Ubuntu Manpage: re-builder.texi

input texinfo @c -*-texinfo-*-

@c Manual for the XEmacs re-builder package.

@c ** #### something uses these headers, find out how and explain here @c %**start of header @setfilename re-builder.info @settitle Visual development of regular expressions @setchapternewpage odd @c %**end of header

@c Version values, for easy modification @set VERSION 1.2 @set UPDATED Sunday, July 24, 2005

@c ** Many people seem to prefer this footenote style @footnotestyle end

@direntry * re-builder:: Write regular expressions with visual feedback. @end direntry

@c ** It is often convenient to use a macro for names which have unusual @c ** spelling or formatting conventions. @c Macro to make formatting of the package name consistent. @macro pkgname @i{re-builder} @end macro

@c Copying permissions, et al @c Note that this whole section is repeated thrice, once for the Info @c version, once for TeX, and once for HTML. @c Note that if you combine this document with others' work, you may @c need to change the permissions statement. Make sure you do so in all @c three places. @c #### Probably not the right place for HTML. @html This file documents the @pkgname{} XEmacs package, which provides visual feedback when developing regular expressions.

This documentation was taken from the source file, @file{re-builder.el}, which is subject to the following conditions; because of the nature of the GNU GPL, this file is as a result also subject to those conditions.

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with GNU Emacs; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

End of permissions notice. @end html

@ifinfo This file documents the @pkgname{} XEmacs package, which provides visual feedback when developing regular expressions.

This file is part of GNU Emacs.

End of permissions notice. @end ifinfo

@tex

@titlepage @title R @subtitle Last updated @value{UPDATED}

@author Detlev Zundel. Texinfo conversion by Aidan Kehoe. @page This file documents the @pkgname{} XEmacs package, which provides visual feedback when developing regular expressions.

@vskip 0pt plus 1filll Copyright @copyright{} 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.

This file is part of GNU Emacs.

@end titlepage @page

@end tex

@ifnottex @node Top, Copying, (dir), (dir) @top Re-builder on XEmacs

When I have to come up with regular expressions that are more complex than simple string matchers, especially if they contain sub expressions, I find myself spending quite some time in the `development cycle'. `re-builder' aims to shorten this time span so I can get on with the more interesting bits.

With it you can have immediate visual feedback about how well the regexp behaves to your expectations on the intended data.

This is version @value{VERSION} of the @pkgname{} manual, last updated on @value{UPDATED}.

@end ifnottex

@menu * Copying:: @pkgname{} copying conditions. * Overview:: @pkgname{} history and general information.

For general users: * Usage:: An overview of the operation of @pkgname{}. * Regex Types:: Types of regular expression handled. * Questions:: A couple of selected queries. @end menu

@node Copying, Overview, Top, Top @chapter @pkgname{} Copying Conditions

@c ** CHECK THE COPYRIGHT DATE(S) AND HOLDER(S)!

@pkgname{} is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

@pkgname{} is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with XEmacs; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

@node Overview, Usage, Copying, Top @chapter An Overview of @pkgname{}

When I have to come up with regular expressions that are more complex than simple string matchers, especially if they contain sub expressions, I find myself spending quite some time in the `development cycle'. @pkgname{} aims to shorten this time span so I can get on with the more interesting bits.

With it you can have immediate visual feedback about how well the regexp behaves to your expectations on the intended data.

@node Usage, Regex Types, Overview, Top @chapter Operation of @pkgname{}

When called up, with @kbd{M-x re-builder RET}, @pkgname{} attaches itself to the current buffer which becomes its target buffer, where all the matching is done. The active window is split so you have a view on the data while authoring the RE. If the edited expression is valid the matches in the target buffer are marked automatically with colored overlays (for non-color displays see below) giving you feedback over the extents of the matched (sub) expressions. The (non-)validity is shown only in the modeline without throwing the errors at you. If you want to know the reason why RE Builder considers it as invalid call @kbd{reb-force-update} (@kbd{C-c C-u}) which should reveal the error.

The target buffer can be changed with @code{reb-change-target-buffer} (@kbd{C-c C-b}). Changing the target buffer automatically removes the overlays from the old buffer and displays the new one in the target window.

@pkgname{} keeps the focus while updating the matches in the target buffer so corrections are easily incorporated. If you are satisfied with the result you can paste the RE to the kill-ring with @code{reb-copy} (@kbd{C-c C-w}) (the copied RE and current syntax is displayed in the echo area), quit @pkgname{} (@kbd{C-c C-q}) and use it wherever you need it.

As the automatic updates can take some time on large buffers, they can be limited by @code{reb-auto-match-limit} so that they should not have a negative impact on the editing. Setting it to nil makes even the auto updates go all the way. Forcing an update overrides this limit allowing an easy way to see all matches.

@node Regex Types, Questions, Usage, Top @chapter Regex Types

Currently @pkgname{} understands six different forms of input, namely @code{lisp-re}, @code{perl}, @code{read}, @code{rx}, @code{sregex}, and @code{string} syntax. Read syntax and string syntax are both delimited by @code{"}s and behave according to their name. With the @code{perl} and @code{string} syntax there's no need to escape the backslashes and double quotes simplifying the editing somewhat. The other four allow editing of symbolic regular expressions supported by the packages of the same name. (@code{lisp-re} is a package by me and its support may go away as it is nearly the same as the @code{sregex} package in Emacs)

Note that the @code{sregex,} @code{rx} and @code{lisp-re} syntaxes will only be available in XEmacs if you've installed them yourself.

Editing symbolic expressions is done through a major mode derived from @code{emacs-lisp-mode} so you'll get all the good stuff like automatic indentation and font-locking etc.

When editing a symbolic regular expression, only the first expression in the RE Builder buffer is considered, which helps limiting the extent of the expression like the @code{"}s do for the text modes. For the @code{sregex} syntax the function @code{sregex} is applied to the evaluated expression read. So you can use quoted arguments with something like '("findme") or you can construct arguments to your heart's content with a valid ELisp expression. The compiled string form will be copied by @code{reb-copy}. If you want to take a glance at the corresponding string you can temporarily change the input syntax using @code{reb-change-syntax} (@kbd{C-c C-i}). The current RE syntax is also displayed in the modeline.

Changing the input syntax is transparent (for the obvious exception non-symbolic -> symbolic) so you can change your mind as often as you like.

There is also a shortcut function, @code{reb-toggle-case} (@kbd{C-c C-c}), for toggling the @code{case-fold-search} variable in the target buffer with an immediate update.

@node Questions, , Regex Types, Top @chapter Questions

Q: But what if my display cannot show colored overlays?

A: Then the cursor will flash around the matched text making it stand out.

Q: But how can I then make out the sub-expressions?

A: That's where the `sub-expression mode' comes in. In it only the digit keys are assigned to perform an update that will flash the corresponding subexp only.

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re-builder.texi