRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(id)
-    /**
-     * The item that was originally to the left of this item.
-     * @type {ID | null}
-     */
-    this.left = (info & binary.BIT8) === binary.BIT8 ? readID(decoder) : null
-    /**
-     * The item that was originally to the right of this item.
-     * @type {ID | null}
-     */
-    this.right = (info & binary.BIT7) === binary.BIT7 ? readID(decoder) : null
-    const canCopyParentInfo = (info & (binary.BIT7 | binary.BIT8)) === 0
-    const hasParentYKey = canCopyParentInfo ? decoding.readVarUint(decoder) === 1 : false
-    /**
-     * If parent = null and neither left nor right are defined, then we know that `parent` is child of `y`
-     * and we read the next string as parentYKey.
-     * It indicates how we store/retrieve parent from `y.share`
-     * @type {string|null}
-     */
-    this.parentYKey = canCopyParentInfo && hasParentYKey ? decoding.readVarString(decoder) : null
-    /**
-     * The parent type.
-     * @type {ID | null}
-     */
-    this.parent = canCopyParentInfo && !hasParentYKey ? readID(decoder) : 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 | null}
-     */
-    this.parentSub = canCopyParentInfo && (info & binary.BIT6) === binary.BIT6 ? decoding.readVarString(decoder) : null
-    const missing = this._missing
-    if (this.left !== null) {
-      missing.push(this.left)
-    }
-    if (this.right !== null) {
-      missing.push(this.right)
-    }
-    if (this.parent !== null) {
-      missing.push(this.parent)
-    }
-  }
-}
-
-/**
- * @param {AbstractItemRef} item
- * @param {number} offset
- *
- * @function
- * @private
- */
-export const changeItemRefOffset = (item, offset) => {
-  item.id = createID(item.id.client, item.id.clock + offset)
-  item.left = createID(item.id.client, item.id.clock - 1)
-}
-
-export class ItemParams {
-  /**
-   * @param {AbstractItem?} left
-   * @param {AbstractItem?} right
-   * @param {AbstractType<YEvent>?} parent
-   * @param {string|null} parentSub
-   */
-  constructor (left, right, parent, parentSub) {
-    this.left = left
-    this.right = right
-    this.parent = parent
-    this.parentSub = parentSub
-  }
-}
-
-/**
- * Outsourcing some of the logic of computing the item params from a received struct.
- * If parent === null, it is expected to gc the read struct. Otherwise apply it.
- *
- * @param {Transaction} transaction
- * @param {StructStore} store
- * @param {ID|null} leftid
- * @param {ID|null} rightid
- * @param {ID|null} parentid
- * @param {string|null} parentSub
- * @param {string|null} parentYKey
- * @return {ItemParams}
- *
- * @private
- * @function
- */
-export const computeItemParams = (transaction, store, leftid, rightid, parentid, parentSub, parentYKey) => {
-  const left = leftid === null ? null : getItemCleanEnd(transaction, store, leftid)
-  const right = rightid === null ? null : getItemCleanStart(transaction, store, rightid)
-  let parent = null
-  if (parentid !== null) {
-    const parentItem = getItemType(store, parentid)
-    switch (parentItem.constructor) {
-      case ItemDeleted:
-      case GC:
-        break
-      default:
-        parent = parentItem.type
-    }
-  } else if (parentYKey !== null) {
-    parent = transaction.y.get(parentYKey)
-  } else if (left !== null) {
-    if (left.constructor !== GC) {
-      parent = left.parent
-      parentSub = left.parentSub
-    }
-  } else if (right !== null) {
-    if (right.constructor !== GC) {
-      parent = right.parent
-      parentSub = right.parentSub
-    }
-  } else {
-    throw error.unexpectedCase()
-  }
-  return new ItemParams(left, right, parent, parentSub)
-}
--- a/src/structs/AbstractStruct.js
+++ b/src/structs/AbstractStruct.js
@@ -1,98 +0,0 @@
-
-import {
-  Y, StructStore, ID, Transaction // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js' // eslint-disable-line
-import * as error from 'lib0/error.js'
-
-/**
- * @private
- */
-export class AbstractStruct {
-  /**
-   * @param {ID} id
-   */
-  constructor (id) {
-    /**
-     * The uniqe identifier of this struct.
-     * @type {ID}
-     * @readonly
-     */
-    this.id = id
-    this.deleted = false
-  }
-  /**
-   * Merge this struct with the item to the right.
-   * This method is already assuming that `this.id.clock + this.length === this.id.clock`.
-   * Also this method does *not* remove right from StructStore!
-   * @param {AbstractStruct} right
-   * @return {boolean} wether this merged with right
-   */
-  mergeWith (right) {
-    return false
-  }
-  /**
-   * @type {number}
-   */
-  get length () {
-    throw error.methodUnimplemented()
-  }
-  /**
-   * @param {encoding.Encoder} encoder The encoder to write data to.
-   * @param {number} offset
-   * @param {number} encodingRef
-   * @private
-   */
-  write (encoder, offset, encodingRef) {
-    throw error.methodUnimplemented()
-  }
-  /**
-   * @param {Transaction} transaction
-   */
-  integrate (transaction) {
-    throw error.methodUnimplemented()
-  }
-}
-
-/**
- * @private
- */
-export class AbstractStructRef {
-  /**
-   * @param {ID} id
-   */
-  constructor (id) {
-    /**
-     * @type {Array<ID>}
-     */
-    this._missing = []
-    /**
-     * The uniqe identifier of this type.
-     * @type {ID}
-     */
-    this.id = id
-  }
-  /**
-   * @param {Transaction} transaction
-   * @return {Array<ID|null>}
-   */
-  getMissing (transaction) {
-    return this._missing
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {AbstractStruct}
-   */
-  toStruct (transaction, store, offset) {
-    throw error.methodUnimplemented()
-  }
-  /**
-   * @type {number}
-   */
-  get length () {
-    return 1
-  }
-}
--- a/src/structs/GC.js
+++ b/src/structs/GC.js
@@ -1,105 +0,0 @@
-
-import {
-  AbstractStructRef,
-  AbstractStruct,
-  createID,
-  addStruct,
-  Y, StructStore, Transaction, ID // eslint-disable-line
-} from '../internals.js'
-
-import * as decoding from 'lib0/decoding.js'
-import * as encoding from 'lib0/encoding.js'
-
-export const structGCRefNumber = 0
-
-/**
- * @private
- */
-export class GC extends AbstractStruct {
-  /**
-   * @param {ID} id
-   * @param {number} length
-   */
-  constructor (id, length) {
-    super(id)
-    /**
-     * @type {number}
-     */
-    this._len = length
-    this.deleted = true
-  }
-
-  get length () {
-    return this._len
-  }
-
-  delete () {}
-
-  /**
-   * @param {AbstractStruct} right
-   * @return {boolean}
-   */
-  mergeWith (right) {
-    this._len += right.length
-    return true
-  }
-
-  /**
-   * @param {Transaction} transaction
-   */
-  integrate (transaction) {
-    addStruct(transaction.y.store, this)
-  }
-
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    encoding.writeUint8(encoder, structGCRefNumber)
-    encoding.writeVarUint(encoder, this._len - offset)
-  }
-}
-
-/**
- * @private
- */
-export class GCRef extends AbstractStructRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(id)
-    /**
-     * @type {number}
-     */
-    this._len = decoding.readVarUint(decoder)
-  }
-  get length () {
-    return this._len
-  }
-  missing () {
-    return [
-      createID(this.id.client, this.id.clock - 1)
-    ]
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {GC}
-   */
-  toStruct (transaction, store, offset) {
-    if (offset > 0) {
-      // @ts-ignore
-      this.id = createID(this.id.client, this.id.clock + offset)
-      this._len = this._len - offset
-    }
-    return new GC(
-      this.id,
-      this._len
-    )
-  }
-}
--- a/src/structs/ItemBinary.js
+++ b/src/structs/ItemBinary.js
@@ -1,98 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  GC,
-  StructStore, Transaction, AbstractType, ID // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structBinaryRefNumber = 1
-
-/**
- * @private
- */
-export class ItemBinary extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {ArrayBuffer} content
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    this.content = content
-  }
-  getContent () {
-    return [this.content]
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemBinary(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structBinaryRefNumber)
-    encoding.writePayload(encoder, this.content)
-  }
-}
-
-/**
- * @private
- */
-export class ItemBinaryRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    /**
-     * @type {ArrayBuffer}
-     */
-    this.content = decoding.readPayload(decoder)
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemBinary|GC}
-   */
-  toStruct (transaction, store, offset) {
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemBinary(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.content
-      )
-  }
-}
--- a/src/structs/ItemDeleted.js
+++ b/src/structs/ItemDeleted.js
@@ -1,142 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  changeItemRefOffset,
-  GC,
-  splitItem,
-  addToDeleteSet,
-  Y, StructStore, Transaction, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structDeletedRefNumber = 2
-
-/**
- * @private
- */
-export class ItemDeleted extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {number} length
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, length) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    this._len = length
-    this.deleted = true
-  }
-  get length () {
-    return this._len
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemDeleted(id, left, origin, right, rightOrigin, parent, parentSub, this.length)
-  }
-  /**
-   * @param {Transaction} transaction
-   */
-  integrate (transaction) {
-    super.integrate(transaction)
-    addToDeleteSet(transaction.deleteSet, this.id, this.length)
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {number} diff
-   */
-  splitAt (transaction, diff) {
-    /**
-     * @type {ItemDeleted}
-     */
-    // @ts-ignore
-    const right = splitItem(transaction, this, diff)
-    right._len -= diff
-    this._len = diff
-    return right
-  }
-  /**
-   * @param {ItemDeleted} right
-   * @return {boolean}
-   */
-  mergeWith (right) {
-    if (super.mergeWith(right)) {
-      this._len += right._len
-      return true
-    }
-    return false
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structDeletedRefNumber)
-    encoding.writeVarUint(encoder, this.length - offset)
-  }
-}
-
-/**
- * @private
- */
-export class ItemDeletedRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    /**
-     * @type {number}
-     */
-    this.len = decoding.readVarUint(decoder)
-  }
-  get length () {
-    return this.len
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemDeleted|GC}
-   */
-  toStruct (transaction, store, offset) {
-    if (offset > 0) {
-      changeItemRefOffset(this, offset)
-      this.len = this.len - offset
-    }
-
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemDeleted(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.len
-      )
-  }
-}
--- a/src/structs/ItemEmbed.js
+++ b/src/structs/ItemEmbed.js
@@ -1,95 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  GC,
-  Transaction, StructStore, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structEmbedRefNumber = 3
-
-/**
- * @private
- */
-export class ItemEmbed extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {Object} embed
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, embed) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    this.embed = embed
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemEmbed(id, left, origin, right, rightOrigin, parent, parentSub, this.embed)
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structEmbedRefNumber)
-    encoding.writeVarString(encoder, JSON.stringify(this.embed))
-  }
-}
-
-/**
- * @private
- */
-export class ItemEmbedRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    /**
-     * @type {ArrayBuffer}
-     */
-    this.embed = JSON.parse(decoding.readVarString(decoder))
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemEmbed|GC}
-   */
-  toStruct (transaction, store, offset) {
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemEmbed(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.embed
-      )
-  }
-}
--- a/src/structs/ItemFormat.js
+++ b/src/structs/ItemFormat.js
@@ -1,103 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  GC,
-  Transaction, StructStore, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structFormatRefNumber = 4
-
-/**
- * @private
- */
-export class ItemFormat extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {string} key
-   * @param {any} value
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, key, value) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    this.key = key
-    this.value = value
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemFormat(id, left, origin, right, rightOrigin, parent, parentSub, this.key, this.value)
-  }
-  get countable () {
-    return false
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structFormatRefNumber)
-    encoding.writeVarString(encoder, this.key)
-    encoding.writeVarString(encoder, JSON.stringify(this.value))
-  }
-}
-
-/**
- * @private
- */
-export class ItemFormatRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    /**
-     * @type {string}
-     */
-    this.key = decoding.readVarString(decoder)
-    this.value = JSON.parse(decoding.readVarString(decoder))
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemFormat|GC}
-   */
-  toStruct (transaction, store, offset) {
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemFormat(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.key,
-        this.value
-      )
-  }
-}
--- a/src/structs/ItemJSON.js
+++ b/src/structs/ItemJSON.js
@@ -1,152 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  splitItem,
-  changeItemRefOffset,
-  GC,
-  Transaction, StructStore, Y, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structJSONRefNumber = 5
-
-/**
- * @private
- */
-export class ItemJSON extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {Array<any>} content
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    /**
-     * @type {Array<any>}
-     */
-    this.content = content
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemJSON(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
-  }
-  get length () {
-    return this.content.length
-  }
-  getContent () {
-    return this.content
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {number} diff
-   */
-  splitAt (transaction, diff) {
-    /**
-     * @type {ItemJSON}
-     */
-    // @ts-ignore
-    const right = splitItem(transaction, this, diff)
-    right.content = this.content.splice(diff)
-    return right
-  }
-  /**
-   * @param {ItemJSON} right
-   * @return {boolean}
-   */
-  mergeWith (right) {
-    if (super.mergeWith(right)) {
-      this.content = this.content.concat(right.content)
-      return true
-    }
-    return false
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structJSONRefNumber)
-    const len = this.content.length
-    encoding.writeVarUint(encoder, len - offset)
-    for (let i = offset; i < len; i++) {
-      const c = this.content[i]
-      encoding.writeVarString(encoder, c === undefined ? 'undefined' : JSON.stringify(c))
-    }
-  }
-}
-
-/**
- * @private
- */
-export class ItemJSONRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    const len = decoding.readVarUint(decoder)
-    const cs = []
-    for (let i = 0; i < len; i++) {
-      const c = decoding.readVarString(decoder)
-      if (c === 'undefined') {
-        cs.push(undefined)
-      } else {
-        cs.push(JSON.parse(c))
-      }
-    }
-    /**
-     * @type {Array<any>}
-     */
-    this.content = cs
-  }
-  get length () {
-    return this.content.length
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemJSON|GC}
-   */
-  toStruct (transaction, store, offset) {
-    if (offset > 0) {
-      changeItemRefOffset(this, offset)
-      this.content = this.content.slice(offset)
-    }
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemJSON(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.content
-      )
-  }
-}
--- a/src/structs/ItemString.js
+++ b/src/structs/ItemString.js
@@ -1,137 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  splitItem,
-  changeItemRefOffset,
-  GC,
-  Transaction, StructStore, Y, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-export const structStringRefNumber = 6
-
-/**
- * @private
- */
-export class ItemString extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {string} string
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, string) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    /**
-     * @type {string}
-     */
-    this.string = string
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemString(id, left, origin, right, rightOrigin, parent, parentSub, this.string)
-  }
-  getContent () {
-    return this.string.split('')
-  }
-  get length () {
-    return this.string.length
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {number} diff
-   * @return {ItemString}
-   */
-  splitAt (transaction, diff) {
-    /**
-     * @type {ItemString}
-     */
-    // @ts-ignore
-    const right = splitItem(transaction, this, diff)
-    right.string = this.string.slice(diff)
-    this.string = this.string.slice(0, diff)
-    return right
-  }
-  /**
-   * @param {ItemString} right
-   * @return {boolean}
-   */
-  mergeWith (right) {
-    if (super.mergeWith(right)) {
-      this.string += right.string
-      return true
-    }
-    return false
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structStringRefNumber)
-    encoding.writeVarString(encoder, offset === 0 ? this.string : this.string.slice(offset))
-  }
-}
-
-/**
- * @private
- */
-export class ItemStringRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    /**
-     * @type {string}
-     */
-    this.string = decoding.readVarString(decoder)
-  }
-  get length () {
-    return this.string.length
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemString|GC}
-   */
-  toStruct (transaction, store, offset) {
-    if (offset > 0) {
-      changeItemRefOffset(this, offset)
-      this.string = this.string.slice(offset)
-    }
-
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemString(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.string
-      )
-  }
-}
--- a/src/structs/ItemType.js
+++ b/src/structs/ItemType.js
@@ -1,178 +0,0 @@
-
-import {
-  AbstractItem,
-  AbstractItemRef,
-  computeItemParams,
-  readYArray,
-  readYMap,
-  readYText,
-  readYXmlElement,
-  readYXmlFragment,
-  readYXmlHook,
-  readYXmlText,
-  StructStore, Y, GC, Transaction, ID, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js' // eslint-disable-line
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-export const structTypeRefNumber = 7
-
-/**
- * @type {Array<function(decoding.Decoder):AbstractType<any>>}
- * @private
- */
-export const typeRefs = [
-  readYArray,
-  readYMap,
-  readYText,
-  readYXmlElement,
-  readYXmlFragment,
-  readYXmlHook,
-  readYXmlText
-]
-
-export const YArrayRefID = 0
-export const YMapRefID = 1
-export const YTextRefID = 2
-export const YXmlElementRefID = 3
-export const YXmlFragmentRefID = 4
-export const YXmlHookRefID = 5
-export const YXmlTextRefID = 6
-
-/**
- * @private
- */
-export class ItemType extends AbstractItem {
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @param {AbstractType<any>} type
-   */
-  constructor (id, left, origin, right, rightOrigin, parent, parentSub, type) {
-    super(id, left, origin, right, rightOrigin, parent, parentSub)
-    this.type = type
-  }
-
-  getContent () {
-    return [this.type]
-  }
-  /**
-   * @param {ID} id
-   * @param {AbstractItem | null} left
-   * @param {ID | null} origin
-   * @param {AbstractItem | null} right
-   * @param {ID | null} rightOrigin
-   * @param {AbstractType<any>} parent
-   * @param {string | null} parentSub
-   * @return {ItemType}
-   */
-  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
-    return new ItemType(id, left, origin, right, rightOrigin, parent, parentSub, this.type._copy())
-  }
-  /**
-   * @param {Transaction} transaction
-   */
-  integrate (transaction) {
-    super.integrate(transaction)
-    this.type._integrate(transaction.y, this)
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   * @param {number} offset
-   */
-  write (encoder, offset) {
-    super.write(encoder, offset, structTypeRefNumber)
-    this.type._write(encoder)
-  }
-  /**
-   * Mark this Item as deleted.
-   *
-   * @param {Transaction} transaction The Yjs instance
-   * @private
-   */
-  delete (transaction) {
-    super.delete(transaction)
-    transaction.changed.delete(this.type)
-    transaction.changedParentTypes.delete(this.type)
-    this.gcChildren(transaction, transaction.y.store)
-  }
-
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   */
-  gcChildren (transaction, store) {
-    let item = this.type._start
-    while (item !== null) {
-      item.gc(transaction, store)
-      item = item.right
-    }
-    this.type._start = null
-    this.type._map.forEach(item => {
-      while (item !== null) {
-        item.gc(transaction, store)
-        // @ts-ignore
-        item = item.left
-      }
-    })
-    this._map = new Map()
-  }
-
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   */
-  gc (transaction, store) {
-    super.gc(transaction, store)
-    this.gcChildren(transaction, store)
-  }
-}
-
-/**
- * @private
- */
-export class ItemTypeRef extends AbstractItemRef {
-  /**
-   * @param {decoding.Decoder} decoder
-   * @param {ID} id
-   * @param {number} info
-   */
-  constructor (decoder, id, info) {
-    super(decoder, id, info)
-    const typeRef = decoding.readVarUint(decoder)
-    /**
-     * @type {AbstractType<any>}
-     */
-    this.type = typeRefs[typeRef](decoder)
-  }
-  /**
-   * @param {Transaction} transaction
-   * @param {StructStore} store
-   * @param {number} offset
-   * @return {ItemType|GC}
-   */
-  toStruct (transaction, store, offset) {
-    const { left, right, parent, parentSub } = computeItemParams(transaction, store, this.left, this.right, this.parent, this.parentSub, this.parentYKey)
-    return parent === null
-      ? new GC(this.id, this.length)
-      : new ItemType(
-        this.id,
-        left,
-        this.left,
-        right,
-        this.right,
-        parent,
-        parentSub,
-        this.type
-      )
-  }
-}
--- a/src/types/AbstractType.js
+++ b/src/types/AbstractType.js
@@ -1,580 +0,0 @@
-
-import {
-  removeEventHandlerListener,
-  callEventHandlerListeners,
-  addEventHandlerListener,
-  createEventHandler,
-  ItemType,
-  nextID,
-  isVisible,
-  ItemJSON,
-  ItemBinary,
-  createID,
-  getItemCleanStart,
-  Y, Snapshot, Transaction, EventHandler, YEvent, AbstractItem, // eslint-disable-line
-} from '../internals.js'
-
-import * as map from 'lib0/map.js'
-import * as iterator from 'lib0/iterator.js'
-import * as error from 'lib0/error.js'
-import * as encoding from 'lib0/encoding.js' // eslint-disable-line
-
-/**
- * Call event listeners with an event. This will also add an event to all
- * parents (for `.observeDeep` handlers).
- * @private
- *
- * @template EventType
- * @param {AbstractType<EventType>} type
- * @param {Transaction} transaction
- * @param {EventType} event
- */
-export const callTypeObservers = (type, transaction, event) => {
-  callEventHandlerListeners(type._eH, event, transaction)
-  const changedParentTypes = transaction.changedParentTypes
-  while (true) {
-    // @ts-ignore
-    map.setIfUndefined(changedParentTypes, type, () => []).push(event)
-    if (type._item === null) {
-      break
-    }
-    type = type._item.parent
-  }
-}
-
-/**
- * @template EventType
- * Abstract Yjs Type class
- */
-export class AbstractType {
-  constructor () {
-    /**
-     * @type {ItemType|null}
-     */
-    this._item = null
-    /**
-     * @private
-     * @type {Map<string,AbstractItem>}
-     */
-    this._map = new Map()
-    /**
-     * @private
-     * @type {AbstractItem|null}
-     */
-    this._start = null
-    /**
-     * @private
-     * @type {Y|null}
-     */
-    this._y = null
-    this._length = 0
-    /**
-     * Event handlers
-     * @type {EventHandler<EventType,Transaction>}
-     */
-    this._eH = createEventHandler()
-    /**
-     * Deep event handlers
-     * @type {EventHandler<Array<YEvent>,Transaction>}
-     */
-    this._dEH = createEventHandler()
-  }
-
-  /**
-   * Integrate this type into the Yjs instance.
