01: /*
02: [The "BSD licence"]
03: Copyright (c) 2005-2006 Terence Parr
04: All rights reserved.
05:
06: Redistribution and use in source and binary forms, with or without
07: modification, are permitted provided that the following conditions
08: are met:
09: 1. Redistributions of source code must retain the above copyright
10: notice, this list of conditions and the following disclaimer.
11: 2. Redistributions in binary form must reproduce the above copyright
12: notice, this list of conditions and the following disclaimer in the
13: documentation and/or other materials provided with the distribution.
14: 3. The name of the author may not be used to endorse or promote products
15: derived from this software without specific prior written permission.
16:
17: THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18: IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20: IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21: INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22: NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26: THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27: */
28: package org.antlr.runtime.debug;
29:
30: import org.antlr.runtime.RecognitionException;
31: import org.antlr.runtime.Token;
32: import org.antlr.runtime.tree.ParseTree;
33:
34: import java.util.Stack;
35:
36: /** This parser listener tracks rule entry/exit and token matches
37: * to build a simple parse tree using ParseTree nodes.
38: */
39: public class ParseTreeBuilder extends BlankDebugEventListener {
40: Stack callStack = new Stack();
41:
42: public ParseTreeBuilder(String grammarName) {
43: ParseTree root = create("<grammar " + grammarName + ">");
44: callStack.push(root);
45: }
46:
47: public ParseTree getTree() {
48: return (ParseTree) callStack.elementAt(0);
49: }
50:
51: /** What kind of node to create. You might want to override
52: * so I factored out creation here.
53: */
54: public ParseTree create(Object payload) {
55: return new ParseTree(payload);
56: }
57:
58: public void enterRule(String ruleName) {
59: ParseTree parentRuleNode = (ParseTree) callStack.peek();
60: ParseTree ruleNode = create(ruleName);
61: parentRuleNode.addChild(ruleNode);
62: callStack.push(ruleNode);
63: }
64:
65: public void exitRule(String ruleName) {
66: callStack.pop();
67: }
68:
69: public void consumeToken(Token token) {
70: ParseTree ruleNode = (ParseTree) callStack.peek();
71: ParseTree elementNode = create(token);
72: ruleNode.addChild(elementNode);
73: }
74:
75: public void recognitionException(RecognitionException e) {
76: ParseTree ruleNode = (ParseTree) callStack.peek();
77: ParseTree errorNode = create(e);
78: ruleNode.addChild(errorNode);
79: }
80: }
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