ArrayInPlace

ArrayInPlace.ts

/**
 * array extended with mutable/in-place array-methods
 */
class ArrayInPlace<T = number> extends Array {
  commands: Command<T>[] = [];
  constructor(values: T[]) {
    super();
    Array.prototype.push.apply(this, values);
  }
  mapInPlace(fn: (value: T, index: number) => T) {
    for (let index = 0; index < this.length; index++) {
      this[index] = fn(this[index], index);
    }
    return this;
  }
  filterInPlace(fn: (value: T, index: number) => boolean) {
    let deleteCount = 0;
    const length = this.length;
    for (let index = length - 1; index >= 0; index--) {
      if (!fn(this[index], index)) {
        deleteCount++;
        if (index === 0) {
          this.splice(index, deleteCount);
        }
        continue;
      }
      if (deleteCount > 0) {
        this.splice(index, deleteCount);
      }
    }
    return this;
  }
  set(index: number, value: T) {
    this[index] = value;
    return this;
  }
}