/*
* Copyright (C) 2010 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.clearsilver.jsilver.syntax;
import com.google.clearsilver.jsilver.syntax.analysis.DepthFirstAdapter;
import com.google.clearsilver.jsilver.syntax.node.AMultipleCommand;
import com.google.clearsilver.jsilver.syntax.node.AOptimizedMultipleCommand;
/**
* Visitor that can be applied to the AST to optimize it by replacing nodes with more efficient
* implementations than the default SableCC generated versions.
*/
public class SyntaxTreeOptimizer extends DepthFirstAdapter {
/**
* Replace AMultipleCommand nodes with AOptimizedMultipleCommands, which iterates over children
* faster.
*/
@Override
public void caseAMultipleCommand(AMultipleCommand originalNode) {
// Recurse through child nodes first. Because the optimised node doesn't
// handle replacement, go leaves-first.
super.caseAMultipleCommand(originalNode);
// Replace this node with the optimized version.
originalNode.replaceBy(new AOptimizedMultipleCommand(originalNode));
}
}