Class SingleShotGen

repos/effect/packages/effect/src/Utils.ts:52–96

  readonly self: T

  constructor(self: T) {
    this.self = self
  }

  /**
   * Yields the stored value once, then completes with the value sent back in.
   *
   * **When to use**
   *
   * Use to advance a `SingleShotGen` through its single yield and completion
   * step.
   *
   * @since 2.0.0
   */
  next(a: A): IteratorResult<T, A> {
    return this.called ?
      ({
        value: a,
        done: true
      }) :
      (this.called = true,
        ({
          value: this.self,
          done: false
        }))
  }

  /**
   * Creates a fresh single-shot iterator over the stored value.
   *
   * **When to use**
   *
   * Use to iterate the wrapped value again without reusing the consumed
   * iterator state.
   *
   * @since 2.0.0
   */
  [Symbol.iterator](): IterableIterator<T, A> {
    return new SingleShotGen<T, A>(this.self)
  }
}

/**
 * Type-level marker encoding the variance of a `TypeLambda`'s type
 * parameters.
 *
 * **When to use**
 *