[p5sagit/p5-mst-13.2.git] / ext / Encode / lib / Encode / Alias.pm

package Encode::Alias;
use strict;
no warnings 'redefine';
use Encode;
our $VERSION = do { my @r = (q$Revision: 2.0 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
sub 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;
    my $find = shift;
    unless (exists $Alias{$find})
    {
        $Alias{$find} = 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' && $find =~ $alias)
	    {
		DEBUG and warn "eval $val";
		$new = eval $val;
		DEBUG and $@ and warn "$val, $@";
	    }
	    elsif (ref($alias) eq 'CODE')
	    {
		DEBUG and warn "$alias", "->", "($find)";
		$new = $alias->($find);
	    }
	    elsif (lc($find) eq lc($alias))
	    {
		$new = $val;
	    }
	    if (defined($new))
	    {
		next if $new eq $find; # avoid (direct) recursion on bugs
		DEBUG and warn "$alias, $new";
		my $enc = (ref($new)) ? $new : Encode::find_encoding($new);
		if ($enc)
		{
		    $Alias{$find} = $enc;
		    last;
		}
	    }
	}
    }
    if (DEBUG){
	my $name;
	if (my $e = $Alias{$find}){
	    $name = $e->name;
	}else{
	    $name = "";
	}
	warn "find_alias($class, $find)->name = $name";
    }
    return $Alias{$find};
}

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/^UTF-?7$/i           => '"UTF-7"');
    define_alias( qr/^UCS-?2-?LE$/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$/i  => '"utf-8"' );
    define_alias( qr/\bkoi8[\s-_]*([ru])$/i => '"koi8-$1"' );

    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$/i => '"cp936"');
	# This fixes gb2312 vs. euc-cn confusion, practically
	define_alias( qr/\bGB[-_ ]?2312(?!-?raw)/i => '"euc-cn"' );
	# for Encode::JP
	define_alias( qr/\bjis$/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.

(or, you don't have to do this yourself because this example is predefined)

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 this feature with caution.

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

  define_alias( sub {shift =~ /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } );

The same effect as the example above in a different way.  The coderef
takes the alias name as an argument and returns a canonical name on
success or undef if not.  Note the second argument is not required.
Use this with even more caution than the regex version.

=back

=head3 Changes in code reference aliasing

As of Encode 1.87, the older form

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

no longer works. 

Encode up to 1.86 internally used "local $_" to implement ths older
form.  But consider the code below;

  use Encode;
  $_ = "eeeee" ;
  while (/(e)/g) {
    my $utf = decode('aliased-encoding-name', $1);
    print "position:",pos,"\n";
  }

Prior to Encode 1.86 this fails because of "local $_".

