NAME¶

Unicode::EastAsianWidth - East Asian Width properties

SYNOPSIS¶

    use Unicode::EastAsianWidth;
    $_ = chr(0x2010); # HYPHEN, an ambiguous-width character
    /\p{InEastAsianAmbiguous}/; # True
    /\p{InFullwidth}/;          # False

To mark ambiguous-width characters as InFullwidth:

    BEGIN { $Unicode::EastAsianWidth::EastAsian = 1; }
    use Unicode::EastAsianWidth;
    $_ = chr(0x2010); # HYPHEN, an ambiguous-width character
    /\p{InFullwidth}/;          # True

DESCRIPTION¶

This module provide user-defined Unicode properties that deal with width status of East Asian characters, as specified in <http://www.unicode.org/unicode/reports/tr11/>.

It exports the following functions to the caller's scope, to be used by Perl's Unicode matching system: "InEastAsianFullwidth", "InEastAsianHalfwidth", "InEastAsianAmbiguous", "InEastAsianNarrow" "InEastAsianWide", "InEastAsianNeutral".

In accord to TR11 cited above, two additional context-sensitive properties are exported: "InFullwidth" (union of "Fullwidth" and "Wide") and "InHalfwidth" (union of "Halfwidth", "Narrow" and "Neutral").

Ambiguous characters are treated by default as part of "InHalfwidth", but you can modify this behaviour by assigning a true value to $Unicode::EastAsianWidth::EastAsian at compile time within a "BEGIN" block before loading this module:

    BEGIN { $Unicode::EastAsianWidth::EastAsian = 1; }
    use Unicode::EastAsianWidth;

Setting $Unicode::EastAsianWidth::EastAsian at run-time used to work on Perl versions between 5.8 and 5.14 due to an implementation detail, but it will no longer work on Perl 5.16 and later versions, and hence is not recommended.

SEE ALSO¶

perlunicode, <http://www.unicode.org/unicode/reports/tr11/>

AUTHORS¶

Audrey Tang <cpan@audreyt.org>

LICENSE¶

This work is under the CC0 1.0 Universal license.

To the extent possible under law, 唐鳳 has waived all copyright and related or neighboring rights to Unicode-EastAsianWidth.

This work is published from Taiwan.

<http://creativecommons.org/publicdomain/zero/1.0>