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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<link rel="stylesheet" href="style.css" type="text/css">
<meta content="text/html; charset=iso-8859-1" http-equiv="Content-Type">
<link rel="Start" href="index.html">
<link rel="previous" href="Lazy.html">
<link rel="next" href="List.html">
<link rel="Up" href="index.html">
<link title="Index of types" rel=Appendix href="index_types.html">
<link title="Index of exceptions" rel=Appendix href="index_exceptions.html">
<link title="Index of values" rel=Appendix href="index_values.html">
<link title="Index of modules" rel=Appendix href="index_modules.html">
<link title="Index of module types" rel=Appendix href="index_module_types.html">
<link title="Arg" rel="Chapter" href="Arg.html">
<link title="Arith_status" rel="Chapter" href="Arith_status.html">
<link title="Array" rel="Chapter" href="Array.html">
<link title="ArrayLabels" rel="Chapter" href="ArrayLabels.html">
<link title="Big_int" rel="Chapter" href="Big_int.html">
<link title="Bigarray" rel="Chapter" href="Bigarray.html">
<link title="Buffer" rel="Chapter" href="Buffer.html">
<link title="Callback" rel="Chapter" href="Callback.html">
<link title="CamlinternalMod" rel="Chapter" href="CamlinternalMod.html">
<link title="CamlinternalOO" rel="Chapter" href="CamlinternalOO.html">
<link title="Char" rel="Chapter" href="Char.html">
<link title="Complex" rel="Chapter" href="Complex.html">
<link title="Condition" rel="Chapter" href="Condition.html">
<link title="Dbm" rel="Chapter" href="Dbm.html">
<link title="Digest" rel="Chapter" href="Digest.html">
<link title="Dynlink" rel="Chapter" href="Dynlink.html">
<link title="Event" rel="Chapter" href="Event.html">
<link title="Filename" rel="Chapter" href="Filename.html">
<link title="Format" rel="Chapter" href="Format.html">
<link title="Gc" rel="Chapter" href="Gc.html">
<link title="Genlex" rel="Chapter" href="Genlex.html">
<link title="Graphics" rel="Chapter" href="Graphics.html">
<link title="GraphicsX11" rel="Chapter" href="GraphicsX11.html">
<link title="Hashtbl" rel="Chapter" href="Hashtbl.html">
<link title="Int32" rel="Chapter" href="Int32.html">
<link title="Int64" rel="Chapter" href="Int64.html">
<link title="Lazy" rel="Chapter" href="Lazy.html">
<link title="Lexing" rel="Chapter" href="Lexing.html">
<link title="List" rel="Chapter" href="List.html">
<link title="ListLabels" rel="Chapter" href="ListLabels.html">
<link title="Map" rel="Chapter" href="Map.html">
<link title="Marshal" rel="Chapter" href="Marshal.html">
<link title="MoreLabels" rel="Chapter" href="MoreLabels.html">
<link title="Mutex" rel="Chapter" href="Mutex.html">
<link title="Nativeint" rel="Chapter" href="Nativeint.html">
<link title="Num" rel="Chapter" href="Num.html">
<link title="Obj" rel="Chapter" href="Obj.html">
<link title="Oo" rel="Chapter" href="Oo.html">
<link title="Parsing" rel="Chapter" href="Parsing.html">
<link title="Pervasives" rel="Chapter" href="Pervasives.html">
<link title="Printexc" rel="Chapter" href="Printexc.html">
<link title="Printf" rel="Chapter" href="Printf.html">
<link title="Queue" rel="Chapter" href="Queue.html">
<link title="Random" rel="Chapter" href="Random.html">
<link title="Scanf" rel="Chapter" href="Scanf.html">
<link title="Set" rel="Chapter" href="Set.html">
<link title="Sort" rel="Chapter" href="Sort.html">
<link title="Stack" rel="Chapter" href="Stack.html">
<link title="StdLabels" rel="Chapter" href="StdLabels.html">
<link title="Str" rel="Chapter" href="Str.html">
<link title="Stream" rel="Chapter" href="Stream.html">
<link title="String" rel="Chapter" href="String.html">
<link title="StringLabels" rel="Chapter" href="StringLabels.html">
<link title="Sys" rel="Chapter" href="Sys.html">
<link title="Thread" rel="Chapter" href="Thread.html">
<link title="ThreadUnix" rel="Chapter" href="ThreadUnix.html">
<link title="Tk" rel="Chapter" href="Tk.html">
<link title="Unix" rel="Chapter" href="Unix.html">
<link title="UnixLabels" rel="Chapter" href="UnixLabels.html">
