strong-trace/lib/unique_queue.js

StrongTrace Node.js Tracer

"use strict";

module.exports = UniqueQueue

function UniqueQueue(initial) {
  if (!(this instanceof UniqueQueue)) return new UniqueQueue(initial)
  this.seen = []
  this.todo = []
  if (initial !== null) {
    this.merge(initial)
  }
}

// Does not accept null/undefined values
UniqueQueue.prototype.add = function add(element) {
  if (element != null && this.seen.indexOf(element) < 0 && this.todo.indexOf(element) < 0) {
    this.todo.push(element)
  }
}

// Does not accept null/undefined values
UniqueQueue.prototype.merge = function merge(toAdd) {
  for (var i = 0; i < toAdd.length; i++) {
    if (toAdd[i] != null && this.seen.indexOf(toAdd[i]) < 0 && this.todo.indexOf(toAdd[i]) < 0) {
      this.todo.push(toAdd[i])
    }
  }
}

UniqueQueue.prototype.hasNext = function hasNext() {
  return this.todo.length > 0
}

UniqueQueue.prototype.next = function next() {
  if (this.todo.length === 0) {
    return
  }
  var n = this.todo.pop()
  this.seen.push(n)
  return n
}