Source: polyfill/Map.js

  1. // Licensed Materials - Property of IBM
  2. //
  3. // IBM Watson Analytics
  4. //
  5. // (C) Copyright IBM Corp. 2015
  6. //
  7. // US Government Users Restricted Rights - Use, duplication or
  8. // disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
  10. module.exports = ( function( ObjectPolyfill, EntryStore )
  11. {
  12. "use strict";
  13. // Putting this in a var allows uglify to minify the code much more
  14. var SET_SIZE = !( ( __ES__ >= 5 ) || ObjectPolyfill.propertyGetSetSupport );
  16. /**
  17.  * @classdesc Iterator for the Map polyfill.
  18.  * @class module:barejs/polyfill.Map~MapIterator
  19.  * @extends module:barejs/polyfill.EntryStore.Iterator
  20.  */
  21. function MapIterator( _kind, _store )
  22. {
  23.     EntryStore.Iterator.call( this, _kind, _store );
  24. }
  26. MapIterator.prototype = Object.create( EntryStore.Iterator.prototype,
  27. /** @lends module:barejs/polyfill.Map~MapIterator */
  28. {
  29.     constructor: { writable: true, value: MapIterator }
  30. } );
  32. /**
  33.  * @classdesc Mimics the implementation of a native {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map Map}.
  34.  * Has an O(n) lookup time for non String or Number keys, so cannot compete with a native Map (Which is supposed to have an O(1) lookup time).
  35.  * @class module:barejs/polyfill.Map
  36.  */
  37. function Map()
  38. {
  39.     ObjectPolyfill.defineProperty( this, "_store", { value: new EntryStore( arguments[0], true ) }  );
  41.     /*istanbul ignore if: NodeJS has property support*/
  42.     if ( SET_SIZE )
  43.         this.size = this._store.size;
  44. }
  46. ObjectPolyfill.defineProperties( Map.prototype,
  47. /** @lends module:barejs/polyfill.Map# */
  48. {
  49.     _store: { value: null },
  51.     /**
  52.      * The size of the Map, which represents the number of entries currently in the Map.
  53.      * @member {number}
  54.      * @readonly
  55.      */
  56.     size: ( SET_SIZE ?
  57.         /*istanbul ignore next*/ { writable: true, value: null } :
  58.         { "get": function size(){ return this._store && this._store.size; } } ),
  60.     /**
  61.      * Set a value for the specified key in the Map.
  62.      * @function
  63.      * @param _key The object to use as key.
  64.      * @param _value The value to add.
  65.      * @returns {module:barejs/polyfill.Map} The Map (for chaining)
  66.      */
  67.     "set": { value: function set( _key, _value )
  68.     {
  69.         this._store.set( _key, _value );
  70.         /*istanbul ignore if: NodeJS has property support*/
  71.         if ( SET_SIZE )
  72.             this.size = this._store.size;
  74.         return this;
  75.     } },
  77.     /**
  78.      * Get the value for the specified key
  79.      * @function
  80.      * @param {object} _key The object to use as key.
  81.      * @returns The value, or undefined if the key is not known.
  82.      */
  83.     "get": { value: function get( _key )
  84.     {
  85.         var entry = this._store.entries[this._store.indexOf( _key )];
  86.         return entry && entry[1];
  87.     } },
  89.     /**
  90.      * Check if the Map has an entry for the specified key
  91.      * @function
  92.      * @param {object} _key The object to use as key.
  93.      * @returns {boolean} True if there is an entry for the key, false otherwise
  94.      */
  95.     has: { value: function has( _key )
  96.     {
  97.         return this._store.indexOf( _key ) >= 0;
  98.     } },
  100.     /**
  101.      * Remove the value for the specified key
  102.      * @function
  103.      * @param {object} _key The object to use as key.
  104.      * @returns {boolean} True if the entry was deleted, false otherwise
  105.      */
  106.     "delete": { value: function _delete( _key )
  107.     {
  108.         var removed = this._store.remove( _key );
  109.         /*istanbul ignore if: NodeJS has property support*/
  110.         if ( SET_SIZE )
  111.             this.size = this._store.size;
  112.         return removed;
  113.     } },
  115.     clear: { value: function clear()
  116.     {
  117.         this._store.clear();
  118.         /*istanbul ignore if: NodeJS has property support*/
  119.         if ( SET_SIZE )
  120.             this.size = this._store.size;
  121.     } },
  123.     /**
  124.      * Iterate the Map
  125.      * @function
  126.      * @param {function} _callback The callback function.
  127.      * @param [_thisArg] Optional: context to call the callback in.
  128.      */
  129.     forEach: { value: function forEach( _callback/*, _thisArg*/ )
  130.     {
  131.         this._store.forEach( this, _callback, arguments[1] );
  132.     } },
  134.     /**
  135.      * Get a key iterator
  136.      * @function
  137.      * @returns {module:barejs/polyfill.Map~MapIterator} A key iterator
  138.      */
  139.     keys: { value: function keys()
  140.     {
  141.         return new MapIterator( "key", this._store );
  142.     } },
  144.     /**
  145.      * Get a value iterator
  146.      * @function
  147.      * @returns {module:barejs/polyfill.Map~MapIterator} A value iterator
  148.      */
  149.     values: { value: function values()
  150.     {
  151.         return new MapIterator( "value", this._store );
  152.     } },
  154.     /**
  155.      * Get an entry iterator
  156.      * @function
  157.      * @returns {module:barejs/polyfill.Map~MapIterator} A entry iterator
  158.      */
  159.     entries: { value: function entries()
  160.     {
  161.         return new MapIterator( "entry", this._store );
  162.     } }
  163. } );
  165. ObjectPolyfill.setIterator( Map.prototype, Map.prototype.entries );
  167. return Map;
  169. }( require( "./Object" ), require( "./EntryStore" ) ) );