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Instead of doing a basic indexed search on keywords, you can perform a regex search, which bypasses the index.A regex search scans the text of each page on Wikipedia in real time, character by character, to find pages that match a specific sequence or pattern of characters.
More generally, an equation E=F between regular-expression terms with variables holds if, and only if, its instantiation with different variables replaced by different symbol constants holds. [30] [31] Every regular expression can be written solely in terms of the Kleene star and set unions over finite words. This is a surprisingly difficult ...
Regex searches are likely to time out unless you further limit the search in some way, such as by including another parameter or a search term outside of the insource component of the search string. (For example, X* intitle:/X/ to restrict the search to initial position.) For more details, see mw:Help:CirrusSearch#Regular expression searches.
List of regular expression libraries Name Official website Programming language Software license Used by Boost.Regex [Note 1] Boost C++ Libraries: C++: Boost: Notepad++ >= 6.0.0, EmEditor: Boost.Xpressive Boost C++ Libraries: C++ Boost DEELX RegExLab: C++ Proprietary FREJ [Note 2] Fuzzy Regular Expressions for Java: Java: LGPL GLib/GRegex [Note 3]
Perl Compatible Regular Expressions (PCRE) is a library written in C, which implements a regular expression engine, inspired by the capabilities of the Perl programming language. Philip Hazel started writing PCRE in summer 1997. [ 3 ]
The expression regex denotes a regular expression in MediaWiki-flavored regular expression syntax. Use regexes responsibly Because regex searching scans each page character by character, it is generally much slower than an index search.
Add word boundaries (\b) to both ends of the regex unless you are matching errors in parts of words or multiple words. Do not expect rules to be applied in the order they appear. Write fast rules:
All terms in a query are indexed searches unless they are a regexp. Indexed terms run word-wise instantly, and a regexp runs character-wise slowly. Even the most basic use of a regexp, just to find an exact string, should always limit the size of its search domain to as little as possible.