<link title="Weak" rel="Chapter" href="Weak.html"><link title="Positions" rel="Section" href="#6_Positions">
<link title="Lexer buffers" rel="Section" href="#6_Lexerbuffers">
<link title="Functions for lexer semantic actions" rel="Section" href="#6_Functionsforlexersemanticactions">
<link title="Miscellaneous functions" rel="Section" href="#6_Miscellaneousfunctions">
<title>Lexing</title>
</head>
<body>
<div class="navbar"><a href="Lazy.html">Previous</a>
<a href="index.html">Up</a>
<a href="List.html">Next</a>
</div>
<center><h1>Module <a href="type_Lexing.html">Lexing</a></h1></center>
<br>
<pre><span class="keyword">module</span> Lexing: <code class="code"><span class="keyword">sig</span></code> <a href="Lexing.html">..</a> <code class="code"><span class="keyword">end</span></code></pre>The run-time library for lexers generated by <code class="code">ocamllex</code>.<br>
<hr width="100%">
<br>
<a name="6_Positions"></a>
<h6>Positions</h6><br>
<br><code><span class="keyword">type</span> <a name="TYPEposition"></a><code class="type"></code>position = {</code><table class="typetable">
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code>pos_fname : <code class="type">string</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code>pos_lnum : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code>pos_bol : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code>pos_cnum : <code class="type">int</code>;</code></td>
</tr></table>
}
<div class="info">
A value of type <code class="code">position</code> describes a point in a source file.
<code class="code">pos_fname</code> is the file name; <code class="code">pos_lnum</code> is the line number;
<code class="code">pos_bol</code> is the offset of the beginning of the line (number
of characters between the beginning of the file and the beginning
of the line); <code class="code">pos_cnum</code> is the offset of the position (number of
characters between the beginning of the file and the position).
<p>
See the documentation of type <code class="code">lexbuf</code> for information about
how the lexing engine will manage positions.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALdummy_pos"></a>dummy_pos : <code class="type"><a href="Lexing.html#TYPEposition">position</a></code></pre><div class="info">
A value of type <code class="code">position</code>, guaranteed to be different from any
valid position.<br>
</div>
<br>
<a name="6_Lexerbuffers"></a>
<h6>Lexer buffers</h6><br>
<br><code><span class="keyword">type</span> <a name="TYPElexbuf"></a><code class="type"></code>lexbuf = {</code><table class="typetable">
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code>refill_buff : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> unit</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_buffer : <code class="type">string</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_buffer_len : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_abs_pos : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_start_pos : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_curr_pos : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_last_pos : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_last_action : <code class="type">int</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_eof_reached : <code class="type">bool</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_mem : <code class="type">int array</code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_start_p : <code class="type"><a href="Lexing.html#TYPEposition">position</a></code>;</code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code> </code></td>
<td align="left" valign="top" >
<code><span class="keyword">mutable </span>lex_curr_p : <code class="type"><a href="Lexing.html#TYPEposition">position</a></code>;</code></td>
</tr></table>
}
<div class="info">
The type of lexer buffers. A lexer buffer is the argument passed
to the scanning functions defined by the generated scanners.
The lexer buffer holds the current state of the scanner, plus
a function to refill the buffer from the input.
