Lib0

import * as array from 'lib0/array'

array.last(arr: ArrayLike<L>): L

Return the last element of an array. The element must exist

array.create(): Array<C>
array.copy(a: Array<D>): Array<D>
array.appendTo(dest: Array<M>, src: Array<M>)

Append elements from src to dest

array.from(arraylike: ArrayLike<T>|Iterable<T>): T

Transforms something array-like to an actual Array.

array.every(arr: ARR, f: function(ITEM, number, ARR):boolean): boolean

True iff condition holds on every element in the Array.

array.some(arr: ARR, f: function(S, number, ARR):boolean): boolean

True iff condition holds on some element in the Array.

array.equalFlat(a: ArrayLike<ELEM>, b: ArrayLike<ELEM>): boolean
array.flatten(arr: Array<Array<ELEM>>): Array<ELEM>
array.isArray
array.unique(arr: Array<T>): Array<T>
array.uniqueBy(arr: ArrayLike<T>, mapper: function(T):M): Array<T>

import * as binary from 'lib0/binary'

binary.BIT1: number

n-th bit activated.

binary.BIT2
binary.BIT3
binary.BIT4
binary.BIT5
binary.BIT6
binary.BIT7
binary.BIT8
binary.BIT9
binary.BIT10
binary.BIT11
binary.BIT12
binary.BIT13
binary.BIT14
binary.BIT15
binary.BIT16
binary.BIT17
binary.BIT18
binary.BIT19
binary.BIT20
binary.BIT21
binary.BIT22
binary.BIT23
binary.BIT24
binary.BIT25
binary.BIT26
binary.BIT27
binary.BIT28
binary.BIT29
binary.BIT30
binary.BIT31
binary.BIT32
binary.BITS0: number

First n bits activated.

binary.BITS1
binary.BITS2
binary.BITS3
binary.BITS4
binary.BITS5
binary.BITS6
binary.BITS7
binary.BITS8
binary.BITS9
binary.BITS10
binary.BITS11
binary.BITS12
binary.BITS13
binary.BITS14
binary.BITS15
binary.BITS16
binary.BITS17
binary.BITS18
binary.BITS19
binary.BITS20
binary.BITS21
binary.BITS22
binary.BITS23
binary.BITS24
binary.BITS25
binary.BITS26
binary.BITS27
binary.BITS28
binary.BITS29
binary.BITS30
binary.BITS31: number
binary.BITS32: number

import * as broadcastchannel from 'lib0/broadcastchannel'

// In browser window A:
broadcastchannel.subscribe('my events', data => console.log(data))
broadcastchannel.publish('my events', 'Hello world!') // => A: 'Hello world!' fires synchronously in same tab

// In browser window B:
broadcastchannel.publish('my events', 'hello from tab B') // => A: 'hello from tab B'

broadcastchannel.subscribe(room: string, f: function(any, any):any)

Subscribe to global publish events.

broadcastchannel.unsubscribe(room: string, f: function(any, any):any)

Unsubscribe from publish global events.

broadcastchannel.publish(room: string, data: any, origin: any)

Publish data to all subscribers (including subscribers on this tab)

import * as buffer from 'lib0/buffer'

buffer.createUint8ArrayFromLen(len: number)
buffer.createUint8ArrayViewFromArrayBuffer(buffer: ArrayBuffer, byteOffset: number, length: number)

Create Uint8Array with initial content from buffer

buffer.createUint8ArrayFromArrayBuffer(buffer: ArrayBuffer)

Create Uint8Array with initial content from buffer

buffer.toBase64
buffer.fromBase64
buffer.copyUint8Array(uint8Array: Uint8Array): Uint8Array

Copy the content of an Uint8Array view to a new ArrayBuffer.

buffer.encodeAny(data: any): Uint8Array

Encode anything as a UInt8Array. It's a pun on typescripts's any type. See encoding.writeAny for more information.

buffer.decodeAny(buf: Uint8Array): any

Decode an any-encoded value.

import * as cache from 'lib0/cache'

new cache.Cache(timeout: number)
cache.removeStale(cache: module:cache.Cache<K, V>): number
cache.set(cache: module:cache.Cache<K, V>, key: K, value: V)
cache.get(cache: module:cache.Cache<K, V>, key: K): V | undefined
cache.refreshTimeout(cache: module:cache.Cache<K, V>, key: K)
cache.getAsync(cache: module:cache.Cache<K, V>, key: K): V | Promise<V> | undefined

Works well in conjunktion with setIfUndefined which has an async init function. Using getAsync & setIfUndefined ensures that the init function is only called once.

cache.remove(cache: module:cache.Cache<K, V>, key: K)
cache.setIfUndefined(cache: module:cache.Cache<K, V>, key: K, init: function():Promise<V>, removeNull: boolean): Promise<V> | V
cache.create(timeout: number)

import * as component from 'lib0/component'

component.registry: CustomElementRegistry
component.define(name: string, constr: any, opts: ElementDefinitionOptions)
component.whenDefined(name: string): Promise<CustomElementConstructor>
new component.Lib0Component(state: S)
component.Lib0Component#state: S|null
component.Lib0Component#setState(state: S, forceStateUpdate: boolean)
component.Lib0Component#updateState(stateUpdate: any)
component.createComponent(name: string, cnf: module:component~CONF<T>): Class<module:component.Lib0Component>
component.createComponentDefiner(definer: function)
component.defineListComponent
component.defineLazyLoadingComponent

import * as conditions from 'lib0/conditions'

conditions.undefinedToNull

import * as crypto from 'lib0/crypto'