=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
Commit	Line	Data
5d030b67	1	package Encode::Alias;
5d030b67	2	use strict;
1485817e	3	no warnings 'redefine';
5129552c	4	use Encode;
7237418a	5	our $VERSION = do { my @r = (q$Revision: 2.0 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
8f139f4c	6	sub DEBUG () { 0 }
5d030b67	7
10c5ecbb	8	use base qw(Exporter);
5d030b67	9
5d030b67	10	# Public, encouraged API is exported by default
5129552c	11
fcb875d4	12	our @EXPORT =
5129552c	13	qw (
	14	define_alias
	15	find_alias
	16	);
5d030b67	17
	18	our @Alias; # ordered matching list
	19	our %Alias; # cached known aliases
	20
5129552c	21	sub find_alias
5d030b67	22	{
5d030b67	23	my $class = shift;
151b5d36	24	my $find = shift;
151b5d36	25	unless (exists $Alias{$find})
5d030b67	26	{
151b5d36	27	$Alias{$find} = undef; # Recursion guard
5d030b67	28	for (my $i=0; $i < @Alias; $i += 2)
	29	{
	30	my $alias = $Alias[$i];
	31	my $val = $Alias[$i+1];
	32	my $new;
151b5d36	33	if (ref($alias) eq 'Regexp' && $find =~ $alias)
5d030b67	34	{
8f139f4c	35	DEBUG and warn "eval $val";
5d030b67	36	$new = eval $val;
8f139f4c	37	DEBUG and $@ and warn "$val, $@";
5d030b67	38	}
	39	elsif (ref($alias) eq 'CODE')
	40	{
8f139f4c	41	DEBUG and warn "$alias", "->", "($find)";
151b5d36	42	$new = $alias->($find);
5d030b67	43	}
151b5d36	44	elsif (lc($find) eq lc($alias))
5d030b67	45	{
	46	$new = $val;
	47	}
	48	if (defined($new))
	49	{
151b5d36	50	next if $new eq $find; # avoid (direct) recursion on bugs
8f139f4c	51	DEBUG and warn "$alias, $new";
5d030b67	52	my $enc = (ref($new)) ? $new : Encode::find_encoding($new);
	53	if ($enc)
	54	{
151b5d36	55	$Alias{$find} = $enc;
5d030b67	56	last;
	57	}
	58	}
	59	}
	60	}
8f139f4c	61	if (DEBUG){
a63c962f	62	my $name;
151b5d36	63	if (my $e = $Alias{$find}){
a63c962f	64	$name = $e->name;
	65	}else{
	66	$name = "";
	67	}
151b5d36	68	warn "find_alias($class, $find)->name = $name";
a63c962f	69	}
151b5d36	70	return $Alias{$find};
5d030b67	71	}
	72
	73	sub define_alias
	74	{
	75	while (@_)
	76	{
	77	my ($alias,$name) = splice(@_,0,2);
	78	unshift(@Alias, $alias => $name); # newer one has precedence
	79	# clear %Alias cache to allow overrides
	80	if (ref($alias)){
5129552c	81	my @a = keys %Alias;
5129552c	82	for my $k (@a){
5d030b67	83	if (ref($alias) eq 'Regexp' && $k =~ $alias)
5d030b67	84	{
8f139f4c	85	DEBUG and warn "delete \$Alias\{$k\}";
5d030b67	86	delete $Alias{$k};
	87	}
	88	elsif (ref($alias) eq 'CODE')
	89	{
8f139f4c	90	DEBUG and warn "delete \$Alias\{$k\}";
5d030b67	91	delete $Alias{$alias->($name)};
	92	}
	93	}
	94	}else{
8f139f4c	95	DEBUG and warn "delete \$Alias\{$alias\}";
5d030b67	96	delete $Alias{$alias};
	97	}
	98	}
	99	}
	100
5d030b67	101	# Allow latin-1 style names as well
	102	# 0 1 2 3 4 5 6 7 8 9 10
	103	our @Latin2iso = ( 0, 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 );
5d030b67	104	# Allow winlatin1 style names as well
	105	our %Winlatin2cp = (
	106	'latin1' => 1252,
	107	'latin2' => 1250,
