1032 lines
32 KiB
TypeScript
1032 lines
32 KiB
TypeScript
import {
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AssociatedCollectionItem,
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Collection, CollectionIndex,
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CollectionItem, ComparisonFunction,
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DeterminesEquality, KeyFunction,
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KeyOperator, KeyReducerFunction, MaybeCollectionIndex, MaybeCollectionItem
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} from './Collection'
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import {Iterable, StopIteration} from './Iterable'
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import {applyWhere, WhereOperator} from './where'
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type AsyncCollectionComparable<T> = CollectionItem<T>[] | Collection<T> | AsyncCollection<T>
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type AsyncKeyFunction<T, T2> = (item: CollectionItem<T>, index: number) => CollectionItem<T2> | Promise<CollectionItem<T2>>
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type AsyncCollectionFunction<T, T2> = (items: AsyncCollection<T>) => T2
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/**
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* Like a collection, but asynchronous.
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*/
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export class AsyncCollection<T> {
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constructor(
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/**
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* Iterable of items to base this collction on.
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* @type Iterable
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*/
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private _items: Iterable<T>,
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/**
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* Size to use when chunking results for memory-optimization.
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* @type number
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*/
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private _chunk_size: number = 1000, // TODO fix this. It's just for testing
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) {}
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private async _chunk(callback: (items: Collection<T>) => any): Promise<void> {
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await this._items.chunk(this._chunk_size, async items => {
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await callback(items)
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})
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await this._items.reset()
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}
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private async _chunk_all<T2>(key: KeyOperator<T, T2>, callback: (items: Collection<T2>) => any): Promise<void> {
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await this._items.chunk(this._chunk_size, async items => {
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await callback(items.pluck(key))
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})
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await this._items.reset()
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}
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private async _chunk_all_numbers<T2>(key: KeyOperator<T, T2>, callback: (items: number[]) => any): Promise<void> {
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await this._items.chunk(this._chunk_size, async items => {
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await callback(items.pluck(key).map(x => Number(x)).all())
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})
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await this._items.reset()
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}
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private async _chunk_all_associate<T2>(key: KeyOperator<T, T2>, callback: (items: AssociatedCollectionItem<T2, T>[]) => any): Promise<void> {
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await this._items.chunk(this._chunk_size, async items => {
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const assoc_items: AssociatedCollectionItem<T2, T>[] = []
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if ( typeof key === 'function' ) {
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items.map((item, index) => {
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const key_item = key(item, index)
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assoc_items.push({ key: key_item, item })
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})
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} else {
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items.map((item, index) => {
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assoc_items.push({key: (<any>item)[key], item})
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})
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}
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await callback(assoc_items)
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})
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await this._items.reset()
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}
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/**
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* Get all items in this collection as an array.
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* @return Promise<array>
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*/
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async all(): Promise<CollectionItem<T>[]> {
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return (await this._items.all()).toArray()
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}
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/**
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* Get all items in this collection as a synchronous Collection
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* @return Promise<Collection>
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*/
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async collect(): Promise<Collection<T>> {
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return this._items.all()
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}
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/**
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* Get the average value of the collection or one of its keys.
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* @param {KeyOperator} key
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* @return Promise<number>
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*/
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async average<T2>(key?: KeyOperator<T, T2>): Promise<number> {
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let running_total = 0
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let running_items = 0
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const chunk_helper = (items: number[]) => {
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running_items += items.length
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running_total += items.reduce((prev, curr) => prev + curr)
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}
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if ( key ) await this._chunk_all_numbers(key, chunk_helper)
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else await this._chunk((items) => {
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chunk_helper(items.map(x => Number(x)).all())
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})
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return running_total / running_items
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}
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/**
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* Get the median value of the collection or one of its keys.
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* @param {KeyOperator} key
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* @return Promise<number>
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*/
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async median<T2>(key?: KeyOperator<T, T2>): Promise<number> {
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let items: number[] = []
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const chunk_helper = (next_items: number[]) => {
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items = items.concat(next_items)
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}
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if ( key ) await this._chunk_all_numbers(key, chunk_helper)
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else await this._chunk(items => {
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chunk_helper(items.map(x => Number(x)).all())
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})
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items = items.sort((a, b) => a - b)
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const middle = Math.floor((items.length - 1) / 2)
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if ( items.length % 2 ) return items[middle]
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else return (items[middle] + items[middle + 1]) / 2
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}
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/**
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* Get the mode value of the collection or one of its keys.
