// Copyright (C) 2005 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.caja.parser.js;
import com.google.caja.lexer.FilePosition;
import com.google.caja.lexer.TokenConsumer;
import com.google.caja.parser.ParseTreeNode;
import com.google.caja.reporting.RenderContext;
import java.util.List;
import java.util.Collections;
/**
* Sometimes called a function literal or a closure, an expression that
* constructs a new function.
*
* <p>E.g.
* <code>function () { return 0; }</code>
*
* @author mikesamuel@gmail.com
*/
public final class FunctionConstructor
extends AbstractExpression implements NestedScope {
private static final long serialVersionUID = 4183249730129328478L;
// Local member variables are only changed in childrenChanged(),
// so this class satisfies the immutability contract of the superclass.
private Identifier identifier;
private List<FormalParam> params;
private Block body;
/** @param value unused. This ctor is provided for reflection. */
@ReflectiveCtor
public FunctionConstructor(
FilePosition pos, Void value, List<? extends ParseTreeNode> children) {
super(pos, ParseTreeNode.class);
createMutation().appendChildren(children).execute();
}
public FunctionConstructor(
FilePosition pos, Identifier identifier, List<FormalParam> params,
Block body) {
super(pos, ParseTreeNode.class);
createMutation()
.appendChild(identifier)
.appendChildren(params)
.appendChild(body)
.execute();
}
@Override
protected void childrenChanged() {
super.childrenChanged();
List<? extends ParseTreeNode> children = children();
int n = children.size();
this.identifier = (Identifier) children.get(0);
this.params = Collections.<FormalParam>unmodifiableList(
childrenPart(1, n - 1, FormalParam.class));
for (ParseTreeNode p : params) {
if (!(p instanceof FormalParam)) {
throw new ClassCastException(p.getClass().getName());
}
}
this.body = (Block) children().get(n - 1);
}
public List<FormalParam> getParams() { return params; }
public Block getBody() { return body; }
public Identifier getIdentifier() { return identifier; }
public String getIdentifierName() { return identifier.getName(); }
@Override
public Object getValue() { return null; }
@Override
public Boolean conditionResult() { return true; }
public void render(RenderContext rc) {
TokenConsumer out = rc.getOut();
out.mark(getFilePosition());
out.consume("function");
String name = identifier.getName();
if (null != name) {
out.consume(name);
}
renderActuals(rc);
renderBody(rc);
}
void renderActuals(RenderContext rc) {
TokenConsumer out = rc.getOut();
out.consume("(");
boolean seen = false;
for (FormalParam e : params) {
if (seen) {
out.consume(",");
} else {
seen = true;
}
e.render(rc);
}
out.consume(")");
}
void renderBody(RenderContext rc) {
body.renderBlock(rc, false);
}
public String typeOf() { return "function"; }
}