org.antlr.v4.runtime.tree.ParseTreeProperty Maven / Gradle / Ivy
/*
* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.runtime.tree;
import java.util.IdentityHashMap;
import java.util.Map;
/**
* Associate a property with a parse tree node. Useful with parse tree listeners
* that need to associate values with particular tree nodes, kind of like
* specifying a return value for the listener event method that visited a
* particular node. Example:
*
*
* ParseTreeProperty<Integer> values = new ParseTreeProperty<Integer>();
* values.put(tree, 36);
* int x = values.get(tree);
* values.removeFrom(tree);
*
*
* You would make one decl (values here) in the listener and use lots of times
* in your event methods.
*/
public class ParseTreeProperty {
protected Map annotations = new IdentityHashMap();
public V get(ParseTree node) { return annotations.get(node); }
public void put(ParseTree node, V value) { annotations.put(node, value); }
public V removeFrom(ParseTree node) { return annotations.remove(node); }
}