Search results
Results From The WOW.Com Content Network
However, it can make a regular expression much more concise—eliminating a single complement operator can cause a double exponential blow-up of its length. [26] [27] [28] Regular expressions in this sense can express the regular languages, exactly the class of languages accepted by deterministic finite automata. There is, however, a ...
This is the "regular expression" (or regexp, or regex). Its metacharacters can represent multiple possibilities for a character position or a range of character positions within a page, using metacharacters for truth logic, grouping, counting, and modifying the characters to be found.
MediaWiki's regular expression syntax works like this: Most characters represent themselves. For example, insource:/C-3p0/ will search for pages containing the literal string "C-3p0" (case-sensitive). The following metacharacters are treated specially: . + * ? | { [ ] ( ) " \ # @ < ~. Any metacharacter can be escaped by preceding it with a ...
Regular Expression Flavor Comparison – Detailed comparison of the most popular regular expression flavors; Regexp Syntax Summary; Online Regular Expression Testing – with support for Java, JavaScript, .Net, PHP, Python and Ruby; Implementing Regular Expressions – series of articles by Russ Cox, author of RE2; Regular Expression Engines
In theoretical computer science and formal language theory, a regular language (also called a rational language) [1] [2] is a formal language that can be defined by a regular expression, in the strict sense in theoretical computer science (as opposed to many modern regular expression engines, which are augmented with features that allow the recognition of non-regular languages).
To decide whether two given regular expressions describe the same language, each can be converted into an equivalent minimal deterministic finite automaton via Thompson's construction, powerset construction, and DFA minimization. If, and only if, the resulting automata agree up to renaming of states, the regular expressions' languages agree.
Besides the built-in RE/flex POSIX regex pattern matcher, RE/flex also supports PCRE2, Boost.Regex and std::regex pattern matching libraries. PCRE2 and Boost.Regex offer a richer regular expression pattern syntax with Perl pattern matching semantics, but are slower due to their intrinsic NFA-based matching algorithm.
Pages in category "Regular expressions" The following 12 pages are in this category, out of 12 total. This list may not reflect recent changes. ...