-   *
-   * * Save this struct in the os
-   * * This type is sent to other client
-   * * Observer functions are fired
-   *
-   * @param {Y} y The Yjs instance
-   * @param {ItemType|null} item
-   * @private
-   */
-  _integrate (y, item) {
-    this._y = y
-    this._item = item
-  }
-
-  /**
-   * @return {AbstractType<EventType>}
-   * @private
-   */
-  _copy () {
-    throw new Error('unimplemented')
-  }
-
-  /**
-   * @param {encoding.Encoder} encoder
-   * @private
-   */
-  _write (encoder) { }
-
-  /**
-   * The first non-deleted item
-   */
-  get _first () {
-    let n = this._start
-    while (n !== null && n.deleted) {
-      n = n.right
-    }
-    return n
-  }
-
-  /**
-   * Creates YEvent and calls all type observers.
-   * Must be implemented by each type.
-   *
-   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
-   *
-   * @private
-   */
-  _callObserver (transaction, parentSubs) { /* skip if no type is specified */ }
-
-  /**
-   * Observe all events that are created on this type.
-   *
-   * @param {function(EventType, Transaction):void} f Observer function
-   */
-  observe (f) {
-    addEventHandlerListener(this._eH, f)
-  }
-
-  /**
-   * Observe all events that are created by this type and its children.
-   *
-   * @param {function(Array<YEvent>,Transaction):void} f Observer function
-   */
-  observeDeep (f) {
-    addEventHandlerListener(this._dEH, f)
-  }
-
-  /**
-   * Unregister an observer function.
-   *
-   * @param {function(EventType,Transaction):void} f Observer function
-   */
-  unobserve (f) {
-    removeEventHandlerListener(this._eH, f)
-  }
-
-  /**
-   * Unregister an observer function.
-   *
-   * @param {function(Array<YEvent>,Transaction):void} f Observer function
-   */
-  unobserveDeep (f) {
-    removeEventHandlerListener(this._dEH, f)
-  }
-
-  /**
-   * @abstract
-   * @return {Object | Array | number | string}
-   */
-  toJSON () {}
-}
-
-/**
- * @param {AbstractType<any>} type
- * @return {Array<any>}
- *
- * @private
- * @function
- */
-export const typeArrayToArray = type => {
-  const cs = []
-  let n = type._start
-  while (n !== null) {
-    if (n.countable && !n.deleted) {
-      const c = n.getContent()
-      for (let i = 0; i < c.length; i++) {
-        cs.push(c[i])
-      }
-    }
-    n = n.right
-  }
-  return cs
-}
-
-/**
- * Executes a provided function on once on overy element of this YArray.
- *
- * @param {AbstractType<any>} type
- * @param {function(any,number,AbstractType<any>):void} f A function to execute on every element of this YArray.
- *
- * @private
- * @function
- */
-export const typeArrayForEach = (type, f) => {
-  let index = 0
-  let n = type._start
-  while (n !== null) {
-    if (n.countable && !n.deleted) {
-      const c = n.getContent()
-      for (let i = 0; i < c.length; i++) {
-        f(c[i], index++, type)
-      }
-    }
-    n = n.right
-  }
-}
-
-/**
- * @template C,R
- * @param {AbstractType<any>} type
- * @param {function(C,number,AbstractType<any>):R} f
- * @return {Array<R>}
- *
- * @private
- * @function
- */
-export const typeArrayMap = (type, f) => {
-  /**
-   * @type {Array<any>}
-   */
-  const result = []
-  typeArrayForEach(type, (c, i) => {
-    result.push(f(c, i, type))
-  })
-  return result
-}
-
-/**
- * @param {AbstractType<any>} type
- * @return {IterableIterator<any>}
- *
- * @private
- * @function
- */
-export const typeArrayCreateIterator = type => {
-  let n = type._start
-  /**
-   * @type {Array<any>|null}
-   */
-  let currentContent = null
-  let currentContentIndex = 0
-  return {
-    [Symbol.iterator] () {
-      return this
-    },
-    next: () => {
-      // find some content
-      if (currentContent === null) {
-        while (n !== null && n.deleted) {
-          n = n.right
-        }
-      }
-      // check if we reached the end, no need to check currentContent, because it does not exist
-      if (n === null) {
-        return {
-          done: true,
-          value: undefined
-        }
-      }
-      // currentContent could exist from the last iteration
-      if (currentContent === null) {
-        // we found n, so we can set currentContent
-        currentContent = n.getContent()
-        currentContentIndex = 0
-        n = n.right // we used the content of n, now iterate to next
-      }
-      const value = currentContent[currentContentIndex++]
-      // check if we need to empty currentContent
-      if (currentContent.length <= currentContentIndex) {
-        currentContent = null
-      }
-      return {
-        done: false,
-        value
-      }
-    }
-  }
-}
-
-/**
- * Executes a provided function on once on overy element of this YArray.
- * Operates on a snapshotted state of the document.
- *
- * @param {AbstractType<any>} type
- * @param {function(any,number,AbstractType<any>):void} f A function to execute on every element of this YArray.
- * @param {Snapshot} snapshot
- *
- * @private
- * @function
- */
-export const typeArrayForEachSnapshot = (type, f, snapshot) => {
-  let index = 0
-  let n = type._start
-  while (n !== null) {
-    if (n.countable && isVisible(n, snapshot)) {
-      const c = n.getContent()
-      for (let i = 0; i < c.length; i++) {
-        f(c[i], index++, type)
-      }
-    }
-    n = n.right
-  }
-}
-
-/**
- * @param {AbstractType<any>} type
- * @param {number} index
- * @return {any}
- *
- * @private
- * @function
- */
-export const typeArrayGet = (type, index) => {
-  for (let n = type._start; n !== null; n = n.right) {
-    if (!n.deleted && n.countable) {
-      if (index < n.length) {
-        return n.getContent()[index]
-      }
-      index -= n.length
-    }
-  }
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {AbstractItem?} referenceItem
- * @param {Array<Object<string,any>|Array<any>|number|string|ArrayBuffer>} content
- *
- * @private
- * @function
- */
-export const typeArrayInsertGenericsAfter = (transaction, parent, referenceItem, content) => {
-  let left = referenceItem
-  const right = referenceItem === null ? parent._start : referenceItem.right
-  /**
-   * @type {Array<Object|Array|number>}
-   */
-  let jsonContent = []
-  const packJsonContent = () => {
-    if (jsonContent.length > 0) {
-      left = new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, jsonContent)
-      left.integrate(transaction)
-      jsonContent = []
-    }
-  }
-  content.forEach(c => {
-    switch (c.constructor) {
-      case Number:
-      case Object:
-      case Array:
-      case String:
-        jsonContent.push(c)
-        break
-      default:
-        packJsonContent()
-        switch (c.constructor) {
-          case ArrayBuffer:
-            // @ts-ignore c is definitely an ArrayBuffer
-            left = new ItemBinary(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c)
-            // @ts-ignore
-            left.integrate(transaction)
-            break
-          default:
-            if (c instanceof AbstractType) {
-              left = new ItemType(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c)
-              left.integrate(transaction)
-            } else {
-              throw new Error('Unexpected content type in insert operation')
-            }
-        }
-    }
-  })
-  packJsonContent()
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {number} index
- * @param {Array<Object<string,any>|Array<any>|number|string|ArrayBuffer>} content
- *
- * @private
- * @function
- */
-export const typeArrayInsertGenerics = (transaction, parent, index, content) => {
-  if (index === 0) {
-    return typeArrayInsertGenericsAfter(transaction, parent, null, content)
-  }
-  let n = parent._start
-  for (; n !== null; n = n.right) {
-    if (!n.deleted && n.countable) {
-      if (index <= n.length) {
-        if (index < n.length) {
-          // insert in-between
-          getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + index))
-        }
-        break
-      }
-      index -= n.length
-    }
-  }
-  return typeArrayInsertGenericsAfter(transaction, parent, n, content)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {number} index
- * @param {number} length
- *
- * @private
- * @function
- */
-export const typeArrayDelete = (transaction, parent, index, length) => {
-  if (length === 0) { return }
-  let n = parent._start
-  // compute the first item to be deleted
-  for (; n !== null; n = n.right) {
-    if (!n.deleted && n.countable) {
-      if (index <= n.length) {
-        if (index < n.length && index > 0) {
-          n = getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + index))
-        }
-        break
-      }
-      index -= n.length
-    }
-  }
-  // delete all items until done
-  while (length > 0 && n !== null) {
-    if (!n.deleted) {
-      if (length < n.length) {
-        getItemCleanStart(transaction, transaction.y.store, createID(n.id.client, n.id.clock + length))
-      }
-      n.delete(transaction)
-      length -= n.length
-    }
-    n = n.right
-  }
-  if (length > 0) {
-    throw error.create('array length exceeded')
-  }
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {string} key
- *
- * @private
- * @function
- */
-export const typeMapDelete = (transaction, parent, key) => {
-  const c = parent._map.get(key)
-  if (c !== undefined) {
-    c.delete(transaction)
-  }
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {string} key
- * @param {Object|number|Array<any>|string|ArrayBuffer|AbstractType<any>} value
- *
- * @private
- * @function
- */
-export const typeMapSet = (transaction, parent, key, value) => {
-  const left = parent._map.get(key) || null
-  if (value == null) {
-    new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, [value]).integrate(transaction)
-    return
-  }
-  switch (value.constructor) {
-    case Number:
-    case Object:
-    case Array:
-    case String:
-      new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, [value]).integrate(transaction)
-      break
-    case ArrayBuffer:
-      new ItemBinary(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, value).integrate(transaction)
-      break
-    default:
-      if (value instanceof AbstractType) {
-        new ItemType(nextID(transaction), left, left === null ? null : left.lastId, null, null, parent, key, value).integrate(transaction)
-      } else {
-        throw new Error('Unexpected content type')
-      }
-  }
-}
-
-/**
- * @param {AbstractType<any>} parent
- * @param {string} key
- * @return {Object<string,any>|number|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined}
- *
- * @private
- * @function
- */
-export const typeMapGet = (parent, key) => {
-  const val = parent._map.get(key)
-  return val !== undefined && !val.deleted ? val.getContent()[0] : undefined
-}
-
-/**
- * @param {AbstractType<any>} parent
- * @return {Object<string,Object<string,any>|number|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined>}
- *
- * @private
- * @function
- */
-export const typeMapGetAll = (parent) => {
-  /**
-   * @type {Object<string,any>}
-   */
-  let res = {}
-  for (const [key, value] of parent._map) {
-    if (!value.deleted) {
-      res[key] = value.getContent()[value.length - 1]
-    }
-  }
-  return res
-}
-
-/**
- * @param {AbstractType<any>} parent
- * @param {string} key
- * @return {boolean}
- *
- * @private
- * @function
- */
-export const typeMapHas = (parent, key) => {
-  const val = parent._map.get(key)
-  return val !== undefined && !val.deleted
-}
-
-/**
- * @param {AbstractType<any>} parent
- * @param {string} key
- * @param {Snapshot} snapshot
- * @return {Object<string,any>|number|Array<any>|string|ArrayBuffer|AbstractType<any>|undefined}
- *
- * @private
- * @function
- */
-export const typeMapGetSnapshot = (parent, key, snapshot) => {
-  let v = parent._map.get(key) || null
-  while (v !== null && (!snapshot.sm.has(v.id.client) || v.id.clock >= (snapshot.sm.get(v.id.client) || 0))) {
-    v = v.left
-  }
-  return v !== null && isVisible(v, snapshot) ? v.getContent()[v.length - 1] : undefined
-}
-
-/**
- * @param {Map<string,AbstractItem>} map
- * @return {IterableIterator<Array<any>>}
- *
- * @private
- * @function
- */
-export const createMapIterator = map => iterator.iteratorFilter(map.entries(), entry => !entry[1].deleted)
--- a/src/types/YArray.js
+++ b/src/types/YArray.js
@@ -1,213 +0,0 @@
-/**
- * @module YArray
- */
-
-import {
-  YEvent,
-  AbstractType,
-  typeArrayGet,
-  typeArrayToArray,
-  typeArrayForEach,
-  typeArrayCreateIterator,
-  typeArrayInsertGenerics,
-  typeArrayDelete,
-  typeArrayMap,
-  YArrayRefID,
-  callTypeObservers,
-  transact,
-  Y, Transaction, ItemType, // eslint-disable-line
-} from '../internals.js'
-
-import * as decoding from 'lib0/decoding.js' // eslint-disable-line
-import * as encoding from 'lib0/encoding.js'
-
-/**
- * Event that describes the changes on a YArray
- * @template T
- */
-export class YArrayEvent extends YEvent {
-  /**
-   * @param {YArray<T>} yarray The changed type
-   * @param {Transaction} transaction The transaction object
-   */
-  constructor (yarray, transaction) {
-    super(yarray, transaction)
-    this._transaction = transaction
-  }
-}
-
-/**
- * A shared Array implementation.
- * @template T
- * @extends AbstractType<YArrayEvent<T>>
- * @implements {IterableIterator<T>}
- */
-export class YArray extends AbstractType {
-  constructor () {
-    super()
-    /**
-     * @type {Array<any>?}
-     * @private
-     */
-    this._prelimContent = []
-  }
-  /**
-   * Integrate this type into the Yjs instance.
-   *
-   * * Save this struct in the os
-   * * This type is sent to other client
-   * * Observer functions are fired
-   *
-   * @param {Y} y The Yjs instance
-   * @param {ItemType} item
-   *
-   * @private
-   */
-  _integrate (y, item) {
-    super._integrate(y, item)
-    // @ts-ignore
-    this.insert(0, this._prelimContent)
-    this._prelimContent = null
-  }
-  get length () {
-    return this._prelimContent === null ? this._length : this._prelimContent.length
-  }
-  /**
-   * Creates YArrayEvent and calls observers.
-   *
-   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
-   *
-   * @private
-   */
-  _callObserver (transaction, parentSubs) {
-    callTypeObservers(this, transaction, new YArrayEvent(this, transaction))
-  }
-
-  /**
-   * Returns the i-th element from a YArray.
-   *
-   * @param {number} index The index of the element to return from the YArray
-   * @return {T}
-   */
-  get (index) {
-    return typeArrayGet(this, index)
-  }
-
-  /**
-   * Transforms this YArray to a JavaScript Array.
-   *
-   * @return {Array<T>}
-   */
-  toArray () {
-    return typeArrayToArray(this)
-  }
-
-  /**
-   * Transforms this Shared Type to a JSON object.
-   *
-   * @return {Array<any>}
-   */
-  toJSON () {
-    return this.map(c => c instanceof AbstractType ? c.toJSON() : c)
-  }
-
-  /**
-   * Returns an Array with the result of calling a provided function on every
-   * element of this YArray.
-   *
-   * @template T,M
-   * @param {function(T,number,YArray<T>):M} f Function that produces an element of the new Array
-   * @return {Array<M>} A new array with each element being the result of the
-   *                 callback function
-   */
-  map (f) {
-    // @ts-ignore
-    return typeArrayMap(this, f)
-  }
-
-  /**
-   * Executes a provided function on once on overy element of this YArray.
-   *
-   * @param {function(T,number):void} f A function to execute on every element of this YArray.
-   */
-  forEach (f) {
-    typeArrayForEach(this, f)
-  }
-
-  /**
-   * @return {IterableIterator<T>}
-   */
-  [Symbol.iterator] () {
-    return typeArrayCreateIterator(this)
-  }
-
-  /**
-   * Deletes elements starting from an index.
-   *
-   * @param {number} index Index at which to start deleting elements
-   * @param {number} length The number of elements to remove. Defaults to 1.
-   */
-  delete (index, length = 1) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeArrayDelete(transaction, this, index, length)
-      })
-    } else {
-      // @ts-ignore _prelimContent is defined because this is not yet integrated
-      this._prelimContent.splice(index, length)
-    }
-  }
-
-  /**
-   * Inserts new content at an index.
-   *
-   * Important: This function expects an array of content. Not just a content
-   * object. The reason for this "weirdness" is that inserting several elements
-   * is very efficient when it is done as a single operation.
-   *
-   * @example
-   *  // Insert character 'a' at position 0
-   *  yarray.insert(0, ['a'])
-   *  // Insert numbers 1, 2 at position 1
-   *  yarray.insert(1, [1, 2])
-   *
-   * @param {number} index The index to insert content at.
-   * @param {Array<T>} content The array of content
-   */
-  insert (index, content) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeArrayInsertGenerics(transaction, this, index, content)
-      })
-    } else {
-      // @ts-ignore _prelimContent is defined because this is not yet integrated
-      this._prelimContent.splice(index, 0, ...content)
-    }
-  }
-
-  /**
-   * Appends content to this YArray.
-   *
-   * @param {Array<T>} content Array of content to append.
-   */
-  push (content) {
-    this.insert(this.length, content)
-  }
-
-  /**
-   * @param {encoding.Encoder} encoder
-   * @private
-   */
-  _write (encoder) {
-    encoding.writeVarUint(encoder, YArrayRefID)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- *
- * @private
- * @function
- */
-export const readYArray = decoder => new YArray()
--- a/src/types/YMap.js
+++ b/src/types/YMap.js
@@ -1,202 +0,0 @@
-
-/**
- * @module YMap
- */
-
-import {
-  YEvent,
-  AbstractType,
-  typeMapDelete,
-  typeMapSet,
-  typeMapGet,
-  typeMapHas,
-  createMapIterator,
-  YMapRefID,
-  callTypeObservers,
-  transact,
-  Y, Transaction, ItemType, // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js' // eslint-disable-line
-import * as iterator from 'lib0/iterator.js'
-
-/**
- * @template T
- * Event that describes the changes on a YMap.
- */
-export class YMapEvent extends YEvent {
-  /**
-   * @param {YMap<T>} ymap The YArray that changed.
-   * @param {Transaction} transaction
-   * @param {Set<any>} subs The keys that changed.
-   */
-  constructor (ymap, transaction, subs) {
-    super(ymap, transaction)
-    this.keysChanged = subs
-  }
-}
-
-/**
- * @template T number|string|Object|Array|ArrayBuffer
- * A shared Map implementation.
- *
- * @extends AbstractType<YMapEvent<T>>
- * @implements {IterableIterator}
- */
-export class YMap extends AbstractType {
-  constructor () {
-    super()
-    /**
-     * @type {Map<string,any>?}
-     * @private
-     */
-    this._prelimContent = new Map()
-  }
-  /**
-   * Integrate this type into the Yjs instance.
-   *
-   * * Save this struct in the os
-   * * This type is sent to other client
-   * * Observer functions are fired
-   *
-   * @param {Y} y The Yjs instance
-   * @param {ItemType} item
-   *
-   * @private
-   */
-  _integrate (y, item) {
-    super._integrate(y, item)
-    // @ts-ignore
-    for (let [key, value] of this._prelimContent) {
-      this.set(key, value)
-    }
-    this._prelimContent = null
-  }
-  /**
-   * Creates YMapEvent and calls observers.
-   *
-   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
-   *
-   * @private
-   */
-  _callObserver (transaction, parentSubs) {
-    callTypeObservers(this, transaction, new YMapEvent(this, transaction, parentSubs))
-  }
-
-  /**
-   * Transforms this Shared Type to a JSON object.
-   *
-   * @return {Object<string,T>}
-   */
-  toJSON () {
-    /**
-     * @type {Object<string,T>}
-     */
-    const map = {}
-    for (let [key, item] of this._map) {
-      if (!item.deleted) {
-        const v = item.getContent()[0]
-        map[key] = v instanceof AbstractType ? v.toJSON() : v
-      }
-    }
-    return map
-  }
-
-  /**
-   * Returns the keys for each element in the YMap Type.
-   *
-   * @return {Iterator<string>}
-   */
-  keys () {
-    return iterator.iteratorMap(createMapIterator(this._map), v => v[0])
-  }
-  /**
-   * Returns the value for each element in the YMap Type.
-   *
-   * @return {IterableIterator<T>}
-   */
-  entries () {
-    return iterator.iteratorMap(createMapIterator(this._map), v => v[1].getContent()[0])
-  }
-
-  /**
-   * @return {IterableIterator<T>}
-   */
-  [Symbol.iterator] () {
-    return this.entries()
-  }
-
-  /**
-   * Remove a specified element from this YMap.
-   *
-   * @param {string} key The key of the element to remove.
-   */
-  delete (key) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeMapDelete(transaction, this, key)
-      })
-    } else {
-      // @ts-ignore
-      this._prelimContent.delete(key)
-    }
-  }
-
-  /**
-   * Adds or updates an element with a specified key and value.
-   *
-   * @param {string} key The key of the element to add to this YMap
-   * @param {T} value The value of the element to add
-   */
-  set (key, value) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeMapSet(transaction, this, key, value)
-      })
-    } else {
-      // @ts-ignore
-      this._prelimContent.set(key, value)
-    }
-    return value
-  }
-
-  /**
-   * Returns a specified element from this YMap.
-   *
-   * @param {string} key
-   * @return {T|undefined}
-   */
-  get (key) {
-    // @ts-ignore
-    return typeMapGet(this, key)
-  }
-
-  /**
-   * Returns a boolean indicating whether the specified key exists or not.
-   *
-   * @param {string} key The key to test.
