==================
Unicode Compliance
==================

*jsre* provides level 1 support for Unicode compliant with `Unicode
Technical Standard #18, UNICODE REGULAR EXPRESSIONS
<http://unicode.org/reports/tr18/tr18-14.html>`_, version 1.7.

The module supports all:

*   Binary Properties (e.g. *\\p{Alphabetic}*).
*   General Category Properties.  (e.g. *\\pP*).
*   Scripts and Script Extensions.
*   Line_Break properties (e.g. *\\p{line_break=hyphen}*).
*   Numeric_Type properties (e.g. *\\p{numeric_type=decimal*).

Property specification within the regular expression pattern is flexible;
case does not matter, '-' and '_' are interchangable, and general categories
and scripts may be referenced by property name. (e.g. *\\p{greek}* as
well as *\\p{script=greek}*)

Some special properties are supported. Appendix C of UTS #18 recommends
a set of properties for use in regular expressions, which provide extensions and combinations
of standard character classes. These are:

    *lower, upper, punct, digit, xdigit, alnum, space, blank, cntrl, graph, print, word*

*word* is defined as in UTS #18 and includes digits, *\\w* uses the same definition. The
zero width tests *\\b* *\\B* also use this definition to determine word boundaries. (Note that
the more extensive algorithm given for word breaks in Unicode Standard Annex #29 is not
used.)

The *\\X* test for Extended Grapheme Cluster boundaries implements the extended version
of the specification given in Unicode Standard Annex #29.

Some additional properties defined in UTS #18 1.2.1 and 1.6 are also supported:

    *any, assigned, ascii*

Note that *any* is every code point, unlike '.' which omits newline characters unless the DOTALL flag is set.

The property:

    *newline*

is provided to specify the set of new line characters in UTS #18 1.6, ie the familiar \\u000A, \\u000B etc
as well as the Unicode characters such as \\u2028.

The actual support for Unicode properties depends on the encoding used for searching; for non-Unicode encodings (e.g. *CP1250*)
properties are interpreted as the set of code points that can be represented under that encoding.