var to_array = require("./to_array"); // Queue class adapted from Tim Caswell's pattern library // http://github.com/creationix/pattern/blob/master/lib/pattern/queue.js function Queue() { this.tail = []; this.head = []; this.offset = 0; } Queue.prototype.shift = function () { if (this.offset === this.head.length) { var tmp = this.head; tmp.length = 0; this.head = this.tail; this.tail = tmp; this.offset = 0; if (this.head.length === 0) { return; } } return this.head[this.offset++]; // sorry, JSLint }; Queue.prototype.push = function (item) { return this.tail.push(item); }; Queue.prototype.forEach = function (fn, thisv) { var array = this.head.slice(this.offset), i, il; array.push.apply(array, this.tail); if (thisv) { for (i = 0, il = array.length; i < il; i += 1) { fn.call(thisv, array[i], i, array); } } else { for (i = 0, il = array.length; i < il; i += 1) { fn(array[i], i, array); } } return array; }; Queue.prototype.getLength = function () { return this.head.length - this.offset + this.tail.length; }; Object.defineProperty(Queue.prototype, 'length', { get: function () { return this.getLength(); } }); if(typeof module !== 'undefined' && module.exports) { module.exports = Queue; }