-   * @return {boolean}
-   */
-  has (key) {
-    return typeMapHas(this, key)
-  }
-
-  /**
-   * @param {encoding.Encoder} encoder
-   *
-   * @private
-   */
-  _write (encoder) {
-    encoding.writeVarUint(encoder, YMapRefID)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- *
- * @private
- * @function
- */
-export const readYMap = decoder => new YMap()
--- a/src/types/YText.js
+++ b/src/types/YText.js
@@ -1,929 +0,0 @@
-
-/**
- * @module YText
- */
-
-import {
-  YEvent,
-  ItemEmbed,
-  ItemString,
-  ItemFormat,
-  AbstractType,
-  nextID,
-  createID,
-  getItemCleanStart,
-  isVisible,
-  YTextRefID,
-  callTypeObservers,
-  transact,
-  Y, ItemType, AbstractItem, Snapshot, StructStore, Transaction // eslint-disable-line
-} from '../internals.js'
-
-import * as decoding from 'lib0/decoding.js' // eslint-disable-line
-import * as encoding from 'lib0/encoding.js'
-
-export class ItemListPosition {
-  /**
-   * @param {AbstractItem|null} left
-   * @param {AbstractItem|null} right
-   */
-  constructor (left, right) {
-    this.left = left
-    this.right = right
-  }
-}
-
-export class ItemTextListPosition extends ItemListPosition {
-  /**
-   * @param {AbstractItem|null} left
-   * @param {AbstractItem|null} right
-   * @param {Map<string,any>} currentAttributes
-   */
-  constructor (left, right, currentAttributes) {
-    super(left, right)
-    this.currentAttributes = currentAttributes
-  }
-}
-
-export class ItemInsertionResult extends ItemListPosition {
-  /**
-   * @param {AbstractItem|null} left
-   * @param {AbstractItem|null} right
-   * @param {Map<string,any>} negatedAttributes
-   */
-  constructor (left, right, negatedAttributes) {
-    super(left, right)
-    this.negatedAttributes = negatedAttributes
-  }
-}
-
-/**
- * @param {Transaction} transaction
- * @param {StructStore} store
- * @param {Map<string,any>} currentAttributes
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {number} count
- * @return {ItemTextListPosition}
- *
- * @private
- * @function
- */
-const findNextPosition = (transaction, store, currentAttributes, left, right, count) => {
-  while (right !== null && count > 0) {
-    switch (right.constructor) {
-      case ItemEmbed:
-      case ItemString:
-        if (!right.deleted) {
-          if (count < right.length) {
-            // split right
-            getItemCleanStart(transaction, store, createID(right.id.client, right.id.clock + count))
-          }
-          count -= right.length
-        }
-        break
-      case ItemFormat:
-        if (!right.deleted) {
-          // @ts-ignore right is ItemFormat
-          updateCurrentAttributes(currentAttributes, right)
-        }
-        break
-    }
-    left = right
-    right = right.right
-  }
-  return new ItemTextListPosition(left, right, currentAttributes)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {StructStore} store
- * @param {AbstractType<any>} parent
- * @param {number} index
- * @return {ItemTextListPosition}
- *
- * @private
- * @function
- */
-const findPosition = (transaction, store, parent, index) => {
-  let currentAttributes = new Map()
-  let left = null
-  let right = parent._start
-  return findNextPosition(transaction, store, currentAttributes, left, right, index)
-}
-
-/**
- * Negate applied formats
- *
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} negatedAttributes
- * @return {ItemListPosition}
- *
- * @private
- * @function
- */
-const insertNegatedAttributes = (transaction, parent, left, right, negatedAttributes) => {
-  // check if we really need to remove attributes
-  while (
-    right !== null && (
-      right.deleted === true || (
-        right.constructor === ItemFormat &&
-        // @ts-ignore right is ItemFormat
-        (negatedAttributes.get(right.key) === right.value)
-      )
-    )
-  ) {
-    if (!right.deleted) {
-      // @ts-ignore right is ItemFormat
-      negatedAttributes.delete(right.key)
-    }
-    left = right
-    right = right.right
-  }
-  for (let [key, val] of negatedAttributes) {
-    left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
-    left.integrate(transaction)
-  }
-  return {left, right}
-}
-
-/**
- * @param {Map<string,any>} currentAttributes
- * @param {ItemFormat} item
- *
- * @private
- * @function
- */
-const updateCurrentAttributes = (currentAttributes, item) => {
-  const value = item.value
-  const key = item.key
-  if (value === null) {
-    currentAttributes.delete(key)
-  } else {
-    currentAttributes.set(key, value)
-  }
-}
-
-/**
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} currentAttributes
- * @param {Object<string,any>} attributes
- * @return {ItemListPosition}
- *
- * @private
- * @function
- */
-const minimizeAttributeChanges = (left, right, currentAttributes, attributes) => {
-  // go right while attributes[right.key] === right.value (or right is deleted)
-  while (true) {
-    if (right === null) {
-      break
-    } else if (right.deleted) {
-      // continue
-    // @ts-ignore right is ItemFormat
-    } else if (right.constructor === ItemFormat && (attributes[right.key] || null) === right.value) {
-      // found a format, update currentAttributes and continue
-      // @ts-ignore right is ItemFormat
-      updateCurrentAttributes(currentAttributes, right)
-    } else {
-      break
-    }
-    left = right
-    right = right.right
-  }
-  return new ItemListPosition(left, right)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} currentAttributes
- * @param {Object<string,any>} attributes
- * @return {ItemInsertionResult}
- *
- * @private
- * @function
- **/
-const insertAttributes = (transaction, parent, left, right, currentAttributes, attributes) => {
-  const negatedAttributes = new Map()
-  // insert format-start items
-  for (let key in attributes) {
-    const val = attributes[key]
-    const currentVal = currentAttributes.get(key)
-    if (currentVal !== val) {
-      // save negated attribute (set null if currentVal undefined)
-      negatedAttributes.set(key, currentVal || null)
-      left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
-      left.integrate(transaction)
-    }
-  }
-  return new ItemInsertionResult(left, right, negatedAttributes)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} currentAttributes
- * @param {string} text
- * @param {Object<string,any>} attributes
- * @return {ItemListPosition}
- *
- * @private
- * @function
- **/
-const insertText = (transaction, parent, left, right, currentAttributes, text, attributes) => {
-  for (let [key] of currentAttributes) {
-    if (attributes[key] === undefined) {
-      attributes[key] = null
-    }
-  }
-  const minPos = minimizeAttributeChanges(left, right, currentAttributes, attributes)
-  const insertPos = insertAttributes(transaction, parent, minPos.left, minPos.right, currentAttributes, attributes)
-  left = insertPos.left
-  right = insertPos.right
-  // insert content
-  if (text.constructor === String) {
-    left = new ItemString(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
-  } else {
-    left = new ItemEmbed(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
-  }
-  left.integrate(transaction)
-  return insertNegatedAttributes(transaction, parent, left, insertPos.right, insertPos.negatedAttributes)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractType<any>} parent
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} currentAttributes
- * @param {number} length
- * @param {Object<string,any>} attributes
- * @return {ItemListPosition}
- *
- * @private
- * @function
- */
-const formatText = (transaction, parent, left, right, currentAttributes, length, attributes) => {
-  const minPos = minimizeAttributeChanges(left, right, currentAttributes, attributes)
-  const insertPos = insertAttributes(transaction, parent, minPos.left, minPos.right, currentAttributes, attributes)
-  const negatedAttributes = insertPos.negatedAttributes
-  left = insertPos.left
-  right = insertPos.right
-  // iterate until first non-format or null is found
-  // delete all formats with attributes[format.key] != null
-  while (length > 0 && right !== null) {
-    if (right.deleted === false) {
-      switch (right.constructor) {
-        case ItemFormat:
-          // @ts-ignore right is ItemFormat
-          const attr = attributes[right.key]
-          if (attr !== undefined) {
-            // @ts-ignore right is ItemFormat
-            if (attr === right.value) {
-              // @ts-ignore right is ItemFormat
-              negatedAttributes.delete(right.key)
-            } else {
-              // @ts-ignore right is ItemFormat
-              negatedAttributes.set(right.key, right.value)
-            }
-            right.delete(transaction)
-          }
-          // @ts-ignore right is ItemFormat
-          updateCurrentAttributes(currentAttributes, right)
-          break
-        case ItemEmbed:
-        case ItemString:
-          if (length < right.length) {
-            getItemCleanStart(transaction, transaction.y.store, createID(right.id.client, right.id.clock + length))
-          }
-          length -= right.length
-          break
-      }
-    }
-    left = right
-    right = right.right
-  }
-  return insertNegatedAttributes(transaction, parent, left, right, negatedAttributes)
-}
-
-/**
- * @param {Transaction} transaction
- * @param {AbstractItem|null} left
- * @param {AbstractItem|null} right
- * @param {Map<string,any>} currentAttributes
- * @param {number} length
- * @return {ItemListPosition}
- *
- * @private
- * @function
- */
-const deleteText = (transaction, left, right, currentAttributes, length) => {
-  while (length > 0 && right !== null) {
-    if (right.deleted === false) {
-      switch (right.constructor) {
-        case ItemFormat:
-          // @ts-ignore right is ItemFormat
-          updateCurrentAttributes(currentAttributes, right)
-          break
-        case ItemEmbed:
-        case ItemString:
-          if (length < right.length) {
-            getItemCleanStart(transaction, transaction.y.store, createID(right.id.client, right.id.clock + length))
-          }
-          length -= right.length
-          right.delete(transaction)
-          break
-      }
-    }
-    left = right
-    right = right.right
-  }
-  return { left, right }
-}
-
-/**
- * The Quill Delta format represents changes on a text document with
- * formatting information. For mor information visit {@link https://quilljs.com/docs/delta/|Quill Delta}
- *
- * @example
- *   {
- *     ops: [
- *       { insert: 'Gandalf', attributes: { bold: true } },
- *       { insert: ' the ' },
- *       { insert: 'Grey', attributes: { color: '#cccccc' } }
- *     ]
- *   }
- *
- */
-
-/**
-  * Attributes that can be assigned to a selection of text.
-  *
-  * @example
-  *   {
-  *     bold: true,
-  *     font-size: '40px'
-  *   }
-  *
-  * @typedef {Object} TextAttributes
-  */
-
-/**
- * @typedef {Object} DeltaItem
- * @property {number|undefined} DeltaItem.delete
- * @property {number|undefined} DeltaItem.retain
- * @property {string|undefined} DeltaItem.string
- * @property {Object<string,any>} DeltaItem.attributes
- */
-
-/**
- * Event that describes the changes on a YText type.
- */
-class YTextEvent extends YEvent {
-  /**
-   * @param {YText} ytext
-   * @param {Transaction} transaction
-   */
-  constructor (ytext, transaction) {
-    super(ytext, transaction)
-    /**
-     * @private
-     * @type {Array<DeltaItem>|null}
-     */
-    this._delta = null
-  }
-  /**
-   * Compute the changes in the delta format.
-   * A {@link https://quilljs.com/docs/delta/|Quill Delta}) that represents the changes on the document.
-   *
-   * @type {Array<DeltaItem>}
-   *
-   * @public
-   */
-  get delta () {
-    if (this._delta === null) {
-      const y = this.target._y
-      // @ts-ignore
-      transact(y, transaction => {
-        /**
-         * @type {Array<DeltaItem>}
-         */
-        const delta = []
-        const currentAttributes = new Map() // saves all current attributes for insert
-        const oldAttributes = new Map()
-        let item = this.target._start
-        /**
-         * @type {string?}
-         */
-        let action = null
-        /**
-         * @type {Object<string,any>}
-         */
-        let attributes = {} // counts added or removed new attributes for retain
-        let insert = ''
-        let retain = 0
-        let deleteLen = 0
-        this._delta = delta
-        const addOp = () => {
-          if (action !== null) {
-            /**
-             * @type {any}
-             */
-            let op
-            switch (action) {
-              case 'delete':
-                op = { delete: deleteLen }
-                deleteLen = 0
-                break
-              case 'insert':
-                op = { insert }
-                if (currentAttributes.size > 0) {
-                  op.attributes = {}
-                  for (let [key, value] of currentAttributes) {
-                    if (value !== null) {
-                      op.attributes[key] = value
-                    }
-                  }
-                }
-                insert = ''
-                break
-              case 'retain':
-                op = { retain }
-                if (Object.keys(attributes).length > 0) {
-                  op.attributes = {}
-                  for (let key in attributes) {
-                    op.attributes[key] = attributes[key]
-                  }
-                }
-                retain = 0
-                break
-            }
-            delta.push(op)
-            action = null
-          }
-        }
-        while (item !== null) {
-          switch (item.constructor) {
-            case ItemEmbed:
-              if (this.adds(item)) {
-                addOp()
-                action = 'insert'
-                // @ts-ignore item is ItemFormat
-                insert = item.embed
-                addOp()
-              } else if (this.deletes(item)) {
-                if (action !== 'delete') {
-                  addOp()
-                  action = 'delete'
-                }
-                deleteLen += 1
-              } else if (!item.deleted) {
-                if (action !== 'retain') {
-                  addOp()
-                  action = 'retain'
-                }
-                retain += 1
-              }
-              break
-            case ItemString:
-              if (this.adds(item)) {
-                if (action !== 'insert') {
-                  addOp()
-                  action = 'insert'
-                }
-                // @ts-ignore
-                insert += item.string
-              } else if (this.deletes(item)) {
-                if (action !== 'delete') {
-                  addOp()
-                  action = 'delete'
-                }
-                deleteLen += item.length
-              } else if (!item.deleted) {
-                if (action !== 'retain') {
-                  addOp()
-                  action = 'retain'
-                }
-                retain += item.length
-              }
-              break
-            case ItemFormat:
-              if (this.adds(item)) {
-                // @ts-ignore item is ItemFormat
-                const curVal = currentAttributes.get(item.key) || null
-                // @ts-ignore item is ItemFormat
-                if (curVal !== item.value) {
-                  if (action === 'retain') {
-                    addOp()
-                  }
-                  // @ts-ignore item is ItemFormat
-                  if (item.value === (oldAttributes.get(item.key) || null)) {
-                    // @ts-ignore item is ItemFormat
-                    delete attributes[item.key]
-                  } else {
-                    // @ts-ignore item is ItemFormat
-                    attributes[item.key] = item.value
-                  }
-                } else {
-                  item.delete(transaction)
-                }
-              } else if (this.deletes(item)) {
-                // @ts-ignore item is ItemFormat
-                oldAttributes.set(item.key, item.value)
-                // @ts-ignore item is ItemFormat
-                const curVal = currentAttributes.get(item.key) || null
-                // @ts-ignore item is ItemFormat
-                if (curVal !== item.value) {
-                  if (action === 'retain') {
-                    addOp()
-                  }
-                  // @ts-ignore item is ItemFormat
-                  attributes[item.key] = curVal
-                }
-              } else if (!item.deleted) {
-                // @ts-ignore item is ItemFormat
-                oldAttributes.set(item.key, item.value)
-                // @ts-ignore item is ItemFormat
-                const attr = attributes[item.key]
-                if (attr !== undefined) {
-                  // @ts-ignore item is ItemFormat
-                  if (attr !== item.value) {
-                    if (action === 'retain') {
-                      addOp()
-                    }
-                    // @ts-ignore item is ItemFormat
-                    if (item.value === null) {
-                      // @ts-ignore item is ItemFormat
-                      attributes[item.key] = item.value
-                    } else {
-                      // @ts-ignore item is ItemFormat
-                      delete attributes[item.key]
-                    }
-                  } else {
-                    item.delete(transaction)
-                  }
-                }
-              }
-              if (!item.deleted) {
-                if (action === 'insert') {
-                  addOp()
-                }
-                // @ts-ignore item is ItemFormat
-                updateCurrentAttributes(currentAttributes, item)
-              }
-              break
-          }
-          item = item.right
-        }
-        addOp()
-        while (this._delta.length > 0) {
-          let lastOp = this._delta[this._delta.length - 1]
-          if (lastOp.retain !== undefined && lastOp.attributes === undefined) {
-            // retain delta's if they don't assign attributes
-            this._delta.pop()
-          } else {
-            break
-          }
-        }
-      })
-    }
-    // @ts-ignore _delta is defined above
-    return this._delta
-  }
-}
-
-/**
- * Type that represents text with formatting information.
- *
- * This type replaces y-richtext as this implementation is able to handle
- * block formats (format information on a paragraph), embeds (complex elements
- * like pictures and videos), and text formats (**bold**, *italic*).
- *
- * @extends AbstractType<YTextEvent>
- */
-export class YText extends AbstractType {
-  /**
-   * @param {String} [string] The initial value of the YText.
-   */
-  constructor (string) {
-    super()
-    /**
-     * @type {Array<string>?}
-     * @private
-     */
-    this._prelimContent = string !== undefined ? [string] : []
-  }
-
-  get length () {
-    return this._length
-  }
-
-  /**
-   * @param {Y} y
-   * @param {ItemType} item
-   *
-   * @private
-   */
-  _integrate (y, item) {
-    super._integrate(y, item)
-    // @ts-ignore this._prelimContent is still defined
-    this.insert(0, this._prelimContent.join(''))
-    this._prelimContent = null
-  }
-
-  /**
-   * Creates YTextEvent and calls observers.
-   *
-   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
-   *
-   * @private
-   */
-  _callObserver (transaction, parentSubs) {
-    callTypeObservers(this, transaction, new YTextEvent(this, transaction))
-  }
-
-  toDom () {
-    return document.createTextNode(this.toString())
-  }
-
-  /**
-   * Returns the unformatted string representation of this YText type.
-   *
-   * @public
-   */
-  toString () {
-    let str = ''
-    /**
-     * @type {AbstractItem|null}
-     */
-    let n = this._start
-    while (n !== null) {
-      if (!n.deleted && n.countable && n.constructor === ItemString) {
-        // @ts-ignore
-        str += n.string
-      }
-      n = n.right
-    }
-    return str
-  }
-
-  toDomString () {
-    // @ts-ignore
-    return this.toDelta().map(delta => {
-      const nestedNodes = []
-      for (let nodeName in delta.attributes) {
-        const attrs = []
-        for (let key in delta.attributes[nodeName]) {
-          attrs.push({ key, value: delta.attributes[nodeName][key] })
-        }
-        // sort attributes to get a unique order
-        attrs.sort((a, b) => a.key < b.key ? -1 : 1)
-        nestedNodes.push({ nodeName, attrs })
-      }
-      // sort node order to get a unique order
-      nestedNodes.sort((a, b) => a.nodeName < b.nodeName ? -1 : 1)
-      // now convert to dom string
-      let str = ''
-      for (let i = 0; i < nestedNodes.length; i++) {
-        const node = nestedNodes[i]
-        str += `<${node.nodeName}`
-        for (let j = 0; j < node.attrs.length; j++) {
-          const attr = node.attrs[i]
-          str += ` ${attr.key}="${attr.value}"`
-        }
-        str += '>'
-      }
-      str += delta.insert
-      for (let i = nestedNodes.length - 1; i >= 0; i--) {
-        str += `</${nestedNodes[i].nodeName}>`
-      }
-      return str
-    })
-  }
-
-  /**
-   * Apply a {@link Delta} on this shared YText type.
-   *
-   * @param {any} delta The changes to apply on this element.
-   *
-   * @public
-   */
-  applyDelta (delta) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        /**
-         * @type {ItemListPosition}
-         */
-        let pos = new ItemListPosition(null, this._start)
-        const currentAttributes = new Map()
-        for (let i = 0; i < delta.length; i++) {
-          const op = delta[i]
-          if (op.insert !== undefined) {
-            pos = insertText(transaction, this, pos.left, pos.right, currentAttributes, op.insert, op.attributes || {})
-          } else if (op.retain !== undefined) {
-            pos = formatText(transaction, this, pos.left, pos.right, currentAttributes, op.retain, op.attributes || {})
-          } else if (op.delete !== undefined) {
-            pos = deleteText(transaction, pos.left, pos.right, currentAttributes, op.delete)
-          }
-        }
-      })
-    }
-  }
-
-  /**
-   * Returns the Delta representation of this YText type.
-   *
-   * @param {Snapshot} [snapshot]
-   * @param {Snapshot} [prevSnapshot]
-   * @return {any} The Delta representation of this type.
-   *
-   * @public
-   */
-  toDelta (snapshot, prevSnapshot) {
-    /**
-     * @type{Array<any>}
-     */
-    const ops = []
-    const currentAttributes = new Map()
-    let str = ''
-    /**
-     * @type {AbstractItem|null}
-     */
-    // @ts-ignore
-    let n = this._start
-    function packStr () {
-      if (str.length > 0) {
-        // pack str with attributes to ops
-        /**
-         * @type {Object<string,any>}
-         */
-        const attributes = {}
-        let addAttributes = false
-        for (let [key, value] of currentAttributes) {
-          addAttributes = true
-          attributes[key] = value
-        }
-        /**
-         * @type {Object<string,any>}
-         */
-        const op = { insert: str }
-        if (addAttributes) {
-          op.attributes = attributes
-        }
-        ops.push(op)
-        str = ''
-      }
-    }
-    while (n !== null) {
-      if (isVisible(n, snapshot) || (prevSnapshot !== undefined && isVisible(n, prevSnapshot))) {
-        switch (n.constructor) {
-          case ItemString:
-            const cur = currentAttributes.get('ychange')
-            if (snapshot !== undefined && !isVisible(n, snapshot)) {
-              if (cur === undefined || cur.user !== n.id.client || cur.state !== 'removed') {
-                packStr()
-                currentAttributes.set('ychange', { user: n.id.client, state: 'removed' })
-              }
-            } else if (prevSnapshot !== undefined && !isVisible(n, prevSnapshot)) {
-              if (cur === undefined || cur.user !== n.id.client || cur.state !== 'added') {
-                packStr()
-                currentAttributes.set('ychange', { user: n.id.client, state: 'added' })
-              }
-            } else if (cur !== undefined) {
-              packStr()
-              currentAttributes.delete('ychange')
-            }
-            // @ts-ignore
-            str += n.string
-            break
-          case ItemFormat:
-            packStr()
-            // @ts-ignore
-            updateCurrentAttributes(currentAttributes, n)
-            break
-        }
-      }
-      n = n.right
-    }
-    packStr()
-    return ops
-  }
-
-  /**
-   * Insert text at a given index.