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* @param {KeyOperator} key
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* @return Promise<number>
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*/
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async mode<T2>(key?: KeyOperator<T, T2>): Promise<number> {
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let counts: any = {}
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const chunk_helper = (items: number[]) => {
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for ( const item of items ) {
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if ( !counts[item] ) counts[item] = 1
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else counts[item] += 1
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}
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}
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if ( key ) await this._chunk_all_numbers(key, chunk_helper)
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else await this._chunk(items => {
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chunk_helper(items.map(x => Number(x)).all())
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})
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return Number(Object.keys(counts).reduce((a, b) => counts[a] > counts[b] ? a : b)[0])
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}
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/**
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* If this collection contains nested collections, collapse them to a single level.
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* @return Promise<Collection>
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*/
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async collapse(): Promise<Collection<any>> {
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const items = await this.collect()
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return items.collapse() as Collection<any>
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}
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/**
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* Returns true if the collection contains an item satisfying the given collection.
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* @example
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* collection.contains('id', '>', 4)
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* @param {KeyOperator} key
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* @param {WhereOperator} operator
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* @param [operand]
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* @return Promise<boolean>
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*/
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async contains<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<boolean> {
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let contains = false
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await this._chunk_all_associate(key, (items: AssociatedCollectionItem<T2, T>[]) => {
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const matches = applyWhere(items, operator, operand)
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if ( matches.length > 0 ) {
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contains = true
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throw new StopIteration()
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}
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})
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return contains
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}
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/**
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* Returns a clean instance of this collection pointing to the same result set of the iterable.
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* @return Promise<AsyncCollection>
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*/
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async clone(): Promise<AsyncCollection<T>> {
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return new AsyncCollection<T>(await this._items.clone())
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}
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/**
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* Returns the elements that are different between the two collections.
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* @param {AsyncCollectionComparable} items
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* @return Promise<Collection>
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*/
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async diff(items: AsyncCollectionComparable<T>): Promise<Collection<T>> {
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const matches: T[] = []
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await this._chunk(async chunk => {
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for ( const item of chunk.all() ) {
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if ( !(await items.includes(item)) ) {
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matches.push(item)
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}
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}
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})
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return new Collection<T>(matches)
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}
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/**
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* Returns the elements that are different between the two collections, using the given function
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* as a comparator for the elements.
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* @param {AsyncCollectionComparable} items
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* @param {DeterminesEquality} compare
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* @return Promise<Collection>
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*/
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async diffUsing(items: AsyncCollectionComparable<T>, compare: DeterminesEquality<T>): Promise<Collection<T>> {
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const matches: T[] = []
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await this._chunk(async chunk => {
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for ( const item of chunk.all() ) {
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if ( !(await items.some(exc => compare(item, exc))) )
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matches.push(item)
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}
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})
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return new Collection<T>(matches)
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}
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/**
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* Returns true if the given item is present in the collection.
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* @param item
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* @return Promise<boolean>
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*/
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async includes(item: CollectionItem<T>): Promise<boolean> {
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let contains = false
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await this._chunk(items => {
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if ( items.includes(item) ) {
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contains = true
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throw new StopIteration()
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}
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})
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return contains
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}
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/**
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* Returns true if there is an item in the collection for which the given operator returns true.
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* @param {function} operator - item => boolean
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* @return Promise<boolean>
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*/
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async some(operator: (item: T) => boolean): Promise<boolean> {
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let contains = false
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await this._chunk(items => {
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for ( const item of items.all() ) {
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if ( operator(item) ) {
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contains = true
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throw new StopIteration()
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}
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}
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})
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return contains
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}
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/**
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* Applies a callback to each item in the collection.
