/*
* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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 java.util.function.Consumer;
import jdk.nashorn.internal.objects.annotations.Attribute;
import jdk.nashorn.internal.objects.annotations.Function;
import jdk.nashorn.internal.objects.annotations.ScriptClass;
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.linker.Bootstrap;
import jdk.nashorn.internal.runtime.linker.InvokeByName;
import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
/**
* ECMA6 25.1.2 The %IteratorPrototype% Object
*/
@ScriptClass("Iterator")
public abstract class AbstractIterator extends ScriptObject {
// initialized by nasgen
private static PropertyMap $nasgenmap$;
private final static Object ITERATOR_INVOKER_KEY = new Object();
private final static Object NEXT_INVOKER_KEY = new Object();
private final static Object DONE_INVOKER_KEY = new Object();
private final static Object VALUE_INVOKER_KEY = new Object();
/** ECMA6 iteration kinds */
enum IterationKind {
/** key iteration */
KEY,
/** value iteration */
VALUE,
/** key+value iteration */
KEY_VALUE
}
/**
* Create an abstract iterator object with the given prototype and property map.
*
* @param prototype the prototype
* @param map the property map
*/
protected AbstractIterator(final ScriptObject prototype, final PropertyMap map) {
super(prototype, map);
}
/**
* 25.1.2.1 %IteratorPrototype% [ @@iterator ] ( )
*
* @param self the self object
* @return this iterator
*/
@Function(attributes = Attribute.NOT_ENUMERABLE, name = "@@iterator")
public static Object getIterator(final Object self) {
return self;
}
@Override
public String getClassName() {
return "Iterator";
}
/**
* ES6 25.1.1.2 The Iterator Interface
*
* @param arg argument
* @return next iterator result
*/
protected abstract IteratorResult next(final Object arg);
/**
* ES6 25.1.1.3 The IteratorResult Interface
*
* @param value result value
* @param done result status
* @param global the global object
* @return result object
*/
protected IteratorResult makeResult(final Object value, final Boolean done, final Global global) {
return new IteratorResult(value, done, global);
}
static MethodHandle getIteratorInvoker(final Global global) {
return global.getDynamicInvoker(ITERATOR_INVOKER_KEY,
() -> Bootstrap.createDynamicCallInvoker(Object.class, Object.class, Object.class));
}
/**
* Get the invoker for the ES6 iterator {@code next} method.
* @param global the global object
* @return the next invoker
*/
public static InvokeByName getNextInvoker(final Global global) {
return global.getInvokeByName(AbstractIterator.NEXT_INVOKER_KEY,
() -> new InvokeByName("next", Object.class, Object.class, Object.class));
}
/**
* Get the invoker for the ES6 iterator result {@code done} property.
* @param global the global object
* @return the done invoker
*/
public static MethodHandle getDoneInvoker(final Global global) {
return global.getDynamicInvoker(AbstractIterator.DONE_INVOKER_KEY,
() -> Bootstrap.createDynamicInvoker("done", NashornCallSiteDescriptor.GET_PROPERTY, Object.class, Object.class));
}
/**
* Get the invoker for the ES6 iterator result {@code value} property.
* @param global the global object
* @return the value invoker
*/
public static MethodHandle getValueInvoker(final Global global) {
return global.getDynamicInvoker(AbstractIterator.VALUE_INVOKER_KEY,
() -> Bootstrap.createDynamicInvoker("value", NashornCallSiteDescriptor.GET_PROPERTY, Object.class, Object.class));
}
/**
* ES6 7.4.1 GetIterator abstract operation
*
* @param iterable an object
* @param global the global object
* @return the iterator
*/
public static Object getIterator(final Object iterable, final Global global) {
final Object object = Global.toObject(iterable);
if (object instanceof ScriptObject) {
// TODO we need to implement fast property access for Symbol keys in order to use InvokeByName here.
final Object getter = ((ScriptObject) object).get(NativeSymbol.iterator);
if (Bootstrap.isCallable(getter)) {
try {
final MethodHandle invoker = getIteratorInvoker(global);
final Object value = invoker.invokeExact(getter, iterable);
if (JSType.isPrimitive(value)) {
throw typeError("not.an.object", ScriptRuntime.safeToString(value));
}
return value;
} catch (final Throwable t) {
throw new RuntimeException(t);
}
}
throw typeError("not.a.function", ScriptRuntime.safeToString(getter));
}
throw typeError("cannot.get.iterator", ScriptRuntime.safeToString(iterable));
}
/**
* Iterate over an iterable object, passing every value to {@code consumer}.
*
* @param iterable an iterable object
* @param global the current global
* @param consumer the value consumer
*/
public static void iterate(final Object iterable, final Global global, final Consumer<Object> consumer) {
final Object iterator = AbstractIterator.getIterator(Global.toObject(iterable), global);
final InvokeByName nextInvoker = getNextInvoker(global);
final MethodHandle doneInvoker = getDoneInvoker(global);
final MethodHandle valueInvoker = getValueInvoker(global);
try {
do {
final Object next = nextInvoker.getGetter().invokeExact(iterator);
if (!Bootstrap.isCallable(next)) {
break;
}
final Object result = nextInvoker.getInvoker().invokeExact(next, iterator, (Object) null);
if (!(result instanceof ScriptObject)) {
break;
}
final Object done = doneInvoker.invokeExact(result);
if (JSType.toBoolean(done)) {
break;
}
consumer.accept(valueInvoker.invokeExact(result));
} while (true);
} catch (final RuntimeException r) {
throw r;
} catch (final Throwable t) {
throw new RuntimeException(t);
}
}
}