-   *
-   * @param {number} index The index at which to start inserting.
-   * @param {String} text The text to insert at the specified position.
-   * @param {TextAttributes} attributes Optionally define some formatting
-   *                                    information to apply on the inserted
-   *                                    Text.
-   * @public
-   */
-  insert (index, text, attributes = {}) {
-    if (text.length <= 0) {
-      return
-    }
-    const y = this._y
-    if (y !== null) {
-      transact(y, transaction => {
-        const {left, right, currentAttributes} = findPosition(transaction, y.store, this, index)
-        insertText(transaction, this, left, right, currentAttributes, text, attributes)
-      })
-    }
-  }
-
-  /**
-   * Inserts an embed at a index.
-   *
-   * @param {number} index The index to insert the embed at.
-   * @param {Object} embed The Object that represents the embed.
-   * @param {TextAttributes} attributes Attribute information to apply on the
-   *                                    embed
-   *
-   * @public
-   */
-  insertEmbed (index, embed, attributes = {}) {
-    if (embed.constructor !== Object) {
-      throw new Error('Embed must be an Object')
-    }
-    const y = this._y
-    if (y !== null) {
-      transact(y, transaction => {
-        const { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
-        insertText(transaction, this, left, right, currentAttributes, embed, attributes)
-      })
-    }
-  }
-
-  /**
-   * Deletes text starting from an index.
-   *
-   * @param {number} index Index at which to start deleting.
-   * @param {number} length The number of characters to remove. Defaults to 1.
-   *
-   * @public
-   */
-  delete (index, length) {
-    if (length === 0) {
-      return
-    }
-    const y = this._y
-    if (y !== null) {
-      transact(y, transaction => {
-        const { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
-        deleteText(transaction, left, right, currentAttributes, length)
-      })
-    }
-  }
-
-  /**
-   * Assigns properties to a range of text.
-   *
-   * @param {number} index The position where to start formatting.
-   * @param {number} length The amount of characters to assign properties to.
-   * @param {TextAttributes} attributes Attribute information to apply on the
-   *                                    text.
-   *
-   * @public
-   */
-  format (index, length, attributes) {
-    const y = this._y
-    if (y !== null) {
-      transact(y, transaction => {
-        let { left, right, currentAttributes } = findPosition(transaction, y.store, this, index)
-        if (right === null) {
-          return
-        }
-        formatText(transaction, this, left, right, currentAttributes, length, attributes)
-      })
-    }
-  }
-
-  /**
-   * @param {encoding.Encoder} encoder
-   *
-   * @private
-   */
-  _write (encoder) {
-    encoding.writeVarUint(encoder, YTextRefID)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @return {YText}
- *
- * @private
- * @function
- */
-export const readYText = decoder => new YText()
--- a/src/types/YXmlElement.js
+++ b/src/types/YXmlElement.js
@@ -1,490 +0,0 @@
-/**
- * @module YXml
- */
-
-import {
-  YXmlEvent,
-  AbstractType,
-  typeArrayMap,
-  typeArrayForEach,
-  typeMapGet,
-  typeMapGetAll,
-  typeArrayInsertGenerics,
-  typeArrayDelete,
-  typeMapSet,
-  typeMapDelete,
-  YXmlElementRefID,
-  callTypeObservers,
-  transact,
-  Y, Transaction, ItemType, YXmlText, YXmlHook, Snapshot // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * Define the elements to which a set of CSS queries apply.
- * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors|CSS_Selectors}
- *
- * @example
- *   query = '.classSelector'
- *   query = 'nodeSelector'
- *   query = '#idSelector'
- *
- * @typedef {string} CSS_Selector
- */
-
-/**
- * Dom filter function.
- *
- * @callback domFilter
- * @param {string} nodeName The nodeName of the element
- * @param {Map} attributes The map of attributes.
- * @return {boolean} Whether to include the Dom node in the YXmlElement.
- */
-
-/**
- * Represents a subset of the nodes of a YXmlElement / YXmlFragment and a
- * position within them.
- *
- * Can be created with {@link YXmlFragment#createTreeWalker}
- *
- * @public
- * @implements {IterableIterator}
- */
-export class YXmlTreeWalker {
-  /**
-   * @param {YXmlFragment | YXmlElement} root
-   * @param {function(AbstractType<any>):boolean} [f]
-   */
-  constructor (root, f = () => true) {
-    this._filter = f
-    this._root = root
-    /**
-     * @type {ItemType | null}
-     */
-    // @ts-ignore
-    this._currentNode = root._start
-    this._firstCall = true
-  }
-
-  [Symbol.iterator] () {
-    return this
-  }
-  /**
-   * Get the next node.
-   *
-   * @return {IteratorResult<YXmlElement|YXmlText|YXmlHook>} The next node.
-   *
-   * @public
-   */
-  next () {
-    let n = this._currentNode
-    if (n !== null && (!this._firstCall || n.deleted || !this._filter(n.type))) { // if first call, we check if we can use the first item
-      do {
-        if (!n.deleted && (n.type.constructor === YXmlElement || n.type.constructor === YXmlFragment) && n.type._start !== null) {
-          // walk down in the tree
-          // @ts-ignore
-          n = n.type._start
-        } else {
-          // walk right or up in the tree
-          while (n !== null) {
-            if (n.right !== null) {
-              // @ts-ignore
-              n = n.right
-              break
-            } else if (n.parent === this._root) {
-              n = null
-            } else {
-              n = n.parent._item
-            }
-          }
-        }
-      } while (n !== null && (n.deleted || !this._filter(n.type)))
-    }
-    this._firstCall = false
-    this._currentNode = n
-    if (n === null) {
-      // @ts-ignore return undefined if done=true (the expected result)
-      return { value: undefined, done: true }
-    }
-    // @ts-ignore
-    return { value: n.type, done: false }
-  }
-}
-
-/**
- * Represents a list of {@link YXmlElement}.and {@link YXmlText} types.
- * A YxmlFragment is similar to a {@link YXmlElement}, but it does not have a
- * nodeName and it does not have attributes. Though it can be bound to a DOM
- * element - in this case the attributes and the nodeName are not shared.
- *
- * @public
- * @extends AbstractType<YXmlEvent>
- */
-export class YXmlFragment extends AbstractType {
-  /**
-   * Create a subtree of childNodes.
-   *
-   * @example
-   * const walker = elem.createTreeWalker(dom => dom.nodeName === 'div')
-   * for (let node in walker) {
-   *   // `node` is a div node
-   *   nop(node)
-   * }
-   *
-   * @param {function(AbstractType<any>):boolean} filter Function that is called on each child element and
-   *                          returns a Boolean indicating whether the child
-   *                          is to be included in the subtree.
-   * @return {YXmlTreeWalker} A subtree and a position within it.
-   *
-   * @public
-   */
-  createTreeWalker (filter) {
-    return new YXmlTreeWalker(this, filter)
-  }
-
-  /**
-   * Returns the first YXmlElement that matches the query.
-   * Similar to DOM's {@link querySelector}.
-   *
-   * Query support:
-   *   - tagname
-   * TODO:
-   *   - id
-   *   - attribute
-   *
-   * @param {CSS_Selector} query The query on the children.
-   * @return {YXmlElement|YXmlText|YXmlHook|null} The first element that matches the query or null.
-   *
-   * @public
-   */
-  querySelector (query) {
-    query = query.toUpperCase()
-    // @ts-ignore
-    const iterator = new YXmlTreeWalker(this, element => element.nodeName === query)
-    const next = iterator.next()
-    if (next.done) {
-      return null
-    } else {
-      return next.value
-    }
-  }
-
-  /**
-   * Returns all YXmlElements that match the query.
-   * Similar to Dom's {@link querySelectorAll}.
-   *
-   * @todo Does not yet support all queries. Currently only query by tagName.
-   *
-   * @param {CSS_Selector} query The query on the children
-   * @return {Array<YXmlElement|YXmlText|YXmlHook|null>} The elements that match this query.
-   *
-   * @public
-   */
-  querySelectorAll (query) {
-    query = query.toUpperCase()
-    // @ts-ignore
-    return Array.from(new YXmlTreeWalker(this, element => element.nodeName === query))
-  }
-
-  /**
-   * Creates YXmlEvent and calls observers.
-   * @private
-   *
-   * @param {Transaction} transaction
-   * @param {Set<null|string>} parentSubs Keys changed on this type. `null` if list was modified.
-   */
-  _callObserver (transaction, parentSubs) {
-    callTypeObservers(this, transaction, new YXmlEvent(this, parentSubs, transaction))
-  }
-
-  toString () {
-    return this.toDomString()
-  }
-
-  /**
-   * Get the string representation of all the children of this YXmlFragment.
-   *
-   * @return {string} The string representation of all children.
-   */
-  toDomString () {
-    return typeArrayMap(this, xml => xml.toDomString()).join('')
-  }
-
-  /**
-   * Creates a Dom Element that mirrors this YXmlElement.
-   *
-   * @param {Document} [_document=document] The document object (you must define
-   *                                        this when calling this method in
-   *                                        nodejs)
-   * @param {Object<string, any>} [hooks={}] Optional property to customize how hooks
-   *                                             are presented in the DOM
-   * @param {any} [binding] You should not set this property. This is
-   *                               used if DomBinding wants to create a
-   *                               association to the created DOM type.
-   * @return {Node} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
-   *
-   * @public
-   */
-  toDom (_document = document, hooks = {}, binding) {
-    const fragment = _document.createDocumentFragment()
-    if (binding !== undefined) {
-      binding._createAssociation(fragment, this)
-    }
-    typeArrayForEach(this, xmlType => {
-      fragment.insertBefore(xmlType.toDom(_document, hooks, binding), null)
-    })
-    return fragment
-  }
-}
-
-/**
- * An YXmlElement imitates the behavior of a
- * {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}.
- *
- * * An YXmlElement has attributes (key value pairs)
- * * An YXmlElement has childElements that must inherit from YXmlElement
- */
-export class YXmlElement extends YXmlFragment {
-  constructor (nodeName = 'UNDEFINED') {
-    super()
-    this.nodeName = nodeName.toUpperCase()
-    /**
-     * @type {Array<any>|null}
-     * @private
-     */
-    this._prelimContent = []
-    /**
-     * @type {Map<string, any>|null}
-     * @private
-     */
-    this._prelimAttrs = new Map()
-  }
-
-  /**
-   * Integrate this type into the Yjs instance.
-   *
-   * * Save this struct in the os
-   * * This type is sent to other client
-   * * Observer functions are fired
-   *
-   * @param {Y} y The Yjs instance
-   * @param {ItemType} item
-   * @private
-   */
-  _integrate (y, item) {
-    super._integrate(y, item)
-    // @ts-ignore
-    this.insert(0, this._prelimContent)
-    this._prelimContent = null
-    // @ts-ignore
-    this._prelimAttrs.forEach((value, key) => {
-      this.setAttribute(key, value)
-    })
-    this._prelimContent = null
-  }
-
-  /**
-   * Creates an Item with the same effect as this Item (without position effect)
-   *
-   * @return {YXmlElement}
-   * @private
-   */
-  _copy () {
-    return new YXmlElement(this.nodeName)
-  }
-
-  toString () {
-    return this.toDomString()
-  }
-
-  /**
-   * Returns the string representation of this YXmlElement.
-   * The attributes are ordered by attribute-name, so you can easily use this
-   * method to compare YXmlElements
-   *
-   * @return {String} The string representation of this type.
-   *
-   * @public
-   */
-  toDomString () {
-    const attrs = this.getAttributes()
-    const stringBuilder = []
-    const keys = []
-    for (let key in attrs) {
-      keys.push(key)
-    }
-    keys.sort()
-    const keysLen = keys.length
-    for (let i = 0; i < keysLen; i++) {
-      const key = keys[i]
-      stringBuilder.push(key + '="' + attrs[key] + '"')
-    }
-    const nodeName = this.nodeName.toLocaleLowerCase()
-    const attrsString = stringBuilder.length > 0 ? ' ' + stringBuilder.join(' ') : ''
-    return `<${nodeName}${attrsString}>${super.toDomString()}</${nodeName}>`
-  }
-
-  /**
-   * Removes an attribute from this YXmlElement.
-   *
-   * @param {String} attributeName The attribute name that is to be removed.
-   *
-   * @public
-   */
-  removeAttribute (attributeName) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeMapDelete(transaction, this, attributeName)
-      })
-    } else {
-      // @ts-ignore
-      this._prelimAttrs.delete(attributeName)
-    }
-  }
-
-  /**
-   * Sets or updates an attribute.
-   *
-   * @param {String} attributeName The attribute name that is to be set.
-   * @param {String} attributeValue The attribute value that is to be set.
-   *
-   * @public
-   */
-  setAttribute (attributeName, attributeValue) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeMapSet(transaction, this, attributeName, attributeValue)
-      })
-    } else {
-      // @ts-ignore
-      this._prelimAttrs.set(attributeName, attributeValue)
-    }
-  }
-
-  /**
-   * Returns an attribute value that belongs to the attribute name.
-   *
-   * @param {String} attributeName The attribute name that identifies the
-   *                               queried value.
-   * @return {String} The queried attribute value.
-   *
-   * @public
-   */
-  getAttribute (attributeName) {
-    // @ts-ignore
-    return typeMapGet(this, attributeName)
-  }
-
-  /**
-   * Returns all attribute name/value pairs in a JSON Object.
-   *
-   * @param {Snapshot} [snapshot]
-   * @return {Object} A JSON Object that describes the attributes.
-   *
-   * @public
-   */
-  getAttributes (snapshot) {
-    return typeMapGetAll(this)
-  }
-
-  /**
-   * Inserts new content at an index.
-   *
-   * @example
-   *  // Insert character 'a' at position 0
-   *  xml.insert(0, [new Y.XmlText('text')])
-   *
-   * @param {number} index The index to insert content at
-   * @param {Array<YXmlElement|YXmlText>} content The array of content
-   */
-  insert (index, content) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeArrayInsertGenerics(transaction, this, index, content)
-      })
-    } else {
-      // @ts-ignore _prelimContent is defined because this is not yet integrated
-      this._prelimContent.splice(index, 0, ...content)
-    }
-  }
-
-  /**
-   * Deletes elements starting from an index.
-   *
-   * @param {number} index Index at which to start deleting elements
-   * @param {number} [length=1] The number of elements to remove. Defaults to 1.
-   */
-  delete (index, length = 1) {
-    if (this._y !== null) {
-      transact(this._y, transaction => {
-        typeArrayDelete(transaction, this, index, length)
-      })
-    } else {
-      // @ts-ignore _prelimContent is defined because this is not yet integrated
-      this._prelimContent.splice(index, length)
-    }
-  }
-
-  /**
-   * Creates a Dom Element that mirrors this YXmlElement.
-   *
-   * @param {Document} [_document=document] The document object (you must define
-   *                                        this when calling this method in
-   *                                        nodejs)
-   * @param {Object<string, any>} [hooks={}] Optional property to customize how hooks
-   *                                             are presented in the DOM
-   * @param {any} [binding] You should not set this property. This is
-   *                               used if DomBinding wants to create a
-   *                               association to the created DOM type.
-   * @return {Node} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
-   *
-   * @public
-   */
-  toDom (_document = document, hooks = {}, binding) {
-    const dom = _document.createElement(this.nodeName)
-    let attrs = this.getAttributes()
-    for (let key in attrs) {
-      dom.setAttribute(key, attrs[key])
-    }
-    typeArrayForEach(this, yxml => {
-      dom.appendChild(yxml.toDom(_document, hooks, binding))
-    })
-    if (binding !== undefined) {
-      binding._createAssociation(dom, this)
-    }
-    return dom
-  }
-
-  /**
-   * 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.
-   *
-   * @private
-   * @param {encoding.Encoder} encoder The encoder to write data to.
-   */
-  _write (encoder) {
-    encoding.writeVarUint(encoder, YXmlElementRefID)
-    encoding.writeVarString(encoder, this.nodeName)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @return {YXmlElement}
- *
- * @private
- * @function
- */
-export const readYXmlElement = decoder => new YXmlElement(decoding.readVarString(decoder))
-/**
- * @param {decoding.Decoder} decoder
- * @return {YXmlFragment}
- *
- * @private
- * @function
- */
-export const readYXmlFragment = decoder => new YXmlFragment()
--- a/src/types/YXmlEvent.js
+++ b/src/types/YXmlEvent.js
@@ -1,39 +0,0 @@
-
-import {
-  YEvent,
-  YXmlElement, YXmlFragment, Transaction // eslint-disable-line
-} from '../internals.js'
-
-/**
- * An Event that describes changes on a YXml Element or Yxml Fragment
- */
-export class YXmlEvent extends YEvent {
-  /**
-   * @param {YXmlElement|YXmlFragment} target The target on which the event is created.
-   * @param {Set<string|null>} subs The set of changed attributes. `null` is included if the
-   *                   child list changed.
-   * @param {Transaction} transaction The transaction instance with wich the
-   *                                  change was created.
-   */
-  constructor (target, subs, transaction) {
-    super(target, transaction)
-    /**
-     * Whether the children changed.
-     * @type {Boolean}
-     * @private
-     */
-    this.childListChanged = false
-    /**
-     * Set of all changed attributes.
-     * @type {Set<string|null>}
-     */
-    this.attributesChanged = new Set()
-    subs.forEach((sub) => {
-      if (sub === null) {
-        this.childListChanged = true
-      } else {
-        this.attributesChanged.add(sub)
-      }
-    })
-  }
-}
--- a/src/types/YXmlHook.js
+++ b/src/types/YXmlHook.js
@@ -1,90 +0,0 @@
-
-import {
-  YMap,
-  YXmlHookRefID
-} from '../internals.js'
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * You can manage binding to a custom type with YXmlHook.
- *
- * @extends {YMap<any>}
- */
-export class YXmlHook extends YMap {
-  /**
-   * @param {string} hookName nodeName of the Dom Node.
-   */
-  constructor (hookName) {
-    super()
-    /**
-     * @type {string}
-     */
-    this.hookName = hookName
-  }
-
-  /**
-   * Creates an Item with the same effect as this Item (without position effect)
-   *
-   * @private
-   */
-  _copy () {
-    return new YXmlHook(this.hookName)
-  }
-
-  /**
-   * Creates a Dom Element that mirrors this YXmlElement.
-   *
-   * @param {Document} [_document=document] The document object (you must define
-   *                                        this when calling this method in
-   *                                        nodejs)
-   * @param {Object.<string, any>} [hooks] Optional property to customize how hooks
-   *                                             are presented in the DOM
-   * @param {any} [binding] You should not set this property. This is
-   *                               used if DomBinding wants to create a
-   *                               association to the created DOM type
-   * @return {Element} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
-   *
-   * @public
-   */
-  toDom (_document = document, hooks = {}, binding) {
-    const hook = hooks[this.hookName]
-    let dom
-    if (hook !== undefined) {
-      dom = hook.createDom(this)
-    } else {
-      dom = document.createElement(this.hookName)
-    }
-    dom.setAttribute('data-yjs-hook', this.hookName)
-    if (binding !== undefined) {
-      binding._createAssociation(dom, this)
-    }
-    return dom
-  }
-
-  /**
-   * 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
-   */
-  _write (encoder) {
-    super._write(encoder)
-    encoding.writeVarUint(encoder, YXmlHookRefID)
-    encoding.writeVarString(encoder, this.hookName)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @return {YXmlHook}
- *
- * @private
- * @function
- */
-export const readYXmlHook = decoder =>
-  new YXmlHook(decoding.readVarString(decoder))
--- a/src/types/YXmlText.js
+++ b/src/types/YXmlText.js
@@ -1,51 +0,0 @@
-
-import { YText, YXmlTextRefID } from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js' // eslint-disable-line
-
-/**
- * Represents text in a Dom Element. In the future this type will also handle
- * simple formatting information like bold and italic.
- */
-export class YXmlText extends YText {
-  /**
-   * Creates a Dom Element that mirrors this YXmlText.
-   *
-   * @param {Document} [_document=document] The document object (you must define
-   *                                        this when calling this method in
-   *                                        nodejs)
-   * @param {Object<string, any>} [hooks] Optional property to customize how hooks
-   *                                             are presented in the DOM
-   * @param {any} [binding] You should not set this property. This is
-   *                               used if DomBinding wants to create a
-   *                               association to the created DOM type.
-   * @return {Text} The {@link https://developer.mozilla.org/en-US/docs/Web/API/Element|Dom Element}
-   *
-   * @public
-   */
-  toDom (_document = document, hooks, binding) {
-    const dom = _document.createTextNode(this.toString())
-    if (binding !== undefined) {
-      binding._createAssociation(dom, this)
-    }
-    return dom
-  }
-  /**
-   * @param {encoding.Encoder} encoder
-   *
-   * @private
-   */
-  _write (encoder) {
-    encoding.writeVarUint(encoder, YXmlTextRefID)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @return {YXmlText}
- *
- * @private
- * @function
- */
-export const readYXmlText = decoder => new YXmlText()
--- a/src/utils/DeleteSet.js
+++ b/src/utils/DeleteSet.js
@@ -1,249 +0,0 @@
-
-import {
-  findIndexSS,
-  createID,
-  getState,
-  AbstractItem, StructStore, Transaction, ID // eslint-disable-line
-} from '../internals.js'
-
-import * as math from 'lib0/math.js'
-import * as map from 'lib0/map.js'
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-/**
- * @private
- */
-class DeleteItem {
-  /**
-   * @param {number} clock
-   * @param {number} len
-   */
-  constructor (clock, len) {
-    /**
-     * @type {number}
-     */
-    this.clock = clock
-    /**
-     * @type {number}
-     */
-    this.len = len
-  }
-}
-
-/**
- * We no longer maintain a DeleteStore. DeleteSet is a temporary object that is created when needed.
