<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Localization</title>
<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.74.0">
<link rel="home" href="../../index.html" title="Boost.Regex">
<link rel="up" href="../background_information.html" title="Background Information">
<link rel="prev" href="headers.html" title="Headers">
<link rel="next" href="thread_safety.html" title="Thread Safety">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
<td align="center"><a href="../../../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="headers.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../background_information.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="thread_safety.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_regex.background_information.locale"></a><a class="link" href="locale.html" title="Localization"> Localization</a>
</h3></div></div></div>
<p>
Boost.Regex provides extensive support for run-time localization, the localization
model used can be split into two parts: front-end and back-end.
</p>
<p>
Front-end localization deals with everything which the user sees - error
messages, and the regular expression syntax itself. For example a French
application could change [[:word:]] to [[:mot:]] and \w to \m. Modifying
the front end locale requires active support from the developer, by providing
the library with a message catalogue to load, containing the localized strings.
Front-end locale is affected by the LC_MESSAGES category only.
</p>
<p>
Back-end localization deals with everything that occurs after the expression
has been parsed - in other words everything that the user does not see or
interact with directly. It deals with case conversion, collation, and character
class membership. The back-end locale does not require any intervention from
the developer - the library will acquire all the information it requires
for the current locale from the underlying operating system / run time library.
This means that if the program user does not interact with regular expressions
directly - for example if the expressions are embedded in your C++ code -
then no explicit localization is required, as the library will take care
of everything for you. For example embedding the expression [[:word:]]+ in
your code will always match a whole word, if the program is run on a machine
with, for example, a Greek locale, then it will still match a whole word,
but in Greek characters rather than Latin ones. The back-end locale is affected
by the LC_TYPE and LC_COLLATE categories.
</p>
<p>
There are three separate localization mechanisms supported by Boost.Regex:
</p>
<a name="boost_regex.background_information.locale.win32_localization_model_"></a><h5>
<a name="id1172833"></a>
<a class="link" href="locale.html#boost_regex.background_information.locale.win32_localization_model_">Win32
localization model.</a>
</h5>
<p>
This is the default model when the library is compiled under Win32, and is
encapsulated by the traits class <code class="computeroutput"><span class="identifier">w32_regex_traits</span></code>.
When this model is in effect each <a class="link" href="../ref/basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> object gets it's own
LCID, by default this is the users default setting as returned by GetUserDefaultLCID,
but you can call imbue on the <code class="computeroutput"><span class="identifier">basic_regex</span></code>
object to set it's locale to some other LCID if you wish. All the settings
used by Boost.Regex are acquired directly from the operating system bypassing
the C run time library. Front-end localization requires a resource dll, containing
a string table with the user-defined strings. The traits class exports the
function:
</p>
<pre class="programlisting"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">set_message_catalogue</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">s</span><span class="special">);</span>
</pre>
<p>
which needs to be called with a string identifying the name of the resource
dll, before your code compiles any regular expressions (but not necessarily
before you construct any <code class="computeroutput"><span class="identifier">basic_regex</span></code>
instances):
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">w32_regex_traits</span><span class="special"><</span><span class="keyword">char</span><span class="special">>::</span><span class="identifier">set_message_catalogue</span><span class="special">(</span><span class="string">"mydll.dll"</span><span class="special">);</span>
</pre>
<p>
The library provides full Unicode support under NT, under Windows 9x the
library degrades gracefully - characters 0 to 255 are supported, the remainder
are treated as "unknown" graphic characters.
</p>
<a name="boost_regex.background_information.locale.c_localization_model_"></a><h5>
<a name="id1172988"></a>
<a class="link" href="locale.html#boost_regex.background_information.locale.c_localization_model_">C
localization model.</a>
</h5>
<p>
This model has been deprecated in favor of the C++ locale for all non-Windows
compilers that support it. This locale is encapsulated by the traits class
<code class="computeroutput"><span class="identifier">c_regex_traits</span></code>, Win32 users
can force this model to take effect by defining the pre-processor symbol
BOOST_REGEX_USE_C_LOCALE. When this model is in effect there is a single
global locale, as set by <code class="computeroutput"><span class="identifier">setlocale</span></code>.
All settings are acquired from your run time library, consequently Unicode
support is dependent upon your run time library implementation.
</p>
<p>
Front end localization is not supported.
</p>
<p>
Note that calling setlocale invalidates all compiled regular expressions,
calling <code class="computeroutput"><span class="identifier">setlocale</span><span class="special">(</span><span class="identifier">LC_ALL</span><span class="special">,</span> <span class="string">"C"</span><span class="special">)</span></code>
will make this library behave equivalent to most traditional regular expression
libraries including version 1 of this library.