y(data: string | Uint8Array): Uint8Array
ymmetricKey(secret: string | Uint8Array, salt: string | Uint8Array, opts: Object, opts.extractable: boolean, opts.usages: Array<'sign'|'verify'|'encrypt'|'decrypt'>): PromiseLike<CryptoKey>
ymmetricKey()
eAsymmetricKey(opts: Object, opts.extractable: boolean, opts.usages: Array<'sign'|'verify'|'encrypt'|'decrypt'>)
eAsymmetricKey()
ey(key: CryptoKey)
ey()
ymmetricKey(jwk: any, opts: Object, opts.extractable: boolean, opts.usages: Array<'sign'|'verify'|'encrypt'|'decrypt'>)
ymmetricKey()
symmetricKey(jwk: any, opts: Object, opts.extractable: boolean, opts.usages: Array<'sign'|'verify'|'encrypt'|'decrypt'>)
symmetricKey()
(data: Uint8Array, key: CryptoKey): PromiseLike<Uint8Array>
()
(data: Uint8Array, key: CryptoKey): PromiseLike<Uint8Array>
()
(data: Uint8Array, privateKey: CryptoKey): PromiseLike<Uint8Array>
()
(signature: Uint8Array, data: Uint8Array, publicKey: CryptoKey): PromiseLike<boolean>
()

import * as decoding from 'lib0/decoding'

Use [lib0/decoding] with [lib0/encoding]. Every encoding function has a corresponding decoding function.

Encodes numbers in little-endian order (least to most significant byte order) and is compatible with Golang's binary encoding (https://golang.org/pkg/encoding/binary/) which is also used in Protocol Buffers.

// encoding step
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, 256)
encoding.writeVarString(encoder, 'Hello world!')
const buf = encoding.toUint8Array(encoder)

// decoding step
const decoder = decoding.createDecoder(buf)
decoding.readVarUint(decoder) // => 256
decoding.readVarString(decoder) // => 'Hello world!'
decoding.hasContent(decoder) // => false - all data is read

new decoding.Decoder(uint8Array: Uint8Array)

A Decoder handles the decoding of an Uint8Array.

decoding.Decoder#arr: Uint8Array

Decoding target.

decoding.Decoder#pos: number

Current decoding position.

decoding.createDecoder(uint8Array: Uint8Array): module:decoding.Decoder
decoding.hasContent(decoder: module:decoding.Decoder): boolean
decoding.clone(decoder: module:decoding.Decoder, newPos: number): module:decoding.Decoder

Clone a decoder instance. Optionally set a new position parameter.

decoding.readUint8Array(decoder: module:decoding.Decoder, len: number): Uint8Array

Create an Uint8Array view of the next len bytes and advance the position by len.

Important: The Uint8Array still points to the underlying ArrayBuffer. Make sure to discard the result as soon as possible to prevent any memory leaks. Use buffer.copyUint8Array to copy the result into a new Uint8Array.

decoding.readVarUint8Array(decoder: module:decoding.Decoder): Uint8Array

Read variable length Uint8Array.

Important: The Uint8Array still points to the underlying ArrayBuffer. Make sure to discard the result as soon as possible to prevent any memory leaks. Use buffer.copyUint8Array to copy the result into a new Uint8Array.

decoding.readTailAsUint8Array(decoder: module:decoding.Decoder): Uint8Array

Read the rest of the content as an ArrayBuffer

decoding.skip8(decoder: module:decoding.Decoder): number

Skip one byte, jump to the next position.

decoding.readUint8(decoder: module:decoding.Decoder): number

Read one byte as unsigned integer.

decoding.readUint16(decoder: module:decoding.Decoder): number

Read 2 bytes as unsigned integer.

decoding.readUint32(decoder: module:decoding.Decoder): number

Read 4 bytes as unsigned integer.

decoding.readUint32BigEndian(decoder: module:decoding.Decoder): number

Read 4 bytes as unsigned integer in big endian order. (most significant byte first)

decoding.peekUint8(decoder: module:decoding.Decoder): number

Look ahead without incrementing the position to the next byte and read it as unsigned integer.

decoding.peekUint16(decoder: module:decoding.Decoder): number

Look ahead without incrementing the position to the next byte and read it as unsigned integer.

decoding.peekUint32(decoder: module:decoding.Decoder): number

Look ahead without incrementing the position to the next byte and read it as unsigned integer.

decoding.readVarUint(decoder: module:decoding.Decoder): number

Read unsigned integer (32bit) with variable length. 1/8th of the storage is used as encoding overhead.

• numbers < 2^7 is stored in one bytlength
• numbers < 2^14 is stored in two bylength

decoding.readVarInt(decoder: module:decoding.Decoder): number

Read signed integer (32bit) with variable length. 1/8th of the storage is used as encoding overhead.

• numbers < 2^7 is stored in one bytlength
• numbers < 2^14 is stored in two bylength

decoding.peekVarUint(decoder: module:decoding.Decoder): number

Look ahead and read varUint without incrementing position

decoding.peekVarInt(decoder: module:decoding.Decoder): number

Look ahead and read varUint without incrementing position

decoding.readVarString
decoding.peekVarString(decoder: module:decoding.Decoder): string

Look ahead and read varString without incrementing position

decoding.readFromDataView(decoder: module:decoding.Decoder, len: number): DataView
decoding.readFloat32(decoder: module:decoding.Decoder)
decoding.readFloat64(decoder: module:decoding.Decoder)
decoding.readBigInt64(decoder: module:decoding.Decoder)
decoding.readBigUint64(decoder: module:decoding.Decoder)
decoding.readAny(decoder: module:decoding.Decoder)
new decoding.RleDecoder(uint8Array: Uint8Array, reader: function(module:decoding.Decoder):T)

T must not be null.

decoding.RleDecoder#s: T|null

Current state

decoding.RleDecoder#read()
decoding.RleDecoder#s: T
new decoding.IntDiffDecoder(uint8Array: Uint8Array, start: number)
decoding.IntDiffDecoder#s: number

Current state

decoding.IntDiffDecoder#read(): number
new decoding.RleIntDiffDecoder(uint8Array: Uint8Array, start: number)
decoding.RleIntDiffDecoder#s: number