- * - When created in a transaction, it must only be accessed after sorting, and merging
- *   - This DeleteSet is send to other clients
- * - We do not create a DeleteSet when we send a sync message. The DeleteSet message is created directly from StructStore
- * - We read a DeleteSet as part of a sync/update message. In this case the DeleteSet is already sorted and merged.
- *
- * @private
- */
-export class DeleteSet {
-  constructor () {
-    /**
-     * @type {Map<number,Array<DeleteItem>>}
-     * @private
-     */
-    this.clients = new Map()
-  }
-}
-
-/**
- * @param {Array<DeleteItem>} dis
- * @param {number} clock
- * @return {number|null}
- *
- * @private
- * @function
- */
-export const findIndexDS = (dis, clock) => {
-  let left = 0
-  let right = dis.length - 1
-  while (left <= right) {
-    const midindex = math.floor((left + right) / 2)
-    const mid = dis[midindex]
-    const midclock = mid.clock
-    if (midclock <= clock) {
-      if (clock < midclock + mid.len) {
-        return midindex
-      }
-      left = midindex + 1
-    } else {
-      right = midindex - 1
-    }
-  }
-  return null
-}
-
-/**
- * @param {DeleteSet} ds
- * @param {ID} id
- * @return {boolean}
- *
- * @private
- * @function
- */
-export const isDeleted = (ds, id) => {
-  const dis = ds.clients.get(id.client)
-  return dis !== undefined && findIndexDS(dis, id.clock) !== null
-}
-
-/**
- * @param {DeleteSet} ds
- *
- * @private
- * @function
- */
-export const sortAndMergeDeleteSet = ds => {
-  ds.clients.forEach(dels => {
-    dels.sort((a, b) => a.clock - b.clock)
-    // merge items without filtering or splicing the array
-    // i is the current pointer
-    // j refers to the current insert position for the pointed item
-    // try to merge dels[i] into dels[j-1] or set dels[j]=dels[i]
-    let i, j
-    for (i = 1, j = 1; i < dels.length; i++) {
-      const left = dels[j - 1]
-      const right = dels[i]
-      if (left.clock + left.len === right.clock) {
-        left.len += right.len
-      } else {
-        if (j < i) {
-          dels[j] = right
-        }
-        j++
-      }
-    }
-    dels.length = j
-  })
-}
-
-/**
- * @param {DeleteSet} ds
- * @param {ID} id
- * @param {number} length
- *
- * @private
- * @function
- */
-export const addToDeleteSet = (ds, id, length) => {
-  map.setIfUndefined(ds.clients, id.client, () => []).push(new DeleteItem(id.clock, length))
-}
-
-/**
- * @param {StructStore} ss
- * @return {DeleteSet} Merged and sorted DeleteSet
- *
- * @private
- * @function
- */
-export const createDeleteSetFromStructStore = ss => {
-  const ds = new DeleteSet()
-  ss.clients.forEach((structs, client) => {
-    /**
-     * @type {Array<DeleteItem>}
-     */
-    const dsitems = []
-    for (let i = 0; i < structs.length; i++) {
-      const struct = structs[i]
-      if (struct.deleted) {
-        const clock = struct.id.clock
-        let len = struct.length
-        if (i + 1 < structs.length) {
-          for (let next = structs[i + 1]; i + 1 < structs.length && next.id.clock === clock + len && next.deleted; next = structs[++i + 1]) {
-            len += next.length
-          }
-        }
-        dsitems.push(new DeleteItem(clock, len))
-      }
-    }
-    if (dsitems.length > 0) {
-      ds.clients.set(client, dsitems)
-    }
-  })
-  return ds
-}
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {DeleteSet} ds
- *
- * @private
- * @function
- */
-export const writeDeleteSet = (encoder, ds) => {
-  encoding.writeVarUint(encoder, ds.clients.size)
-  ds.clients.forEach((dsitems, client) => {
-    encoding.writeVarUint(encoder, client)
-    const len = dsitems.length
-    encoding.writeVarUint(encoder, len)
-    for (let i = 0; i < len; i++) {
-      const item = dsitems[i]
-      encoding.writeVarUint(encoder, item.clock)
-      encoding.writeVarUint(encoder, item.len)
-    }
-  })
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @param {Transaction} transaction
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-export const readDeleteSet = (decoder, transaction, store) => {
-  const unappliedDS = new DeleteSet()
-  const numClients = decoding.readVarUint(decoder)
-  for (let i = 0; i < numClients; i++) {
-    const client = decoding.readVarUint(decoder)
-    const numberOfDeletes = decoding.readVarUint(decoder)
-    const structs = store.clients.get(client) || []
-    const state = getState(store, client)
-    for (let i = 0; i < numberOfDeletes; i++) {
-      const clock = decoding.readVarUint(decoder)
-      const len = decoding.readVarUint(decoder)
-      if (clock < state) {
-        if (state < clock + len) {
-          addToDeleteSet(unappliedDS, createID(client, state), clock + len - state)
-        }
-        let index = findIndexSS(structs, clock)
-        /**
-         * We can ignore the case of GC and Delete structs, because we are going to skip them
-         * @type {AbstractItem}
-         */
-        // @ts-ignore
-        let struct = structs[index]
-        // split the first item if necessary
-        if (!struct.deleted && struct.id.clock < clock) {
-          structs.splice(index + 1, 0, struct.splitAt(transaction, clock - struct.id.clock))
-          index++ // increase we now want to use the next struct
-        }
-        while (index < structs.length) {
-          // @ts-ignore
-          struct = structs[index++]
-          if (struct.id.clock < clock + len) {
-            if (!struct.deleted) {
-              if (clock + len < struct.id.clock + struct.length) {
-                structs.splice(index, 0, struct.splitAt(transaction, clock + len - struct.id.clock))
-              }
-              struct.delete(transaction)
-            }
-          } else {
-            break
-          }
-        }
-      } else {
-        addToDeleteSet(unappliedDS, createID(client, clock), len)
-      }
-    }
-  }
-  if (unappliedDS.clients.size > 0) {
-    const unappliedDSEncoder = encoding.createEncoder()
-    writeDeleteSet(unappliedDSEncoder, unappliedDS)
-    store.pendingDeleteReaders.push(decoding.createDecoder(encoding.toBuffer(unappliedDSEncoder)))
-  }
-}
--- a/src/utils/EventHandler.js
+++ b/src/utils/EventHandler.js
@@ -1,82 +0,0 @@
-import * as f from 'lib0/function.js'
-
-/**
- * General event handler implementation.
- *
- * @template ARG0, ARG1
- *
- * @private
- */
-export class EventHandler {
-  constructor () {
-    /**
-     * @type {Array<function(ARG0, ARG1):void>}
-     */
-    this.l = []
-  }
-}
-
-/**
- * @template ARG0,ARG1
- * @returns {EventHandler<ARG0,ARG1>}
- *
- * @private
- * @function
- */
-export const createEventHandler = () => new EventHandler()
-
-/**
- * Adds an event listener that is called when
- * {@link EventHandler#callEventListeners} is called.
- *
- * @template ARG0,ARG1
- * @param {EventHandler<ARG0,ARG1>} eventHandler
- * @param {function(ARG0,ARG1):void} f The event handler.
- *
- * @private
- * @function
- */
-export const addEventHandlerListener = (eventHandler, f) =>
-  eventHandler.l.push(f)
-
-/**
- * Removes an event listener.
- *
- * @template ARG0,ARG1
- * @param {EventHandler<ARG0,ARG1>} eventHandler
- * @param {function(ARG0,ARG1):void} f The event handler that was added with
- *                     {@link EventHandler#addEventListener}
- *
- * @private
- * @function
- */
-export const removeEventHandlerListener = (eventHandler, f) => {
-  eventHandler.l = eventHandler.l.filter(g => f !== g)
-}
-
-/**
- * Removes all event listeners.
- * @template ARG0,ARG1
- * @param {EventHandler<ARG0,ARG1>} eventHandler
- *
- * @private
- * @function
- */
-export const removeAllEventHandlerListeners = eventHandler => {
-  eventHandler.l.length = 0
-}
-
-/**
- * Call all event listeners that were added via
- * {@link EventHandler#addEventListener}.
- *
- * @template ARG0,ARG1
- * @param {EventHandler<ARG0,ARG1>} eventHandler
- * @param {ARG0} arg0
- * @param {ARG1} arg1
- *
- * @private
- * @function
- */
-export const callEventHandlerListeners = (eventHandler, arg0, arg1) =>
-  f.callAll(eventHandler.l, [arg0, arg1])
--- a/src/utils/ID.js
+++ b/src/utils/ID.js
@@ -1,100 +0,0 @@
-
-import { AbstractType } from '../internals' // eslint-disable-line
-
-import * as decoding from 'lib0/decoding.js'
-import * as encoding from 'lib0/encoding.js'
-import * as error from 'lib0/error.js'
-
-export class ID {
-  /**
-   * @param {number} client client id
-   * @param {number} clock unique per client id, continuous number
-   */
-  constructor (client, clock) {
-    /**
-     * Client id
-     * @type {number}
-     */
-    this.client = client
-    /**
-     * unique per client id, continuous number
-     * @type {number}
-     */
-    this.clock = clock
-  }
-  /**
-   * @deprecated
-   * @todo remove and adapt relative position implementation
-   */
-  toJSON () {
-    return {
-      client: this.client,
-      clock: this.clock
-    }
-  }
-}
-
-/**
- * @param {ID | null} a
- * @param {ID | null} b
- * @return {boolean}
- *
- * @function
- */
-export const compareIDs = (a, b) => a === b || (a !== null && b !== null && a.client === b.client && a.clock === b.clock)
-
-/**
- * @param {number} client
- * @param {number} clock
- *
- * @private
- * @function
- */
-export const createID = (client, clock) => new ID(client, clock)
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {ID} id
- *
- * @private
- * @function
- */
-export const writeID = (encoder, id) => {
-  encoding.writeVarUint(encoder, id.client)
-  encoding.writeVarUint(encoder, id.clock)
-}
-
-/**
- * Read ID.
- * * If first varUint read is 0xFFFFFF a RootID is returned.
- * * Otherwise an ID is returned
- *
- * @param {decoding.Decoder} decoder
- * @return {ID}
- *
- * @private
- * @function
- */
-export const readID = decoder =>
-  createID(decoding.readVarUint(decoder), decoding.readVarUint(decoder))
-
-/**
- * The top types are mapped from y.share.get(keyname) => type.
- * `type` does not store any information about the `keyname`.
- * This function finds the correct `keyname` for `type` and throws otherwise.
- *
- * @param {AbstractType<any>} type
- * @return {string}
- *
- * @private
- * @function
- */
-export const findRootTypeKey = type => {
-  // @ts-ignore _y must be defined, otherwise unexpected case
-  for (let [key, value] of type._y.share) {
-    if (value === type) {
-      return key
-    }
-  }
-  throw error.unexpectedCase()
-}
--- a/src/utils/Snapshot.js
+++ b/src/utils/Snapshot.js
@@ -1,44 +0,0 @@
-
-import {
-  DeleteSet,
-  isDeleted,
-  AbstractItem // eslint-disable-line
-} from '../internals.js'
-
-export class Snapshot {
-  /**
-   * @param {DeleteSet} ds delete store
-   * @param {Map<number,number>} sm state map
-   * @param {Map<number,string>} userMap
-   * @private
-   */
-  constructor (ds, sm, userMap) {
-    /**
-     * @type {DeleteSet}
-     * @private
-     */
-    this.ds = new DeleteSet()
-    /**
-     * State Map
-     * @type {Map<number,number>}
-     * @private
-     */
-    this.sm = sm
-    /**
-     * @type {Map<number,string>}
-     * @private
-     */
-    this.userMap = userMap
-  }
-}
-
-/**
- * @param {AbstractItem} item
- * @param {Snapshot|undefined} snapshot
- *
- * @protected
- * @function
- */
-export const isVisible = (item, snapshot) => snapshot === undefined ? !item.deleted : (
-  snapshot.sm.has(item.id.client) && (snapshot.sm.get(item.id.client) || 0) > item.id.clock && !isDeleted(snapshot.ds, item.id)
-)
--- a/src/utils/StructStore.js
+++ b/src/utils/StructStore.js
@@ -1,303 +0,0 @@
-
-import {
-  GC,
-  Transaction, AbstractStructRef, ID, ItemType, AbstractItem, AbstractStruct // eslint-disable-line
-} from '../internals.js'
-
-import * as math from 'lib0/math.js'
-import * as error from 'lib0/error.js'
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-
-export class StructStore {
-  constructor () {
-    /**
-     * @type {Map<number,Array<AbstractStruct>>}
-     * @private
-     */
-    this.clients = new Map()
-    /**
-     * Store incompleted struct reads here
-     * `i` denotes to the next read operation
-     * We could shift the array of refs instead, but shift is incredible
-     * slow in Chrome for arrays with more than 100k elements
-     * @see tryResumePendingStructRefs
-     * @type {Map<number,{i:number,refs:Array<AbstractStructRef>}>}
-     * @private
-     */
-    this.pendingClientsStructRefs = new Map()
-    /**
-     * Stack of pending structs waiting for struct dependencies
-     * Maximum length of stack is structReaders.size
-     * @type {Array<AbstractStructRef>}
-     * @private
-     */
-    this.pendingStack = []
-    /**
-     * @type {Array<decoding.Decoder>}
-     * @private
-     */
-    this.pendingDeleteReaders = []
-  }
-}
-
-/**
- * Return the states as a Map<client,clock>.
- * Note that clock refers to the next expected clock id.
- *
- * @param {StructStore} store
- * @return {Map<number,number>}
- *
- * @public
- * @function
- */
-export const getStates = store => {
-  const sm = new Map()
-  store.clients.forEach((structs, client) => {
-    const struct = structs[structs.length - 1]
-    sm.set(client, struct.id.clock + struct.length)
-  })
-  return sm
-}
-
-/**
- * @param {StructStore} store
- * @param {number} client
- * @return {number}
- *
- * @public
- * @function
- */
-export const getState = (store, client) => {
-  const structs = store.clients.get(client)
-  if (structs === undefined) {
-    return 0
-  }
-  const lastStruct = structs[structs.length - 1]
-  return lastStruct.id.clock + lastStruct.length
-}
-
-/**
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-export const integretyCheck = store => {
-  store.clients.forEach(structs => {
-    for (let i = 1; i < structs.length; i++) {
-      const l = structs[i - 1]
-      const r = structs[i]
-      if (l.id.clock + l.length !== r.id.clock) {
-        throw new Error('StructStore failed integrety check')
-      }
-    }
-  })
-}
-
-/**
- * @param {StructStore} store
- * @param {AbstractStruct} struct
- *
- * @private
- * @function
- */
-export const addStruct = (store, struct) => {
-  let structs = store.clients.get(struct.id.client)
-  if (structs === undefined) {
-    structs = []
-    store.clients.set(struct.id.client, structs)
-  } else {
-    const lastStruct = structs[structs.length - 1]
-    if (lastStruct.id.clock + lastStruct.length !== struct.id.clock) {
-      throw error.unexpectedCase()
-    }
-  }
-  structs.push(struct)
-}
-
-/**
- * Perform a binary search on a sorted array
- * @param {Array<any>} structs
- * @param {number} clock
- * @return {number}
- *
- * @private
- * @function
- */
-export const findIndexSS = (structs, clock) => {
-  let left = 0
-  let right = structs.length - 1
-  while (left <= right) {
-    const midindex = math.floor((left + right) / 2)
-    const mid = structs[midindex]
-    const midclock = mid.id.clock
-    if (midclock <= clock) {
-      if (clock < midclock + mid.length) {
-        return midindex
-      }
-      left = midindex + 1
-    } else {
-      right = midindex - 1
-    }
-  }
-  // Always check state before looking for a struct in StructStore
-  // Therefore the case of not finding a struct is unexpected
-  throw error.unexpectedCase()
-}
-
-/**
- * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
- *
- * @param {StructStore} store
- * @param {ID} id
- * @return {AbstractStruct}
- *
- * @private
- * @function
- */
-export const find = (store, id) => {
-  /**
-   * @type {Array<AbstractStruct>}
-   */
-  // @ts-ignore
-  const structs = store.clients.get(id.client)
-  return structs[findIndexSS(structs, id.clock)]
-}
-
-/**
- * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
- *
- * @param {StructStore} store
- * @param {ID} id
- * @return {AbstractItem}
- *
- * @private
- * @function
- */
-// @ts-ignore
-export const getItem = (store, id) => find(store, id)
-
-/**
- * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
- *
- * @param {StructStore} store
- * @param {ID} id
- * @return {ItemType}
- *
- * @private
- * @function
- */
-// @ts-ignore
-export const getItemType = (store, id) => find(store, id)
-
-/**
- * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
- *
- * @param {Transaction} transaction
- * @param {StructStore} store
- * @param {ID} id
- * @return {AbstractItem}
- *
- * @private
- * @function
- */
-export const getItemCleanStart = (transaction, store, id) => {
-  /**
-   * @type {Array<AbstractItem>}
-   */
-  // @ts-ignore
-  const structs = store.clients.get(id.client)
-  const index = findIndexSS(structs, id.clock)
-  /**
-   * @type {AbstractItem}
-   */
-  let struct = structs[index]
-  if (struct.id.clock < id.clock && struct.constructor !== GC) {
-    struct = struct.splitAt(transaction, id.clock - struct.id.clock)
-    structs.splice(index + 1, 0, struct)
-  }
-  return struct
-}
-
-/**
- * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
- *
- * @param {Transaction} transaction
- * @param {StructStore} store
- * @param {ID} id
- * @return {AbstractItem}
- *
- * @private
- * @function
- */
-export const getItemCleanEnd = (transaction, store, id) => {
-  /**
-   * @type {Array<AbstractItem>}
-   */
-  // @ts-ignore
-  const structs = store.clients.get(id.client)
-  const index = findIndexSS(structs, id.clock)
-  const struct = structs[index]
-  if (id.clock !== struct.id.clock + struct.length - 1 && struct.constructor !== GC) {
-    structs.splice(index + 1, 0, struct.splitAt(transaction, id.clock - struct.id.clock + 1))
-  }
-  return struct
-}
-
-/**
- * Replace `item` with `newitem` in store
- * @param {StructStore} store
- * @param {AbstractStruct} struct
- * @param {AbstractStruct} newStruct
- *
- * @private
- * @function
- */
-export const replaceStruct = (store, struct, newStruct) => {
-  /**
-   * @type {Array<AbstractStruct>}
-   */
-  // @ts-ignore
-  const structs = store.clients.get(struct.id.client)
-  structs[findIndexSS(structs, struct.id.clock)] = newStruct
-}
-
-/**
- * Read StateMap from Decoder and return as Map
- *
- * @param {decoding.Decoder} decoder
- * @return {Map<number,number>}
- *
- * @private
- * @function
- */
-export const readStatesAsMap = decoder => {
-  const ss = new Map()
-  const ssLength = decoding.readVarUint(decoder)
-  for (let i = 0; i < ssLength; i++) {
-    const client = decoding.readVarUint(decoder)
-    const clock = decoding.readVarUint(decoder)
-    ss.set(client, clock)
-  }
-  return ss
-}
-
-/**
- * Write StateMap to Encoder
- *
- * @param {encoding.Encoder} encoder
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-export const writeStates = (encoder, store) => {
-  encoding.writeVarUint(encoder, store.clients.size)
-  store.clients.forEach((structs, client) => {
-    const id = structs[structs.length - 1].id
-    encoding.writeVarUint(encoder, id.client)
-    encoding.writeVarUint(encoder, id.clock)
-  })
-  return encoder
-}
--- a/src/utils/Transaction.js
+++ b/src/utils/Transaction.js
@@ -1,244 +0,0 @@
-
-import {
-  getState,
-  createID,
-  writeStructsFromTransaction,
-  writeDeleteSet,
-  DeleteSet,
-  sortAndMergeDeleteSet,
-  getStates,
-  findIndexSS,
-  callEventHandlerListeners,
-  AbstractItem,
-  ItemDeleted,
-  ID, AbstractType, AbstractStruct, YEvent, Y // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as map from 'lib0/map.js'
-import * as math from 'lib0/math.js'
-
-/**
- * A transaction is created for every change on the Yjs model. It is possible
- * to bundle changes on the Yjs model in a single transaction to
- * minimize the number on messages sent and the number of observer calls.
- * If possible the user of this library should bundle as many changes as
- * possible. Here is an example to illustrate the advantages of bundling:
- *
- * @example
- * const map = y.define('map', YMap)
- * // Log content when change is triggered
- * map.observe(() => {
- *   console.log('change triggered')
- * })
- * // Each change on the map type triggers a log message:
- * map.set('a', 0) // => "change triggered"
- * map.set('b', 0) // => "change triggered"
- * // When put in a transaction, it will trigger the log after the transaction:
- * y.transact(() => {
- *   map.set('a', 1)
- *   map.set('b', 1)
- * }) // => "change triggered"
- *
- * @public
- */
-export class Transaction {
-  /**
-   * @param {Y} y
-   */
-  constructor (y) {
-    /**
-     * The Yjs instance.
-     * @type {Y}
-     */
-    this.y = y
-    /**
-     * Describes the set of deleted items by ids
-     * @type {DeleteSet}
-     */
-    this.deleteSet = new DeleteSet()
-    /**
-     * Holds the state before the transaction started.
