docs/latex/wx/regex.tex

   1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2 %% Name:        regex.tex
   3 %% Purpose:     wxRegEx documentation
   4 %% Author:      Vadim Zeitlin
   5 %% Modified by:
   6 %% Created:     14.07.01
   7 %% RCS-ID:      $Id$
   8 %% Copyright:   (c) 2001 Vadim Zeitlin
   9 %% License:     wxWindows license
  10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  11
  12 \section{\class{wxRegEx}}\label{wxregex}
  13
  14 wxRegEx represents a regular expression. The regular expressions syntax
  15 supported is the POSIX one. Both basic and extended regular expressions are
  16 supported but, unlike POSIX C API, the extended ones are used by default.
  17
  18 This class provides support for regular expressions matching and also
  19 replacement. It is built on top of either the system library (if it has support
  20 for POSIX regular expressions - which is the case of the most modern Unices) or
  21 uses the built in Henry Spencer's library. In the latter case you need to abide
  22 by the terms of its copyright:
  23
  24 \begin{verbatim}
  25 Copyright 1992, 1993, 1994, 1997 Henry Spencer.  All rights reserved.
  26 This software is not subject to any license of the American Telephone
  27 and Telegraph Company or of the Regents of the University of California.
  28
  29 Permission is granted to anyone to use this software for any purpose on
  30 any computer system, and to alter it and redistribute it, subject
  31 to the following restrictions:
  32
  33 1. The author is not responsible for the consequences of use of this
  34    software, no matter how awful, even if they arise from flaws in it.
  35
  36 2. The origin of this software must not be misrepresented, either by
  37    explicit claim or by omission.  Since few users ever read sources,
  38    credits must appear in the documentation.
  39
  40 3. Altered versions must be plainly marked as such, and must not be
  41    misrepresented as being the original software.  Since few users
  42    ever read sources, credits must appear in the documentation.
  43
  44 4. This notice may not be removed or altered.
  45 \end{verbatim}
  46
  47 \wxheading{Derived from}
  48
  49 No base class
  50
  51 \wxheading{Data structures}
  52
  53 Flags for regex compilation to be used with \helpref{Compile()}{wxregexcompile}:
  54
  55 \begin{verbatim}
  56 enum
  57 {
  58     // use extended regex syntax (default)
  59     wxRE_EXTENDED = 0,
  60
  61     // use basic RE syntax
  62     wxRE_BASIC    = 2,
  63
  64     // ignore case in match
  65     wxRE_ICASE    = 4,
  66
  67     // only check match, don't set back references
  68     wxRE_NOSUB    = 8,
  69
  70     // if not set, treat '\n' as an ordinary character, otherwise it is
  71     // special: it is not matched by '.' and '^' and '$' always match
  72     // after/before it regardless of the setting of wxRE_NOT[BE]OL
  73     wxRE_NEWLINE  = 16,
  74
  75     // default flags
  76     wxRE_DEFAULT  = wxRE_EXTENDED
  77 }
  78 \end{verbatim}
  79
  80 Flags for regex matching to be used with \helpref{Matches()}{wxregexmatches}.
  81
  82 These flags are mainly useful when doing several matches in a long string
  83 to prevent erroneous matches for \verb|'^'| and {\tt '\$'}:
  84
  85 \begin{verbatim}
  86 enum
  87 {
  88     // '^' doesn't match at the start of line
  89     wxRE_NOTBOL = 32,
  90
  91     // '$' doesn't match at the end of line
  92     wxRE_NOTEOL = 64
  93 }
  94 \end{verbatim}
  95
  96 \wxheading{Examples}
  97
  98 A bad example of processing some text containing email addresses (the example
  99 is bad because the real email addresses can have more complicated form than
 100 {\tt user@host.net}):
 101
 102 \begin{verbatim}
 103 wxString text;
 104 ...
 105 wxRegEx reEmail = "([^@]+)@([[:alnum:].-_].)+([[:alnum:]]+)";
 106 if ( reEmail.Matches(text) )
 107 {
 108     wxString text = reEmail.GetMatch(email);
 109     wxString username = reEmail.GetMatch(email, 1);
 110     if ( reEmail.GetMatch(email, 3) == "com" ) // .com TLD?
 111     {
 112         ...
 113     }
 114 }
 115
 116 // or we could do this to hide the email address
 117 size_t count = reEmail.ReplaceAll(text, "HIDDEN@\\2\\3");
 118 printf("text now contains %u hidden addresses", count);
 119 \end{verbatim}
 120
 121 \latexignore{\rtfignore{\wxheading{Members}}}
 122
 123 \membersection{wxRegEx::wxRegEx}\label{wxregexwxregex}
 124
 125 \func{}{wxRegEx}{\void}
 126
 127 Default ctor: use \helpref{Compile()}{wxregexcompile} later.
 128
 129 \func{}{wxRegEx}{\param{const wxString\& }{expr}, \param{int }{flags = wxRE\_DEFAULT}}
 130
 131 Create and compile the regular expression, use
 132 \helpref{IsValid}{wxregexisvalid} to test for compilation errors.