Current state

decoding.RleIntDiffDecoder#read(): number
decoding.RleIntDiffDecoder#s: number
new decoding.UintOptRleDecoder(uint8Array: Uint8Array)
decoding.UintOptRleDecoder#s: number
decoding.UintOptRleDecoder#read()
decoding.UintOptRleDecoder#s: number
new decoding.IncUintOptRleDecoder(uint8Array: Uint8Array)
decoding.IncUintOptRleDecoder#s: number
decoding.IncUintOptRleDecoder#read()
new decoding.IntDiffOptRleDecoder(uint8Array: Uint8Array)
decoding.IntDiffOptRleDecoder#s: number
decoding.IntDiffOptRleDecoder#read(): number
new decoding.StringDecoder(uint8Array: Uint8Array)
decoding.StringDecoder#spos: number
decoding.StringDecoder#read(): string
decoding.RleDecoder#arr: Uint8Array

Decoding target.

decoding.RleDecoder#pos: number

Current decoding position.

decoding.IntDiffDecoder#arr: Uint8Array

Decoding target.

decoding.IntDiffDecoder#pos: number

Current decoding position.

decoding.RleIntDiffDecoder#arr: Uint8Array

Decoding target.

decoding.RleIntDiffDecoder#pos: number

Current decoding position.

decoding.UintOptRleDecoder#arr: Uint8Array

Decoding target.

decoding.UintOptRleDecoder#pos: number

Current decoding position.

decoding.IncUintOptRleDecoder#arr: Uint8Array

Decoding target.

decoding.IncUintOptRleDecoder#pos: number

Current decoding position.

decoding.IntDiffOptRleDecoder#arr: Uint8Array

Decoding target.

decoding.IntDiffOptRleDecoder#pos: number

Current decoding position.

import * as diff from 'lib0/diff'

diff.simpleDiffString(a: string, b: string): module:diff~SimpleDiff<string>

Create a diff between two strings. This diff implementation is highly efficient, but not very sophisticated.

diff.simpleDiff
diff.simpleDiffArray(a: Array<T>, b: Array<T>, compare: function(T, T):boolean): module:diff~SimpleDiff<Array<T>>

Create a diff between two arrays. This diff implementation is highly efficient, but not very sophisticated.

Note: This is basically the same function as above. Another function was created so that the runtime can better optimize these function calls.

diff.simpleDiffStringWithCursor(a: string, b: string, cursor: number)

Diff text and try to diff at the current cursor position.

import * as dom from 'lib0/dom'

dom.doc: Document
dom.createElement
dom.createDocumentFragment
dom.createTextNode
dom.domParser
dom.emitCustomEvent
dom.setAttributes
dom.setAttributesMap
dom.fragment
dom.append
dom.remove
dom.addEventListener
dom.removeEventListener
dom.addEventListeners
dom.removeEventListeners
dom.element
dom.canvas
dom.text
dom.pairToStyleString
dom.pairsToStyleString
dom.mapToStyleString
dom.querySelector
dom.querySelectorAll
dom.getElementById
dom.parseFragment
dom.childNodes: any
dom.parseElement
dom.replaceWith
dom.insertBefore
dom.appendChild
dom.ELEMENT_NODE
dom.TEXT_NODE
dom.CDATA_SECTION_NODE
dom.COMMENT_NODE
dom.DOCUMENT_NODE
dom.DOCUMENT_TYPE_NODE
dom.DOCUMENT_FRAGMENT_NODE
dom.checkNodeType(node: any, type: number)
dom.isParentOf(parent: Node, child: HTMLElement)

import * as encoding from 'lib0/encoding'

Use [lib0/encoding] with [lib0/decoding]. Every encoding function has a corresponding decoding function.

Encodes numbers in little-endian order (least to most significant byte order) and is compatible with Golang's binary encoding (https://golang.org/pkg/encoding/binary/) which is also used in Protocol Buffers.

// encoding step
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, 256)
encoding.writeVarString(encoder, 'Hello world!')
const buf = encoding.toUint8Array(encoder)

// decoding step
const decoder = decoding.createDecoder(buf)
decoding.readVarUint(decoder) // => 256
decoding.readVarString(decoder) // => 'Hello world!'
decoding.hasContent(decoder) // => false - all data is read

new encoding.Encoder()

A BinaryEncoder handles the encoding to an Uint8Array.

encoding.Encoder#bufs: Array<Uint8Array>
encoding.createEncoder(): module:encoding.Encoder
encoding.length(encoder: module:encoding.Encoder): number

The current length of the encoded data.

encoding.toUint8Array(encoder: module:encoding.Encoder): Uint8Array

Transform to Uint8Array.

encoding.verifyLen(encoder: module:encoding.Encoder, len: number)

Verify that it is possible to write len bytes wtihout checking. If necessary, a new Buffer with the required length is attached.

encoding.write(encoder: module:encoding.Encoder, num: number)

Write one byte to the encoder.

encoding.set(encoder: module:encoding.Encoder, pos: number, num: number)

Write one byte at a specific position. Position must already be written (i.e. encoder.length > pos)

encoding.writeUint8(encoder: module:encoding.Encoder, num: number)

Write one byte as an unsigned integer.

encoding.setUint8(encoder: module:encoding.Encoder, pos: number, num: number)

Write one byte as an unsigned Integer at a specific location.

encoding.writeUint16(encoder: module:encoding.Encoder, num: number)

Write two bytes as an unsigned integer.

encoding.setUint16(encoder: module:encoding.Encoder, pos: number, num: number)

Write two bytes as an unsigned integer at a specific location.

encoding.writeUint32(encoder: module:encoding.Encoder, num: number)

Write two bytes as an unsigned integer

encoding.writeUint32BigEndian(encoder: module:encoding.Encoder, num: number)

Write two bytes as an unsigned integer in big endian order. (most significant byte first)

encoding.setUint32(encoder: module:encoding.Encoder, pos: number, num: number)

Write two bytes as an unsigned integer at a specific location.

encoding.writeVarUint(encoder: module:encoding.Encoder, num: number)

Write a variable length unsigned integer. Max encodable integer is 2^53.

encoding.writeVarInt(encoder: module:encoding.Encoder, num: number)

Write a variable length integer.

