1 /*
   2  * Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.objects;
  27 
  28 import jdk.nashorn.internal.objects.annotations.Function;
  29 import jdk.nashorn.internal.objects.annotations.ScriptClass;
  30 import jdk.nashorn.internal.runtime.PropertyMap;
  31 import jdk.nashorn.internal.runtime.ScriptRuntime;
  32 import jdk.nashorn.internal.runtime.Undefined;
  33 
  34 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
  35 
  36 /**
  37  * ECMA6 23.1.5 Map Iterator Objects
  38  */
  39 @ScriptClass("MapIterator")
  40 public class MapIterator extends AbstractIterator {
  41     // initialized by nasgen
  42     private static PropertyMap $nasgenmap$;
  43 
  44     private LinkedMap.LinkedMapIterator iterator;
  45 
  46     private final IterationKind iterationKind;
  47 
  48     // Cached global needed for each iteration result
  49     private final Global global;
  50 
  51     /**
  52      * Constructor for Map iterators.
  53      * @param map the map to iterate over
  54      * @param iterationKind the iteration kind
  55      * @param global the current global object
  56      */
  57     MapIterator(final NativeMap map, final IterationKind iterationKind, final Global global) {
  58         super(global.getMapIteratorPrototype(), $nasgenmap$);
  59         this.iterator = map.getJavaMap().getIterator();
  60         this.iterationKind = iterationKind;
  61         this.global = global;
  62     }
  63 
  64     /**
  65      * ES6 23.1.5.2.1 %MapIteratorPrototype%.next()
  66      *
  67      * @param self the self reference
  68      * @param arg the argument
  69      * @return the next result
  70      */
  71     @Function
  72     public static Object next(final Object self, final Object arg) {
  73         if (!(self instanceof MapIterator)) {
  74             throw typeError("not.a.map.iterator", ScriptRuntime.safeToString(self));
  75         }
  76         return ((MapIterator)self).next(arg);
  77     }
  78 
  79     @Override
  80     public String getClassName() {
  81         return "Map Iterator";
  82     }
  83 
  84     @Override
  85     protected  IteratorResult next(final Object arg) {
  86         if (iterator == null) {
  87             return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
  88         }
  89 
  90         final LinkedMap.Node node = iterator.next();
  91 
  92         if (node == null) {
  93             iterator = null;
  94             return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
  95         }
  96 
  97         if (iterationKind == IterationKind.KEY_VALUE) {
  98             final NativeArray array = new NativeArray(new Object[] {node.getKey(), node.getValue()});
  99             return makeResult(array, Boolean.FALSE, global);
 100         }
 101 
 102         return makeResult(iterationKind == IterationKind.KEY ? node.getKey() : node.getValue(), Boolean.FALSE, global);
 103     }
 104 
 105 }