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* @param {AsyncKeyFunction} func
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* @return Promise<void>
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*/
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async each<T2>(func: AsyncKeyFunction<T, T2>): Promise<void> {
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let index = 0
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await this._chunk(async items => {
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for ( const item of items.all() ) {
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await func(item, index)
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index += 1
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}
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})
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}
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/**
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* Applies a callback to each item in the collection and returns the results as a collection.
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* @param {AsyncKeyFunction} func
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* @return Promise<Collection>
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*/
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async map<T2>(func: AsyncKeyFunction<T, T2>): Promise<Collection<T2>> {
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const new_items: CollectionItem<T2>[] = []
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await this.each(async (item, index) => {
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new_items.push(await func(item, index))
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})
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return new Collection<T2>(new_items)
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}
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/**
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* Returns true if the given operator returns true for every item in the collection.
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* @param {AsyncKeyFunction} func
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* @return Promise<boolean>
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*/
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async every<T2>(func: AsyncKeyFunction<T, T2>): Promise<boolean> {
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let pass = true
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let index = 0
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await this._chunk(async items => {
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for ( const item of items.all() ) {
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if ( !(await func(item, index)) ) {
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pass = false
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throw new StopIteration()
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}
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index += 1
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}
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})
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return pass
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}
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/**
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* Returns true if every item in the collection satisfies the given where clause.
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* @param {KeyOperator} key
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* @param {WhereOperator} operator
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* @param [operand]
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*/
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async everyWhere<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<boolean> {
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let pass = true
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await this._chunk(async items => {
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pass = pass && items.everyWhere(key, operator, operand)
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if ( !pass ) {
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throw new StopIteration()
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}
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})
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return pass
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}
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/**
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* Applies a filter to every item in the collection and returns the results that pass the filter.
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* @param {KeyFunction} func
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* @return Promise<Collection>
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*/
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async filter<T2>(func: KeyFunction<T, T2>): Promise<Collection<T>> {
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let new_items: CollectionItem<T>[] = []
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await this._chunk(async items => {
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new_items = new_items.concat(items.filter(func).all())
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})
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return new Collection<T>(new_items)
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}
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/**
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* Calls the passed in function if the boolean condition is true. Allows for functional syntax.
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* @param {boolean} bool
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* @param {AsyncCollectionFunction} then
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* @return AsyncCollection
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*/
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when<T2>(bool: boolean, then: AsyncCollectionFunction<T, T2>): AsyncCollection<T> {
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if ( bool ) then(this)
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return this
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}
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/**
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* Calls the passed in function if the boolean condition is false. Allows for functional syntax.
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* @param {boolean} bool
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* @param {AsyncCollectionFunction} then
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* @return AsyncCollection
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*/
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unless<T2>(bool: boolean, then: AsyncCollectionFunction<T, T2>): AsyncCollection<T> {
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if ( !bool ) then(this)
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return this
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}
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/**
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* Applies the given where condition to the collection and returns a new collection of the results.
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* @param {KeyOperator} key
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* @param {WhereOperator} operator
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* @param [operand]
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* @return Promise<Collection>
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*/
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async where<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<Collection<T>> {
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let new_items: CollectionItem<T>[] = []
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await this._chunk(async items => {
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new_items = new_items.concat(items.where(key, operator, operand).all())
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})
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return new Collection<T>(new_items)
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}
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/**
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* Applies the given where condition to the collection and returns a new collection of the items
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* that did not satisfy the condition.
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* @param {KeyOperator} key
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* @param {WhereOperator} operator
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* @param [operand]
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* @return Promise<Collection>
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*/
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async whereNot<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<Collection<T>> {
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let new_items: CollectionItem<T>[] = []
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await this._chunk(async items => {
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new_items = new_items.concat(items.whereNot(key, operator, operand).all())
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})
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return new Collection<T>(new_items)
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}
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/**
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* Applies a WHERE ... IN ... condition to the collection an returns a new collection of the results.
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* @param {KeyOperator} key
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* @param {AsyncCollectionComparable} items
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* @return Promise<Collection>
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*/
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async whereIn<T2>(key: KeyOperator<T, T2>, items: AsyncCollectionComparable<T2>): Promise<Collection<T>> {
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let new_items: CollectionItem<T>[] = []
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await this._chunk_all_associate(key,async chunk => {
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for ( const item of chunk ) {
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if ( await items.includes(item.key) ) {
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new_items.push(item.item)
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}
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}
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})
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return new Collection<T>(new_items)
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}
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/**
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* Applies a WHERE ... IN ... condition to the collection and returns a new collection of the items
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* that did not satisfy the condition.
