1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/*
* [The "BSD licence"]
* Copyright (c) 2005-2008 Terence Parr
* All rights reserved.
*
* Conversion to C#:
* Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
namespace Antlr.Runtime.Debug
{
using System.Collections.Generic;
using ParseTree = Antlr.Runtime.Tree.ParseTree;
/** <summary>
* This parser listener tracks rule entry/exit and token matches
* to build a simple parse tree using ParseTree nodes.
* </summary>
*/
public class ParseTreeBuilder : BlankDebugEventListener
{
public const string EPSILON_PAYLOAD = "<epsilon>";
Stack<ParseTree> callStack = new Stack<ParseTree>();
List<IToken> hiddenTokens = new List<IToken>();
int backtracking = 0;
public ParseTreeBuilder( string grammarName )
{
ParseTree root = Create( "<grammar " + grammarName + ">" );
callStack.Push( root );
}
public virtual ParseTree Tree
{
get
{
ParseTree[] stack = callStack.ToArray();
return stack[stack.Length - 1];
}
}
/** <summary>
* What kind of node to create. You might want to override
* so I factored out creation here.
* </summary>
*/
public virtual ParseTree Create( object payload )
{
return new ParseTree( payload );
}
public virtual ParseTree EpsilonNode()
{
return Create( EPSILON_PAYLOAD );
}
/** <summary>Backtracking or cyclic DFA, don't want to add nodes to tree</summary> */
public override void EnterDecision( int d, bool couldBacktrack )
{
backtracking++;
}
public override void ExitDecision( int i )
{
backtracking--;
}
public override void EnterRule( string filename, string ruleName )
{
if ( backtracking > 0 )
return;
ParseTree parentRuleNode = callStack.Peek();
ParseTree ruleNode = Create( ruleName );
parentRuleNode.AddChild( ruleNode );
callStack.Push( ruleNode );
}
public override void ExitRule( string filename, string ruleName )
{
if ( backtracking > 0 )
return;
ParseTree ruleNode = callStack.Peek();
if ( ruleNode.ChildCount == 0 )
{
ruleNode.AddChild( EpsilonNode() );
}
callStack.Pop();
}
public override void ConsumeToken( IToken token )
{
if ( backtracking > 0 )
return;
ParseTree ruleNode = callStack.Peek();
ParseTree elementNode = Create( token );
elementNode.hiddenTokens = this.hiddenTokens;
this.hiddenTokens = new List<IToken>();
ruleNode.AddChild( elementNode );
}
public override void ConsumeHiddenToken( IToken token )
{
if ( backtracking > 0 )
return;
hiddenTokens.Add( token );
}
public override void RecognitionException( RecognitionException e )
{
if ( backtracking > 0 )
return;
ParseTree ruleNode = callStack.Peek();
ParseTree errorNode = Create( e );
ruleNode.AddChild( errorNode );
}
}
}
|