We use the 7th bit instead for signaling that this is a negative number.

encoding.writeVarString
encoding.writeBinaryEncoder(encoder: module:encoding.Encoder, append: module:encoding.Encoder)

Write the content of another Encoder.

encoding.writeUint8Array(encoder: module:encoding.Encoder, uint8Array: Uint8Array)

Append fixed-length Uint8Array to the encoder.

encoding.writeVarUint8Array(encoder: module:encoding.Encoder, uint8Array: Uint8Array)

Append an Uint8Array to Encoder.

encoding.writeOnDataView(encoder: module:encoding.Encoder, len: number): DataView

Create an DataView of the next len bytes. Use it to write data after calling this function.

// write float32 using DataView
const dv = writeOnDataView(encoder, 4)
dv.setFloat32(0, 1.1)
// read float32 using DataView
const dv = readFromDataView(encoder, 4)
dv.getFloat32(0) // => 1.100000023841858 (leaving it to the reader to find out why this is the correct result)

encoding.writeFloat32(encoder: module:encoding.Encoder, num: number)
encoding.writeFloat64(encoder: module:encoding.Encoder, num: number)
encoding.writeBigInt64(encoder: module:encoding.Encoder, num: bigint)
encoding.writeBigUint64(encoder: module:encoding.Encoder, num: bigint)
encoding.writeAny(encoder: module:encoding.Encoder, data: undefined|null|number|bigint|boolean|string|Object<string,any>|Array<any>|Uint8Array)

Encode data with efficient binary format.

Differences to JSON: • Transforms data to a binary format (not to a string) • Encodes undefined, NaN, and ArrayBuffer (these can't be represented in JSON) • Numbers are efficiently encoded either as a variable length integer, as a 32 bit float, as a 64 bit float, or as a 64 bit bigint.

Encoding table:

Data Type	Prefix	Encoding Method	Comment
undefined	127		Functions, symbol, and everything that cannot be identified is encoded as undefined
null	126
integer	125	writeVarInt	Only encodes 32 bit signed integers
float32	124	writeFloat32
float64	123	writeFloat64
bigint	122	writeBigInt64
boolean (false)	121		True and false are different data types so we save the following byte
boolean (true)	120		- 0b01111000 so the last bit determines whether true or false
string	119	writeVarString
object<string,any>	118	custom	Writes {length} then {length} key-value pairs
array	117	custom	Writes {length} then {length} json values
Uint8Array	116	writeVarUint8Array	We use Uint8Array for any kind of binary data

Reasons for the decreasing prefix: We need the first bit for extendability (later we may want to encode the prefix with writeVarUint). The remaining 7 bits are divided as follows: [0-30] the beginning of the data range is used for custom purposes (defined by the function that uses this library) [31-127] the end of the data range is used for data encoding by lib0/encoding.js

new encoding.RleEncoder(writer: function(module:encoding.Encoder, T):void)

Now come a few stateful encoder that have their own classes.

encoding.RleEncoder#s: T|null

Current state

encoding.RleEncoder#write(v: T)
new encoding.IntDiffEncoder(start: number)

Basic diff decoder using variable length encoding.

Encodes the values [3, 1100, 1101, 1050, 0] to [3, 1097, 1, -51, -1050] using writeVarInt.

encoding.IntDiffEncoder#s: number

Current state

encoding.IntDiffEncoder#write(v: number)
new encoding.RleIntDiffEncoder(start: number)

A combination of IntDiffEncoder and RleEncoder.

Basically first writes the IntDiffEncoder and then counts duplicate diffs using RleEncoding.

Encodes the values [1,1,1,2,3,4,5,6] as [1,1,0,2,1,5] (RLE([1,0,0,1,1,1,1,1]) ⇒ RleIntDiff[1,1,0,2,1,5])

encoding.RleIntDiffEncoder#s: number

Current state

encoding.RleIntDiffEncoder#write(v: number)
new encoding.UintOptRleEncoder()

Optimized Rle encoder that does not suffer from the mentioned problem of the basic Rle encoder.

Internally uses VarInt encoder to write unsigned integers. If the input occurs multiple times, we write write it as a negative number. The UintOptRleDecoder then understands that it needs to read a count.

Encodes [1,2,3,3,3] as [1,2,-3,3] (once 1, once 2, three times 3)

encoding.UintOptRleEncoder#s: number
encoding.UintOptRleEncoder#write(v: number)
encoding.UintOptRleEncoder#toUint8Array()
new encoding.IncUintOptRleEncoder()

Increasing Uint Optimized RLE Encoder

The RLE encoder counts the number of same occurences of the same value. The IncUintOptRle encoder counts if the value increases. I.e. 7, 8, 9, 10 will be encoded as [-7, 4]. 1, 3, 5 will be encoded as [1, 3, 5].

encoding.IncUintOptRleEncoder#s: number
encoding.IncUintOptRleEncoder#write(v: number)
encoding.IncUintOptRleEncoder#toUint8Array()
new encoding.IntDiffOptRleEncoder()

A combination of the IntDiffEncoder and the UintOptRleEncoder.

The count approach is similar to the UintDiffOptRleEncoder, but instead of using the negative bitflag, it encodes in the LSB whether a count is to be read. Therefore this Encoder only supports 31 bit integers!

Encodes [1, 2, 3, 2] as [3, 1, 6, -1] (more specifically [(1 << 1) | 1, (3 << 0) | 0, -1])

Internally uses variable length encoding. Contrary to normal UintVar encoding, the first byte contains:

• 1 bit that denotes whether the next value is a count (LSB)
• 1 bit that denotes whether this value is negative (MSB - 1)
• 1 bit that denotes whether to continue reading the variable length integer (MSB)

Therefore, only five bits remain to encode diff ranges.

Use this Encoder only when appropriate. In most cases, this is probably a bad idea.

encoding.IntDiffOptRleEncoder#s: number
encoding.IntDiffOptRleEncoder#write(v: number)
encoding.IntDiffOptRleEncoder#toUint8Array()
new encoding.StringEncoder()

Optimized String Encoder.

