modules/compat/Map.js

   1 /**
   2  * (C) Copyright 2014 Jeremy Maitin-Shepard
   3  *
   4  * Use, modification, and distribution are subject to the terms specified in the
   5  * COPYING file.
   6  **/
   7
   8 /**
   9  * Simple emulation of Map for Gecko versions < 13 Keys are based on
  10  * string representation of Object, rather than Object identity, but
  11  * for numbers and strings the effect is the same.
  12  **/
  13
  14 if (typeof(Map) == "undefined") {
  15     var Map = function Map() {
  16         this.data = {}
  17         this.size = 0;
  18     }
  19     Map.prototype.get = function (k) { return this.data["K" + k]; };
  20     Map.prototype.set = function (k, v) {
  21         if (!(("K" + k) in this.data)) ++this.size;
  22         this.data["K" + k] = v;
  23     };
  24     Map.prototype.has = function (k) { return ("K" + k) in this.data; };
  25     Map.prototype.delete = function (k) {
  26         if (("K" + k) in this.data) {
  27             delete this.data["K" + k];
  28             --this.size;
  29         }
  30     };
  31     Map.prototype.clear = function (k) { this.data = {}; this.size = 0; };
  32
  33     // Note: This does not return in insertion order.
  34     Map.prototype.keys = function () {
  35         for (k in this.data)
  36             yield k.substring(1);
  37     };
  38
  39     // Note: This does not return in insertion order.
  40     Map.prototype.values = function () {
  41         for (k in this.data)
  42             yield this.data[k];
  43     };
  44
  45     // Note: This does not return in insertion order.
  46     Map.prototype.entries = function () {
  47         for (k in this.data)
  48             yield [k.substring(1), this.data[k]];
  49     };
  50
  51     Map.prototype.forEach = function (callbackFn, thisArg) {
  52         for (k in this.data)
  53             callbackFn.call(thisArg, k.substring(1), this.data[k]);
  54     };
  55 }