charnames

NAME

SYNOPSIS

  use charnames ':full';
  print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n";

  use charnames ':short';
  print "\N{greek:Sigma} is an upper-case sigma.\n";

  use charnames qw(cyrillic greek);
  print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n";

  use charnames ":full", ":alias" => {
    e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
  };
  print "\N{e_ACUTE} is a small letter e with an acute.\n";

  use charnames ();
  print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE"
  printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330"

DESCRIPTION

For lookup of "CHARNAME" inside a given script "SCRIPTNAME" this pragma looks for the names

  SCRIPTNAME CAPITAL LETTER CHARNAME
  SCRIPTNAME SMALL LETTER CHARNAME
  SCRIPTNAME LETTER CHARNAME

in the table of standard Unicode names. If "CHARNAME" is lowercase, then the "CAPITAL" variant is ignored, otherwise the "SMALL" variant is ignored.

Note that "\N{...}" is compile-time, it's a special form of string constant used inside double-quoted strings: in other words, you cannot use variables inside the "\N{...}". If you want similar run-time functionality, use charnames::vianame().

For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F) as of Unicode 3.1, there are no official Unicode names but you can use instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth). In Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429 has been updated, see ``ALIASES''. Also note that the U+UU80, U+0081, U+0084, and U+0099 do not have names even in ISO 6429.

Since the Unicode standard uses ``U+HHHH'', so can you: ``\N{U+263a}'' is the Unicode smiley face, or ``\N{WHITE SMILING FACE}''.  

ALIASES

    LINE FEED (LF)
    FORM FEED (FF)
    CARRIAGE RETURN (CR)
    NEXT LINE (NEL)

(yes, with parentheses) one can use

    LINE FEED
    FORM FEED
    CARRIAGE RETURN
    NEXT LINE
    LF
    FF
    CR
    NEL

One can also use

    BYTE ORDER MARK
    BOM

and

    ZWNJ
    ZWJ

for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER.

For backward compatibility one can use the old names for certain C0 and C1 controls

    old                         new

    HORIZONTAL TABULATION       CHARACTER TABULATION
    VERTICAL TABULATION         LINE TABULATION
    FILE SEPARATOR              INFORMATION SEPARATOR FOUR
    GROUP SEPARATOR             INFORMATION SEPARATOR THREE
    RECORD SEPARATOR            INFORMATION SEPARATOR TWO
    UNIT SEPARATOR              INFORMATION SEPARATOR ONE
    PARTIAL LINE DOWN           PARTIAL LINE FORWARD
    PARTIAL LINE UP             PARTIAL LINE BACKWARD

but the old names in addition to giving the character will also give a warning about being deprecated.  

CUSTOM ALIASES

Anonymous hashes

    use charnames ":full", ":alias" => {
        e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
        };
    my $str = "\N{e_ACUTE}";

Alias file

    use charnames ":full", ":alias" => "pro";

    will try to read "unicore/pro_alias.pl" from the @INC path. This
    file should return a list in plain perl:

    (
    A_GRAVE         => "LATIN CAPITAL LETTER A WITH GRAVE",
    A_CIRCUM        => "LATIN CAPITAL LETTER A WITH CIRCUMFLEX",
    A_DIAERES       => "LATIN CAPITAL LETTER A WITH DIAERESIS",
    A_TILDE         => "LATIN CAPITAL LETTER A WITH TILDE",
    A_BREVE         => "LATIN CAPITAL LETTER A WITH BREVE",
    A_RING          => "LATIN CAPITAL LETTER A WITH RING ABOVE",
    A_MACRON        => "LATIN CAPITAL LETTER A WITH MACRON",
    );

Alias shortcut

    use charnames ":alias" => ":pro";

    works exactly the same as the alias pairs, only this time,
    ":full" is inserted automatically as first argument (if no
    other argument is given).

charnames::viacode(code)

    print charnames::viacode(0x2722);

prints ``FOUR TEARDROP-SPOKED ASTERISK''.

Returns undef if no name is known for the code.

This works only for the standard names, and does not yet apply to custom translators.

Notice that the name returned for of U+FEFF is ``ZERO WIDTH NO-BREAK SPACE'', not ``BYTE ORDER MARK''.  

charnames::vianame(name)

    printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK");

prints ``2722''.

Returns undef if the name is unknown.

This works only for the standard names, and does not yet apply to custom translators.  

CUSTOM TRANSLATORS

    sub import {
        shift;
        $^H{charnames} = \&translator;
    }

Here translator() is a subroutine which takes "CHARNAME" as an argument, and returns text to insert into the string instead of the "\N{CHARNAME}" escape. Since the text to insert should be different in "bytes" mode and out of it, the function should check the current state of "bytes"-flag as in:

    use bytes ();                       # for $bytes::hint_bits
    sub translator {
        if ($^H & $bytes::hint_bits) {
            return bytes_translator(@_);
        }
        else {
            return utf8_translator(@_);
        }
    }

ILLEGAL CHARACTERS

If you ask by code for a character that does not exist, no warning is given and "undef" is returned. (Though if you ask for a code point past U+10FFFF you do get a warning.)  

BUGS