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* @param {KeyOperator} key
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* @param {AsyncCollectionComparable} items
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* @return Promise<Collection>
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*/
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async whereNotIn<T2>(key: KeyOperator<T, T2>, items: AsyncCollectionComparable<T2>): Promise<Collection<T>> {
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let new_items: CollectionItem<T>[] = []
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await this._chunk_all_associate(key,async chunk => {
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for ( const item of chunk ) {
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if ( !(await items.includes(item.key)) ) {
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new_items.push(item.item)
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}
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}
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})
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return new Collection<T>(new_items)
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}
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/**
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* Returns the first item in the collection, if one exists.
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* @return Promise<MaybeCollectionItem>
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*/
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async first(): Promise<MaybeCollectionItem<T>> {
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return this._items.at(0)
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}
|
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/**
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* Return the first item in the collection that satisfies the given where condition, if one exists.
|
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* @param {KeyOperator} key
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* @param {WhereOperator} [operator = '=']
|
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* @param [operand = true]
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* @return Promise<MaybeCollectionItem>
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*/
|
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async firstWhere<T2>(key: KeyOperator<T, T2>, operator: WhereOperator = '=', operand: any = true): Promise<MaybeCollectionItem<T>> {
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let item = undefined
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await this._chunk_all_associate(key, async items => {
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const matches = applyWhere(items, operator, operand)
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if ( matches.length > 0 ) {
|
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item = matches[0]
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throw new StopIteration()
|
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}
|
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})
|
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return item
|
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}
|
|
|
|
/**
|
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* Return the first item in the collection that does not satisfy the given where condition, if one exists.
|
|
* @param {KeyOperator} key
|
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* @param {WhereOperator} [operator = '=']
|
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* @param [operand = true]
|
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*/
|
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async firstWhereNot<T2>(key: KeyOperator<T, T2>, operator: WhereOperator = '=', operand: any = true): Promise<MaybeCollectionItem<T>> {
|
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let item: MaybeCollectionItem<T> = undefined
|
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await this._chunk(async items => {
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const matches = items.whereNot(key, operator, operand)
|
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if ( matches.length > 0 ) {
|
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item = matches.first()
|
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throw new StopIteration()
|
|
}
|
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})
|
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return item
|
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}
|
|
|
|
/**
|
|
* Returns the number of elements in this collection.
|
|
* @return Promise<number>
|
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*/
|
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async count() {
|
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return this._items.count()
|
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}
|
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|
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/**
|
|
* Returns the number of elements in this collection.
|
|
* @return Promise<number>
|
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*/
|
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async length() {
|
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return this._items.count()
|
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}
|
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|
|
/**
|
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* Get the item at the given index of this collection, if one exists.
|
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* If none exists and a fallback value is provided, that value will be returned.
|
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* @param {number} index
|
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* @param [fallback]
|
|
* @return Promise<any>
|
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*/
|
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async get(index: number, fallback?: any) {
|
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if ( (await this.count()) > index ) return this._items.at(index)
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else return fallback
|
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}
|
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|
|
/**
|
|
* Get the item at the given index of this collection, if one exists.
|
|
* @param {number} index
|
|
*/
|
|
async at(index: number): Promise<MaybeCollectionItem<T>> {
|
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return this.get(index)
|
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}
|
|
|
|
/**
|
|
* Return an object which maps key values to arrays of items in the collection that satisfy that value.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<object>
|
|
*/
|
|
async groupBy<T2>(key: KeyOperator<T, T2>): Promise<any> {
|
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return (await this.collect()).groupBy(key)
|
|
}
|
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|
|
/**
|
|
* Return an object mapping the given key value to items in this collection.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<object>
|
|
*/
|
|
async associate<T2>(key: KeyOperator<T, T2>): Promise<any> {
|
|
return (await this.collect()).associate(key)
|
|
}
|
|
|
|
/**
|
|
* Join the items in this collection with the given delimiter.
