1 /*
2  * [The "BSD licence"]
3  * Copyright (c) 2005-2011 Terence Parr
4  * All rights reserved.
5  *
6  * Conversion to C#:
7  * Copyright (c) 2008-2011 Sam Harwell, Pixel Mine, Inc.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 namespace Antlr.Runtime
34 {
35     using ConditionalAttribute = System.Diagnostics.ConditionalAttribute;
36 
37     /** <summary>
38      *  A parser for TokenStreams.  "parser grammars" result in a subclass
39      *  of this.
40      *  </summary>
41      */
42     public class Parser : BaseRecognizer
43     {
44         public ITokenStream input;
45 
Parser( ITokenStream input )46         public Parser( ITokenStream input )
47             : base()
48         {
49             //super(); // highlight that we go to super to set state object
50             TokenStream = input;
51         }
52 
Parser( ITokenStream input, RecognizerSharedState state )53         public Parser( ITokenStream input, RecognizerSharedState state )
54             : base(state) // share the state object with another parser
55         {
56             this.input = input;
57         }
58 
Reset()59         public override void Reset()
60         {
61             base.Reset(); // reset all recognizer state variables
62             if ( input != null )
63             {
64                 input.Seek( 0 ); // rewind the input
65             }
66         }
67 
GetCurrentInputSymbol( IIntStream input )68         protected override object GetCurrentInputSymbol( IIntStream input )
69         {
70             return ( (ITokenStream)input ).LT( 1 );
71         }
72 
GetMissingSymbol( IIntStream input, RecognitionException e, int expectedTokenType, BitSet follow )73         protected override object GetMissingSymbol( IIntStream input,
74                                           RecognitionException e,
75                                           int expectedTokenType,
76                                           BitSet follow )
77         {
78             string tokenText = null;
79             if ( expectedTokenType == TokenTypes.EndOfFile )
80                 tokenText = "<missing EOF>";
81             else
82                 tokenText = "<missing " + TokenNames[expectedTokenType] + ">";
83             CommonToken t = new CommonToken( expectedTokenType, tokenText );
84             IToken current = ( (ITokenStream)input ).LT( 1 );
85             if ( current.Type == TokenTypes.EndOfFile )
86             {
87                 current = ( (ITokenStream)input ).LT( -1 );
88             }
89             t.Line = current.Line;
90             t.CharPositionInLine = current.CharPositionInLine;
91             t.Channel = DefaultTokenChannel;
92             t.InputStream = current.InputStream;
93             return t;
94         }
95 
96         /** <summary>Gets or sets the token stream; resets the parser upon a set.</summary> */
97         public virtual ITokenStream TokenStream
98         {
99             get
100             {
101                 return input;
102             }
103             set
104             {
105                 input = null;
106                 Reset();
107                 input = value;
108             }
109         }
110 
111         public override string SourceName
112         {
113             get
114             {
115                 return input.SourceName;
116             }
117         }
118 
119         [Conditional("ANTLR_TRACE")]
TraceIn( string ruleName, int ruleIndex )120         public virtual void TraceIn( string ruleName, int ruleIndex )
121         {
122             base.TraceIn( ruleName, ruleIndex, input.LT( 1 ) );
123         }
124 
125         [Conditional("ANTLR_TRACE")]
TraceOut( string ruleName, int ruleIndex )126         public virtual void TraceOut( string ruleName, int ruleIndex )
127         {
128             base.TraceOut( ruleName, ruleIndex, input.LT( 1 ) );
129         }
130     }
131 }
132