Encoding many small strings in a simple Encoder is not very efficient. The function call to decode a string takes some time and creates references that must be eventually deleted. In practice, when decoding several million small strings, the GC will kick in more and more often to collect orphaned string objects (or maybe there is another reason?).

This string encoder solves the above problem. All strings are concatenated and written as a single string using a single encoding call.

The lengths are encoded using a UintOptRleEncoder.

encoding.StringEncoder#sarr: Array<string>
encoding.StringEncoder#write(string: string)
encoding.StringEncoder#toUint8Array()
encoding.RleEncoder#bufs: Array<Uint8Array>
encoding.IntDiffEncoder#bufs: Array<Uint8Array>
encoding.RleIntDiffEncoder#bufs: Array<Uint8Array>

import * as env from 'lib0/environment'

env.isNode
env.isBrowser
env.isMac
env.hasParam
env.getParam
env.getVariable
env.getConf(name: string): string|null
env.hasConf
env.production
env.supportsColor

import * as error from 'lib0/error'

error.create(s: string): Error
error.methodUnimplemented(): never
error.unexpectedCase(): never

import * as eventloop from 'lib0/eventloop'

eventloop.enqueue(f: function():void)
eventloop#destroy()
eventloop.timeout(timeout: number, callback: function): module:eventloop~TimeoutObject
eventloop.interval(timeout: number, callback: function): module:eventloop~TimeoutObject
eventloop.Animation
eventloop.animationFrame(cb: function(number):void): module:eventloop~TimeoutObject
eventloop.idleCallback(cb: function): module:eventloop~TimeoutObject

Note: this is experimental and is probably only useful in browsers.

eventloop.createDebouncer(timeout: number): function(function():void):void

import * as function from 'lib0/function'

function.callAll(fs: Array<function>, args: Array<any>)

Calls all functions in fs with args. Only throws after all functions were called.

function.nop
function.apply(f: function():T): T
function.id(a: A): A
function.equalityStrict(a: T, b: T): boolean
function.equalityFlat(a: Array<T>|object, b: Array<T>|object): boolean
function.equalityDeep(a: any, b: any): boolean
function.isOneOf(value: V, options: Array<OPTS>)

import * as lib0 from 'lib0/index'

Not recommended if the module bundler doesn't support dead code elimination.

import * as indexeddb from 'lib0/indexeddb'

indexeddb.rtop(request: IDBRequest): Promise<any>

IDB Request to Promise transformer

indexeddb.openDB(name: string, initDB: function(IDBDatabase):any): Promise<IDBDatabase>
indexeddb.deleteDB(name: string)
indexeddb.createStores(db: IDBDatabase, definitions: Array<Array<string>|Array<string|IDBObjectStoreParameters|undefined>>)
indexeddb.transact(db: IDBDatabase, stores: Array<string>, access: "readwrite"|"readonly"): Array<IDBObjectStore>
indexeddb.count(store: IDBObjectStore, range: IDBKeyRange): Promise<number>
indexeddb.get(store: IDBObjectStore, key: String | number | ArrayBuffer | Date | Array<any> ): Promise<String | number | ArrayBuffer | Date | Array<any>>
indexeddb.del(store: IDBObjectStore, key: String | number | ArrayBuffer | Date | IDBKeyRange | Array<any> )
indexeddb.put(store: IDBObjectStore, item: String | number | ArrayBuffer | Date | boolean, key: String | number | ArrayBuffer | Date | Array<any>)
indexeddb.add(store: IDBObjectStore, item: String|number|ArrayBuffer|Date|boolean, key: String|number|ArrayBuffer|Date|Array.<any>): Promise<any>
indexeddb.addAutoKey(store: IDBObjectStore, item: String|number|ArrayBuffer|Date): Promise<number>
indexeddb.getAll(store: IDBObjectStore, range: IDBKeyRange, limit: number): Promise<Array<any>>
indexeddb.getAllKeys(store: IDBObjectStore, range: IDBKeyRange, limit: number): Promise<Array<any>>
indexeddb.queryFirst(store: IDBObjectStore, query: IDBKeyRange|null, direction: 'next'|'prev'|'nextunique'|'prevunique'): Promise<any>
indexeddb.getLastKey(store: IDBObjectStore, range: IDBKeyRange?): Promise<any>
indexeddb.getFirstKey(store: IDBObjectStore, range: IDBKeyRange?): Promise<any>
indexeddb.getAllKeysValues(store: IDBObjectStore, range: IDBKeyRange, limit: number): Promise<Array<KeyValuePair>>
indexeddb.iterate(store: IDBObjectStore, keyrange: IDBKeyRange|null, f: function(any,any):void|boolean|Promise<void|boolean>, direction: 'next'|'prev'|'nextunique'|'prevunique')

Iterate on keys and values

indexeddb.iterateKeys(store: IDBObjectStore, keyrange: IDBKeyRange|null, f: function(any):void|boolean|Promise<void|boolean>, direction: 'next'|'prev'|'nextunique'|'prevunique')

Iterate on the keys (no values)

indexeddb.getStore(t: IDBTransaction, store: String)IDBObjectStore

Open store from transaction

indexeddb.createIDBKeyRangeBound(lower: any, upper: any, lowerOpen: boolean, upperOpen: boolean)
indexeddb.createIDBKeyRangeUpperBound(upper: any, upperOpen: boolean)
indexeddb.createIDBKeyRangeLowerBound(lower: any, lowerOpen: boolean)

import * as isomorphic from 'lib0/isomorphic'

import * as iterator from 'lib0/iterator'

iterator.mapIterator(iterator: Iterator<T>, f: function(T):R): IterableIterator<R>
iterator.createIterator(next: function():IteratorResult<T>): IterableIterator<T>
iterator.iteratorFilter(iterator: Iterator<T>, filter: function(T):boolean)
iterator.iteratorMap(iterator: Iterator<T>, fmap: function(T):M)

import * as json from 'lib0/json'

json.stringify(object: any): string

Transform JavaScript object to JSON.

json.parse(json: string): any

Parse JSON object.

import * as list from 'lib0/list'

new e#ListNode()
e#next: this|null
e#prev: this|null
new st()
art: N | null
d: N | null
(): module:list.List<N>
()
(queue: module:list.List<N>)
()
(queue: module:list.List<N>, node: N)

Remove a single node from the queue. Only works with Queues that operate on Doubly-linked lists of nodes.