|
|
* @example
|
|
* await collection.join(',') // => '1,2,3,4'
|
|
* @param {string} delimiter
|
|
* @return Promise<string>
|
|
*/
|
|
async join(delimiter: string): Promise<string> {
|
|
let running_strings: string[] = []
|
|
|
|
await this._chunk(async items => {
|
|
running_strings.push(items.join(delimiter))
|
|
})
|
|
|
|
return running_strings.join(delimiter)
|
|
}
|
|
|
|
/**
|
|
* Join the items in this collection with the given delimiter.
|
|
* @example
|
|
* await collection.implode(',') // => '1,2,3,4'
|
|
* @param {string} delimiter
|
|
* @return Promise<string>
|
|
*/
|
|
async implode(delimiter: string): Promise<string> {
|
|
return this.join(delimiter)
|
|
}
|
|
|
|
// TODO intersect
|
|
|
|
/**
|
|
* Returns true if there are no items in this collection.
|
|
* @return Promise<boolean>
|
|
*/
|
|
async isEmpty(): Promise<boolean> {
|
|
return (await this._items.count()) < 1
|
|
}
|
|
|
|
/**
|
|
* Returns true if there is at least one item in this collection.
|
|
* @return Promise<boolean>
|
|
*/
|
|
async isNotEmpty(): Promise<boolean> {
|
|
return (await this._items.count()) > 0
|
|
}
|
|
|
|
/**
|
|
* Return the last item in this collection, if one exists.
|
|
* @return Promise<MaybeCollectionItem>
|
|
*/
|
|
async last(): Promise<MaybeCollectionItem<T>> {
|
|
const length = await this._items.count()
|
|
if ( length > 0 ) return this._items.at(length - 1)
|
|
}
|
|
|
|
/**
|
|
* Return the last item in this collection which satisfies the given where condition, if one exists.
|
|
* @param {KeyOperator} key
|
|
* @param {WhereOperator} operator
|
|
* @param [operand]
|
|
* @return Promise<MaybeCollectionItem>
|
|
*/
|
|
async lastWhere<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<MaybeCollectionItem<T>> {
|
|
return (await this.where(key, operator, operand)).last()
|
|
}
|
|
|
|
/**
|
|
* Return the last item in this collection which does not satisfy the given condition, if one exists.
|
|
* @param {KeyOperator} key
|
|
* @param {WhereOperator} operator
|
|
* @param [operand]
|
|
* @return Promise<MaybeCollectionItem>
|
|
*/
|
|
async lastWhereNot<T2>(key: KeyOperator<T, T2>, operator: WhereOperator, operand?: any): Promise<MaybeCollectionItem<T>> {
|
|
return (await this.whereNot(key, operator, operand)).last()
|
|
}
|
|
|
|
/**
|
|
* Builds a collection of the values of a given key for each item in this collection.
|
|
* @example
|
|
* // collection has { a: 1 }, { a: 2 }, { a: 3 }
|
|
* await collection.pluck('a') // => [1, 2, 3]
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async pluck<T2>(key: KeyOperator<T, T2>): Promise<Collection<T2>> {
|
|
let new_items: CollectionItem<T2>[] = []
|
|
|
|
await this._chunk_all(key, async items => {
|
|
new_items = new_items.concat(items.all())
|
|
})
|
|
|
|
return new Collection<T2>(new_items)
|
|
}
|
|
|
|
/**
|
|
* Return the max value of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<number>
|
|
*/
|
|
async max<T2>(key: KeyOperator<T, T2>): Promise<number> {
|
|
let running_max: number
|
|
|
|
await this._chunk_all_numbers(key, async items => {
|
|
const local_max = Math.max(...items)
|
|
if ( typeof running_max === 'undefined' ) running_max = local_max
|
|
else running_max = Math.max(running_max, local_max)
|
|
})
|
|
|
|
// @ts-ignore
|
|
return running_max
|
|
}
|
|
|
|
/**
|
|
* Return a collection of items that have the max value of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async whereMax<T2>(key: KeyOperator<T, T2>): Promise<Collection<T>> {
|
|
return this.where(key, '=', await this.max(key))
|
|
}
|
|
|
|
/**
|
|
* Return the min value of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<number>
|
|
*/
|
|
async min<T2>(key: KeyOperator<T, T2>): Promise<number> {
|
|
let running_min: number
|
|
|
|
await this._chunk_all_numbers(key, async items => {
|
|
const local_min = Math.min(...items)
|
|
if ( typeof running_min === 'undefined' ) running_min = local_min
|
|
else running_min = Math.min(running_min, local_min)
|
|
})
|
|
|
|
// @ts-ignore
|
|
return running_min
|
|
}
|
|
|
|
/**
|
|
* Return a collection of items that have the min value of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async whereMin<T2>(key: KeyOperator<T, T2>): Promise<Collection<T>> {
|
|
return this.where(key, '=', await this.min(key))
|
|
}
|
|
|
|
/**
|
|
* Merge the two collections.
