| [/ |
| Copyright 2006-2007 John Maddock. |
| Distributed under the Boost Software License, Version 1.0. |
| (See accompanying file LICENSE_1_0.txt or copy at |
| http://www.boost.org/LICENSE_1_0.txt). |
| ] |
| |
| |
| [section:standards Standards Conformance] |
| |
| [h4 C++] |
| |
| Boost.Regex is intended to conform to the [tr1]. |
| |
| [h4 ECMAScript / JavaScript] |
| |
| All of the ECMAScript regular expression syntax features are supported, except that: |
| |
| The escape sequence \\u matches any upper case character (the same as \[\[:upper:\]\]) |
| rather than a Unicode escape sequence; use \\x{DDDD} for Unicode escape sequences. |
| |
| [h4 Perl] |
| |
| Almost all Perl features are supported, except for: |
| |
| (?{code}) Not implementable in a compiled strongly typed language. |
| |
| (??{code}) Not implementable in a compiled strongly typed language. |
| |
| (*VERB) The [@http://perldoc.perl.org/perlre.html#Special-Backtracking-Control-Verbs |
| backtracking control verbs] are not recognised or implemented at this time. |
| |
| In addition the following features behave slightly differently from Perl: |
| |
| ^ $ \Z These recognise any line termination sequence, and not just \\n: see the Unicode requirements below. |
| |
| [h4 POSIX] |
| |
| All the POSIX basic and extended regular expression features are supported, |
| except that: |
| |
| No character collating names are recognized except those specified in the |
| POSIX standard for the C locale, unless they are explicitly registered with the |
| traits class. |
| |
| Character equivalence classes ( \[\[\=a\=\]\] etc) are probably buggy except on Win32. |
| Implementing this feature requires knowledge of the format of the string sort |
| keys produced by the system; if you need this, and the default implementation |
| doesn't work on your platform, then you will need to supply a custom traits class. |
| |
| [h4 Unicode] |
| |
| The following comments refer to |
| [@http://unicode.org/reports/tr18/ Unicode Technical Standard #18: Unicode |
| Regular Expressions version 11]. |
| |
| [table |
| [[Item][Feature][Support]] |
| [[1.1][Hex Notation][Yes: use \x{DDDD} to refer to code point UDDDD.]] |
| [[1.2][Character Properties][All the names listed under the General Category Property are supported. Script names and Other Names are not currently supported.]] |
| [[1.3][Subtraction and Intersection][Indirectly support by forward-lookahead: |
| |
| `(?=[[:X:]])[[:Y:]]` |
| |
| Gives the intersection of character properties X and Y. |
| |
| `(?![[:X:]])[[:Y:]]` |
| |
| Gives everything in Y that is not in X (subtraction).]] |
| [[1.4][Simple Word Boundaries][Conforming: non-spacing marks are included in the set of word characters.]] |
| [[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").]] |
| [[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.]] |
| [[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.]] |
| [[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.]] |
| [[2.2][Default Grapheme Clusters][Not supported.]] |
| [[2.3Default Word Boundaries][Not supported.]] |
| [[2.4][Default Loose Matches][Not Supported.]] |
| [[2.5][Named Properties][Supported: the expression "\[\[:name:\]\]" or \\N{name} matches the named character "name".]] |
| [[2.6][Wildcard properties][Not Supported.]] |
| [[3.1][Tailored Punctuation.][Not Supported.]] |
| [[3.2][Tailored Grapheme Clusters][Not Supported.]] |
| [[3.3][Tailored Word Boundaries.][Not Supported.]] |
| [[3.4][Tailored Loose Matches][Partial support: \[\[\=c\=\]\] matches characters with the same primary equivalence class as "c".]] |
| [[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.]] |
| [[3.6][Context Matches][Not Supported.]] |
| [[3.7][Incremental Matches][Supported: pass the flag `match_partial` to the regex algorithms.]] |
| [[3.8][Unicode Set Sharing][Not Supported.]] |
| [[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.]] |
| [[3.10][Folded Matching][Partial Support: It is possible to achieve a similar effect by using a custom regular expression traits class.]] |
| [[3.11][Custom Submatch Evaluation][Not Supported.]] |
| ] |
| |
| [endsect] |
| |