</p>
<a name="boost_regex.background_information.locale.c___localization_model_"></a><h5>
<a name="id1173056"></a>
<a class="link" href="locale.html#boost_regex.background_information.locale.c___localization_model_">C++
localization model.</a>
</h5>
<p>
This model is the default for non-Windows compilers.
</p>
<p>
When this model is in effect each instance of <a class="link" href="../ref/basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> has its own instance
of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">locale</span></code>, class <a class="link" href="../ref/basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a> also has a member function
<code class="computeroutput"><span class="identifier">imbue</span></code> which allows the locale
for the expression to be set on a per-instance basis. Front end localization
requires a POSIX message catalogue, which will be loaded via the <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">messages</span></code>
facet of the expression's locale, the traits class exports the symbol:
</p>
<pre class="programlisting"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">set_message_catalogue</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">s</span><span class="special">);</span>
</pre>
<p>
which needs to be called with a string identifying the name of the message
catalogue, before your code compiles any regular expressions (but not necessarily
before you construct any basic_regex instances):
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">cpp_regex_traits</span><span class="special"><</span><span class="keyword">char</span><span class="special">>::</span><span class="identifier">set_message_catalogue</span><span class="special">(</span><span class="string">"mycatalogue"</span><span class="special">);</span>
</pre>
<p>
Note that calling <code class="computeroutput"><span class="identifier">basic_regex</span><span class="special"><>::</span><span class="identifier">imbue</span></code>
will invalidate any expression currently compiled in that instance of <a class="link" href="../ref/basic_regex.html" title="basic_regex"><code class="computeroutput"><span class="identifier">basic_regex</span></code></a>.
</p>
<p>
Finally note that if you build the library with a non-default localization
model, then the appropriate pre-processor symbol (BOOST_REGEX_USE_C_LOCALE
or BOOST_REGEX_USE_CPP_LOCALE) must be defined both when you build the support
library, and when you include <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
or <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cregex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
in your code. The best way to ensure this is to add the #define to <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">/</span><span class="identifier">user</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>.
</p>
<a name="boost_regex.background_information.locale.providing_a_message_catalogue"></a><h5>
<a name="id1173357"></a>
<a class="link" href="locale.html#boost_regex.background_information.locale.providing_a_message_catalogue">Providing
a message catalogue</a>
</h5>
<p>
In order to localize the front end of the library, you need to provide the
library with the appropriate message strings contained either in a resource
dll's string table (Win32 model), or a POSIX message catalogue (C++ models).
In the latter case the messages must appear in message set zero of the catalogue.
The messages and their id's are as follows:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Message
</p>
</th>
<th>
<p>
id
</p>
</th>
<th>
<p>
Meaning
</p>
</th>
<th>
<p>
Default value
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
101
</p>
</td>
<td>
<p>
The character used to start a sub-expression.
</p>
</td>
<td>
<p>
"("
</p>
</td>
</tr>
<tr>
<td>
<p>
102
</p>
</td>
<td>
<p>
The character used to end a sub-expression declaration.
</p>
</td>
<td>
<p>
")"
</p>
</td>
</tr>
<tr>
<td>
<p>
103
</p>
</td>
<td>
<p>
The character used to denote an end of line assertion.
</p>
</td>
<td>
<p>
"$"
</p>
</td>
</tr>
<tr>
<td>
<p>
104
</p>
</td>
<td>
<p>
The character used to denote the start of line assertion.
</p>
</td>
<td>
<p>
"^"
</p>
</td>
</tr>
<tr>
<td>
<p>
105
</p>
</td>
<td>
<p>
The character used to denote the "match any character expression".
</p>
</td>
<td>
<p>
"."
</p>
</td>
</tr>
<tr>
<td>
<p>
106
</p>
</td>
<td>
<p>
The match zero or more times repetition operator.
</p>
</td>
<td>
<p>
"*"
</p>
</td>
</tr>
<tr>
<td>
<p>
107
</p>
</td>
<td>
<p>
The match one or more repetition operator.
</p>
</td>
<td>
<p>
"+"
</p>
</td>
</tr>
<tr>
<td>
<p>
108
</p>
</td>
<td>
<p>
The match zero or one repetition operator.
</p>
</td>
<td>
<p>
"?"
</p>
</td>
</tr>
<tr>
<td>
<p>
109
</p>
</td>
<td>
<p>
The character set opening character.
</p>
</td>
<td>
<p>
"["
</p>
</td>
</tr>
<tr>
<td>
<p>
110
</p>
</td>
<td>
<p>
The character set closing character.
