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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/*
* [The "BSD licence"]
* Copyright (c) 2005-2008 Terence Parr
* All rights reserved.
*
* Conversion to C#:
* Copyright (c) 2009 Sam Harwell
* 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
{
using Antlr.Runtime.Misc;
using CLSCompliant = System.CLSCompliantAttribute;
using NotSupportedException = System.NotSupportedException;
using IndexOutOfRangeException = System.IndexOutOfRangeException;
/** A token stream that pulls tokens from the code source on-demand and
* without tracking a complete buffer of the tokens. This stream buffers
* the minimum number of tokens possible. It's the same as
* OnDemandTokenStream except that OnDemandTokenStream buffers all tokens.
*
* You can't use this stream if you pass whitespace or other off-channel
* tokens to the parser. The stream can't ignore off-channel tokens.
*
* You can only look backwards 1 token: LT(-1).
*
* Use this when you need to read from a socket or other infinite stream.
*
* @see BufferedTokenStream
* @see CommonTokenStream
*/
public class UnbufferedTokenStream : LookaheadStream<IToken>, ITokenStream, ITokenStreamInformation
{
[CLSCompliant(false)]
protected ITokenSource tokenSource;
protected int tokenIndex; // simple counter to set token index in tokens
/** Skip tokens on any channel but this one; this is how we skip whitespace... */
protected int channel = TokenChannels.Default;
private readonly ListStack<IToken> _realTokens = new ListStack<IToken>() { null };
public UnbufferedTokenStream(ITokenSource tokenSource)
{
this.tokenSource = tokenSource;
}
public ITokenSource TokenSource
{
get
{
return this.tokenSource;
}
}
public string SourceName
{
get
{
return TokenSource.SourceName;
}
}
#region ITokenStreamInformation Members
public IToken LastToken
{
get
{
return LB(1);
}
}
public IToken LastRealToken
{
get
{
return _realTokens.Peek();
}
}
public int MaxLookBehind
{
get
{
return 1;
}
}
public override int Mark()
{
_realTokens.Push(_realTokens.Peek());
return base.Mark();
}
public override void Release(int marker)
{
base.Release(marker);
_realTokens.Pop();
}
public override void Clear()
{
_realTokens.Clear();
_realTokens.Push(null);
}
public override void Consume()
{
base.Consume();
if (PreviousElement != null && PreviousElement.Line > 0)
_realTokens[_realTokens.Count - 1] = PreviousElement;
}
#endregion
public override IToken NextElement()
{
IToken t = this.tokenSource.NextToken();
t.TokenIndex = this.tokenIndex++;
return t;
}
public override bool IsEndOfFile(IToken o)
{
return o.Type == CharStreamConstants.EndOfFile;
}
public IToken Get(int i)
{
throw new NotSupportedException("Absolute token indexes are meaningless in an unbuffered stream");
}
public int LA(int i)
{
return LT(i).Type;
}
public string ToString(int start, int stop)
{
return "n/a";
}
public string ToString(IToken start, IToken stop)
{
return "n/a";
}
}
}
|
