<body>
<h1>RE2C</h1>
Section: User Commands (1)<br />
-Updated: 1 May 2006<br />
+Updated: 8 May 2006<br />
<a href="#index">Index</a>
<hr />
<a name="lbAB" id="lbAB"> </a>
<p>re2c - convert regular expressions to C/C++</p>
<a name="lbAC" id="lbAC"> </a>
<h2>SYNOPSIS</h2>
-<p><b>re2c</b> [<b>-bdefhisvVw1</b>] [<b>-o output</b>] file</p>
+<p><b>re2c</b> [<b>-bdefghisvVw1</b>] [<b>-o output</b>] file</p>
<a name="lbAD" id="lbAD"> </a>
<h2>DESCRIPTION</h2>
<p><b>re2c</b> is a preprocessor that generates C-based recognizers from
#define YYFILL(n)
{
YYCTYPE yych;
- unsigned int yyaccept;
if((YYLIMIT - YYCURSOR) < 2) YYFILL(2);
yych = *YYCURSOR;
<dt><b>-f</b></dt>
<dd>Generate a scanner with support for storable state. For details see below
at <b>SCANNER WITH STORABLE STATES</b>.<br /><br /></dd>
+<dt><b>-g</b></dt>
+<dd>Generate a scanner that utilizes GCC's computed goto feature. That is re2c
+generates jump tables whenever a decision is of a certain complexity (e.g. a
+lot of if conditions are otherwise necessary). This is only useable with GCC
+and produces output that cannot be compiled with any other compiler. Note that
+this implies -b and that the complexity threshold can be configured using the
+inplace configuration "cgoto:threshold".</dd>
<dt><b>-i</b></dt>
<dd>Do not output #line information. This is usefull when you want use a CMS
tool with the re2c output which you might want if you do not require your users
<dd>Create a parser that supports wide chars (UCS-2). This implies <b>-s</b>
and cannot be used together with <b>-e</b> switch.<br /><br /></dd>
<dt><b>-1</b></dt>
-<dd>Force single pass generation. This cannot be combined with -f.<br /><br /></dd>
+<dd>Force single pass generation, this cannot be combined with -f and disables
+YYMAXFILL generation prior to last re2c block.<br /><br /></dd>
</dl>
<br />
<br />
placing a "/*!getstate:re2c */" comment. This is especially useful when
the scanner code should be wrapped inside a loop.</p>
<p>Please see examples/push.re for push-model scanner. The generated code can be
-tweaked using configurations "state:abort" and "state:nextlabel".</p>
+tweaked using inplace configurations "state:abort" and "state:nextlabel".</p>
<a name="lbAH" id="lbAH"> </a>
<h2>SCANNER SPECIFICATIONS</h2>
<p>Each scanner specification consists of a set of <i>rules</i>, <i>name
is often better to separate the YYGETSTATE code from the actual scanner code by
placing a "/*!getstate:re2c */" comment.
</dd>
+<dd><i>re2c:cgoto:threshold</i> <b>=</b> 9 <b>;</b></dt>
+<dd>When -g is active this value specifies the complexity threshold that triggers
+generation of jump tables rather than using nested if's and decision bitfields.
+The threshold is compared against a calculated estimation of if-s needed where
+every used bitmap divides the threshold by 2.</dd>
</dl>
<a name="lbAK" id="lbAK"> </a>
<h2>UNDERSTANDING RE2C</h2>
<br />
<a name="lbAO" id="lbAO"> </a>
<h2>VERSION INFORMATION</h2>
-<p>This manpage describes <b>re2c</b>, version 0.10.2.</p>
+<p>This manpage describes <b>re2c</b>, version 0.10.3.</p>
<hr />
<a name="index" id="index"> </a>
<h2>Index</h2>
<br />
<hr />
<p>This document was created by man2html, using the manual pages.<br />
-Time: 23:39:44 GMT, May 1, 2006</p>
+Time: 23:39:44 GMT, May 8, 2006</p>
</body>
</html>
re2c \- convert regular expressions to C/C++
.SH SYNOPSIS
-\*(re [\fB-bdefhisvVw1\fP] [\fB-o output\fP] file\fP
+\*(re [\fB-bdefghisvVw1\fP] [\fB-o output\fP] file\fP
.SH DESCRIPTION
\*(re is a preprocessor that generates C-based recognizers from regular
Generate a scanner with support for storable state.
For details see below at \fBSCANNER WITH STORABLE STATES\fP.
.TP
+\fB-g\fP
+Generate a scanner that utilizes GCC's computed goto feature. That is re2c
+generates jump tables whenever a decision is of a certain complexity (e.g. a
+lot of if conditions are otherwise necessary). This is only useable with GCC
+and produces output that cannot be compiled with any other compiler. Note that
+this implies -b and that the complexity threshold can be configured using the
+inplace configuration "cgoto:threshold".
+.TP
\fB-i\fP
Do not output #line information. This is usefull when you want use a CMS tool
with the re2c output which you might want if you do not require your users to
cannot be used together with \fB-e\fP switch.
.TP
\fB-1\fP
-Force single pass generation, this cannot be combined with -f.
+Force single pass generation, this cannot be combined with -f and disables
+YYMAXFILL generation prior to last re2c block.
.SH "INTERFACE CODE"
Unlike other scanner generators, \*(re does not generate complete scanners:
the user must supply some interface code.
the scanner code should be wrapped inside a loop.
Please see examples/push.re for push-model scanner. The generated code can be
-tweaked using configurations "\fBstate:abort\fP" and "\fBstate:nextlabel\fP".
+tweaked using inplace configurations "\fBstate:abort\fP" and "\fBstate:nextlabel\fP".
.SH "SCANNER SPECIFICATIONS"
Each scanner specification consists of a set of \fIrules\fP, \fIname
or default to \fCyy0\fP as start label. Instead of using a dedicated label it
is often better to separate the YYGETSTATE code from the actual scanner code by
placing a "\fC/*!getstate:re2c */\fP" comment.
+.TP
+\fIre2c:cgoto:threshold\fP \fB=\fP 9 \fB;\fP
+When -g is active this value specifies the complexity threshold that triggers
+generation of jump tables rather than using nested if's and decision bitfields.
+The threshold is compared against a calculated estimation of if-s needed where
+every used bitmap divides the threshold by 2.
.SH "UNDERSTANDING RE2C"
.LP
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