	108	'cyrillic' => 1251,
	109	'greek' => 1253,
	110	'turkish' => 1254,
	111	'hebrew' => 1255,
	112	'arabic' => 1256,
	113	'baltic' => 1257,
	114	'vietnamese' => 1258,
	115	);
	116
5129552c	117	init_aliases();
	118
	119	sub undef_aliases{
	120	@Alias = ();
	121	%Alias = ();
	122	}
	123
	124	sub init_aliases
	125	{
	126	undef_aliases();
a999c27c	127
f2a2953c	128	# Try all-lower-case version should all else fails
a999c27c	129	define_alias( qr/^(.*)$/ => '"\L$1"' );
a999c27c	130
f2a2953c	131	# UTF/UCS stuff
1485817e	132	define_alias( qr/^UTF-?7$/i => '"UTF-7"');
11067275	133	define_alias( qr/^UCS-?2-?LE$/i => '"UCS-2LE"' );
11067275	134	define_alias( qr/^UCS-?2-?(BE)?$/i => '"UCS-2BE"',
126bf8bf	135	qr/^UCS-?4-?(BE\|LE)?$/i => 'uc("UTF-32$1")',
11067275	136	qr/^iso-10646-1$/i => '"UCS-2BE"' );
	137	define_alias( qr/^UTF(16\|32)-?BE$/i => '"UTF-$1BE"',
	138	qr/^UTF(16\|32)-?LE$/i => '"UTF-$1LE"',
	139	qr/^UTF(16\|32)$/i => '"UTF-$1"',
f2a2953c	140	);
f2a2953c	141	# ASCII
a999c27c	142	define_alias(qr/^(?:US-?)ascii$/i => '"ascii"');
a999c27c	143	define_alias('C' => 'ascii');
2d06ad02	144	define_alias(qr/\bISO[-_]?646[-_]?US$/i => '"ascii"');
67d7b5ef	145	# Allow variants of iso-8859-1 etc.
67d7b5ef	146	define_alias( qr/\biso[-_]?(\d+)[-_](\d+)$/i => '"iso-$1-$2"' );
5129552c	147
67d7b5ef	148	# At least HP-UX has these.
67d7b5ef	149	define_alias( qr/\biso8859(\d+)$/i => '"iso-8859-$1"' );
5129552c	150
67d7b5ef	151	# More HP stuff.
67d7b5ef	152	define_alias( qr/\b(?:hp-)?(arabic\|greek\|hebrew\|kana\|roman\|thai\|turkish)8$/i => '"${1}8"' );
5129552c	153
67d7b5ef	154	# The Official name of ASCII.
67d7b5ef	155	define_alias( qr/\bANSI[-_]?X3\.4[-_]?1968$/i => '"ascii"' );
5129552c	156
67d7b5ef	157	# This is a font issue, not an encoding issue.
	158	# (The currency symbol of the Latin 1 upper half
	159	# has been redefined as the euro symbol.)
5129552c	160	define_alias( qr/^(.+)\@euro$/i => '"$1"' );
5129552c	161
fcb875d4	162	define_alias( qr/\b(?:iso[-_]?)?latin[-_]?(\d+)$/i
bb7af5ca	163	=> 'defined $Encode::Alias::Latin2iso[$1] ? "iso-8859-$Encode::Alias::Latin2iso[$1]" : undef' );
5129552c	164
67d7b5ef	165	define_alias( qr/\bwin(latin[12]\|cyrillic\|baltic\|greek\|turkish\|
fcb875d4	166	hebrew\|arabic\|baltic\|vietnamese)$/ix =>
5129552c	167	'"cp" . $Encode::Alias::Winlatin2cp{lc($1)}' );
5d030b67	168
67d7b5ef	169	# Common names for non-latin prefered MIME names
5129552c	170	define_alias( 'ascii' => 'US-ascii',
	171	'cyrillic' => 'iso-8859-5',
	172	'arabic' => 'iso-8859-6',
	173	'greek' => 'iso-8859-7',
	174	'hebrew' => 'iso-8859-8',
	175	'thai' => 'iso-8859-11',
	176	'tis620' => 'iso-8859-11',
	177	);
5d030b67	178
67d7b5ef	179	# At least AIX has IBM-NNN (surprisingly...) instead of cpNNN.
67d7b5ef	180	# And Microsoft has their own naming (again, surprisingly).
fcb875d4	181	# And windows-* is registered in IANA!
2d06ad02	182	define_alias( qr/\b(?:cp\|ibm\|ms\|windows)[-_ ]?(\d{2,4})$/i => '"cp$1"');
5d030b67	183
