Talk:Comparison of regular expression engines: Difference between revisions

Revision as of 03:32, 14 July 2011

Revision as of 21:44, 22 January 2012

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{{WikiProject Computing|class=|importance=|software=yes|software-importance=}}

= Status/Edit Notes =

== Jan-2010 Update ==

Made some updates -- not enough room to document them on the 1 line summary. Some of these address comments made previously (below).

Updates include:

* removing notes that something has only been available since '2007' (version was mentioned, but released 5 years ago)....

* remove notes on Unicode support where the note was (supports ALL, including binary )... if it supports it, it supports it, a special note should not be required for 'all', rather, only 'partial' support cases should be noted.

* modified ref-note for 'partial support' to indicate that such status was transient and that 'complete compliance' was dependent on updates after new versions are released.

* removed comparison columns for 'partial' matches and 'fuzzy matches' -- neither a feature of "*Regular* Expressions. The latter, which was defined, is specifically NOT a feature of regular expressions but rather an extra feature of some *products* that include a regex engine. Comparing products that include regex's isn't the same thing as comparing regex'. Though it wasn't defined, (how can you compare something that is 'undefined'), I believe it referred to a *product feature* in, for example something like 'vim', where it matches in your source text, whatever you have typed into a *search string*, in real time. This isn't a feature of a regex engine, but a product feature of some *EDITORS* -- I.e. it's not about the 'RegEx Engine'. I would wager that all of the products can match valid substring comprising a larger RegEx. Equally, I would wager any program using those regex's could be programmed to ignore errors while things were being 'typed in'. Thus -- irrelevant to this article.

* Notes: 1) 'Fuzzy' matching, involves fuzzy logic, which by definition is not a state-driven logic, and thus by definition cannot be part of a *Regular* expression engine. It may, however be a product feature to allow various levels of 'mistakes' on matching the given RegEx, but the magnitude of mistake is not a binary property (thus fuzzy) -- thus not Regular. Fuzzy logic is generally in the ___domain of "AI" - not regex's.

* Note 2: (not mentioned in the article) -- PCRE gets it's code from Perl -- so it's features generally track Perl's. PCRE is an acronym for Perl Compatible Regular Expression. and the engine in ruby derives from PCRE -- and tries to track it's features. The Ruby engine was done, specifically to add Japanese support BEFORE UTF-8 started becoming prevalent. Thus it supported 16-bits early on, but for locale-based charsets for Japanese. It wasn't really until it added UTF-8 support that it got full Unicode support.

<small> (This is written after updating ""Part 2"" . I'm looking at ""Part 3"" to see what is salvageable there... started to writeup comments, but better I do it and then say what was done, as if I get hung up on saying what I'll do, I may not get it done...(am getting a bit tired of this update stuff already)... </small> [[User:Athenae|Astara Athenea]] ([[User talk:Athenae|talk]]) 21:44, 22 January 2012 (UTC)

== Ill-defined terms ==