</p>
</td>
<td>
<p>
"]"
</p>
</td>
</tr>
<tr>
<td>
<p>
111
</p>
</td>
<td>
<p>
The alternation operator.
</p>
</td>
<td>
<p>
"|"
</p>
</td>
</tr>
<tr>
<td>
<p>
112
</p>
</td>
<td>
<p>
The escape character.
</p>
</td>
<td>
<p>
"\"
</p>
</td>
</tr>
<tr>
<td>
<p>
113
</p>
</td>
<td>
<p>
The hash character (not currently used).
</p>
</td>
<td>
<p>
"#"
</p>
</td>
</tr>
<tr>
<td>
<p>
114
</p>
</td>
<td>
<p>
The range operator.
</p>
</td>
<td>
<p>
"-"
</p>
</td>
</tr>
<tr>
<td>
<p>
115
</p>
</td>
<td>
<p>
The repetition operator opening character.
</p>
</td>
<td>
<p>
"{"
</p>
</td>
</tr>
<tr>
<td>
<p>
116
</p>
</td>
<td>
<p>
The repetition operator closing character.
</p>
</td>
<td>
<p>
"}"
</p>
</td>
</tr>
<tr>
<td>
<p>
117
</p>
</td>
<td>
<p>
The digit characters.
</p>
</td>
<td>
<p>
"0123456789"
</p>
</td>
</tr>
<tr>
<td>
<p>
118
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the word boundary assertion.
</p>
</td>
<td>
<p>
"b"
</p>
</td>
</tr>
<tr>
<td>
<p>
119
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the non-word boundary assertion.
</p>
</td>
<td>
<p>
"B"
</p>
</td>
</tr>
<tr>
<td>
<p>
120
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the word-start boundary assertion.
</p>
</td>
<td>
<p>
"<"
</p>
</td>
</tr>
<tr>
<td>
<p>
121
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the word-end boundary assertion.
</p>
</td>
<td>
<p>
">"
</p>
</td>
</tr>
<tr>
<td>
<p>
122
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any word character.
</p>
</td>
<td>
<p>
"w"
</p>
</td>
</tr>
<tr>
<td>
<p>
123
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
a non-word character.
</p>
</td>
<td>
<p>
"W"
</p>
</td>
</tr>
<tr>
<td>
<p>
124
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
a start of buffer assertion.
</p>
</td>
<td>
<p>
"`A"
</p>
</td>
</tr>
<tr>
<td>
<p>
125
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
an end of buffer assertion.
</p>
</td>
<td>
<p>
"'z"
</p>
</td>
</tr>
<tr>
<td>
<p>
126
</p>
</td>
<td>
<p>
The newline character.
</p>
</td>
<td>
<p>
"\n"
</p>
</td>
</tr>
<tr>
<td>
<p>
127
</p>
</td>
<td>
<p>
The comma separator.
</p>
</td>
<td>
<p>
","
</p>
</td>
</tr>
<tr>
<td>
<p>
128
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the bell character.
</p>
</td>
<td>
<p>
"a"
</p>
</td>
</tr>
<tr>
<td>
<p>
129
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the form feed character.
</p>
</td>
<td>
<p>
"f"
</p>
</td>
</tr>
<tr>
<td>
<p>
130
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the newline character.
</p>
</td>
<td>
<p>
"n"
</p>
</td>
</tr>
<tr>
<td>
<p>
131
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the carriage return character.
</p>
</td>
<td>
<p>
"r"
</p>
</td>
</tr>
<tr>
<td>
<p>
132
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the tab character.
</p>
</td>
<td>
<p>
"t"
</p>
</td>
</tr>
<tr>
<td>
<p>
133
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the vertical tab character.
</p>
</td>
<td>
<p>
"v"
</p>
</td>
</tr>
<tr>
<td>
<p>
134
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the start of a hexadecimal character constant.
</p>
</td>
<td>
<p>
"x"
</p>
</td>
</tr>
<tr>
<td>
<p>
135
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the start of an ASCII escape character.
</p>
</td>
<td>
<p>
"c"
</p>
</td>
</tr>
<tr>
<td>
<p>
136
</p>
</td>
<td>
<p>
The colon character.
</p>
</td>
<td>
<p>
":"
</p>
</td>
</tr>
<tr>
<td>
<p>
137
</p>
</td>
<td>
<p>
The equals character.
</p>
</td>
<td>
<p>
"="
</p>
</td>
</tr>
<tr>
<td>
<p>
138
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the ASCII escape character.
</p>
</td>
<td>
<p>
"e"
</p>
</td>
</tr>
<tr>
<td>
<p>
139
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any lower case character.
