tools/perl-5.8.0/lib/5.8.0/sun4-solaris/Encode/Alias.pm

package Encode::Alias;
use strict;
use Encode;
our $VERSION = do { my @r = (q$Revision: 1.32 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
our $DEBUG = 0;

use base qw(Exporter);

# Public, encouraged API is exported by default

our @EXPORT =
    qw (
        define_alias
        find_alias
        );

our @Alias;  # ordered matching list
our %Alias;  # cached known aliases

sub find_alias
{
    my $class = shift;
    local $_ = shift;
    unless (exists $Alias{$_})
    {
        $Alias{$_} = undef; # Recursion guard
        for (my $i=0; $i < @Alias; $i += 2)
        {
            my $alias = $Alias[$i];
            my $val   = $Alias[$i+1];
            my $new;
            if (ref($alias) eq 'Regexp' && $_ =~ $alias)
            {
                $DEBUG and warn "eval $val";
                $new = eval $val;
                # $@ and warn "$val, $@";
            }
            elsif (ref($alias) eq 'CODE')
            {
                $DEBUG and warn "$alias", "->", "($val)";
                $new = $alias->($val);
            }
            elsif (lc($_) eq lc($alias))
            {
                $new = $val;
            }
            if (defined($new))
            {
                next if $new eq $_; # avoid (direct) recursion on bugs
                $DEBUG and warn "$alias, $new";
                my $enc = (ref($new)) ? $new : Encode::find_encoding($new);
                if ($enc)
                {
                    $Alias{$_} = $enc;
                    last;
                }
            }
        }
    }
    if ($DEBUG){
        my $name;
        if (my $e = $Alias{$_}){
            $name = $e->name;
        }else{
            $name = "";
        }
        warn "find_alias($class, $_)->name = $name";
    }
    return $Alias{$_};
}

sub define_alias
{
    while (@_)
    {
        my ($alias,$name) = splice(@_,0,2);
        unshift(@Alias, $alias => $name);   # newer one has precedence
        # clear %Alias cache to allow overrides
        if (ref($alias)){
            my @a = keys %Alias;
            for my $k (@a){
                if (ref($alias) eq 'Regexp' && $k =~ $alias)
                {
                    $DEBUG and warn "delete \$Alias\{$k\}";
                    delete $Alias{$k};
                }
                elsif (ref($alias) eq 'CODE')
                {
                    $DEBUG and warn "delete \$Alias\{$k\}";
                    delete $Alias{$alias->($name)};
                }
            }
        }else{
            $DEBUG and warn "delete \$Alias\{$alias\}";
            delete $Alias{$alias};
        }
    }
}

# Allow latin-1 style names as well
                     # 0  1  2  3  4  5   6   7   8   9  10
our @Latin2iso = ( 0, 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 );
# Allow winlatin1 style names as well
our %Winlatin2cp   = (
                      'latin1'     => 1252,
                      'latin2'     => 1250,
                      'cyrillic'   => 1251,
                      'greek'      => 1253,
                      'turkish'    => 1254,
                      'hebrew'     => 1255,
                      'arabic'     => 1256,
                      'baltic'     => 1257,
                      'vietnamese' => 1258,
                     );

init_aliases();

sub undef_aliases{
    @Alias = ();
    %Alias = ();
}

sub init_aliases
{
    undef_aliases();

    # Try all-lower-case version should all else fails
    define_alias( qr/^(.*)$/ => '"\L$1"' );

    # UTF/UCS stuff
    define_alias( qr/^UCS-?2-?LE$/i       => '"UCS-2LE"' );
    define_alias( qr/^UCS-?2-?(BE)?$/i    => '"UCS-2BE"',
                  qr/^UCS-?4-?(BE|LE)?$/i => 'uc("UTF-32$1")',
                  qr/^iso-10646-1$/i      => '"UCS-2BE"' );
    define_alias( qr/^UTF(16|32)-?BE$/i   => '"UTF-$1BE"',
                  qr/^UTF(16|32)-?LE$/i   => '"UTF-$1LE"',
                  qr/^UTF(16|32)$/i       => '"UTF-$1"',
                );
    # ASCII
    define_alias(qr/^(?:US-?)ascii$/i => '"ascii"');
    define_alias('C' => 'ascii');
    define_alias(qr/\bISO[-_]?646[-_]?US$/i => '"ascii"');
    # Allow variants of iso-8859-1 etc.
    define_alias( qr/\biso[-_]?(\d+)[-_](\d+)$/i => '"iso-$1-$2"' );