<p>
Note that the lexing engine will only change the <code class="code">pos_cnum</code> field
of <code class="code">lex_curr_p</code> by updating it with the number of characters read
since the start of the <code class="code">lexbuf</code>. The other fields are copied
without change by the lexing engine. In order to keep them
accurate, they must be initialised before the first use of the
lexbuf, and updated by the relevant lexer actions (i.e. at each
end of line).<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_channel"></a>from_channel : <code class="type"><a href="Pervasives.html#TYPEin_channel">in_channel</a> -> <a href="Lexing.html#TYPElexbuf">lexbuf</a></code></pre><div class="info">
Create a lexer buffer on the given input channel.
<code class="code"><span class="constructor">Lexing</span>.from_channel inchan</code> returns a lexer buffer which reads
from the input channel <code class="code">inchan</code>, at the current reading position.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_string"></a>from_string : <code class="type">string -> <a href="Lexing.html#TYPElexbuf">lexbuf</a></code></pre><div class="info">
Create a lexer buffer which reads from
the given string. Reading starts from the first character in
the string. An end-of-input condition is generated when the
end of the string is reached.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_function"></a>from_function : <code class="type">(string -> int -> int) -> <a href="Lexing.html#TYPElexbuf">lexbuf</a></code></pre><div class="info">
Create a lexer buffer with the given function as its reading method.
When the scanner needs more characters, it will call the given
function, giving it a character string <code class="code">s</code> and a character
count <code class="code">n</code>. The function should put <code class="code">n</code> characters or less in <code class="code">s</code>,
starting at character number 0, and return the number of characters
provided. A return value of 0 means end of input.<br>
</div>
<br>
<a name="6_Functionsforlexersemanticactions"></a>
<h6>Functions for lexer semantic actions</h6><br>
<br>
The following functions can be called from the semantic actions
of lexer definitions (the ML code enclosed in braces that
computes the value returned by lexing functions). They give
access to the character string matched by the regular expression
associated with the semantic action. These functions must be
applied to the argument <code class="code">lexbuf</code>, which, in the code generated by
<code class="code">ocamllex</code>, is bound to the lexer buffer passed to the parsing
function.<br>
<pre><span class="keyword">val</span> <a name="VALlexeme"></a>lexeme : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> string</code></pre><div class="info">
<code class="code"><span class="constructor">Lexing</span>.lexeme lexbuf</code> returns the string matched by
the regular expression.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlexeme_char"></a>lexeme_char : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> int -> char</code></pre><div class="info">
<code class="code"><span class="constructor">Lexing</span>.lexeme_char lexbuf i</code> returns character number <code class="code">i</code> in
the matched string.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlexeme_start"></a>lexeme_start : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> int</code></pre><div class="info">
<code class="code"><span class="constructor">Lexing</span>.lexeme_start lexbuf</code> returns the offset in the
input stream of the first character of the matched string.
The first character of the stream has offset 0.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlexeme_end"></a>lexeme_end : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> int</code></pre><div class="info">
<code class="code"><span class="constructor">Lexing</span>.lexeme_end lexbuf</code> returns the offset in the input stream
of the character following the last character of the matched
string. The first character of the stream has offset 0.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlexeme_start_p"></a>lexeme_start_p : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> <a href="Lexing.html#TYPEposition">position</a></code></pre><div class="info">
Like <code class="code">lexeme_start</code>, but return a complete <code class="code">position</code> instead
of an offset.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlexeme_end_p"></a>lexeme_end_p : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> <a href="Lexing.html#TYPEposition">position</a></code></pre><div class="info">
Like <code class="code">lexeme_end</code>, but return a complete <code class="code">position</code> instead
of an offset.<br>
</div>
<br>
<a name="6_Miscellaneousfunctions"></a>
<h6>Miscellaneous functions</h6><br>
<pre><span class="keyword">val</span> <a name="VALflush_input"></a>flush_input : <code class="type"><a href="Lexing.html#TYPElexbuf">lexbuf</a> -> unit</code></pre><div class="info">
Discard the contents of the buffer and reset the current
position to 0. The next use of the lexbuf will trigger a
refill.<br>
</div>
</body></html>
|