|
|
* @param {AsyncCollectionComparable} merge_with
|
|
* @return Promise<Collection>
|
|
*/
|
|
async merge<T2>(merge_with: AsyncCollectionComparable<T2>): Promise<Collection<T|T2>> {
|
|
let items: T2[]
|
|
if ( merge_with instanceof Collection ) items = await merge_with.all()
|
|
else if ( merge_with instanceof AsyncCollection ) items = await merge_with.all()
|
|
else if ( Array.isArray(merge_with) ) items = merge_with
|
|
|
|
// @ts-ignore
|
|
return new Collection<T|T2>([...items, ...await this.all()])
|
|
}
|
|
|
|
/**
|
|
* Return a collection of every nth item in this collection.
|
|
* @param {number} n
|
|
* @return Promise<Collection>
|
|
*/
|
|
async nth(n: number): Promise<Collection<T>> {
|
|
const matches: CollectionItem<T>[] = []
|
|
let current = 1
|
|
|
|
await this._chunk(async chunk => {
|
|
for ( const item of chunk.all() ) {
|
|
if ( current === 1 ) matches.push(item)
|
|
current += 1
|
|
if ( current > n ) current = 1
|
|
}
|
|
})
|
|
|
|
return new Collection<T>(matches)
|
|
}
|
|
|
|
/**
|
|
* Return a collection containing the items that would be on the given page, with the given number of items per page.
|
|
* @param {number} page
|
|
* @param {number} per_page
|
|
*/
|
|
async forPage(page: number, per_page: number): Promise<Collection<T>> {
|
|
const start = page * per_page - per_page
|
|
const end = page * per_page - 1
|
|
return this._items.range(start, end)
|
|
}
|
|
|
|
/**
|
|
* Return the value of the function, passing this collection to it.
|
|
* @param {AsyncCollectionFunction} func
|
|
*/
|
|
pipe<T2>(func: AsyncCollectionFunction<T, T2>): any {
|
|
return func(this)
|
|
}
|
|
|
|
/*async pop(): Promise<MaybeCollectionItem<T>> {
|
|
const next_item = await this._items.next()
|
|
if ( !next_item.done ) {
|
|
return next_item.value
|
|
}
|
|
}*/ // TODO Fix this
|
|
|
|
/**
|
|
* Get n random items from this collection.
|
|
* @todo add safety check for it loop exceeds max number of items
|
|
* @param {number} n
|
|
* @return Promise<Collection>
|
|
*/
|
|
async random(n: number): Promise<Collection<T>> {
|
|
const random_items: CollectionItem<T>[] = []
|
|
const fetched_indices: number[] = []
|
|
|
|
const max_n = await this._items.count()
|
|
if ( n > max_n ) n = max_n
|
|
|
|
while ( random_items.length < n ) {
|
|
const index = Math.floor(Math.random() * max_n)
|
|
|
|
if ( !fetched_indices.includes(index) ) {
|
|
fetched_indices.push(index)
|
|
const item = await this._items.at(index)
|
|
if ( typeof item !== 'undefined' )
|
|
random_items.push(item)
|
|
}
|
|
}
|
|
|
|
return new Collection<T>(random_items)
|
|
}
|
|
|
|
/**
|
|
* Collapse the collection into a single value using a reducer function.
