From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/elisp/posix-regexps.html | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 devdocs/elisp/posix-regexps.html (limited to 'devdocs/elisp/posix-regexps.html') diff --git a/devdocs/elisp/posix-regexps.html b/devdocs/elisp/posix-regexps.html new file mode 100644 index 00000000..989beca6 --- /dev/null +++ b/devdocs/elisp/posix-regexps.html @@ -0,0 +1,14 @@ +

POSIX Regular Expression Searching

The usual regular expression functions do backtracking when necessary to handle the ‘\|’ and repetition constructs, but they continue this only until they find some match. Then they succeed and report the first match found.

This section describes alternative search functions which perform the full backtracking specified by the POSIX standard for regular expression matching. They continue backtracking until they have tried all possibilities and found all matches, so they can report the longest match, as required by POSIX. This is much slower, so use these functions only when you really need the longest match.

The POSIX search and match functions do not properly support the non-greedy repetition operators (see non-greedy). This is because POSIX backtracking conflicts with the semantics of non-greedy repetition.

Command: posix-search-forward regexp &optional limit noerror count +

This is like re-search-forward except that it performs the full backtracking specified by the POSIX standard for regular expression matching.

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Command: posix-search-backward regexp &optional limit noerror count +

This is like re-search-backward except that it performs the full backtracking specified by the POSIX standard for regular expression matching.

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Function: posix-looking-at regexp +

This is like looking-at except that it performs the full backtracking specified by the POSIX standard for regular expression matching.

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Function: posix-string-match regexp string &optional start +

This is like string-match except that it performs the full backtracking specified by the POSIX standard for regular expression matching.

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+ Copyright © 1990-1996, 1998-2022 Free Software Foundation, Inc.
Licensed under the GNU GPL license.
+ https://www.gnu.org/software/emacs/manual/html_node/elisp/POSIX-Regexps.html +

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