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import { type Deferred, deferred } from "../deps.ts";
export class DeferredStack<T> {  #elements: Array<T>;  #creator?: () => Promise<T>;  #max_size: number;  #queue: Array<Deferred<T>>;  #size: number;
  constructor(    max?: number,    ls?: Iterable<T>,    creator?: () => Promise<T>,  ) {    this.#elements = ls ? [...ls] : [];    this.#creator = creator;    this.#max_size = max || 10;    this.#queue = [];    this.#size = this.#elements.length;  }
  get available(): number {    return this.#elements.length;  }
  async pop(): Promise<T> {    if (this.#elements.length > 0) {      return this.#elements.pop()!;    } else if (this.#size < this.#max_size && this.#creator) {      this.#size++;      return await this.#creator();    }    const d = deferred<T>();    this.#queue.push(d);    return await d;  }
  push(value: T): void {    if (this.#queue.length > 0) {      const d = this.#queue.shift()!;      d.resolve(value);    } else {      this.#elements.push(value);    }  }
  get size(): number {    return this.#size;  }}
/** * The DeferredAccessStack provides access to a series of elements provided on the stack creation, * but with the caveat that they require an initialization of sorts before they can be used * * Instead of providing a `creator` function as you would with the `DeferredStack`, you provide * an initialization callback to execute for each element that is retrieved from the stack and a check * callback to determine if the element requires initialization and return a count of the initialized * elements */export class DeferredAccessStack<T> {  #elements: Array<T>;  #initializeElement: (element: T) => Promise<void>;  #checkElementInitialization: (element: T) => Promise<boolean> | boolean;  #queue: Array<Deferred<T>>;  #size: number;
  get available(): number {    return this.#elements.length;  }
  /**   * The max number of elements that can be contained in the stack a time   */  get size(): number {    return this.#size;  }
  /**   * @param initialize This function will execute for each element that hasn't been initialized when requested from the stack   */  constructor(    elements: T[],    initCallback: (element: T) => Promise<void>,    checkInitCallback: (element: T) => Promise<boolean> | boolean,  ) {    this.#checkElementInitialization = checkInitCallback;    this.#elements = elements;    this.#initializeElement = initCallback;    this.#queue = [];    this.#size = elements.length;  }
  /**   * Will execute the check for initialization on each element of the stack   * and then return the number of initialized elements that pass the check   */  async initialized(): Promise<number> {    const initialized = await Promise.all(      this.#elements.map((e) => this.#checkElementInitialization(e)),    );
    return initialized      .filter((initialized) => initialized === true)      .length;  }
  async pop(): Promise<T> {    let element: T;    if (this.available > 0) {      element = this.#elements.pop()!;    } else {      // If there are not elements left in the stack, it will await the call until      // at least one is restored and then return it      const d = deferred<T>();      this.#queue.push(d);      element = await d;    }
    if (!await this.#checkElementInitialization(element)) {      await this.#initializeElement(element);    }    return element;  }
  push(value: T): void {    // If an element has been requested while the stack was empty, indicate    // that an element has been restored    if (this.#queue.length > 0) {      const d = this.#queue.shift()!;      d.resolve(value);    } else {      this.#elements.push(value);    }  }}