()
ode
ode()
etween(queue: module:list.List<N>, left: N| null, right: N| null, node: N)
etween()
(queue: module:list.List<N>, node: N, newNode: N)

Remove a single node from the queue. Only works with Queues that operate on Doubly-linked lists of nodes.

()
(queue: module:list.List<N>, n: N)
()
nt(queue: module:list.List<N>, n: N)
nt()
t(list: module:list.List<N>): N| null
t()
(list: module:list.List<N>): N| null
()
(list: module:list.List<N>, f: function(N):M): Array<M>
()
(list: module:list.List<N>)
()
(list: module:list.List<N>, f: function(N):M)
()

import * as logging from 'lib0/logging'

logging.BOLD
logging.UNBOLD
logging.BLUE
logging.GREY
logging.GREEN
logging.RED
logging.PURPLE
logging.ORANGE
logging.UNCOLOR
logging.print(args: Array<string|Symbol|Object|number>)
logging.warn(args: Array<string|Symbol|Object|number>)
logging.printError(err: Error)
logging.printImg(url: string, height: number)
logging.printImgBase64(base64: string, height: number)
logging.group(args: Array<string|Symbol|Object|number>)
logging.groupCollapsed(args: Array<string|Symbol|Object|number>)
logging.groupEnd
logging.printDom(createNode: function():Node)
logging.printCanvas(canvas: HTMLCanvasElement, height: number)
logging.vconsoles
new logging.VConsole(dom: Element)
logging.VConsole#ccontainer: Element
logging.VConsole#group(args: Array<string|Symbol|Object|number>, collapsed: boolean)
logging.VConsole#groupCollapsed(args: Array<string|Symbol|Object|number>)
logging.VConsole#groupEnd()
logging.VConsole#print(args: Array<string|Symbol|Object|number>)
logging.VConsole#printError(err: Error)
logging.VConsole#printImg(url: string, height: number)
logging.VConsole#printDom(node: Node)
logging.VConsole#destroy()
logging.createVConsole(dom: Element)
logging.createModuleLogger(moduleName: string): function(...any):void

import * as map from 'lib0/map'

map.create(): Map<any, any>

Creates a new Map instance.

map.copy(m: Map<X,Y>): Map<X,Y>

Copy a Map object into a fresh Map object.

map.setIfUndefined(map: Map<K, T>, key: K, createT: function():T): T

Get map property. Create T if property is undefined and set T on map.

const listeners = map.setIfUndefined(events, 'eventName', set.create)
listeners.add(listener)

map.map(m: Map<K,V>, f: function(V,K):R): Array<R>

Creates an Array and populates it with the content of all key-value pairs using the f(value, key) function.

map.any(m: Map<K,V>, f: function(V,K):boolean): boolean

Tests whether any key-value pairs pass the test implemented by f(value, key).

map.all(m: Map<K,V>, f: function(V,K):boolean): boolean

Tests whether all key-value pairs pass the test implemented by f(value, key).

import * as math from 'lib0/math'

math.floor
math.ceil
math.abs
math.imul
math.round
math.log10
math.log2
math.log
math.sqrt
math.add(a: number, b: number): number
math.min(a: number, b: number): number
math.max(a: number, b: number): number
math.isNaN
math.pow
math.exp10(exp: number): number

Base 10 exponential function. Returns the value of 10 raised to the power of pow.

math.sign
math.isNegativeZero(n: number): boolean

import * as metric from 'lib0/metric'

metric.yotta
metric.zetta
metric.exa
metric.peta
metric.tera
metric.giga
metric.mega
metric.kilo
metric.hecto
metric.deca
metric.deci
metric.centi
metric.milli
metric.micro
metric.nano
metric.pico
metric.femto
metric.atto
metric.zepto
metric.yocto
metric.prefix(n: number, baseMultiplier: number): {n:number,prefix:string}

Calculate the metric prefix for a number. Assumes E.g. prefix(1000) = { n: 1, prefix: 'k' }

import * as mutex from 'lib0/mutex'

mutex.createMutex(): mutex

Creates a mutual exclude function with the following property:

const mutex = createMutex()
mutex(() => {
  // This function is immediately executed
  mutex(() => {
    // This function is not executed, as the mutex is already active.
  })
})

import * as number from 'lib0/number'

number.MAX_SAFE_INTEGER
number.MIN_SAFE_INTEGER
number.LOWEST_INT32
number.HIGHEST_INT32: number
number.isInteger
number.isNaN
number.parseInt

import * as object from 'lib0/object'

object.create(): Object<string,any>
object.assign

Object.assign

object.keys(obj: Object<string,any>)
object.forEach(obj: Object<string,any>, f: function(any,string):any)
object.map(obj: Object<string,any>, f: function(any,string):R): Array<R>
object.length(obj: Object<string,any>): number
object.some(obj: Object<string,any>, f: function(any,string):boolean): boolean
object.isEmpty(obj: Object|undefined)
object.every(obj: Object<string,any>, f: function(any,string):boolean): boolean
object.hasProperty(obj: any, key: string|symbol): boolean

Calls Object.prototype.hasOwnProperty.

object.equalFlat(a: Object<string,any>, b: Object<string,any>): boolean

import * as observable from 'lib0/observable'

new observable.Observable()

Handles named events.

observable.Observable#on(name: N, f: function)
observable.Observable#once(name: N, f: function)
observable.Observable#off(name: N, f: function)
observable.Observable#emit(name: N, args: Array<any>)

Emit a named event. All registered event listeners that listen to the specified name will receive the event.