</p>
</td>
<td>
<p>
"l"
</p>
</td>
</tr>
<tr>
<td>
<p>
140
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any non-lower case character.
</p>
</td>
<td>
<p>
"L"
</p>
</td>
</tr>
<tr>
<td>
<p>
141
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any upper case character.
</p>
</td>
<td>
<p>
"u"
</p>
</td>
</tr>
<tr>
<td>
<p>
142
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any non-upper case character.
</p>
</td>
<td>
<p>
"U"
</p>
</td>
</tr>
<tr>
<td>
<p>
143
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any space character.
</p>
</td>
<td>
<p>
"s"
</p>
</td>
</tr>
<tr>
<td>
<p>
144
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any non-space character.
</p>
</td>
<td>
<p>
"S"
</p>
</td>
</tr>
<tr>
<td>
<p>
145
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any digit character.
</p>
</td>
<td>
<p>
"d"
</p>
</td>
</tr>
<tr>
<td>
<p>
146
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any non-digit character.
</p>
</td>
<td>
<p>
"D"
</p>
</td>
</tr>
<tr>
<td>
<p>
147
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the end quote operator.
</p>
</td>
<td>
<p>
"E"
</p>
</td>
</tr>
<tr>
<td>
<p>
148
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the start quote operator.
</p>
</td>
<td>
<p>
"Q"
</p>
</td>
</tr>
<tr>
<td>
<p>
149
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
a Unicode combining character sequence.
</p>
</td>
<td>
<p>
"X"
</p>
</td>
</tr>
<tr>
<td>
<p>
150
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
any single character.
</p>
</td>
<td>
<p>
"C"
</p>
</td>
</tr>
<tr>
<td>
<p>
151
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
end of buffer operator.
</p>
</td>
<td>
<p>
"Z"
</p>
</td>
</tr>
<tr>
<td>
<p>
152
</p>
</td>
<td>
<p>
The character which when preceded by an escape character represents
the continuation assertion.
</p>
</td>
<td>
<p>
"G"
</p>
</td>
</tr>
<tr>
<td>
<p>
153
</p>
</td>
<td>
<p>
The character which when preceeded by (? indicates a zero width
negated forward lookahead assert.
</p>
</td>
<td>
<p>
!
</p>
</td>
</tr>
</tbody>
</table></div>
<p>
Custom error messages are loaded as follows:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Message ID
</p>
</th>
<th>
<p>
Error message ID
</p>
</th>
<th>
<p>
Default string
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
201
</p>
</td>
<td>
<p>
REG_NOMATCH
</p>
</td>
<td>
<p>
"No match"
</p>
</td>
</tr>
<tr>
<td>
<p>
202
</p>
</td>
<td>
<p>
REG_BADPAT
</p>
</td>
<td>
<p>
"Invalid regular expression"
</p>
</td>
</tr>
<tr>
<td>
<p>
203
</p>
</td>
<td>
<p>
REG_ECOLLATE
</p>
</td>
<td>
<p>
"Invalid collation character"
</p>
</td>
</tr>
<tr>
<td>
<p>
204
</p>
</td>
<td>
<p>
REG_ECTYPE
</p>
</td>
<td>
<p>
"Invalid character class name"
</p>
</td>
</tr>
<tr>
<td>
<p>
205
</p>
</td>
<td>
<p>
REG_EESCAPE
</p>
</td>
<td>
<p>
"Trailing backslash"
</p>
</td>
</tr>
<tr>
<td>
<p>
206
</p>
</td>
<td>
<p>
REG_ESUBREG
</p>
</td>
<td>
<p>
"Invalid back reference"
</p>
</td>
</tr>
<tr>
<td>
<p>
207
</p>
</td>
<td>
<p>
REG_EBRACK
</p>
</td>
<td>
<p>
"Unmatched [ or <code class="literal">" </code>
</p>
</td>
<td>
<p>
[208
</p>
</td>
<td>
<p>
REG_EPAREN
</p>
</td>
<td>
<p>
"Unmatched ( or \("
</p>
</td>
</tr>
<tr>
<td>
<p>
209
</p>
</td>
<td>
<p>
REG_EBRACE
</p>
</td>
<td>
<p>
"Unmatched \{"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
210
</p>
</td>
<td>
<p>
REG_BADBR
</p>
</td>
<td>
<p>
"Invalid content of \{\}"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
211
</p>
</td>
<td>
<p>
REG_ERANGE
</p>
</td>
<td>
<p>
"Invalid range end"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
212
</p>
</td>
<td>
<p>
REG_ESPACE
</p>
</td>
<td>
<p>
"Memory exhausted"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
213
</p>
</td>
<td>
<p>
REG_BADRPT
</p>
</td>
<td>
<p>
"Invalid preceding regular expression"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
214
</p>
</td>
<td>
<p>
REG_EEND
</p>
</td>
<td>
<p>
"Premature end of regular expression"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
215
</p>
</td>
<td>
<p>
REG_ESIZE
</p>
</td>
<td>
<p>
"Regular expression too big"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
216
</p>
</td>
<td>
<p>
REG_ERPAREN
</p>
</td>
<td>
<p>
"Unmatched ) or \)"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
217
</p>
</td>
<td>
<p>
REG_EMPTY
</p>
</td>
<td>
<p>
"Empty expression"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
<tr>
<td>
<p>
218
</p>
</td>
<td>
<p>
REG_E_UNKNOWN
</p>
</td>
<td>
<p>
"Unknown error"
</p>
</td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
<td class="auto-generated"> </td>
</tr>
</tbody>
</table></div>
<p>
Custom character class names are loaded as followed:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Message ID
</p>
</th>
<th>
<p>
Description
</p>
</th>
<th>
<p>
Equivalent default class name
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
300
</p>
</td>
<td>
<p>
The character class name for alphanumeric characters.
