js.util.Dictionary.js代码

js.util = (js.util || {});

 

js.util.Dictionary = newjs.lang.Class()  ({

   /** Utility class providing common java-like dictionary functionality tohelp keep code D-R-Y. **/

   __init__ : function( map )  {

       /** Initializer for Dictionary **/

       this.clear();

       

       // NOTE: be very careful when using the constructor as a wrapper for anexisting dictionary;

       //   this action iterates theentire dictionary.

       if( map )  {

           this.putAll( map );

       }

   },

   

   clear : function()  {

       /** Clear contents of this dict. **/

       this._size = 0;

       this._dictionary = {};

   },

 

   containsKey : function( key )  {

       /** Check if given key exists in this dict. **/

       return( this._dictionary.hasOwnProperty( key ) );

   },

   

   containsValue : function( value ) {

       /** Check if given value exists in this dict. **/

       var key;

       this.iterate(function( k, v )  {

           if( value === v )  {

                key = k;

                return( true );

           }

       });

       return( key !== undefined );

   },

   

   entrySet : function()  {

       /** Retrieve a unique list of values from this dict. **/

       var items = [];

       //  acquire entries

       this.iterate(function( k, v )  {

           items.push( v );

       });

       return( new js.util.Set( items ) );

   },

   

   get : function( key )  {

       /** Retrieve value associated with given key. **/

       return( this._dictionary[ key ] );

   },

   

   isEmpty : function()  {

       /** Check if this dict contains zero elements. **/

       return( this.size() === 0 );

   },

   

   keySet  : function()  {

       /** Retrieve a unique list of keys from this dict. **/

       var keys = [];

       //  acquire entries

       this.iterate( function( k, v )  {

           keys.push( k );

       });

       return( new js.util.Set( keys ) );

   },

   

   put : function( key, value )  {

       /** Assign given value to given key within this dict. **/

       if( ! this._dictionary.hasOwnProperty( key ) )  {

           this._size++;

       }

       

       this._dictionary[ key ] = value;

       

       return( this );

   },

   

   putAll : function( map )  {

       /** Assign every value within given map to their associated keys, withinthis dict. **/

       var that = this;

       map.iterate( function( k, v )  {

           that.put( k, v );

       });

   },

   

   iterate : function( callback )  {

       /** Convenient, unified method of iterating elements in this dict.

           This pattern is common to all collection classes. **/

       var dictionary = this._dictionary;

       for( var property in dictionary ) {

           if( ! dictionary.hasOwnProperty( property ) )  { continue; }

           

           if( callback( property, dictionary[ property ] ) )  {

                break;

           }

       }

   },

 

   remove : function( key )  {

       /** Remove key from this dict. **/

        var success = false;

       if( this._dictionary.hasOwnProperty( key ) )  {

           success = delete( this._dictionary[ key ] );

           this._size--;

       }

       return( success );

   },

   

   size : function()  {

       /** Retrieve the size of this dict. **/

       return( this._size );

   },

   

   values : function()  {

       /** Retrieve a list of all values within this dict. **/

       var values = [];

       for( var key in this._dictionary ) {

           if( ! this._dictionary.hasOwnProperty( key ) )  { continue; }

           

           values.push( key );

       }

       return( new js.util.ArrayList( values ) );

   },

   

   clone : function()  {

       /** Retrieve a deep-clone (if values implement a clone method), of thisdict. **/

       var dictionary = new js.util.Dictionary();

       this.iterate( function( k, v )  {

           dictionary.put( k, (v && (v.clone instanceof Function) ?v.clone() : v) );

       });

       return( dictionary );

   },

   

   toDict : function()  {

       /** Retrieve a deep-clone (if values implement a clone method), of

           this dict as an Object rather than a Dictionary. **/

       return( this.clone()._dictionary );

    }

})

.Static({

   Iterate : function( dictionary, callback )  {

       /** Iterate given dict, invoking given callback for each element.

           Helper method to avoid the requirement to instantiate this class forone-off use-cases. **/

       js.util.Dictionary.prototype.iterate.call( { _dictionary : dictionary },callback );

   },

   

   Iterator : function( dictionary ) {

       /** Retrieve an object which contains an 'iterate' method to be invokedat a later date. **/

       // TODO: implement full iterator capabilities.

       return({

           iterate : function( callback )  {

               js.util.Dictionary.prototype.iterate.call( { _dictionary : dictionary },callback );

           }

       });

    }

});

转自http://code.google.com/p/javascript-classes/source/browse/trunk/js.util.Dictionary.js