observable.Observable#destroy()
websocket.WebsocketClient#on(name: N, f: function)
websocket.WebsocketClient#once(name: N, f: function)
websocket.WebsocketClient#off(name: N, f: function)
websocket.WebsocketClient#emit(name: N, args: Array<any>)

Emit a named event. All registered event listeners that listen to the specified name will receive the event.

import * as pair from 'lib0/pair'

new pair.Pair(left: L, right: R)
pair.create(left: L, right: R): module:pair.Pair<L,R>
pair.createReversed(right: R, left: L): module:pair.Pair<L,R>
pair.forEach(arr: Array<module:pair.Pair<L,R>>, f: function(L, R):any)
pair.map(arr: Array<module:pair.Pair<L,R>>, f: function(L, R):X): Array<X>

import * as prng from 'lib0/prng'

Given a seed a PRNG generates a sequence of numbers that cannot be reasonably predicted. Two PRNGs must generate the same random sequence of numbers if given the same seed.

prng.DefaultPRNG
prng.create(seed: number): module:prng~PRNG

Create a Xoroshiro128plus Pseudo-Random-Number-Generator. This is the fastest full-period generator passing BigCrush without systematic failures. But there are more PRNGs available in ./PRNG/.

prng.bool(gen: module:prng~PRNG): Boolean

Generates a single random bool.

prng.int53(gen: module:prng~PRNG, min: Number, max: Number): Number

Generates a random integer with 53 bit resolution.

prng.uint53(gen: module:prng~PRNG, min: Number, max: Number): Number

Generates a random integer with 53 bit resolution.

prng.int32(gen: module:prng~PRNG, min: Number, max: Number): Number

Generates a random integer with 32 bit resolution.

prng.uint32(gen: module:prng~PRNG, min: Number, max: Number): Number

Generates a random integer with 53 bit resolution.

prng.int31(gen: module:prng~PRNG, min: Number, max: Number): Number
prng.real53(gen: module:prng~PRNG): Number

Generates a random real on [0, 1) with 53 bit resolution.

prng.char(gen: module:prng~PRNG): string

Generates a random character from char code 32 - 126. I.e. Characters, Numbers, special characters, and Space:

prng.letter(gen: module:prng~PRNG): string
prng.word(gen: module:prng~PRNG, minLen: number, maxLen: number): string
prng.utf16Rune(gen: module:prng~PRNG): string

TODO: this function produces invalid runes. Does not cover all of utf16!!

prng.utf16String(gen: module:prng~PRNG, maxlen: number)
prng.oneOf(gen: module:prng~PRNG, array: Array<T>): T

Returns one element of a given array.

prng.uint8Array(gen: module:prng~PRNG, len: number): Uint8Array
prng.uint16Array(gen: module:prng~PRNG, len: number): Uint16Array
prng.uint32Array(gen: module:prng~PRNG, len: number): Uint32Array

import * as promise from 'lib0/promise'

promise.create(f: function(PromiseResolve<T>,function(Error):void):any): Promise<T>
promise.createEmpty(f: function(function():void,function(Error):void):void): Promise<void>
promise.all(arrp: Array<Promise<T>>): Promise<Array<T>>

Promise.all wait for all promises in the array to resolve and return the result

promise.reject(reason: Error): Promise<never>
promise.resolve(res: T|void): Promise<T|void>
promise.resolveWith(res: T): Promise<T>
promise.until(timeout: number, check: function():boolean, intervalResolution: number): Promise<void>
promise.wait(timeout: number): Promise<undefined>
promise.isPromise(p: any): boolean

Checks if an object is a promise using ducktyping.

Promises are often polyfilled, so it makes sense to add some additional guarantees if the user of this library has some insane environment where global Promise objects are overwritten.

import * as queue from 'lib0/queue'

new de#QueueNode()
de#next: module:queue.QueueNode|null
new ueue()
tart: module:queue.QueueNode | null
nd: module:queue.QueueNode | null
(): module:queue.Queue
()
(queue: module:queue.Queue)
()
(queue: module:queue.Queue, n: module:queue.QueueNode)
()
(queue: module:queue.Queue): module:queue.QueueNode | null
()

import * as random from 'lib0/random'

Attention: falls back to Math.random if the browser does not support crypto.

random.rand
random.uint32
random.uint53
random.oneOf(arr: Array<T>): T
random.uuidv4

import * as set from 'lib0/set'

set.create
set.toArray(set: Set<T>): Array<T>
set.first(set: Set<T>): T
set.from(entries: Iterable<T>): Set<T>

import * as sort from 'lib0/sort'

Note: These sort implementations were created to compare different sorting algorithms in JavaScript. Don't use them if you don't know what you are doing. Native Array.sort is almost always a better choice.

sort.insertionSort(arr: Array<T>, compare: function(T,T):number): void
sort.quicksort(arr: Array<T>, compare: function(T,T):number): void

This algorithm beats Array.prototype.sort in Chrome only with arrays with 10 million entries. In most cases [].sort will do just fine. Make sure to performance test your use-case before you integrate this algorithm.

Note that Chrome's sort is now a stable algorithm (Timsort). Quicksort is not stable.

import * as statistics from 'lib0/statistics'

statistics.median(arr: Array<number>): number
statistics.average(arr: Array<number>): number

import * as storage from 'lib0/storage'

Uses LocalStorage in the browser and falls back to in-memory storage.

storage.varStorage

This is basically localStorage in browser, or a polyfill in nodejs

storage.onChange(eventHandler: function({ key: string, newValue: string, oldValue: string }): void)

A polyfill for addEventListener('storage', event => {..}) that does nothing if the polyfill is being used.

import * as string from 'lib0/string'

string.fromCharCode
string.fromCodePoint
string.trimLeft(s: string): string
string.fromCamelCase(s: string, separator: string): string
string.utf8ByteLength(str: string): number

Compute the utf8ByteLength

string.utf8TextEncoder
string.encodeUtf8
string.decodeUtf8
string.splice(str: string, index: number, remove: number, insert: string)

import * as symbol from 'lib0/symbol'

symbol.create(): Symbol

Return fresh symbol.

