Search results
Results from the WOW.Com Content Network
Raku rules are the regular expression, string matching and general-purpose parsing facility of the Raku programming language, and are a core part of the language. Since Perl's pattern-matching constructs have exceeded the capabilities of formal regular expressions for some time, Raku documentation refers to them exclusively as regexes, distancing the term from the formal definition.
A regular expression (shortened as regex or regexp), [1] sometimes referred to as rational expression, [2] [3] is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation.
As of Perl 5.10, PCRE is also available as a replacement for Perl's default regular-expression engine through the re::engine::PCRE module. The library can be built on Unix, Windows, and several other environments.
The regular-expression engine uses a backtracking algorithm, extending its capabilities from simple pattern matching to string capture and substitution. The regular-expression engine is derived from regex written by Henry Spencer. The Perl regular-expression syntax was originally taken from Unix Version 8 regular expressions.
Sed regular expressions, particularly those using the "s" operator, are much similar to Perl (sed is a predecessor to Perl). The default delimiter is "/", but any delimiter can be used; the default is s / regexp / replacement /, but s: regexp: replacement: is also a valid form. For example, to match a "pub" directory (as in the Perl example ...
Greed, in regular expression context, describes the number of characters which will be matched (often also stated as "consumed") by a variable length portion of a regular expression – a token or group followed by a quantifier, which specifies a number (or range of numbers) of tokens. If the portion of the regular expression is "greedy", it ...
Perl interpreters have been developed for most operating systems (platforms), taking into account the idiosyncrasies of each, so all such platforms can theoretically run the same code. Text manipulation – anything from spell checking, to search and replace operations using regex, to natural language processing.
The Raku design process was first announced on 19 July 2000, on the fourth day of that year's Perl Conference, [10] by Larry Wall in his State of the Onion 2000 talk. [11] At that time, the primary goals were to remove "historical warts" from the language; "easy things should stay easy, hard things should get easier, and impossible things should get hard"; and a general cleanup of the internal ...