|
|
* @param {KeyReducerFunction} reducer
|
|
* @param [initial_value]
|
|
* @return Promise<any>
|
|
*/
|
|
async reduce<T2>(reducer: KeyReducerFunction<T, T2>, initial_value?: T2): Promise<T2 | undefined> {
|
|
let current_value = initial_value
|
|
let index = 0
|
|
|
|
await this._chunk(async items => {
|
|
for ( const item of items.all() ) {
|
|
current_value = reducer(current_value, item, index)
|
|
index += 1
|
|
}
|
|
})
|
|
|
|
return current_value
|
|
}
|
|
|
|
/**
|
|
* Returns a collection of items that fail the truth test.
|
|
* @param {AsyncKeyFunction} truth_test
|
|
* @return Promise<Collection>
|
|
*/
|
|
async reject<T2>(truth_test: AsyncKeyFunction<T, T2>): Promise<Collection<T>> {
|
|
let rejected: CollectionItem<T>[] = []
|
|
|
|
await this._chunk(async items => {
|
|
rejected = rejected.concat(items.all().filter((item, index) => {
|
|
return !truth_test(item, index)
|
|
}))
|
|
})
|
|
|
|
return new Collection<T>(rejected)
|
|
}
|
|
|
|
/**
|
|
* Get a reversed collection of this collection's items.
|
|
* @return Promise<Collection>
|
|
*/
|
|
async reverse(): Promise<Collection<T>> {
|
|
return (await this.collect()).reverse()
|
|
}
|
|
|
|
/**
|
|
* Search the collection and return the index of that item, if one exists.
|
|
* @param {CollectionItem} item
|
|
* @return Promise<MaybeCollectionIndex>
|
|
*/
|
|
async search(item: CollectionItem<T>): Promise<MaybeCollectionIndex> {
|
|
let found_index
|
|
let index = 0
|
|
|
|
await this._chunk(async items => {
|
|
items.some(possible_item => {
|
|
if ( possible_item === item ) {
|
|
found_index = index
|
|
throw new StopIteration()
|
|
}
|
|
|
|
index += 1
|
|
return false
|
|
})
|
|
})
|
|
|
|
return found_index
|
|
}
|
|
|
|
/**
|
|
* Get the next item in the collection and remove it.
|
|
* @return Promise<MaybeCollectionItem>
|
|
*/
|
|
async shift(): Promise<MaybeCollectionItem<T>> {
|
|
const next_item = await this._items.next()
|
|
if ( !next_item.done ) {
|
|
return next_item.value
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Shuffle the items in the collection to a random order.
|
|
* @return Promise<Collection>
|
|
*/
|
|
async shuffle(): Promise<Collection<T>> {
|
|
return (await this.collect()).shuffle()
|
|
}
|
|
|
|
/**
|
|
* Return a slice of this collection.
|
|
* @param {number} start - the starting index
|
|
* @param {number} end - the ending index
|
|
* @return Promise<Collection>
|
|
*/
|
|
async slice(start: number, end: number): Promise<Collection<T>> {
|
|
return this._items.range(start, end - 1)
|
|
}
|
|
|
|
/**
|
|
* Sort the collection, optionally with the given comparison function.
|
|
* @param {ComparisonFunction} compare_func
|
|
* @return Promise<Collection>
|
|
*/
|
|
async sort(compare_func?: ComparisonFunction<T>): Promise<Collection<T>> {
|
|
return (await this.collect()).sort(compare_func)
|
|
}
|
|
|
|
/**
|
|
* Sort the collection by the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async sortBy<T2>(key?: KeyOperator<T, T2>): Promise<Collection<T>> {
|
|
return (await this.collect()).sortBy(key)
|
|
}
|
|
|
|
/**
|
|
* Reverse sort the collection, optionally with the given comparison function.
|
|
* @param {ComparisonFunction} compare_func
|
|
* @return Promise<Collection>
|
|
*/
|
|
async sortDesc(compare_func?: ComparisonFunction<T>): Promise<Collection<T>> {
|
|
return (await this.collect()).sortDesc(compare_func)
|
|
}
|
|
|
|
/**
|
|
* Reverse sort the collection by the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async sortByDesc<T2>(key?: KeyOperator<T, T2>): Promise<Collection<T>> {
|
|
return (await this.collect()).sortByDesc(key)
|
|
}
|
|
|
|
/**
|
|
* Splice the collection at the given index. Optionally, removing the given number of items.