symbol.isSymbol(s: any): boolean

import * as testing from 'lib0/testing'

// test.js template for creating a test executable
import { runTests } from 'lib0/testing'
import * as log from 'lib0/logging'
import * as mod1 from './mod1.test.js'
import * as mod2 from './mod2.test.js'
import { isBrowser, isNode } from 'lib0/environment.js'

if (isBrowser) {
  // optional: if this is ran in the browser, attach a virtual console to the dom
  log.createVConsole(document.body)
}

runTests({
 mod1,
 mod2,
}).then(success => {
  if (isNode) {
    process.exit(success ? 0 : 1)
  }
})

// mod1.test.js
/**
 * runTests automatically tests all exported functions that start with "test".
 * The name of the function should be in camelCase and is used for the logging output.
 *
 * @param {t.TestCase} tc
 *\/
export const testMyFirstTest = tc => {
  t.compare({ a: 4 }, { a: 4 }, 'objects are equal')
}

Now you can simply run node test.js to run your test or run test.js in the browser.

testing.extensive
testing.envSeed
new testing.TestCase(moduleName: string, testName: string)
testing.TestCase#moduleName: string
testing.TestCase#testName: string
testing.TestCase#resetSeed()
testing.TestCase#prng: prng.PRNG

A PRNG for this test case. Use only this PRNG for randomness to make the test case reproducible.

testing.repetitionTime
testing.run(moduleName: string, name: string, f: function(module:testing.TestCase):void|Promise<any>, i: number, numberOfTests: number)
testing.describe(description: string, info: string)

Describe what you are currently testing. The message will be logged.

export const testMyFirstTest = tc => {
  t.describe('crunching numbers', 'already crunched 4 numbers!') // the optional second argument can describe the state.
}

testing.info(info: string)

Describe the state of the current computation.

export const testMyFirstTest = tc => {
  t.info(already crunched 4 numbers!') // the optional second argument can describe the state.
}

testing.printDom
testing.printCanvas
testing.group(description: string, f: function(void):void)

Group outputs in a collapsible category.

export const testMyFirstTest = tc => {
  t.group('subtest 1', () => {
    t.describe('this message is part of a collapsible section')
  })
  await t.groupAsync('subtest async 2', async () => {
    await someaction()
    t.describe('this message is part of a collapsible section')
  })
}

testing.groupAsync(description: string, f: function(void):Promise<any>)

Group outputs in a collapsible category.

export const testMyFirstTest = async tc => {
  t.group('subtest 1', () => {
    t.describe('this message is part of a collapsible section')
  })
  await t.groupAsync('subtest async 2', async () => {
    await someaction()
    t.describe('this message is part of a collapsible section')
  })
}

testing.measureTime(message: string, f: function():void): number

Measure the time that it takes to calculate something.

export const testMyFirstTest = async tc => {
  t.measureTime('measurement', () => {
    heavyCalculation()
  })
  await t.groupAsync('async measurement', async () => {
    await heavyAsyncCalculation()
  })
}

testing.measureTimeAsync(message: string, f: function():Promise<any>): Promise<number>

Measure the time that it takes to calculate something.

export const testMyFirstTest = async tc => {
  t.measureTimeAsync('measurement', async () => {
    await heavyCalculation()
  })
  await t.groupAsync('async measurement', async () => {
    await heavyAsyncCalculation()
  })
}

testing.compareArrays(as: Array<T>, bs: Array<T>, m: string): boolean
testing.compareStrings(a: string, b: string, m: string)
testing.compareObjects(a: Object<K,V>, b: Object<K,V>, m: string)
testing.compare(a: T, b: T, message: string?, customCompare: function(any,T,T,string,any):boolean)
testing.assert(condition: boolean, message: string?)
testing.promiseRejected(f: function():Promise<any>)
testing.fails(f: function():void)
testing.runTests(tests: Object<string, Object<string, function(module:testing.TestCase):void|Promise<any>>>)
testing.fail(reason: string)
testing.skip(cond: boolean)

import * as time from 'lib0/time'

time.getDate(): Date

Return current time.

time.getUnixTime(): number

Return current unix time.

time.humanizeDuration(d: number): string

Transform time (in ms) to a human readable format. E.g. 1100 => 1.1s. 60s => 1min. .001 => 10μs.

import * as tree from 'lib0/tree'

new tree.Tree()

This is a Red Black Tree implementation

tree.Tree#findNext(id: K)
tree.Tree#findPrev(id: K)
tree.Tree#findNodeWithLowerBound(from: K)
tree.Tree#findNodeWithUpperBound(to: K)
tree.Tree#findSmallestNode(): V
tree.Tree#findWithLowerBound(from: K): V
tree.Tree#findWithUpperBound(to: K): V
tree.Tree#iterate(from: K, from: K, f: K)
tree.Tree#find(id: K): V|null
tree.Tree#findNode(id: K): module:tree~N<V>|null
tree.Tree#delete(id: K)
tree.Tree#put()

import * as url from 'lib0/url'

url.decodeQueryParams(url: string): Object<string,string>

Parse query parameters from an url.

url.encodeQueryParams(params: Object<string,string>): string

import * as webcrypto.browser from 'lib0/webcrypto.browser'

()
omValues
omValues()

import * as webcrypto.node from 'lib0/webcrypto.node'

()
to.subtle: any
omValues
omValues()

import * as websocket from 'lib0/websocket'

Implements exponential backoff reconnects, ping/pong, and a nice event system using [lib0/observable].

new websocket.WebsocketClient(url: string, opts: object, opts.binaryType: 'arraybuffer' | 'blob' | null)
websocket.WebsocketClient#ws: WebSocket?
websocket.WebsocketClient#shouldConnect: boolean

Whether to connect to other peers or not

websocket.WebsocketClient#send(message: any)
websocket.WebsocketClient#destroy()
websocket.WebsocketClient#disconnect()
websocket.WebsocketClient#connect()