    # At least HP-UX has these.
    define_alias( qr/\biso8859(\d+)$/i => '"iso-8859-$1"' );

    # More HP stuff.
    define_alias( qr/\b(?:hp-)?(arabic|greek|hebrew|kana|roman|thai|turkish)8$/i => '"${1}8"' );

    # The Official name of ASCII.
    define_alias( qr/\bANSI[-_]?X3\.4[-_]?1968$/i => '"ascii"' );

    # This is a font issue, not an encoding issue.
    # (The currency symbol of the Latin 1 upper half
    #  has been redefined as the euro symbol.)
    define_alias( qr/^(.+)\@euro$/i => '"$1"' );

    define_alias( qr/\b(?:iso[-_]?)?latin[-_]?(\d+)$/i
                  => 'defined $Encode::Alias::Latin2iso[$1] ? "iso-8859-$Encode::Alias::Latin2iso[$1]" : undef' );

    define_alias( qr/\bwin(latin[12]|cyrillic|baltic|greek|turkish|
                         hebrew|arabic|baltic|vietnamese)$/ix =>
                  '"cp" . $Encode::Alias::Winlatin2cp{lc($1)}' );

    # Common names for non-latin prefered MIME names
    define_alias( 'ascii'    => 'US-ascii',
                  'cyrillic' => 'iso-8859-5',
                  'arabic'   => 'iso-8859-6',
                  'greek'    => 'iso-8859-7',
                  'hebrew'   => 'iso-8859-8',
                  'thai'     => 'iso-8859-11',
                  'tis620'   => 'iso-8859-11',
                  );

    # At least AIX has IBM-NNN (surprisingly...) instead of cpNNN.
    # And Microsoft has their own naming (again, surprisingly).
    # And windows-* is registered in IANA!
    define_alias( qr/\b(?:cp|ibm|ms|windows)[-_ ]?(\d{2,4})$/i => '"cp$1"');

    # Sometimes seen with a leading zero.
    # define_alias( qr/\bcp037\b/i => '"cp37"');

    # Mac Mappings
    # predefined in *.ucm; unneeded
    # define_alias( qr/\bmacIcelandic$/i => '"macIceland"');
    define_alias( qr/^mac_(.*)$/i => '"mac$1"');
    # Ououououou. gone.  They are differente!
    # define_alias( qr/\bmacRomanian$/i => '"macRumanian"');

    # Standardize on the dashed versions.
    # define_alias( qr/\butf8$/i  => 'utf-8' );
    define_alias( qr/\bkoi8r$/i => 'koi8-r' );
    define_alias( qr/\bkoi8u$/i => 'koi8-u' );

