Class RedBlackTreeIterator

packages/effect/src/internal/redBlackTree/iterator.ts:14–200

/** @internal */
export class RedBlackTreeIterator<in out K, out V> implements Iterator<[K, V]> {
  private count = 0

  constructor(
    readonly self: RBT.RedBlackTree<K, V>,
    readonly stack: Array<Node.Node<K, V>>,
    readonly direction: RBT.RedBlackTree.Direction
  ) {}

  /**
   * Clones the iterator
   */
  clone(): RedBlackTreeIterator<K, V> {
    return new RedBlackTreeIterator(this.self, this.stack.slice(), this.direction)
  }

  /**
   * Reverse the traversal direction
   */
  reversed(): RedBlackTreeIterator<K, V> {
    return new RedBlackTreeIterator(
      this.self,
      this.stack.slice(),
      this.direction === Direction.Forward ? Direction.Backward : Direction.Forward
    )
  }

  /**
   * Iterator next
   */
  next(): IteratorResult<[K, V], number> {
    const entry = this.entry
    this.count++
    if (this.direction === Direction.Forward) {
      this.moveNext()
    } else {
      this.movePrev()
    }
    switch (entry._tag) {
      case "None": {
        return { done: true, value: this.count }
      }
      case "Some": {
        return { done: false, value: entry.value }
      }
    }
  }

  /**
   * Returns the key
   */
  get key(): Option.Option<K> {
    if (this.stack.length > 0) {
      return Option.some(this.stack[this.stack.length - 1]!.key)
    }
    return Option.none()
  }