1[/ 2 Copyright 2006-2007 John Maddock. 3 Distributed under the Boost Software License, Version 1.0. 4 (See accompanying file LICENSE_1_0.txt or copy at 5 http://www.boost.org/LICENSE_1_0.txt). 6] 7 8 9[section:standards Standards Conformance] 10 11[h4 C++] 12 13Boost.Regex is intended to conform to the [tr1]. 14 15[h4 ECMAScript / JavaScript] 16 17All of the ECMAScript regular expression syntax features are supported, except that: 18 19The escape sequence \\u matches any upper case character (the same as \[\[:upper:\]\]) 20rather than a Unicode escape sequence; use \\x{DDDD} for Unicode escape sequences. 21 22[h4 Perl] 23 24Almost all Perl features are supported, except for: 25 26(?{code}) Not implementable in a compiled strongly typed language. 27 28(??{code}) Not implementable in a compiled strongly typed language. 29 30(*VERB) The [@http://perldoc.perl.org/perlre.html#Special-Backtracking-Control-Verbs 31backtracking control verbs] are not recognised or implemented at this time. 32 33In addition the following features behave slightly differently from Perl: 34 35^ $ \Z These recognise any line termination sequence, and not just \\n: see the Unicode requirements below. 36 37[h4 POSIX] 38 39All the POSIX basic and extended regular expression features are supported, 40except that: 41 42No character collating names are recognized except those specified in the 43POSIX standard for the C locale, unless they are explicitly registered with the 44traits class. 45 46Character equivalence classes ( \[\[\=a\=\]\] etc) are probably buggy except on Win32. 47Implementing this feature requires knowledge of the format of the string sort 48keys produced by the system; if you need this, and the default implementation 49doesn't work on your platform, then you will need to supply a custom traits class. 50 51[h4 Unicode] 52 53The following comments refer to 54[@http://unicode.org/reports/tr18/ Unicode Technical Standard #18: Unicode 55Regular Expressions version 11]. 56 57[table 58[[Item][Feature][Support]] 59[[1.1][Hex Notation][Yes: use \x{DDDD} to refer to code point UDDDD.]] 60[[1.2][Character Properties][All the names listed under the General Category Property are supported. Script names and Other Names are not currently supported.]] 61[[1.3][Subtraction and Intersection][Indirectly support by forward-lookahead: 62 63`(?=[[:X:]])[[:Y:]]` 64 65Gives the intersection of character properties X and Y. 66 67`(?![[:X:]])[[:Y:]]` 68 69Gives everything in Y that is not in X (subtraction).]] 70[[1.4][Simple Word Boundaries][Conforming: non-spacing marks are included in the set of word characters.]] 71[[1.5][Caseless Matching][Supported, note that at this level, case transformations are 1:1, many to many case folding operations are not supported (for example "'''ß'''" to "SS").]] 72[[1.6][Line Boundaries][Supported, except that "." matches only one character of "\\r\\n". Other than that word boundaries match correctly; including not matching in the middle of a "\\r\\n" sequence.]] 73[[1.7][Code Points][Supported: provided you use the u32* algorithms, then UTF-8, UTF-16 and UTF-32 are all treated as sequences of 32-bit code points.]] 74[[2.1][Canonical Equivalence][Not supported: it is up to the user of the library to convert all text into the same canonical form as the regular expression.]] 75[[2.2][Default Grapheme Clusters][Not supported.]] 76[[2.3Default Word Boundaries][Not supported.]] 77[[2.4][Default Loose Matches][Not Supported.]] 78[[2.5][Named Properties][Supported: the expression "\[\[:name:\]\]" or \\N{name} matches the named character "name".]] 79[[2.6][Wildcard properties][Not Supported.]] 80[[3.1][Tailored Punctuation.][Not Supported.]] 81[[3.2][Tailored Grapheme Clusters][Not Supported.]] 82[[3.3][Tailored Word Boundaries.][Not Supported.]] 83[[3.4][Tailored Loose Matches][Partial support: \[\[\=c\=\]\] matches characters with the same primary equivalence class as "c".]] 84[[3.5][Tailored Ranges][Supported: \[a-b\] matches any character that collates in the range a to b, when the expression is constructed with the collate flag set.]] 85[[3.6][Context Matches][Not Supported.]] 86[[3.7][Incremental Matches][Supported: pass the flag `match_partial` to the regex algorithms.]] 87[[3.8][Unicode Set Sharing][Not Supported.]] 88[[3.9][Possible Match Sets][Not supported, however this information is used internally to optimise the matching of regular expressions, and return quickly if no match is possible.]] 89[[3.10][Folded Matching][Partial Support: It is possible to achieve a similar effect by using a custom regular expression traits class.]] 90[[3.11][Custom Submatch Evaluation][Not Supported.]] 91] 92 93[endsect] 94 95