-     * @type {Map<Number,Number>}
-     */
-    this.beforeState = getStates(y.store)
-    /**
-     * Holds the state after the transaction.
-     * @type {Map<Number,Number>}
-     */
-    this.afterState = new Map()
-    /**
-     * All types that were directly modified (property added or child
-     * inserted/deleted). New types are not included in this Set.
-     * Maps from type to parentSubs (`item._parentSub = null` for YArray)
-     * @type {Map<AbstractType<YEvent>,Set<String|null>>}
-     */
-    this.changed = new Map()
-    /**
-     * Stores the events for the types that observe also child elements.
-     * It is mainly used by `observeDeep`.
-     * @type {Map<AbstractType<YEvent>,Array<YEvent>>}
-     */
-    this.changedParentTypes = new Map()
-    /**
-     * @type {encoding.Encoder|null}
-     * @private
-     */
-    this._updateMessage = null
-    /**
-     * @type {Set<ID>}
-     * @private
-     */
-    this._mergeStructs = new Set()
-  }
-  /**
-   * @type {encoding.Encoder|null}
-   * @public
-   */
-  get updateMessage () {
-    // only create if content was added in transaction (state or ds changed)
-    if (this._updateMessage === null && (this.deleteSet.clients.size > 0 || map.any(this.afterState, (clock, client) => this.beforeState.get(client) !== clock))) {
-      const encoder = encoding.createEncoder()
-      sortAndMergeDeleteSet(this.deleteSet)
-      writeStructsFromTransaction(encoder, this)
-      writeDeleteSet(encoder, this.deleteSet)
-      this._updateMessage = encoder
-    }
-    return this._updateMessage
-  }
-}
-
-/**
- * @param {Transaction} transaction
- *
- * @private
- * @function
- */
-export const nextID = transaction => {
-  const y = transaction.y
-  return createID(y.clientID, getState(y.store, y.clientID))
-}
-
-/**
- * Implements the functionality of `y.transact(()=>{..})`
- *
- * @param {Y} y
- * @param {function(Transaction):void} f
- *
- * @private
- * @function
- */
-export const transact = (y, f) => {
-  let initialCall = false
-  if (y._transaction === null) {
-    initialCall = true
-    y._transaction = new Transaction(y)
-    y.emit('beforeTransaction', [y._transaction, y])
-  }
-  const transaction = y._transaction
-  try {
-    f(transaction)
-  } finally {
-    if (initialCall) {
-      y._transaction = null
-      y.emit('beforeObserverCalls', [transaction, y])
-      // emit change events on changed types
-      transaction.changed.forEach((subs, itemtype) => {
-        itemtype._callObserver(transaction, subs)
-      })
-      transaction.changedParentTypes.forEach((events, type) => {
-        events = events
-          .filter(event =>
-            event.target._item === null || !event.target._item.deleted
-          )
-        events
-          .forEach(event => {
-            event.currentTarget = type
-          })
-        // we don't need to check for events.length
-        // because we know it has at least one element
-        callEventHandlerListeners(type._dEH, events, transaction)
-      })
-      // only call afterTransaction listeners if anything changed
-      transaction.afterState = getStates(transaction.y.store)
-      // when all changes & events are processed, emit afterTransaction event
-      // transaction cleanup
-      const store = transaction.y.store
-      const ds = transaction.deleteSet
-      // replace deleted items with ItemDeleted / GC
-      sortAndMergeDeleteSet(ds)
-      y.emit('afterTransaction', [transaction, y])
-      for (const [client, deleteItems] of ds.clients) {
-        /**
-         * @type {Array<AbstractStruct>}
-         */
-        // @ts-ignore
-        const structs = store.clients.get(client)
-        for (let di = 0; di < deleteItems.length; di++) {
-          const deleteItem = deleteItems[di]
-          for (let si = findIndexSS(structs, deleteItem.clock); si < structs.length; si++) {
-            const struct = structs[si]
-            if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
-              break
-            }
-            if (struct.deleted && struct instanceof AbstractItem && (struct.constructor !== ItemDeleted || (struct.parent._item !== null && struct.parent._item.deleted))) {
-              // check if we can GC
-              struct.gc(transaction, store)
-            }
-          }
-        }
-      }
-      /**
-       * @param {Array<AbstractStruct>} structs
-       * @param {number} pos
-       */
-      const tryToMergeWithLeft = (structs, pos) => {
-        const left = structs[pos - 1]
-        const right = structs[pos]
-        if (left.deleted === right.deleted && left.constructor === right.constructor) {
-          if (left.mergeWith(right)) {
-            structs.splice(pos, 1)
-            if (right instanceof AbstractItem && right.parentSub !== null && right.parent._map.get(right.parentSub) === right) {
-              // @ts-ignore we already did a constructor check above
-              right.parent._map.set(right.parentSub, left)
-            }
-          }
-        }
-      }
-      // on all affected store.clients props, try to merge
-      for (const [client, clock] of transaction.afterState) {
-        const beforeClock = transaction.beforeState.get(client) || 0
-        if (beforeClock !== clock) {
-          /**
-           * @type {Array<AbstractStruct>}
-           */
-          // @ts-ignore
-          const structs = store.clients.get(client)
-          // we iterate from right to left so we can safely remove entries
-          const firstChangePos = math.max(findIndexSS(structs, beforeClock), 1)
-          for (let i = structs.length - 1; i >= firstChangePos; i--) {
-            tryToMergeWithLeft(structs, i)
-          }
-        }
-      }
-      // try to merge mergeStructs
-      for (const mid of transaction._mergeStructs) {
-        const client = mid.client
-        const clock = mid.clock
-        /**
-         * @type {Array<AbstractStruct>}
-         */
-        // @ts-ignore
-        const structs = store.clients.get(client)
-        const replacedStructPos = findIndexSS(structs, clock)
-        if (replacedStructPos + 1 < structs.length) {
-          tryToMergeWithLeft(structs, replacedStructPos + 1)
-        }
-        if (replacedStructPos > 0) {
-          tryToMergeWithLeft(structs, replacedStructPos)
-        }
-      }
-      y.emit('afterTransactionCleanup', [transaction, y])
-    }
-  }
-}
--- a/src/utils/UndoManager.js
+++ b/src/utils/UndoManager.js
@@ -1,202 +0,0 @@
-// @ts-nocheck
-
-import {
-  isParentOf,
-  createID,
-  transact
-} from '../internals.js'
-
-/**
- * @private
- */
-class ReverseOperation {
-  constructor (y, transaction, bindingInfos) {
-    this.created = new Date()
-    const beforeState = transaction.beforeState
-    if (beforeState.has(y.userID)) {
-      this.toState = createID(y.userID, y.ss.getState(y.userID) - 1)
-      this.fromState = createID(y.userID, beforeState.get(y.userID))
-    } else {
-      this.toState = null
-      this.fromState = null
-    }
-    this.deletedStructs = new Set()
-    transaction.deletedStructs.forEach(struct => {
-      this.deletedStructs.add({
-        from: struct._id,
-        len: struct._length
-      })
-    })
-    /**
-     * Maps from binding to binding information (e.g. cursor information)
-     */
-    this.bindingInfos = bindingInfos
-  }
-}
-
-/**
- * @private
- * @function
- */
-function applyReverseOperation (y, scope, reverseBuffer) {
-  let performedUndo = false
-  let undoOp = null
-  transact(y, () => {
-    while (!performedUndo && reverseBuffer.length > 0) {
-      undoOp = reverseBuffer.pop()
-      // make sure that it is possible to iterate {from}-{to}
-      if (undoOp.fromState !== null) {
-        y.os.getItemCleanStart(undoOp.fromState)
-        y.os.getItemCleanEnd(undoOp.toState)
-        y.os.iterate(undoOp.fromState, undoOp.toState, op => {
-          while (op._deleted && op._redone !== null) {
-            op = op._redone
-          }
-          if (op._deleted === false && isParentOf(scope, op)) {
-            performedUndo = true
-            op._delete(y)
-          }
-        })
-      }
-      const redoitems = new Set()
-      for (let del of undoOp.deletedStructs) {
-        const fromState = del.from
-        const toState = createID(fromState.user, fromState.clock + del.len - 1)
-        y.os.getItemCleanStart(fromState)
-        y.os.getItemCleanEnd(toState)
-        y.os.iterate(fromState, toState, op => {
-          if (
-            isParentOf(scope, op) &&
-            op._parent !== y &&
-            (
-              op._id.user !== y.userID ||
-              undoOp.fromState === null ||
-              op._id.clock < undoOp.fromState.clock ||
-              op._id.clock > undoOp.toState.clock
-            )
-          ) {
-            redoitems.add(op)
-          }
-        })
-      }
-      redoitems.forEach(op => {
-        const opUndone = op._redo(y, redoitems)
-        performedUndo = performedUndo || opUndone
-      })
-    }
-  })
-  if (performedUndo && undoOp !== null) {
-    // should be performed after the undo transaction
-    undoOp.bindingInfos.forEach((info, binding) => {
-      binding._restoreUndoStackInfo(info)
-    })
-  }
-  return performedUndo
-}
-
-/**
- * Saves a history of locally applied operations. The UndoManager handles the
- * undoing and redoing of locally created changes.
- *
- * @private
- * @function
- */
-export class UndoManager {
-  /**
-   * @param {YType} scope The scope on which to listen for changes.
-   * @param {Object} options Optionally provided configuration.
-   */
-  constructor (scope, options = {}) {
-    this.options = options
-    this._bindings = new Set(options.bindings)
-    options.captureTimeout = options.captureTimeout == null ? 500 : options.captureTimeout
-    this._undoBuffer = []
-    this._redoBuffer = []
-    this._scope = scope
-    this._undoing = false
-    this._redoing = false
-    this._lastTransactionWasUndo = false
-    const y = scope._y
-    this.y = y
-    let bindingInfos
-    y.on('beforeTransaction', (y, transaction, remote) => {
-      if (!remote) {
-        // Store binding information before transaction is executed
-        // By restoring the binding information, we can make sure that the state
-        // before the transaction can be recovered
-        bindingInfos = new Map()
-        this._bindings.forEach(binding => {
-          bindingInfos.set(binding, binding._getUndoStackInfo())
-        })
-      }
-    })
-    y.on('afterTransaction', (y, transaction, remote) => {
-      if (!remote && transaction.changedParentTypes.has(scope)) {
-        let reverseOperation = new ReverseOperation(y, transaction, bindingInfos)
-        if (!this._undoing) {
-          let lastUndoOp = this._undoBuffer.length > 0 ? this._undoBuffer[this._undoBuffer.length - 1] : null
-          if (
-            this._redoing === false &&
-            this._lastTransactionWasUndo === false &&
-            lastUndoOp !== null &&
-            ((options.captureTimeout < 0) || (reverseOperation.created.getTime() - lastUndoOp.created.getTime()) <= options.captureTimeout)
-          ) {
-            lastUndoOp.created = reverseOperation.created
-            if (reverseOperation.toState !== null) {
-              lastUndoOp.toState = reverseOperation.toState
-              if (lastUndoOp.fromState === null) {
-                lastUndoOp.fromState = reverseOperation.fromState
-              }
-            }
-            reverseOperation.deletedStructs.forEach(lastUndoOp.deletedStructs.add, lastUndoOp.deletedStructs)
-          } else {
-            this._lastTransactionWasUndo = false
-            this._undoBuffer.push(reverseOperation)
-          }
-          if (!this._redoing) {
-            this._redoBuffer = []
-          }
-        } else {
-          this._lastTransactionWasUndo = true
-          this._redoBuffer.push(reverseOperation)
-        }
-      }
-    })
-  }
-
-  /**
-   * Enforce that the next change is created as a separate item in the undo stack
-   *
-   * @private
-   * @function
-   */
-  flushChanges () {
-    this._lastTransactionWasUndo = true
-  }
-
-  /**
-   * Undo the last locally created change.
-   *
-   * @private
-   * @function
-   */
-  undo () {
-    this._undoing = true
-    const performedUndo = applyReverseOperation(this.y, this._scope, this._undoBuffer)
-    this._undoing = false
-    return performedUndo
-  }
-
-  /**
-   * Redo the last locally created change.
-   *
-   * @private
-   * @function
-   */
-  redo () {
-    this._redoing = true
-    const performedRedo = applyReverseOperation(this.y, this._scope, this._redoBuffer)
-    this._redoing = false
-    return performedRedo
-  }
-}
--- a/src/utils/Y.js
+++ b/src/utils/Y.js
@@ -1,169 +0,0 @@
-/**
- * @module Y
- */
-
-import {
-  StructStore,
-  AbstractType,
-  YArray,
-  YText,
-  YMap,
-  YXmlFragment,
-  transact,
-  Transaction, YEvent // eslint-disable-line
-} from '../internals.js'
-
-import { Observable } from 'lib0/observable.js'
-import * as random from 'lib0/random.js'
-import * as map from 'lib0/map.js'
-
-/**
- * A Yjs instance handles the state of shared data.
- * @extends Observable<string>
- */
-export class Y extends Observable {
-  /**
-   * @param {Object|undefined} conf configuration
-   */
-  constructor (conf = {}) {
-    super()
-    // todo: change to clientId
-    this.clientID = random.uint32()
-    /**
-     * @type {Map<string, AbstractType<YEvent>>}
-     */
-    this.share = new Map()
-    this.store = new StructStore()
-    /**
-     * @type {Transaction | null}
-     * @private
-     */
-    this._transaction = null
-  }
-  /**
-   * Changes that happen inside of a transaction are bundled. This means that
-   * the observer fires _after_ the transaction is finished and that all changes
-   * that happened inside of the transaction are sent as one message to the
-   * other peers.
-   *
-   * @param {function(Transaction):void} f The function that should be executed as a transaction
-   *
-   * @public
-   */
-  transact (f) {
-    transact(this, f)
-  }
-  /**
-   * Define a shared data type.
-   *
-   * Multiple calls of `y.get(name, TypeConstructor)` yield the same result
-   * and do not overwrite each other. I.e.
-   * `y.define(name, Y.Array) === y.define(name, Y.Array)`
-   *
-   * After this method is called, the type is also available on `y.share.get(name)`.
-   *
-   * *Best Practices:*
-   * Define all types right after the Yjs instance is created and store them in a separate object.
-   * Also use the typed methods `getText(name)`, `getArray(name)`, ..
-   *
-   * @example
-   *   const y = new Y(..)
-   *   const appState = {
-   *     document: y.getText('document')
-   *     comments: y.getArray('comments')
-   *   }
-   *
-   * @param {string} name
-   * @param {Function} TypeConstructor The constructor of the type definition
-   * @return {AbstractType<any>} The created type. Constructed with TypeConstructor
-   *
-   * @public
-   */
-  get (name, TypeConstructor = AbstractType) {
-    const type = map.setIfUndefined(this.share, name, () => {
-      // @ts-ignore
-      const t = new TypeConstructor()
-      t._integrate(this, null)
-      return t
-    })
-    const Constr = type.constructor
-    if (TypeConstructor !== AbstractType && Constr !== TypeConstructor) {
-      if (Constr === AbstractType) {
-        const t = new Constr()
-        t._map = type._map
-        t._start = type._start
-        t._length = type._length
-        this.share.set(name, t)
-        t._integrate(this, null)
-        return t
-      } else {
-        throw new Error(`Type with the name ${name} has already been defined with a different constructor`)
-      }
-    }
-    return type
-  }
-  /**
-   * @template T
-   * @param {string} name
-   * @return {YArray<T>}
-   *
-   * @public
-   */
-  getArray (name) {
-    // @ts-ignore
-    return this.get(name, YArray)
-  }
-  /**
-   * @param {string} name
-   * @return {YText}
-   *
-   * @public
-   */
-  getText (name) {
-    // @ts-ignore
-    return this.get(name, YText)
-  }
-  /**
-   * @param {string} name
-   * @return {YMap<any>}
-   *
-   * @public
-   */
-  getMap (name) {
-    // @ts-ignore
-    return this.get(name, YMap)
-  }
-  /**
-   * @param {string} name
-   * @return {YXmlFragment}
-   *
-   * @public
-   */
-  getXmlFragment (name) {
-    // @ts-ignore
-    return this.get(name, YXmlFragment)
-  }
-  /**
-   * Emit `destroy` event and unregister all event handlers.
-   *
-   * @protected
-   */
-  destroy () {
-    this.emit('destroyed', [true])
-    super.destroy()
-  }
-  /**
-   * @param {string} eventName
-   * @param {function} f
-   */
-  on (eventName, f) {
-    super.on(eventName, f)
-  }
-  /**
-   * @param {string} eventName
-   * @param {function} f
-   */
-  off (eventName, f) {
-    super.off(eventName, f)
-  }
-}
--- a/src/utils/YEvent.js
+++ b/src/utils/YEvent.js
@@ -1,108 +0,0 @@
-
-import {
-  isDeleted,
-  AbstractType, Transaction, AbstractStruct // eslint-disable-line
-} from '../internals.js'
-
-/**
- * YEvent describes the changes on a YType.
- */
-export class YEvent {
-  /**
-   * @param {AbstractType<any>} target The changed type.
-   * @param {Transaction} transaction
-   */
-  constructor (target, transaction) {
-    /**
-     * The type on which this event was created on.
-     * @type {AbstractType<any>}
-     */
-    this.target = target
-    /**
-     * The current target on which the observe callback is called.
-     * @type {AbstractType<any>}
-     */
-    this.currentTarget = target
-    /**
-     * The transaction that triggered this event.
-     * @type {Transaction}
-     */
-    this.transaction = transaction
-  }
-
-  /**
-   * Computes the path from `y` to the changed type.
-   *
-   * The following property holds:
-   * @example
-   *   let type = y
-   *   event.path.forEach(dir => {
-   *     type = type.get(dir)
-   *   })
-   *   type === event.target // => true
-   */
-  get path () {
-    // @ts-ignore _item is defined because target is integrated
-    return getPathTo(this.currentTarget, this.target)
-  }
-
-  /**
-   * Check if a struct is deleted by this event.
-   *
-   * @param {AbstractStruct} struct
-   * @return {boolean}
-   */
-  deletes (struct) {
-    return isDeleted(this.transaction.deleteSet, struct.id)
-  }
-
-  /**
-   * Check if a struct is added by this event.
-   *
-   * @param {AbstractStruct} struct
-   * @return {boolean}
-   */
-  adds (struct) {
-    return struct.id.clock >= (this.transaction.beforeState.get(struct.id.client) || 0)
-  }
-}
-
-/**
- * Compute the path from this type to the specified target.
- *
- * @example
- *   // `child` should be accessible via `type.get(path[0]).get(path[1])..`
- *   const path = type.getPathTo(child)
- *   // assuming `type instanceof YArray`
- *   console.log(path) // might look like => [2, 'key1']
- *   child === type.get(path[0]).get(path[1])
- *
- * @param {AbstractType<any>} parent
- * @param {AbstractType<any>} child target
- * @return {Array<string|number>} Path to the target
- *
- * @private
- * @function
- */
-const getPathTo = (parent, child) => {
-  const path = []
-  while (child._item !== null && child !== parent) {
-    if (child._item.parentSub !== null) {
-      // parent is map-ish
-      path.unshift(child._item.parentSub)
-    } else {
-      // parent is array-ish
-      let i = 0
-      let c = child._item.parent._start
-      while (c !== child._item && c !== null) {
-        if (!c.deleted) {
-          i++
-        }
-        c = c.right
-      }
-      path.unshift(i)
-    }
-    child = child._item.parent
-  }
-  return path
-}
--- a/src/utils/cursor.js
+++ b/src/utils/cursor.js
@@ -1,266 +0,0 @@
-/**
- * @module Cursors
- */
-
-import {
-  getItem,
-  getItemType,
-  createID,
-  writeID,
-  readID,
-  compareIDs,
-  getState,
-  findRootTypeKey,
-  AbstractItem,
-  ID, StructStore, Y, AbstractType // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-import * as error from 'lib0/error.js'
-
-/**
- * A Cursor is a relative position that is based on the Yjs model. In contrast to an
- * absolute position (position by index), the Cursor can be
- * recomputed when remote changes are received. For example:
- *
- * ```Insert(0, 'x')('a|bc') = 'xa|bc'``` Where | is the cursor position.
- *
- * A relative cursor position can be obtained with the function
- *
- * One of the properties must be defined.
- *
- * @example
- *   // Current cursor position is at position 10
- *   const relativePosition = createCursorFromOffset(yText, 10)
- *   // modify yText
- *   yText.insert(0, 'abc')
- *   yText.delete(3, 10)
- *   // Compute the cursor position
- *   const absolutePosition = toAbsolutePosition(y, relativePosition)
- *   absolutePosition.type === yText // => true
- *   console.log('cursor location is ' + absolutePosition.offset) // => cursor location is 3
- *
- */
-export class Cursor {
-  /**
-   * @param {ID|null} type
-   * @param {string|null} tname
-   * @param {ID|null} item
-   */
-  constructor (type, tname, item) {
-    /**
-     * @type {ID|null}
-     */
-    this.type = type
-    /**
-     * @type {string|null}
-     */
-    this.tname = tname
-    /**
-     * @type {ID | null}
-     */
-    this.item = item
-  }
-  toJSON () {
-    const json = {}
-    if (this.type !== null) {
-      json.type = this.type.toJSON()
-    }
-    if (this.tname !== null) {
-      json.tname = this.tname
-    }
-    if (this.item !== null) {
-      json.item = this.item.toJSON()
-    }
-    return json
-  }
-}
-
-/**
- * @param {Object} json
- * @return {Cursor}
- *
- * @function
- */
-export const createCursorFromJSON = json => new Cursor(json.type == null ? null : createID(json.type.client, json.type.clock), json.tname || null, json.item == null ? null : createID(json.item.client, json.item.clock))
-
-export class AbsolutePosition {
-  /**
-   * @param {AbstractType<any>} type
-   * @param {number} offset
-   */
-  constructor (type, offset) {
-    /**
-     * @type {AbstractType<any>}
-     */
-    this.type = type
-    /**
-     * @type {number}
-     */
-    this.offset = offset
-  }
-}
-
-/**
- * @param {AbstractType<any>} type
- * @param {number} offset
- *
- * @function
- */
-export const createAbsolutePosition = (type, offset) => new AbsolutePosition(type, offset)
-
-/**
- * @param {AbstractType<any>} type
- * @param {ID|null} item
- *
- * @function
- */
-export const createCursor = (type, item) => {
-  let typeid = null
-  let tname = null
-  if (type._item === null) {
-    tname = findRootTypeKey(type)
-  } else {
-    typeid = type._item.id
-  }
-  return new Cursor(typeid, tname, item)
-}
-
-/**
- * Create a relativePosition based on a absolute position.