 133
 134 \membersection{wxRegEx::\destruct{wxRegEx}}\label{wxregexdtor}
 135
 136 \func{}{\destruct{wxRegEx}}{\void}
 137
 138 dtor not virtual, don't derive from this class
 139
 140 \membersection{wxRegEx::Compile}\label{wxregexcompile}
 141
 142 \func{bool}{Compile}{\param{const wxString\& }{pattern}, \param{int }{flags = wxRE\_DEFAULT}}
 143
 144 Compile the string into regular expression, return {\tt TRUE} if ok or {\tt FALSE}
 145 if string has a syntax error.
 146
 147 \membersection{wxRegEx::IsValid}\label{wxregexisvalid}
 148
 149 \constfunc{bool}{IsValid}{\void}
 150
 151 Return {\tt TRUE} if this is a valid compiled regular expression, {\tt FALSE}
 152 otherwise.
 153
 154 \membersection{wxRegEx::GetMatch}\label{wxregexgetmatch}
 155
 156 \constfunc{bool}{GetMatch}{\param{size\_t* }{start}, \param{size\_t* }{len}, \param{size\_t }{index = 0}}
 157
 158 Get the start index and the length of the match of the expression
 159 (if {\it index} is $0$) or a bracketed subexpression ({\it index} different
 160 from $0$).
 161
 162 May only be called after successful call to \helpref{Matches()}{wxregexmatches}
 163 and only if {\tt wxRE\_NOSUB} was {\bf not} used in
 164 \helpref{Compile()}{wxregexcompile}.
 165
 166 Returns {\tt FALSE} if no match or if an error occured.
 167
 168 \constfunc{wxString}{GetMatch}{\param{const wxString\& }{text}, \param{size\_t }{index = 0}}
 169
 170 Returns the part of string corresponding to the match where {\it index} is
 171 interpreted as above. Empty string is returned if match failed
 172
 173 May only be called after successful call to \helpref{Matches()}{wxregexmatches}
 174 and only if {\tt wxRE\_NOSUB} was {\bf not} used in
 175 \helpref{Compile()}{wxregexcompile}.
 176
 177 \membersection{wxRegEx::Matches}\label{wxregexmatches}
 178
 179 \constfunc{bool}{Matches}{\param{const wxChar* }{text}, \param{int }{flags = 0}}
 180
 181 Matches the precompiled regular expression against the string {\it text},
 182 returns {\tt TRUE} if matches and {\tt FALSE} otherwise.
 183
 184 Flags may be combination of {\tt wxRE\_NOTBOL} and {\tt wxRE\_NOTEOL}.
 185
 186 May only be called after successful call to \helpref{Compile()}{wxregexcompile}.
 187
 188 \membersection{wxRegEx::Replace}\label{wxregexreplace}
 189
 190 \constfunc{int}{Replace}{\param{wxString* }{text}, \param{const wxString\& }{replacement}, \param{size\_t }{maxMatches = 0}}
 191
 192 Replaces the current regular expression in the string pointed to by
 193 {\it text}, with the text in {\it replacement} and return number of matches
 194 replaced (maybe $0$ if none found) or $-1$ on error.
 195
 196 The replacement text may contain back references {\tt $\backslash$number} which will be
 197 replaced with the value of the corresponding subexpression in the
 198 pattern match. {\tt $\backslash$0} corresponds to the entire match and {\tt \&} is a
 199 synonym for it. Backslash may be used to quote itself or {\tt \&} character.
 200
 201 {\it maxMatches} may be used to limit the number of replacements made, setting
 202 it to $1$, for example, will only replace first occurence (if any) of the
 203 pattern in the text while default value of $0$ means replace all.
 204
 205 \membersection{wxRegEx::ReplaceAll}\label{wxregexreplaceall}
 206
 207 \constfunc{int}{ReplaceAll}{\param{wxString* }{text}, \param{const wxString\& }{replacement}}
 208
 209 Replace all occurences: this is actually a synonym for
 210 \helpref{Replace()}{wxregexreplace}.
 211
 212 \wxheading{See also}
 213
 214 \helpref{ReplaceFirst}{wxregexreplacefirst}
 215
 216 \membersection{wxRegEx::ReplaceFirst}\label{wxregexreplacefirst}
 217
 218 \constfunc{int}{ReplaceFirst}{\param{wxString* }{text}, \param{const wxString\& }{replacement}}
 219
 220 Replace the first occurence.
 221
 222 \wxheading{See also}
 223
 224 \helpref{Replace}{wxregexreplace}
 225