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Rhino JavaScript runtime jar, excludes tools & JSR-223 Script Engine wrapper.
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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
import java.util.Iterator;
/**
* This class implements iterator objects. See
* http://developer.mozilla.org/en/docs/New_in_JavaScript_1.7#Iterators
*
* @author Norris Boyd
*/
public final class NativeIterator extends IdScriptableObject {
private static final long serialVersionUID = -4136968203581667681L;
private static final Object ITERATOR_TAG = "Iterator";
static void init(Context cx, ScriptableObject scope, boolean sealed) {
// Iterator
NativeIterator iterator = new NativeIterator();
iterator.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
// Generator
if (cx.getLanguageVersion() >= Context.VERSION_ES6) {
ES6Generator.init(scope, sealed);
} else {
NativeGenerator.init(scope, sealed);
}
// StopIteration
NativeObject obj = new StopIteration();
obj.setPrototype(getObjectPrototype(scope));
obj.setParentScope(scope);
if (sealed) {
obj.sealObject();
}
ScriptableObject.defineProperty(scope, STOP_ITERATION, obj, ScriptableObject.DONTENUM);
// Use "associateValue" so that generators can continue to
// throw StopIteration even if the property of the global
// scope is replaced or deleted.
scope.associateValue(ITERATOR_TAG, obj);
}
/** Only for constructing the prototype object. */
private NativeIterator() {}
private NativeIterator(Object objectIterator) {
this.objectIterator = objectIterator;
}
/**
* Get the value of the "StopIteration" object. Note that this value is stored in the top-level
* scope using "associateValue" so the value can still be found even if a script overwrites or
* deletes the global "StopIteration" property.
*
* @param scope a scope whose parent chain reaches a top-level scope
* @return the StopIteration object
*/
public static Object getStopIterationObject(Scriptable scope) {
Scriptable top = ScriptableObject.getTopLevelScope(scope);
return ScriptableObject.getTopScopeValue(top, ITERATOR_TAG);
}
private static final String STOP_ITERATION = "StopIteration";
public static final String ITERATOR_PROPERTY_NAME = "__iterator__";
public static class StopIteration extends NativeObject {
private static final long serialVersionUID = 2485151085722377663L;
private Object value = Undefined.instance;
public StopIteration() {}
public StopIteration(Object val) {
this.value = val;
}
public Object getValue() {
return value;
}
@Override
public String getClassName() {
return STOP_ITERATION;
}
/* StopIteration has custom instanceof behavior since it
* doesn't have a constructor.
*/
@Override
public boolean hasInstance(Scriptable instance) {
return instance instanceof StopIteration;
}
}
@Override
public String getClassName() {
return "Iterator";
}
@Override
protected void initPrototypeId(int id) {
String s;
int arity;
switch (id) {
case Id_constructor:
arity = 2;
s = "constructor";
break;
case Id_next:
arity = 0;
s = "next";
break;
case Id___iterator__:
arity = 1;
s = ITERATOR_PROPERTY_NAME;
break;
default:
throw new IllegalArgumentException(String.valueOf(id));
}
initPrototypeMethod(ITERATOR_TAG, id, s, arity);
}
@Override
public Object execIdCall(
IdFunctionObject f, Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
if (!f.hasTag(ITERATOR_TAG)) {
return super.execIdCall(f, cx, scope, thisObj, args);
}
int id = f.methodId();
if (id == Id_constructor) {
return jsConstructor(cx, scope, thisObj, args);
}
NativeIterator iterator = ensureType(thisObj, NativeIterator.class, f);
switch (id) {
case Id_next:
return iterator.next(cx, scope);
case Id___iterator__:
/// XXX: what about argument? SpiderMonkey apparently ignores it
return thisObj;
default:
throw new IllegalArgumentException(String.valueOf(id));
}
}
/* The JavaScript constructor */
private static Object jsConstructor(
Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
if (args.length == 0 || args[0] == null || args[0] == Undefined.instance) {
Object argument = args.length == 0 ? Undefined.instance : args[0];
throw ScriptRuntime.typeErrorById(
"msg.no.properties", ScriptRuntime.toString(argument));
}
Scriptable obj = ScriptRuntime.toObject(cx, scope, args[0]);
boolean keyOnly = args.length > 1 && ScriptRuntime.toBoolean(args[1]);
if (thisObj != null) {
// Called as a function. Convert to iterator if possible.
// For objects that implement java.lang.Iterable or
// java.util.Iterator, have JavaScript Iterator call the underlying
// iteration methods
Iterator iterator = getJavaIterator(obj);
if (iterator != null) {
scope = ScriptableObject.getTopLevelScope(scope);
return cx.getWrapFactory()
.wrap(
cx,
scope,
new WrappedJavaIterator(iterator, scope),
WrappedJavaIterator.class);
}
// Otherwise, just call the runtime routine
Scriptable jsIterator = ScriptRuntime.toIterator(cx, scope, obj, keyOnly);
if (jsIterator != null) {
return jsIterator;
}
}
// Otherwise, just set up to iterate over the properties of the object.
// Do not call __iterator__ method.
Object objectIterator =
ScriptRuntime.enumInit(
obj,
cx,
scope,
keyOnly
? ScriptRuntime.ENUMERATE_KEYS_NO_ITERATOR
: ScriptRuntime.ENUMERATE_ARRAY_NO_ITERATOR);
ScriptRuntime.setEnumNumbers(objectIterator, true);
NativeIterator result = new NativeIterator(objectIterator);
result.setPrototype(ScriptableObject.getClassPrototype(scope, result.getClassName()));
result.setParentScope(scope);
return result;
}
private Object next(Context cx, Scriptable scope) {
Boolean b = ScriptRuntime.enumNext(this.objectIterator, cx);
if (!b.booleanValue()) {
// Out of values. Throw StopIteration.
throw new JavaScriptException(NativeIterator.getStopIterationObject(scope), null, 0);
}
return ScriptRuntime.enumId(this.objectIterator, cx);
}
/**
* If "obj" is a java.util.Iterator or a java.lang.Iterable, return a wrapping as a JavaScript
* Iterator. Otherwise, return null. This method is in VMBridge since Iterable is a JDK 1.5
* addition.
*/
private static Iterator getJavaIterator(Object obj) {
if (obj instanceof Wrapper) {
Object unwrapped = ((Wrapper) obj).unwrap();
Iterator iterator = null;
if (unwrapped instanceof Iterator) iterator = (Iterator) unwrapped;
if (unwrapped instanceof Iterable) iterator = ((Iterable) unwrapped).iterator();
return iterator;
}
return null;
}
public static class WrappedJavaIterator {
WrappedJavaIterator(Iterator iterator, Scriptable scope) {
this.iterator = iterator;
this.scope = scope;
}
public Object next() {
if (!iterator.hasNext()) {
// Out of values. Throw StopIteration.
throw new JavaScriptException(
NativeIterator.getStopIterationObject(scope), null, 0);
}
return iterator.next();
}
public Object __iterator__(boolean b) {
return this;
}
private Iterator iterator;
private Scriptable scope;
}
@Override
protected int findPrototypeId(String s) {
int id;
switch (s) {
case "constructor":
id = Id_constructor;
break;
case "next":
id = Id_next;
break;
case "__iterator__":
id = Id___iterator__;
break;
default:
id = 0;
break;
}
return id;
}
private static final int Id_constructor = 1,
Id_next = 2,
Id___iterator__ = 3,
MAX_PROTOTYPE_ID = 3;
private Object objectIterator;
}