|
|
* @param {CollectionIndex} start
|
|
* @param {number} [deleteCount]
|
|
* @return Promise<Collection>
|
|
*/
|
|
async splice(start: CollectionIndex, deleteCount?: number): Promise<Collection<T>> {
|
|
return (await this.collect()).splice(start, deleteCount)
|
|
}
|
|
|
|
/**
|
|
* Sum the items in the collection, or the values of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<number>
|
|
*/
|
|
async sum<T2>(key?: KeyOperator<T, T2>): Promise<number> {
|
|
let running_sum: number = 0
|
|
|
|
const chunk_handler = (items: number[]) => {
|
|
for ( const item of items ) {
|
|
running_sum += item
|
|
}
|
|
}
|
|
|
|
if ( key ) await this._chunk_all_numbers(key, chunk_handler)
|
|
else await this._chunk(async chunk => {
|
|
chunk_handler(chunk.map(x => Number(x)).all())
|
|
})
|
|
|
|
return running_sum
|
|
}
|
|
|
|
/**
|
|
* Take the first n items from the front or back of the collection.
|
|
* @param {number} limit
|
|
* @return Promise<Collection>
|
|
*/
|
|
async take(limit: number): Promise<Collection<T>> {
|
|
if ( limit === 0 ) return new Collection<T>()
|
|
else if ( limit > 0 ) {
|
|
return this.slice(0, limit)
|
|
} else {
|
|
const cnt = await this._items.count()
|
|
return this._items.range(cnt - (-1 * limit), cnt - 1)
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Call the given function, passing in this collection. Allows functional syntax.
|
|
* @param {AsyncCollectionFunction} func
|
|
* @return Promise<AsyncCollection>
|
|
*/
|
|
async tap<T2>(func: AsyncCollectionFunction<T, T2>): Promise<AsyncCollection<T>> {
|
|
await func(this)
|
|
return this
|
|
}
|
|
|
|
/**
|
|
* Return all the unique values in the collection, or the unique values of the given key.
|
|
* @param {KeyOperator} key
|
|
* @return Promise<Collection>
|
|
*/
|
|
async unique<T2>(key?: KeyOperator<T, T2>): Promise<Collection<T|T2>> {
|
|
const has: CollectionItem<T|T2>[] = []
|
|
|
|
if ( !key ) {
|
|
await this._chunk(async items => {
|
|
for ( const item of items.all() ) {
|
|
if ( !has.includes(item) ) has.push(item)
|
|
}
|
|
})
|
|
} else {
|
|
await this._chunk_all(key, async items => {
|
|
for ( const item of items.all() ) {
|
|
if ( !has.includes(item) ) has.push(item)
|
|
}
|
|
})
|
|
}
|
|
|
|
return new Collection<T|T2>(has)
|
|
}
|
|
|
|
/**
|
|
* Cast this collection to an array.
|
|
* @return Promise<array>
|
|
*/
|
|
async toArray(): Promise<any[]> {
|
|
const returns: any = []
|
|
for ( const item of (await this.all()) ) {
|
|
if ( item instanceof Collection ) returns.push(item.toArray())
|
|
else if ( item instanceof AsyncCollection ) returns.push(await item.toArray())
|
|
else returns.push(item)
|
|
}
|
|
return returns
|
|
}
|
|
|
|
/**
|
|
* Cast this collection to a JSON string.
|
|
* @param [replacer] - the replacer to use
|
|
* @param {number} [space = 4] number of indentation spaces to use
|
|
*/
|
|
async toJSON(replacer = undefined, space = 4): Promise<string> {
|
|
return JSON.stringify(this.toArray(), replacer, space)
|
|
}
|
|
|
|
/**
|
|
* Get a clone of the underlying iterator of this collection.
|
|
* @return Iterable
|
|
*/
|
|
iterator() {
|
|
return this._items.clone()
|
|
}
|
|
}
|