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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package jdk.nashorn.internal.objects;

import java.lang.invoke.MethodHandle;

import jdk.nashorn.internal.objects.annotations.Attribute;
import jdk.nashorn.internal.objects.annotations.Constructor;
import jdk.nashorn.internal.objects.annotations.Function;
import jdk.nashorn.internal.objects.annotations.Getter;
import jdk.nashorn.internal.objects.annotations.ScriptClass;
import jdk.nashorn.internal.objects.annotations.Where;
import jdk.nashorn.internal.runtime.ConsString;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
import jdk.nashorn.internal.runtime.Undefined;
import jdk.nashorn.internal.runtime.linker.Bootstrap;

import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;

This implements the ECMA6 Map object.
/** * This implements the ECMA6 Map object. */
@ScriptClass("Map") public class NativeMap extends ScriptObject { // our underlying map private final LinkedMap map = new LinkedMap(); // key for the forEach invoker callback private final static Object FOREACH_INVOKER_KEY = new Object(); // initialized by nasgen private static PropertyMap $nasgenmap$; private NativeMap(final ScriptObject proto, final PropertyMap map) { super(proto, map); }
ECMA6 23.1.1 The Map Constructor
Params:
  • isNew – is this called with the new operator?
  • self – self reference
  • arg – optional iterable argument
Returns: a new Map instance
/** * ECMA6 23.1.1 The Map Constructor * * @param isNew is this called with the new operator? * @param self self reference * @param arg optional iterable argument * @return a new Map instance */
@Constructor(arity = 0) public static Object construct(final boolean isNew, final Object self, final Object arg) { if (!isNew) { throw typeError("constructor.requires.new", "Map"); } final Global global = Global.instance(); final NativeMap map = new NativeMap(global.getMapPrototype(), $nasgenmap$); populateMap(map.getJavaMap(), arg, global); return map; }
ECMA6 23.1.3.1 Map.prototype.clear ( )
Params:
  • self – the self reference
/** * ECMA6 23.1.3.1 Map.prototype.clear ( ) * * @param self the self reference */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static void clear(final Object self) { getNativeMap(self).map.clear(); }
ECMA6 23.1.3.3 Map.prototype.delete ( key )
Params:
  • self – the self reference
  • key – the key to delete
Returns:true if the key was deleted
/** * ECMA6 23.1.3.3 Map.prototype.delete ( key ) * * @param self the self reference * @param key the key to delete * @return true if the key was deleted */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static boolean delete(final Object self, final Object key) { return getNativeMap(self).map.delete(convertKey(key)); }
ECMA6 23.1.3.7 Map.prototype.has ( key )
Params:
  • self – the self reference
  • key – the key
Returns:true if key is contained
/** * ECMA6 23.1.3.7 Map.prototype.has ( key ) * * @param self the self reference * @param key the key * @return true if key is contained */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static boolean has(final Object self, final Object key) { return getNativeMap(self).map.has(convertKey(key)); }
ECMA6 23.1.3.9 Map.prototype.set ( key , value )
Params:
  • self – the self reference
  • key – the key
  • value – the value
Returns:this Map object
/** * ECMA6 23.1.3.9 Map.prototype.set ( key , value ) * * @param self the self reference * @param key the key * @param value the value * @return this Map object */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static Object set(final Object self, final Object key, final Object value) { getNativeMap(self).map.set(convertKey(key), value); return self; }
ECMA6 23.1.3.6 Map.prototype.get ( key )
Params:
  • self – the self reference
  • key – the key
Returns:the associated value or undefined
/** * ECMA6 23.1.3.6 Map.prototype.get ( key ) * * @param self the self reference * @param key the key * @return the associated value or undefined */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static Object get(final Object self, final Object key) { return getNativeMap(self).map.get(convertKey(key)); }
ECMA6 23.1.3.10 get Map.prototype.size
Params:
  • self – the self reference
Returns:the size of the map
/** * ECMA6 23.1.3.10 get Map.prototype.size * * @param self the self reference * @return the size of the map */
@Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.IS_ACCESSOR, where = Where.PROTOTYPE) public static int size(final Object self) { return getNativeMap(self).map.size(); }
ECMA6 23.1.3.4 Map.prototype.entries ( )