- *
- * @param {AbstractType<any>} type The base type (e.g. YText or YArray).
- * @param {number} offset The absolute position.
- * @return {Cursor}
- *
- * @function
- */
-export const createCursorFromTypeOffset = (type, offset) => {
-  let t = type._start
-  while (t !== null) {
-    if (!t.deleted && t.countable) {
-      if (t.length > offset) {
-        // case 1: found position somewhere in the linked list
-        return createCursor(type, createID(t.id.client, t.id.clock + offset))
-      }
-      offset -= t.length
-    }
-    t = t.right
-  }
-  return createCursor(type, null)
-}
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {Cursor} rpos
- *
- * @function
- */
-export const writeCursor = (encoder, rpos) => {
-  const { type, tname, item } = rpos
-  if (item !== null) {
-    encoding.writeVarUint(encoder, 0)
-    writeID(encoder, item)
-  } else if (tname !== null) {
-    // case 2: found position at the end of the list and type is stored in y.share
-    encoding.writeUint8(encoder, 1)
-    encoding.writeVarString(encoder, tname)
-  } else if (type !== null) {
-    // case 3: found position at the end of the list and type is attached to an item
-    encoding.writeUint8(encoder, 2)
-    writeID(encoder, type)
-  } else {
-    throw error.unexpectedCase()
-  }
-  return encoder
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @param {Y} y
- * @param {StructStore} store
- * @return {Cursor|null}
- *
- * @function
- */
-export const readCursor = (decoder, y, store) => {
-  let type = null
-  let tname = null
-  let itemID = null
-  switch (decoding.readVarUint(decoder)) {
-    case 0:
-      // case 1: found position somewhere in the linked list
-      itemID = readID(decoder)
-      break
-    case 1:
-      // case 2: found position at the end of the list and type is stored in y.share
-      tname = decoding.readVarString(decoder)
-      break
-    case 2: {
-      // case 3: found position at the end of the list and type is attached to an item
-      type = readID(decoder)
-    }
-  }
-  return new Cursor(type, tname, itemID)
-}
-
-/**
- * @param {Cursor} cursor
- * @param {Y} y
- * @return {AbsolutePosition|null}
- *
- * @function
- */
-export const createAbsolutePositionFromCursor = (cursor, y) => {
-  const store = y.store
-  const rightID = cursor.item
-  const typeID = cursor.type
-  const tname = cursor.tname
-  let type = null
-  let offset = 0
-  if (rightID !== null) {
-    if (getState(store, rightID.client) <= rightID.clock) {
-      return null
-    }
-    const right = getItem(store, rightID)
-    if (!(right instanceof AbstractItem)) {
-      return null
-    }
-    offset = right.deleted || !right.countable ? 0 : rightID.clock - right.id.clock
-    let n = right.left
-    while (n !== null) {
-      if (!n.deleted && n.countable) {
-        offset += n.length
-      }
-      n = n.left
-    }
-    type = right.parent
-  } else {
-    if (tname !== null) {
-      type = y.get(tname)
-    } else if (typeID !== null) {
-      type = getItemType(store, typeID).type
-    } else {
-      throw error.unexpectedCase()
-    }
-    offset = type._length
-  }
-  if (type._item !== null && type._item.deleted) {
-    return null
-  }
-  return createAbsolutePosition(type, offset)
-}
-
-/**
- * @param {Cursor|null} a
- * @param {Cursor|null} b
- *
- * @function
- */
-export const compareCursors = (a, b) => a === b || (
-  a !== null && b !== null && a.tname === b.tname && (
-    (a.item !== null && b.item !== null && compareIDs(a.item, b.item)) ||
-    (a.type !== null && b.type !== null && compareIDs(a.type, b.type))
-  )
-)
--- a/src/utils/encoding.js
+++ b/src/utils/encoding.js
@@ -1,321 +0,0 @@
-
-/**
- * @module encoding
- */
-
-import {
-  findIndexSS,
-  GCRef,
-  ItemBinaryRef,
-  ItemDeletedRef,
-  ItemEmbedRef,
-  ItemFormatRef,
-  ItemJSONRef,
-  ItemStringRef,
-  ItemTypeRef,
-  writeID,
-  createID,
-  readID,
-  getState,
-  getStates,
-  readDeleteSet,
-  writeDeleteSet,
-  createDeleteSetFromStructStore,
-  Transaction, AbstractStruct, AbstractStructRef, StructStore, ID // eslint-disable-line
-} from '../internals.js'
-
-import * as encoding from 'lib0/encoding.js'
-import * as decoding from 'lib0/decoding.js'
-import * as binary from 'lib0/binary.js'
-
-/**
- * @private
- */
-export const structRefs = [
-  GCRef,
-  ItemBinaryRef,
-  ItemDeletedRef,
-  ItemEmbedRef,
-  ItemFormatRef,
-  ItemJSONRef,
-  ItemStringRef,
-  ItemTypeRef
-]
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {Array<AbstractStruct>} structs All structs by `client`
- * @param {number} client
- * @param {number} clock write structs starting with `ID(client,clock)`
- *
- * @function
- */
-const writeStructs = (encoder, structs, client, clock) => {
-  // write first id
-  const startNewStructs = findIndexSS(structs, clock)
-  // write # encoded structs
-  encoding.writeVarUint(encoder, structs.length - startNewStructs)
-  writeID(encoder, createID(client, clock))
-  const firstStruct = structs[startNewStructs]
-  // write first struct with an offset
-  firstStruct.write(encoder, clock - firstStruct.id.clock, 0)
-  for (let i = startNewStructs + 1; i < structs.length; i++) {
-    structs[i].write(encoder, 0, 0)
-  }
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @param {number} numOfStructs
- * @param {ID} nextID
- * @return {Array<AbstractStructRef>}
- *
- * @private
- * @function
- */
-const readStructRefs = (decoder, numOfStructs, nextID) => {
-  /**
-   * @type {Array<AbstractStructRef>}
-   */
-  const refs = []
-  for (let i = 0; i < numOfStructs; i++) {
-    const info = decoding.readUint8(decoder)
-    const ref = new structRefs[binary.BITS5 & info](decoder, nextID, info)
-    nextID = createID(nextID.client, nextID.clock + ref.length)
-    refs.push(ref)
-  }
-  return refs
-}
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {StructStore} store
- * @param {Map<number,number>} _sm
- *
- * @private
- * @function
- */
-export const writeClientsStructs = (encoder, store, _sm) => {
-  // we filter all valid _sm entries into sm
-  const sm = new Map()
-  _sm.forEach((clock, client) => {
-    // only write if new structs are available
-    if (getState(store, client) > clock) {
-      sm.set(client, clock)
-    }
-  })
-  getStates(store).forEach((clock, client) => {
-    if (!_sm.has(client)) {
-      sm.set(client, 0)
-    }
-  })
-  // write # states that were updated
-  encoding.writeVarUint(encoder, sm.size)
-  sm.forEach((clock, client) => {
-    // @ts-ignore
-    writeStructs(encoder, store.clients.get(client), client, clock)
-  })
-}
-
-/**
- * @param {decoding.Decoder} decoder The decoder object to read data from.
- * @return {Map<number,Array<AbstractStructRef>>}
- *
- * @private
- * @function
- */
-export const readClientsStructRefs = decoder => {
-  /**
-   * @type {Map<number,Array<AbstractStructRef>>}
-   */
-  const clientRefs = new Map()
-  const numOfStateUpdates = decoding.readVarUint(decoder)
-  for (let i = 0; i < numOfStateUpdates; i++) {
-    const numberOfStructs = decoding.readVarUint(decoder)
-    const nextID = readID(decoder)
-    const refs = readStructRefs(decoder, numberOfStructs, nextID)
-    clientRefs.set(nextID.client, refs)
-  }
-  return clientRefs
-}
-
-/**
- * Resume computing structs generated by struct readers.
- *
- * While there is something to do, we integrate structs in this order
- * 1. top element on stack, if stack is not empty
- * 2. next element from current struct reader (if empty, use next struct reader)
- *
- * If struct causally depends on another struct (ref.missing), we put next reader of
- * `ref.id.client` on top of stack.
- *
- * At some point we find a struct that has no causal dependencies,
- * then we start emptying the stack.
- *
- * It is not possible to have circles: i.e. struct1 (from client1) depends on struct2 (from client2)
- * depends on struct3 (from client1). Therefore the max stack size is eqaul to `structReaders.length`.
- *
- * This method is implemented in a way so that we can resume computation if this update
- * causally depends on another update.
- *
- * @param {Transaction} transaction
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-const resumeStructIntegration = (transaction, store) => {
-  const stack = store.pendingStack
-  const clientsStructRefs = store.pendingClientsStructRefs
-  // iterate over all struct readers until we are done
-  while (stack.length !== 0 || clientsStructRefs.size !== 0) {
-    if (stack.length === 0) {
-      // take any first struct from clientsStructRefs and put it on the stack
-      const [client, structRefs] = clientsStructRefs.entries().next().value
-      stack.push(structRefs.refs[structRefs.i++])
-      if (structRefs.refs.length === structRefs.i) {
-        clientsStructRefs.delete(client)
-      }
-    }
-    const ref = stack[stack.length - 1]
-    const m = ref._missing
-    const client = ref.id.client
-    const localClock = getState(store, client)
-    const offset = ref.id.clock < localClock ? localClock - ref.id.clock : 0
-    if (ref.id.clock + offset !== localClock) {
-      // A previous message from this client is missing
-      // check if there is a pending structRef with a smaller clock and switch them
-      const structRefs = clientsStructRefs.get(client)
-      if (structRefs !== undefined) {
-        const r = structRefs.refs[structRefs.i]
-        if (r.id.clock < ref.id.clock) {
-          // put ref with smaller clock on stack instead and continue
-          structRefs.refs[structRefs.i] = ref
-          stack[stack.length - 1] = r
-          // sort the set because this approach might bring the list out of order
-          structRefs.refs = structRefs.refs.slice(structRefs.i).sort((r1, r2) => r1.id.client - r2.id.client)
-          structRefs.i = 0
-          continue
-        }
-      }
-      // wait until missing struct is available
-      return
-    }
-    while (m.length > 0) {
-      const missing = m[m.length - 1]
-      if (getState(store, missing.client) <= missing.clock) {
-        const client = missing.client
-        // get the struct reader that has the missing struct
-        const structRefs = clientsStructRefs.get(client)
-        if (structRefs === undefined) {
-          // This update message causally depends on another update message.
-          return
-        }
-        stack.push(structRefs.refs[structRefs.i++])
-        if (structRefs.i === structRefs.refs.length) {
-          clientsStructRefs.delete(client)
-        }
-        break
-      }
-      ref._missing.pop()
-    }
-    if (m.length === 0) {
-      if (offset < ref.length) {
-        ref.toStruct(transaction, store, offset).integrate(transaction)
-      }
-      stack.pop()
-    }
-  }
-}
-
-/**
- * @param {Transaction} transaction
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-export const tryResumePendingDeleteReaders = (transaction, store) => {
-  const pendingReaders = store.pendingDeleteReaders
-  store.pendingDeleteReaders = []
-  for (let i = 0; i < pendingReaders.length; i++) {
-    readDeleteSet(pendingReaders[i], transaction, store)
-  }
-}
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {Transaction} transaction
- *
- * @private
- * @function
- */
-export const writeStructsFromTransaction = (encoder, transaction) => writeClientsStructs(encoder, transaction.y.store, transaction.beforeState)
-
-/**
- * @param {StructStore} store
- * @param {Map<number, Array<AbstractStructRef>>} clientsStructsRefs
- *
- * @private
- * @function
- */
-const mergeReadStructsIntoPendingReads = (store, clientsStructsRefs) => {
-  const pendingClientsStructRefs = store.pendingClientsStructRefs
-  for (const [client, structRefs] of clientsStructsRefs) {
-    const pendingStructRefs = pendingClientsStructRefs.get(client)
-    if (pendingStructRefs === undefined) {
-      pendingClientsStructRefs.set(client, { refs: structRefs, i: 0 })
-    } else {
-      // merge into existing structRefs
-      const merged = pendingStructRefs.i > 0 ? pendingStructRefs.refs.slice(pendingStructRefs.i) : pendingStructRefs.refs
-      for (let i = 0; i < structRefs.length; i++) {
-        merged.push(structRefs[i])
-      }
-      pendingStructRefs.i = 0
-      pendingStructRefs.refs = merged.sort((r1, r2) => r1.id.clock - r2.id.clock)
-    }
-  }
-}
-
-/**
- * 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 {decoding.Decoder} decoder The decoder object to read data from.
- * @param {Transaction} transaction
- * @param {StructStore} store
- *
- * @private
- * @function
- */
-export const readStructs = (decoder, transaction, store) => {
-  const clientsStructRefs = readClientsStructRefs(decoder)
-  mergeReadStructsIntoPendingReads(store, clientsStructRefs)
-  resumeStructIntegration(transaction, store)
-  tryResumePendingDeleteReaders(transaction, store)
-}
-
-/**
- * @param {decoding.Decoder} decoder
- * @param {Transaction} transaction
- * @param {StructStore} store
- *
- * @function
- */
-export const readModel = (decoder, transaction, store) => {
-  readStructs(decoder, transaction, store)
-  readDeleteSet(decoder, transaction, store)
-}
-
-/**
- * @param {encoding.Encoder} encoder
- * @param {StructStore} store
- * @param {Map<number,number>} [targetState] The state of the target that receives the update. Leave empty to write all known structs
- *
- * @function
- */
-export const writeModel = (encoder, store, targetState = new Map()) => {
-  writeClientsStructs(encoder, store, targetState)
-  writeDeleteSet(encoder, createDeleteSetFromStructStore(store))
-}
--- a/src/utils/isParentOf.js
+++ b/src/utils/isParentOf.js
@@ -1,22 +0,0 @@
-
-import { AbstractType } from '../internals.js' // eslint-disable-line
-
-/**
- * Check if `parent` is a parent of `child`.
- *
- * @param {AbstractType<any>} parent
- * @param {AbstractType<any>} child
- * @return {Boolean} Whether `parent` is a parent of `child`.
- *
- * @private
- * @function
- */
-export const isParentOf = (parent, child) => {
-  while (child._item !== null) {
-    if (child === parent) {
-      return true
-    }
-    child = child._item.parent
-  }
-  return false
-}
--- a/src/y.js
+++ b/src/y.js
@@ -0,0 +1,244 @@
+import extendConnector from './Connector.js'
+import extendDatabase from './Database.js'
+import extendTransaction from './Transaction.js'
+import extendStruct from './Struct.js'
+import extendUtils from './Utils.js'
+import debug from 'debug'
+import { formatYjsMessage, formatYjsMessageType } from './MessageHandler.js'
+
+extendConnector(Y)
+extendDatabase(Y)
+extendTransaction(Y)
+extendStruct(Y)
+extendUtils(Y)
+
+Y.debug = debug
+debug.formatters.Y = formatYjsMessage
+debug.formatters.y = formatYjsMessageType
+
+var requiringModules = {}
+
+Y.requiringModules = requiringModules
+
+Y.extend = function (name, value) {
+  if (arguments.length === 2 && typeof name === 'string') {
+    if (value instanceof Y.utils.CustomTypeDefinition) {
+      Y[name] = value.parseArguments
+    } else {
+      Y[name] = value
+    }
+    if (requiringModules[name] != null) {
+      requiringModules[name].resolve()
+      delete requiringModules[name]
+    }
+  } else {
+    for (var i = 0; i < arguments.length; i++) {
+      var f = arguments[i]
+      if (typeof f === 'function') {
+        f(Y)
+      } else {
+        throw new Error('Expected function!')
+      }
+    }
+  }
+}
+
+Y.requestModules = requestModules
+function requestModules (modules) {
+  var sourceDir
+  if (Y.sourceDir === null) {
+    sourceDir = null
+  } else {
+    sourceDir = Y.sourceDir || '/bower_components'
+  }
+  // determine if this module was compiled for es5 or es6 (y.js vs. y.es6)
+  // if Insert.execute is a Function, then it isnt a generator..
+  // then load the es5(.js) files..
+  var extention = typeof regeneratorRuntime !== 'undefined' ? '.js' : '.es6'
+  var promises = []
+  for (var i = 0; i < modules.length; i++) {
+    var module = modules[i].split('(')[0]
+    var modulename = 'y-' + module.toLowerCase()
+    if (Y[module] == null) {
+      if (requiringModules[module] == null) {
+        // module does not exist
+        if (typeof window !== 'undefined' && window.Y !== 'undefined') {
+          if (sourceDir != null) {
+            var imported = document.createElement('script')
+            imported.src = sourceDir + '/' + modulename + '/' + modulename + extention
+            document.head.appendChild(imported)
+          }
+          let requireModule = {}
+          requiringModules[module] = requireModule
+          requireModule.promise = new Promise(function (resolve) {
+            requireModule.resolve = resolve
+          })
+          promises.push(requireModule.promise)
+        } else {
+          console.info('YJS: Please do not depend on automatic requiring of modules anymore! Extend modules as follows `require(\'y-modulename\')(Y)`')
+          require(modulename)(Y)
+        }
+      } else {
+        promises.push(requiringModules[modules[i]].promise)
+      }
+    }
+  }
+  return Promise.all(promises)
+}
+
+/* ::
+type MemoryOptions = {
+  name: 'memory'
+}
+type IndexedDBOptions = {
+  name: 'indexeddb',
+  namespace: string
+}
+type DbOptions = MemoryOptions | IndexedDBOptions
+
+type WebRTCOptions = {
+  name: 'webrtc',
+  room: string
+}
+type WebsocketsClientOptions = {
+  name: 'websockets-client',
+  room: string
+}
+type ConnectionOptions = WebRTCOptions | WebsocketsClientOptions
+
+type YOptions = {
+  connector: ConnectionOptions,
+  db: DbOptions,
+  types: Array<TypeName>,
+  sourceDir: string,
+  share: {[key: string]: TypeName}
+}
+*/
+
+export default function Y (opts/* :YOptions */) /* :Promise<YConfig> */ {
+  if (opts.hasOwnProperty('sourceDir')) {
+    Y.sourceDir = opts.sourceDir
+  }
+  opts.types = opts.types != null ? opts.types : []
+  var modules = [opts.db.name, opts.connector.name].concat(opts.types)
+  for (var name in opts.share) {
+    modules.push(opts.share[name])
+  }
+  return new Promise(function (resolve, reject) {
+    if (opts == null) reject(new Error('An options object is expected!'))
+    else if (opts.connector == null) reject(new Error('You must specify a connector! (missing connector property)'))
+    else if (opts.connector.name == null) reject(new Error('You must specify connector name! (missing connector.name property)'))
+    else if (opts.db == null) reject(new Error('You must specify a database! (missing db property)'))
+    else if (opts.connector.name == null) reject(new Error('You must specify db name! (missing db.name property)'))
+    else {
+      opts = Y.utils.copyObject(opts)
+      opts.connector = Y.utils.copyObject(opts.connector)
+      opts.db = Y.utils.copyObject(opts.db)
+      opts.share = Y.utils.copyObject(opts.share)
+      Y.requestModules(modules).then(function () {
+        var yconfig = new YConfig(opts)
+        yconfig.db.whenUserIdSet(function () {
+          yconfig.init(function () {
+            resolve(yconfig)
+          })
+        })
+      }).catch(reject)
+    }
+  })
+}
+
+class YConfig extends Y.utils.NamedEventHandler {
+  /* ::
+  db: Y.AbstractDatabase;
+  connector: Y.AbstractConnector;
+  share: {[key: string]: any};
+  options: Object;
+  */
+  constructor (opts, callback) {
+    super()
+    this.options = opts
+    this.db = new Y[opts.db.name](this, opts.db)
+    this.connector = new Y[opts.connector.name](this, opts.connector)
+    this.connected = true
+  }
+  init (callback) {
+    var opts = this.options
+    var share = {}
+    this.share = share
+    this.db.requestTransaction(function * requestTransaction () {
+      // create shared object
+      for (var propertyname in opts.share) {
+        var typeConstructor = opts.share[propertyname].split('(')
+        var typeName = typeConstructor.splice(0, 1)
+        var type = Y[typeName]
+        var typedef = type.typeDefinition
+        var id = [0xFFFFFF, typedef.struct + '_' + typeName + '_' + propertyname + '_' + typeConstructor]
+        var args = []
+        if (typeConstructor.length === 1) {
+          try {
+            args = JSON.parse('[' + typeConstructor[0].split(')')[0] + ']')
+          } catch (e) {
+            throw new Error('Was not able to parse type definition! (share.' + propertyname + ')')
+          }
+          if (type.typeDefinition.parseArguments == null) {
+            throw new Error(typeName + ' does not expect arguments!')