</p>
</td>
<td>
<p>
"alnum"
</p>
</td>
</tr>
<tr>
<td>
<p>
301
</p>
</td>
<td>
<p>
The character class name for alphabetic characters.
</p>
</td>
<td>
<p>
"alpha"
</p>
</td>
</tr>
<tr>
<td>
<p>
302
</p>
</td>
<td>
<p>
The character class name for control characters.
</p>
</td>
<td>
<p>
"cntrl"
</p>
</td>
</tr>
<tr>
<td>
<p>
303
</p>
</td>
<td>
<p>
The character class name for digit characters.
</p>
</td>
<td>
<p>
"digit"
</p>
</td>
</tr>
<tr>
<td>
<p>
304
</p>
</td>
<td>
<p>
The character class name for graphics characters.
</p>
</td>
<td>
<p>
"graph"
</p>
</td>
</tr>
<tr>
<td>
<p>
305
</p>
</td>
<td>
<p>
The character class name for lower case characters.
</p>
</td>
<td>
<p>
"lower"
</p>
</td>
</tr>
<tr>
<td>
<p>
306
</p>
</td>
<td>
<p>
The character class name for printable characters.
</p>
</td>
<td>
<p>
"print"
</p>
</td>
</tr>
<tr>
<td>
<p>
307
</p>
</td>
<td>
<p>
The character class name for punctuation characters.
</p>
</td>
<td>
<p>
"punct"
</p>
</td>
</tr>
<tr>
<td>
<p>
308
</p>
</td>
<td>
<p>
The character class name for space characters.
</p>
</td>
<td>
<p>
"space"
</p>
</td>
</tr>
<tr>
<td>
<p>
309
</p>
</td>
<td>
<p>
The character class name for upper case characters.
</p>
</td>
<td>
<p>
"upper"
</p>
</td>
</tr>
<tr>
<td>
<p>
310
</p>
</td>
<td>
<p>
The character class name for hexadecimal characters.
</p>
</td>
<td>
<p>
"xdigit"
</p>
</td>
</tr>
<tr>
<td>
<p>
311
</p>
</td>
<td>
<p>
The character class name for blank characters.
</p>
</td>
<td>
<p>
"blank"
</p>
</td>
</tr>
<tr>
<td>
<p>
312
</p>
</td>
<td>
<p>
The character class name for word characters.
</p>
</td>
<td>
<p>
"word"
</p>
</td>
</tr>
<tr>
<td>
<p>
313
</p>
</td>
<td>
<p>
The character class name for Unicode characters.
</p>
</td>
<td>
<p>
"unicode"
</p>
</td>
</tr>
</tbody>
</table></div>
<p>
Finally, custom collating element names are loaded starting from message
id 400, and terminating when the first load thereafter fails. Each message
looks something like: "tagname string" where tagname is the name
used inside [[.tagname.]] and string is the actual text of the collating
element. Note that the value of collating element [[.zero.]] is used for
the conversion of strings to numbers - if you replace this with another value
then that will be used for string parsing - for example use the Unicode character
0x0660 for [[.zero.]] if you want to use Unicode Arabic-Indic digits in your
regular expressions in place of Latin digits.
</p>
<p>
Note that the POSIX defined names for character classes and collating elements
are always available - even if custom names are defined, in contrast, custom
error messages, and custom syntax messages replace the default ones.
</p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 1998 -2007 John Maddock<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="headers.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../background_information.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="thread_safety.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
