Bug 113975 - Expand the documentation for regular expressions
Summary: Expand the documentation for regular expressions
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Documentation (show other bugs)
(earliest affected)
Hardware: All All
: medium normal
Assignee: Not Assigned
Depends on:
Blocks: Help-Changes-Features
  Show dependency treegraph
Reported: 2017-11-21 16:42 UTC by Dan Dascalescu
Modified: 2018-09-29 19:51 UTC (History)
2 users (show)

See Also:
Crash report or crash signature:


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Description Dan Dascalescu 2017-11-21 16:42:52 UTC
https://help.libreoffice.org/Common/List_of_Regular_Expressions doesn't say anything about regexp lookaround patterns (see https://www.regular-expressions.info/lookaround.html).

Steps to Reproduce:
I'd love to add this information but https://help.libreoffice.org/Main_Page says there's no way to participate.

Actual Results:  
Lookaround patterns do in fact work

Expected Results:
=SEARCH("(?<=a)b", "cab")  // 3

Reproducible: Always

User Profile Reset: No

Additional Info:

User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.89 Safari/537.36
Comment 1 Olivier Hallot 2017-11-21 17:22:27 UTC
help.libreoffice.org is not editable because it is a transformation of the local help system written in XML.

However, if you are willing to write about the issue, please just write in a LibreOffice Writer document, and attach to this bug. I'll review and convert it in XML for the help system, with your authorship.

Please be factual and concise, your contents will be translated into >60 languages.
Comment 2 V Stuart Foote 2017-11-23 06:59:47 UTC
Actually, LibreOffice's RegEx support is via ICU libraries, our documentation comes from there including coverage of ICU RegEx Operators to lookahead and lookbehind and their negatives--the Lookarounds

The Help now links to the Wiki https://wiki.documentfoundation.org/Documentation/HowTo/Writer/Regular_Expressions  or to https://wiki.documentfoundation.org/Documentation/HowTo/Calc/Regular_Expressions both of which correctly defer to the ICU content [1].

It is a little thin, but authoritative, and should be basis for addition to our Help and Documentation--with some practical examples included, preferably on our Wiki. The OOo era content at AOO should probably go away.

[1] http://userguide.icu-project.org/strings/regexp#TOC-Regular-Expression-Operators