Params:
  • self – the self reference
Returns:an iterator over the Map's entries
/** * ECMA6 23.1.3.4 Map.prototype.entries ( ) * * @param self the self reference * @return an iterator over the Map's entries */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static Object entries(final Object self) { return new MapIterator(getNativeMap(self), AbstractIterator.IterationKind.KEY_VALUE, Global.instance()); }
ECMA6 23.1.3.8 Map.prototype.keys ( )
Params:
  • self – the self reference
Returns:an iterator over the Map's keys
/** * ECMA6 23.1.3.8 Map.prototype.keys ( ) * * @param self the self reference * @return an iterator over the Map's keys */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static Object keys(final Object self) { return new MapIterator(getNativeMap(self), AbstractIterator.IterationKind.KEY, Global.instance()); }
ECMA6 23.1.3.11 Map.prototype.values ( )
Params:
  • self – the self reference
Returns:an iterator over the Map's values
/** * ECMA6 23.1.3.11 Map.prototype.values ( ) * * @param self the self reference * @return an iterator over the Map's values */
@Function(attributes = Attribute.NOT_ENUMERABLE) public static Object values(final Object self) { return new MapIterator(getNativeMap(self), AbstractIterator.IterationKind.VALUE, Global.instance()); }
ECMA6 23.1.3.12 Map.prototype [ @@iterator ]( )
Params:
  • self – the self reference
Returns:An iterator over the Map's entries
/** * ECMA6 23.1.3.12 Map.prototype [ @@iterator ]( ) * * @param self the self reference * @return An iterator over the Map's entries */
@Function(attributes = Attribute.NOT_ENUMERABLE, name = "@@iterator") public static Object getIterator(final Object self) { return new MapIterator(getNativeMap(self), AbstractIterator.IterationKind.KEY_VALUE, Global.instance()); }
Params:
  • self – the self reference
  • callbackFn – the callback function
  • thisArg – optional this-object
/** * * @param self the self reference * @param callbackFn the callback function * @param thisArg optional this-object */
@Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1) public static void forEach(final Object self, final Object callbackFn, final Object thisArg) { final NativeMap map = getNativeMap(self); if (!Bootstrap.isCallable(callbackFn)) { throw typeError("not.a.function", ScriptRuntime.safeToString(callbackFn)); } final MethodHandle invoker = Global.instance().getDynamicInvoker(FOREACH_INVOKER_KEY, () -> Bootstrap.createDynamicCallInvoker(Object.class, Object.class, Object.class, Object.class, Object.class, Object.class)); final LinkedMap.LinkedMapIterator iterator = map.getJavaMap().getIterator(); for (;;) { final LinkedMap.Node node = iterator.next(); if (node == null) { break; } try { final Object result = invoker.invokeExact(callbackFn, thisArg, node.getValue(), node.getKey(), self); } catch (final RuntimeException | Error e) { throw e; } catch (final Throwable t) { throw new RuntimeException(t); } } } @Override public String getClassName() { return "Map"; } static void populateMap(final LinkedMap map, final Object arg, final Global global) { if (arg != null && arg != Undefined.getUndefined()) { AbstractIterator.iterate(arg, global, value -> { if (JSType.isPrimitive(value)) { throw typeError(global, "not.an.object", ScriptRuntime.safeToString(value)); } if (value instanceof ScriptObject) { final ScriptObject sobj = (ScriptObject) value; map.set(convertKey(sobj.get(0)), sobj.get(1)); } }); } }
Returns a canonicalized key object by converting numbers to their narrowest representation and ConsStrings to strings. Conversion of Double to Integer also takes care of converting -0 to 0 as required by step 6 of ECMA6 23.1.3.9.
Params:
  • key – a key
Returns:the canonical key
/** * Returns a canonicalized key object by converting numbers to their narrowest representation and * ConsStrings to strings. Conversion of Double to Integer also takes care of converting -0 to 0 * as required by step 6 of ECMA6 23.1.3.9. * * @param key a key * @return the canonical key */
static Object convertKey(final Object key) { if (key instanceof ConsString) { return key.toString(); } if (key instanceof Double) { final Double d = (Double) key; if (JSType.isRepresentableAsInt(d.doubleValue())) { return d.intValue(); } } return key; }
Get the underlying Java map.
Returns:the Java map
/** * Get the underlying Java map. * @return the Java map */
LinkedMap getJavaMap() { return map; } private static NativeMap getNativeMap(final Object self) { if (self instanceof NativeMap) { return (NativeMap)self; } else { throw typeError("not.a.map", ScriptRuntime.safeToString(self)); } } }