+          } else {
+            args = typedef.parseArguments(args[0])[1]
+          }
+        }
+        share[propertyname] = yield * this.store.initType.call(this, id, args)
+      }
+      this.store.whenTransactionsFinished()
+        .then(callback)
+    })
+  }
+  isConnected () {
+    return this.connector.isSynced
+  }
+  disconnect () {
+    if (this.connected) {
+      this.connected = false
+      return this.connector.disconnect()
+    } else {
+      return Promise.resolve()
+    }
+  }
+  reconnect () {
+    if (!this.connected) {
+      this.connected = true
+      return this.connector.reconnect()
+    } else {
+      return Promise.resolve()
+    }
+  }
+  destroy () {
+    var self = this
+    return this.close().then(function () {
+      if (self.db.deleteDB != null) {
+        return self.db.deleteDB()
+      } else {
+        return Promise.resolve()
+      }
+    }).then(() => {
+      // remove existing event listener
+      super.destroy()
+    })
+  }
+  close () {
+    var self = this
+    this.share = null
+    if (this.connector.destroy != null) {
+      this.connector.destroy()
+    } else {
+      this.connector.disconnect()
+    }
+    return this.db.whenTransactionsFinished().then(function () {
+      self.db.destroyTypes()
+      // make sure to wait for all transactions before destroying the db
+      self.db.requestTransaction(function * () {
+        yield * self.db.destroy()
+      })
+      return self.db.whenTransactionsFinished()
+    })
+  }
+}
--- a/test.html
+++ b/test.html
@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-  <title>Testing Yjs</title>
-</head>
-<body>
-  <script type="module" src="./dist/tests.js"></script>
-</body>
-</html>
--- a/test/encode-decode.js
+++ b/test/encode-decode.js
@@ -0,0 +1,229 @@
+import { test } from 'cutest'
+import Chance from 'chance'
+import Y from '../src/y.js'
+import { BinaryEncoder, BinaryDecoder } from '../src/Encoding.js'
+
+function testEncoding (t, write, read, val) {
+  let encoder = new BinaryEncoder()
+  write(encoder, val)
+  let reader = new BinaryDecoder(encoder.createBuffer())
+  let result = read(reader)
+  t.log(`string encode: ${JSON.stringify(val).length} bytes / binary encode: ${encoder.data.length} bytes`)
+  t.compare(val, result, 'Compare results')
+}
+
+const writeVarUint = (encoder, val) => encoder.writeVarUint(val)
+const readVarUint = decoder => decoder.readVarUint()
+
+test('varUint 1 byte', async function varUint1 (t) {
+  testEncoding(t, writeVarUint, readVarUint, 42)
+})
+
+test('varUint 2 bytes', async function varUint2 (t) {
+  testEncoding(t, writeVarUint, readVarUint, 1 << 9 | 3)
+  testEncoding(t, writeVarUint, readVarUint, 1 << 9 | 3)
+})
+test('varUint 3 bytes', async function varUint3 (t) {
+  testEncoding(t, writeVarUint, readVarUint, 1 << 17 | 1 << 9 | 3)
+})
+
+test('varUint 4 bytes', async function varUint4 (t) {
+  testEncoding(t, writeVarUint, readVarUint, 1 << 25 | 1 << 17 | 1 << 9 | 3)
+})
+
+test('varUint of 2839012934', async function varUint2839012934 (t) {
+  testEncoding(t, writeVarUint, readVarUint, 2839012934)
+})
+
+test('varUint random', async function varUintRandom (t) {
+  const chance = new Chance(t.getSeed() * Math.pow(Number.MAX_SAFE_INTEGER))
+  testEncoding(t, writeVarUint, readVarUint, chance.integer({min: 0, max: (1 << 28) - 1}))
+})
+
+test('varUint random user id', async function varUintRandomUserId (t) {
+  t.getSeed() // enforces that this test is repeated
+  testEncoding(t, writeVarUint, readVarUint, Y.utils.generateUserId())
+})
+
+const writeVarString = (encoder, val) => encoder.writeVarString(val)
+const readVarString = decoder => decoder.readVarString()
+
+test('varString', async function varString (t) {
+  testEncoding(t, writeVarString, readVarString, 'hello')
+  testEncoding(t, writeVarString, readVarString, 'test!')
+  testEncoding(t, writeVarString, readVarString, '☺☺☺')
+  testEncoding(t, writeVarString, readVarString, '1234')
+})
+
+test('varString random', async function varStringRandom (t) {
+  const chance = new Chance(t.getSeed() * 1000000000)
+  testEncoding(t, writeVarString, readVarString, chance.string())
+})
+
+const writeDelete = Y.Struct.Delete.binaryEncode
+const readDelete = Y.Struct.Delete.binaryDecode
+
+test('encode/decode Delete operation', async function binDelete (t) {
+  let op = {
+    target: [10, 3000],
+    length: 40000,
+    struct: 'Delete'
+  }
+  testEncoding(t, writeDelete, readDelete, op)
+})
+
+const writeInsert = Y.Struct.Insert.binaryEncode
+const readInsert = Y.Struct.Insert.binaryDecode
+
+test('encode/decode Insert operations', async function binInsert (t) {
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: [7, 8],
+    parent: [9, 10],
+    struct: 'Insert',
+    content: ['a']
+  })
+
+  t.log('left === origin')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: [3, 4],
+    parent: [9, 10],
+    struct: 'Insert',
+    content: ['a']
+  })
+
+  t.log('parentsub')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: [3, 4],
+    parent: [9, 10],
+    parentSub: 'sub',
+    struct: 'Insert',
+    content: ['a']
+  })
+
+  t.log('opContent')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: [3, 4],
+    parent: [9, 10],
+    struct: 'Insert',
+    opContent: [1000, 10000]
+  })
+
+  t.log('mixed content')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: [3, 4],
+    parent: [9, 10],
+    struct: 'Insert',
+    content: ['a', 1]
+  })
+
+  t.log('origin is null')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: [5, 6],
+    left: [3, 4],
+    origin: null,
+    parent: [9, 10],
+    struct: 'Insert',
+    content: ['a']
+  })
+
+  t.log('left = origin = right = null')
+  testEncoding(t, writeInsert, readInsert, {
+    id: [1, 2],
+    right: null,
+    left: null,
+    origin: null,
+    parent: [9, 10],
+    struct: 'Insert',
+    content: ['a']
+  })
+})
+
+const writeList = Y.Struct.List.binaryEncode
+const readList = Y.Struct.List.binaryDecode
+
+test('encode/decode List operations', async function binList (t) {
+  testEncoding(t, writeList, readList, {
+    struct: 'List',
+    id: [100, 33],
+    type: 'Array'
+  })
+
+  t.log('info is an object')
+  testEncoding(t, writeList, readList, {
+    struct: 'List',
+    id: [100, 33],
+    type: 'Array',
+    info: { prop: 'yay' }
+  })
+
+  t.log('info is a string')
+  testEncoding(t, writeList, readList, {
+    struct: 'List',
+    id: [100, 33],
+    type: 'Array',
+    info: 'hi'
+  })
+
+  t.log('info is a number')
+  testEncoding(t, writeList, readList, {
+    struct: 'List',
+    id: [100, 33],
+    type: 'Array',
+    info: 400
+  })
+})
+
+const writeMap = Y.Struct.Map.binaryEncode
+const readMap = Y.Struct.Map.binaryDecode
+
+test('encode/decode Map operations', async function binMap (t) {
+  testEncoding(t, writeMap, readMap, {
+    struct: 'Map',
+    id: [100, 33],
+    type: 'Map',
+    map: {}
+  })
+
+  t.log('info is an object')
+  testEncoding(t, writeMap, readMap, {
+    struct: 'Map',
+    id: [100, 33],
+    type: 'Map',
+    info: { prop: 'yay' },
+    map: {}
+  })
+
+  t.log('info is a string')
+  testEncoding(t, writeMap, readMap, {
+    struct: 'Map',
+    id: [100, 33],
+    type: 'Map',
+    map: {},
+    info: 'hi'
+  })
+
+  t.log('info is a number')
+  testEncoding(t, writeMap, readMap, {
+    struct: 'Map',
+    id: [100, 33],
+    type: 'Map',
+    map: {},
+    info: 400
+  })
+})
--- a/tests-lib/helper.js
+++ b/tests-lib/helper.js
@@ -0,0 +1,222 @@
+
+import _Y from '../../yjs/src/y.js'
+
+import yMemory from '../../y-memory/src/y-memory.js'
+import yArray from '../../y-array/src/y-array.js'
+import yMap from '../../y-map/src/Map.js'
+import yTest from './test-connector.js'
+
+import Chance from 'chance'
+
+export let Y = _Y
+
+Y.extend(yMemory, yArray, yMap, yTest)
+
+function * getStateSet () {
+  var ss = {}
+  yield * this.ss.iterate(this, null, null, function * (n) {
+    var user = n.id[0]
+    var clock = n.clock
+    ss[user] = clock
+  })
+  return ss
+}
+
+function * getDeleteSet () {
+  var ds = {}
+  yield * this.ds.iterate(this, null, null, function * (n) {
+    var user = n.id[0]
+    var counter = n.id[1]
+    var len = n.len
+    var gc = n.gc
+    var dv = ds[user]
+    if (dv === void 0) {
+      dv = []
+      ds[user] = dv
+    }
+    dv.push([counter, len, gc])
+  })
+  return ds
+}
+
+export async function garbageCollectUsers (t, users) {
+  await flushAll(t, users)
+  await Promise.all(users.map(u => u.db.emptyGarbageCollector()))
+}
+
+/*
+ * 1. reconnect and flush all
+ * 2. user 0 gc
+ * 3. get type content
+ * 4. disconnect & reconnect all (so gc is propagated)
+ * 5. compare os, ds, ss
+ */
+export async function compareUsers (t, users) {
+  await Promise.all(users.map(u => u.reconnect()))
+  if (users[0].connector.testRoom == null) {
+    await wait(100)
+  }
+  await flushAll(t, users)
+  await wait()
+  await flushAll(t, users)
+
+  var userTypeContents = users.map(u => u.share.array._content.map(c => c.val || JSON.stringify(c.type)))
+
+  await users[0].db.garbageCollect()
+  await users[0].db.garbageCollect()
+
+  // disconnect all except user 0
+  await Promise.all(users.slice(1).map(async u =>
+    u.disconnect()
+  ))
+  if (users[0].connector.testRoom == null) {
+    await wait(100)
+  }
+  // reconnect all
+  await Promise.all(users.map(u => u.reconnect()))
+  if (users[0].connector.testRoom == null) {
+    await wait(100)
+  }
+  await users[0].connector.testRoom.flushAll(users)
+  await Promise.all(users.map(u =>
+    new Promise(function (resolve) {
+      u.connector.whenSynced(resolve)
+    })
+  ))
+  let filterDeletedOps = users.every(u => u.db.gc === false)
+  var data = await Promise.all(users.map(async (u) => {
+    var data = {}
+    u.db.requestTransaction(function * () {
+      let ops = []
+      yield * this.os.iterate(this, null, null, function * (op) {
+        ops.push(Y.Struct[op.struct].encode(op))
+      })
+
+      data.os = {}
+      for (let i = 0; i < ops.length; i++) {
+        let op = ops[i]
+        op = Y.Struct[op.struct].encode(op)
+        delete op.origin
+        /*
+          If gc = false, it is necessary to filter deleted ops
+          as they might have been split up differently..
+         */
+        if (filterDeletedOps) {
+          let opIsDeleted = yield * this.isDeleted(op.id)
+          if (!opIsDeleted) {
+            data.os[JSON.stringify(op.id)] = op
+          }
+        } else {
+          data.os[JSON.stringify(op.id)] = op
+        }
+      }
+      data.ds = yield * getDeleteSet.apply(this)
+      data.ss = yield * getStateSet.apply(this)
+    })
+    await u.db.whenTransactionsFinished()
+    return data
+  }))
+  for (var i = 0; i < data.length - 1; i++) {
+    await t.asyncGroup(async () => {
+      t.compare(userTypeContents[i], userTypeContents[i + 1], 'types')
+      t.compare(data[i].os, data[i + 1].os, 'os')
+      t.compare(data[i].ds, data[i + 1].ds, 'ds')
+      t.compare(data[i].ss, data[i + 1].ss, 'ss')
+    }, `Compare user${i} with user${i + 1}`)
+  }
+  await Promise.all(users.map(async (u) => {
+    await u.close()
+  }))
+}
+
+export async function initArrays (t, opts) {
+  var result = {
+    users: []
+  }
+  var share = Object.assign({ flushHelper: 'Map', array: 'Array', map: 'Map' }, opts.share)
+  var chance = opts.chance || new Chance(t.getSeed() * 1000000000)
+  var connector = Object.assign({ room: 'debugging_' + t.name, generateUserId: false, testContext: t, chance }, opts.connector)
+  for (let i = 0; i < opts.users; i++) {
+    let dbOpts
+    let connOpts
+    if (i === 0) {
+      // Only one instance can gc!
+      dbOpts = Object.assign({ gc: false }, opts.db)
+      connOpts = Object.assign({ role: 'master' }, connector)
+    } else {
+      dbOpts = Object.assign({ gc: false }, opts.db)
+      connOpts = Object.assign({ role: 'slave' }, connector)
+    }
+    let y = await Y({
+      connector: connOpts,
+      db: dbOpts,
+      share: share
+    })
+    result.users.push(y)
+    for (let name in share) {
+      result[name + i] = y.share[name]
+    }
+  }
+  result.array0.delete(0, result.array0.length)
+  if (result.users[0].connector.testRoom != null) {
+    // flush for sync if test-connector
+    await result.users[0].connector.testRoom.flushAll(result.users)
+  }
+  await Promise.all(result.users.map(u => {
+    return new Promise(function (resolve) {
+      u.connector.whenSynced(resolve)
+    })
+  }))
+  await flushAll(t, result.users)
+  return result
+}
+
+export async function flushAll (t, users) {
+  // users = users.filter(u => u.connector.isSynced)
+  if (users.length === 0) {
+    return
+  }
+  await wait(0)
+  if (users[0].connector.testRoom != null) {
+    // use flushAll method specified in Test Connector
+    await users[0].connector.testRoom.flushAll(users)
+  } else {
+    // flush for any connector
+    await Promise.all(users.map(u => { return u.db.whenTransactionsFinished() }))
+
+    var flushCounter = users[0].share.flushHelper.get('0') || 0
+    flushCounter++
+    await Promise.all(users.map(async (u, i) => {
+      // wait for all users to set the flush counter to the same value
+      await new Promise(resolve => {
+        function observer () {
+          var allUsersReceivedUpdate = true
+          for (var i = 0; i < users.length; i++) {
+            if (u.share.flushHelper.get(i + '') !== flushCounter) {
+              allUsersReceivedUpdate = false
+              break
+            }
+          }
+          if (allUsersReceivedUpdate) {
+            resolve()
+          }
+        }
+        u.share.flushHelper.observe(observer)
+        u.share.flushHelper.set(i + '', flushCounter)
+      })
+    }))
+  }
+}
+
+export async function flushSome (t, users) {
+  if (users[0].connector.testRoom == null) {
+    // if not test-connector, wait for some time for operations to arrive
+    await wait(100)
+  }
+}
+
+export function wait (t) {
+  return new Promise(function (resolve) {
+    setTimeout(resolve, t != null ? t : 100)
+  })
+}
--- a/tests-lib/test-connector.js
+++ b/tests-lib/test-connector.js
@@ -0,0 +1,166 @@
+/* global Y */
+import { wait } from './helper.js'
+import { formatYjsMessage } from '../src/MessageHandler.js'
+
+var rooms = {}
+
+export class TestRoom {
+  constructor (roomname) {
+    this.room = roomname
+    this.users = new Map()
+    this.nextUserId = 0
+  }
+  join (connector) {
+    if (connector.userId == null) {
+      connector.setUserId(this.nextUserId++)
+    }
+    this.users.forEach((user, uid) => {
+      if (user.role === 'master' || connector.role === 'master') {
+        this.users.get(uid).userJoined(connector.userId, connector.role)
+        connector.userJoined(uid, this.users.get(uid).role)
+      }
+    })
+    this.users.set(connector.userId, connector)
+  }
+  leave (connector) {
+    this.users.delete(connector.userId)
+    this.users.forEach(user => {
+      user.userLeft(connector.userId)
+    })
+  }
+  send (sender, receiver, m) {
+    var user = this.users.get(receiver)
+    if (user != null) {
+      user.receiveMessage(sender, m)
+    }
+  }
+  broadcast (sender, m) {
+    this.users.forEach((user, receiver) => {
+      this.send(sender, receiver, m)
+    })
+  }
+  async flushAll (users) {
+    let flushing = true
+    let allUserIds = Array.from(this.users.keys())
+    if (users == null) {
+      users = allUserIds.map(id => this.users.get(id).y)
+    }
+    while (flushing) {
+      await wait(10)
+      let res = await Promise.all(allUserIds.map(id => this.users.get(id)._flushAll(users)))
+      flushing = res.some(status => status === 'flushing')
+    }
+  }
+}
+
+function getTestRoom (roomname) {
+  if (rooms[roomname] == null) {
+    rooms[roomname] = new TestRoom(roomname)
+  }
+  return rooms[roomname]
+}
+
+export default function extendTestConnector (Y) {
+  class TestConnector extends Y.AbstractConnector {
+    constructor (y, options) {
+      if (options === undefined) {
+        throw new Error('Options must not be undefined!')
+      }
+      if (options.room == null) {
+        throw new Error('You must define a room name!')
+      }
+      options.forwardAppliedOperations = options.role === 'master'
+      super(y, options)
+      this.options = options
+      this.room = options.room
+      this.chance = options.chance
+      this.testRoom = getTestRoom(this.room)
+      this.testRoom.join(this)
+    }
+    disconnect () {
+      this.testRoom.leave(this)
+      return super.disconnect()
+    }
+    logBufferParsed () {
+      console.log(' === Logging buffer of user ' + this.userId + ' === ')
+      for (let [user, conn] of this.connections) {
+        console.log(` ${user}:`)
+        for (let i = 0; i < conn.buffer.length; i++) {
+          console.log(formatYjsMessage(conn.buffer[i]))
+        }
+      }
+    }
+    reconnect () {
+      this.testRoom.join(this)
+      return super.reconnect()
+    }
+    send (uid, message) {
+      super.send(uid, message)
+      this.testRoom.send(this.userId, uid, message)
+    }
+    broadcast (message) {
+      super.broadcast(message)
+      this.testRoom.broadcast(this.userId, message)
+    }
+    async whenSynced (f) {
+      var synced = false
+      var periodicFlushTillSync = () => {
+        if (synced) {
+          f()
+        } else {
+          this.testRoom.flushAll([this.y]).then(function () {
+            setTimeout(periodicFlushTillSync, 10)
+          })
+        }
+      }
+      periodicFlushTillSync()
+      return super.whenSynced(function () {
+        synced = true
+      })
+    }
+    receiveMessage (sender, m) {
+      if (this.userId !== sender && this.connections.has(sender)) {
+        var buffer = this.connections.get(sender).buffer
+        if (buffer == null) {
+          buffer = this.connections.get(sender).buffer = []
+        }
+        buffer.push(m)
+        if (this.chance.bool({likelihood: 30})) {
+          // flush 1/2 with 30% chance
+          var flushLength = Math.round(buffer.length / 2)
+          buffer.splice(0, flushLength).forEach(m => {
+            super.receiveMessage(sender, m)
+          })
+        }
+      }
+    }
+    async _flushAll (flushUsers) {
+      if (flushUsers.some(u => u.connector.userId === this.userId)) {
+        // this one needs to sync with every other user
+        flushUsers = Array.from(this.connections.keys()).map(uid => this.testRoom.users.get(uid).y)
+      }
+      var finished = []
+      for (let i = 0; i < flushUsers.length; i++) {
+        let userId = flushUsers[i].connector.userId
+        if (userId !== this.userId && this.connections.has(userId)) {
+          let buffer = this.connections.get(userId).buffer
+          if (buffer != null) {
+            var messages = buffer.splice(0)
+            for (let j = 0; j < messages.length; j++) {
+              let p = super.receiveMessage(userId, messages[j])
+              finished.push(p)
+            }
+          }
+        }
+      }
+      await Promise.all(finished)
+      await this.y.db.whenTransactionsFinished()
+      return finished.length > 0 ? 'flushing' : 'done'
+    }
+  }
+  Y.extend('test', TestConnector)
+}
+
+if (typeof Y !== 'undefined') {
+  extendTestConnector(Y)
+}
--- a/tests/encoding.tests.js
+++ b/tests/encoding.tests.js
@@ -1,36 +0,0 @@
-import * as t from 'lib0/testing.js'
-
-import {
-  structRefs,
-  structGCRefNumber,
-  structBinaryRefNumber,
-  structDeletedRefNumber,
-  structEmbedRefNumber,
-  structFormatRefNumber,
-  structJSONRefNumber,
-  structStringRefNumber,
-  structTypeRefNumber,
-  GCRef,
-  ItemBinaryRef,
-  ItemDeletedRef,
-  ItemEmbedRef,
-  ItemFormatRef,
-  ItemJSONRef,
-  ItemStringRef,
-  ItemTypeRef
-} from '../src/internals.js'
-
-/**
- * @param {t.TestCase} tc
- */
-export const testStructReferences = tc => {
-  t.assert(structRefs.length === 8)
-  t.assert(structRefs[structGCRefNumber] === GCRef)
-  t.assert(structRefs[structBinaryRefNumber] === ItemBinaryRef)
-  t.assert(structRefs[structDeletedRefNumber] === ItemDeletedRef)
-  t.assert(structRefs[structEmbedRefNumber] === ItemEmbedRef)
-  t.assert(structRefs[structFormatRefNumber] === ItemFormatRef)
-  t.assert(structRefs[structJSONRefNumber] === ItemJSONRef)
-  t.assert(structRefs[structStringRefNumber] === ItemStringRef)
-  t.assert(structRefs[structTypeRefNumber] === ItemTypeRef)
-}
--- a/Show More
+++ b/Show More