    unless ($Encode::ON_EBCDIC){
        # for Encode::CN
        define_alias( qr/\beuc.*cn$/i        => '"euc-cn"' );
        define_alias( qr/\bcn.*euc$/i        => '"euc-cn"' );
        # define_alias( qr/\bGB[- ]?(\d+)$/i => '"euc-cn"' )
        # CP936 doesn't have vendor-addon for GBK, so they're identical.
        define_alias( qr/^gbk$/i => '"cp936"');
        # This fixes gb2312 vs. euc-cn confusion, practically
        define_alias( qr/\bGB[-_ ]?2312(?:\D.*$|$)/i => '"euc-cn"' );
        # for Encode::JP
        define_alias( qr/\bjis$/i            => '"7bit-jis"' );
        define_alias( qr/\beuc.*jp$/i        => '"euc-jp"' );
        define_alias( qr/\bjp.*euc$/i        => '"euc-jp"' );
        define_alias( qr/\bujis$/i           => '"euc-jp"' );
        define_alias( qr/\bshift.*jis$/i     => '"shiftjis"' );
        define_alias( qr/\bsjis$/i           => '"shiftjis"' );
        # for Encode::KR
        define_alias( qr/\beuc.*kr$/i        => '"euc-kr"' );
        define_alias( qr/\bkr.*euc$/i        => '"euc-kr"' );
        # This fixes ksc5601 vs. euc-kr confusion, practically
        define_alias( qr/(?:x-)?uhc$/i            => '"cp949"' );
        define_alias( qr/(?:x-)?windows-949$/i    => '"cp949"' );
        define_alias( qr/\bks_c_5601-1987$/i      => '"cp949"' );
        # for Encode::TW
        define_alias( qr/\bbig-?5$/i              => '"big5-eten"' );
        define_alias( qr/\bbig5-?et(?:en)$/i      => '"big5-eten"' );
        define_alias( qr/\btca[-_]?big5$/i        => '"big5-eten"' );
        define_alias( qr/\bbig5-?hk(?:scs)?$/i    => '"big5-hkscs"' );
        define_alias( qr/\bhk(?:scs)?[-_]?big5$/i  => '"big5-hkscs"' );
    }
    # utf8 is blessed :)
    define_alias( qr/^UTF-8$/i => '"utf8"',);
    # At last, Map white space and _ to '-'
    define_alias( qr/^(\S+)[\s_]+(.*)$/i => '"$1-$2"' );
}

1;
__END__

# TODO: HP-UX '8' encodings arabic8 greek8 hebrew8 kana8 thai8 turkish8
# TODO: HP-UX '15' encodings japanese15 korean15 roi15
# TODO: Cyrillic encoding ISO-IR-111 (useful?)
# TODO: Armenian encoding ARMSCII-8
# TODO: Hebrew encoding ISO-8859-8-1
# TODO: Thai encoding TCVN
# TODO: Vietnamese encodings VPS
# TODO: Mac Asian+African encodings: Arabic Armenian Bengali Burmese
#       ChineseSimp ChineseTrad Devanagari Ethiopic ExtArabic
#       Farsi Georgian Gujarati Gurmukhi Hebrew Japanese
#       Kannada Khmer Korean Laotian Malayalam Mongolian
#       Oriya Sinhalese Symbol Tamil Telugu Tibetan Vietnamese

=head1 NAME

Encode::Alias - alias definitions to encodings

=head1 SYNOPSIS

  use Encode;
  use Encode::Alias;
  define_alias( newName => ENCODING);

=head1 DESCRIPTION

Allows newName to be used as an alias for ENCODING. ENCODING may be
either the name of an encoding or an encoding object (as described
in L<Encode>).

Currently I<newName> can be specified in the following ways:

=over 4

=item As a simple string.

=item As a qr// compiled regular expression, e.g.:

  define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' );

In this case, if I<ENCODING> is not a reference, it is C<eval>-ed
in order to allow C<$1> etc. to be substituted.  The example is one
way to alias names as used in X11 fonts to the MIME names for the
iso-8859-* family.  Note the double quotes inside the single quotes.

If you are using a regex here, you have to use the quotes as shown or
it won't work.  Also note that regex handling is tricky even for the
experienced.  Use it with caution.

=item As a code reference, e.g.:

  define_alias( sub { return /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } , '');

In this case, C<$_> will be set to the name that is being looked up and
I<ENCODING> is passed to the sub as its first argument.  The example
is another way to alias names as used in X11 fonts to the MIME names
for the iso-8859-* family.

=back

=head2 Alias overloading

You can override predefined aliases by simply applying define_alias().
The new alias is always evaluated first, and when neccessary,
define_alias() flushes the internal cache to make the new definition
available.

  # redirect SHIFT_JIS to MS/IBM Code Page 932, which is a
  # superset of SHIFT_JIS

  define_alias( qr/shift.*jis$/i  => '"cp932"' );
  define_alias( qr/sjis$/i        => '"cp932"' );

If you want to zap all predefined aliases, you can use

  Encode::Alias->undef_aliases;

to do so.  And

  Encode::Alias->init_aliases;

gets the factory settings back.

=head1 SEE ALSO

L<Encode>, L<Encode::Supported>

=cut