substance/util/ArrayIterator.js

Substance is a JavaScript library for web-based content editing. It provides building blocks for realizing custom text editors and web-based publishing system. It is developed to power our online editing platform [Substance](http://substance.io).

/*
  An iterator for arrays.

  @class
  @param {Array} arr
 */
class ArrayIterator {
  constructor (arr) {
    this.arr = arr
    this.pos = -1
  }

  get _isArrayIterator () {
    return true
  }

  /**
    @returns {Boolean} true if there is another child node left.
   */
  hasNext () {
    return this.pos < this.arr.length - 1
  }

  /**
    Increments the iterator providing the next child node.

    @returns {HTMLElement} The next child node.
   */
  next () {
    this.pos += 1
    var next = this.arr[this.pos]
    return next
  }

  /**
    Decrements the iterator.
   */
  back () {
    if (this.pos >= 0) {
      this.pos -= 1
    }
    return this
  }

  peek () {
    return this.arr[this.pos + 1]
  }
}

export default ArrayIterator