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import { Deferred, deferred } from "./deps.ts";
export class DeferredStack<T> {  private _array: Array<T>;  private _queue: Array<Deferred<T>>;  private _maxSize: number;  private _size: number;
  constructor(    max?: number,    ls?: Iterable<T>,    private _creator?: () => Promise<T>,  ) {    this._maxSize = max || 10;    this._array = ls ? [...ls] : [];    this._size = this._array.length;    this._queue = [];  }
  async pop(): Promise<T> {    if (this._array.length > 0) {      return this._array.pop()!;    } else if (this._size < this._maxSize && this._creator) {      this._size++;      return await this._creator();    }    const d = deferred<T>();    this._queue.push(d);    await d;    return this._array.pop()!;  }
  push(value: T): void {    this._array.push(value);    if (this._queue.length > 0) {      const d = this._queue.shift()!;      d.resolve();    }  }
  get size(): number {    return this._size;  }
  get available(): number {    return this._array.length;  }}