67d7b5ef	184	# Sometimes seen with a leading zero.
c731e18e	185	# define_alias( qr/\bcp037\b/i => '"cp37"');
5d030b67	186
3ef515df	187	# Mac Mappings
a999c27c	188	# predefined in *.ucm; unneeded
a999c27c	189	# define_alias( qr/\bmacIcelandic$/i => '"macIceland"');
3ef515df	190	define_alias( qr/^mac_(.*)$/i => '"mac$1"');
a999c27c	191	# Ououououou. gone. They are differente!
a999c27c	192	# define_alias( qr/\bmacRomanian$/i => '"macRumanian"');
fcb875d4	193
f2a2953c	194	# Standardize on the dashed versions.
78c56a8c	195	# define_alias( qr/\butf8$/i => '"utf-8"' );
f9674d83	196	define_alias( qr/\bkoi8[\s-_]*([ru])$/i => '"koi8-$1"' );
5129552c	197
a63c962f	198	unless ($Encode::ON_EBCDIC){
a63c962f	199	# for Encode::CN
67d7b5ef	200	define_alias( qr/\beuc.*cn$/i => '"euc-cn"' );
	201	define_alias( qr/\bcn.*euc$/i => '"euc-cn"' );
	202	# define_alias( qr/\bGB[- ]?(\d+)$/i => '"euc-cn"' )
	203	# CP936 doesn't have vendor-addon for GBK, so they're identical.
	204	define_alias( qr/^gbk$/i => '"cp936"');
	205	# This fixes gb2312 vs. euc-cn confusion, practically
b9531c19	206	define_alias( qr/\bGB[-_ ]?2312(?!-?raw)/i => '"euc-cn"' );
67d7b5ef	207	# for Encode::JP
	208	define_alias( qr/\bjis$/i => '"7bit-jis"' );
	209	define_alias( qr/\beuc.*jp$/i => '"euc-jp"' );
	210	define_alias( qr/\bjp.*euc$/i => '"euc-jp"' );
	211	define_alias( qr/\bujis$/i => '"euc-jp"' );
	212	define_alias( qr/\bshift.*jis$/i => '"shiftjis"' );
	213	define_alias( qr/\bsjis$/i => '"shiftjis"' );
a63c962f	214	# for Encode::KR
67d7b5ef	215	define_alias( qr/\beuc.*kr$/i => '"euc-kr"' );
	216	define_alias( qr/\bkr.*euc$/i => '"euc-kr"' );
	217	# This fixes ksc5601 vs. euc-kr confusion, practically
	218	define_alias( qr/(?:x-)?uhc$/i => '"cp949"' );
	219	define_alias( qr/(?:x-)?windows-949$/i => '"cp949"' );
	220	define_alias( qr/\bks_c_5601-1987$/i => '"cp949"' );
a63c962f	221	# for Encode::TW
b0b300a3	222	define_alias( qr/\bbig-?5$/i => '"big5-eten"' );
4b291ae6	223	define_alias( qr/\bbig5-?et(?:en)?$/i => '"big5-eten"' );
2d06ad02	224	define_alias( qr/\btca[-_]?big5$/i => '"big5-eten"' );
b0b300a3	225	define_alias( qr/\bbig5-?hk(?:scs)?$/i => '"big5-hkscs"' );
2d06ad02	226	define_alias( qr/\bhk(?:scs)?[-_]?big5$/i => '"big5-hkscs"' );
a63c962f	227	}
f2a2953c	228	# utf8 is blessed :)
f2a2953c	229	define_alias( qr/^UTF-8$/i => '"utf8"',);
67d7b5ef	230	# At last, Map white space and _ to '-'
5129552c	231	define_alias( qr/^(\S+)[\s_]+(.*)$/i => '"$1-$2"' );
	232	}
	233
	234	1;
	235	__END__
5d030b67	236
	237	# TODO: HP-UX '8' encodings arabic8 greek8 hebrew8 kana8 thai8 turkish8
	238	# TODO: HP-UX '15' encodings japanese15 korean15 roi15
	239	# TODO: Cyrillic encoding ISO-IR-111 (useful?)
	240	# TODO: Armenian encoding ARMSCII-8
	241	# TODO: Hebrew encoding ISO-8859-8-1
	242	# TODO: Thai encoding TCVN
5d030b67	243	# TODO: Vietnamese encodings VPS
	244	# TODO: Mac Asian+African encodings: Arabic Armenian Bengali Burmese
	245	# ChineseSimp ChineseTrad Devanagari Ethiopic ExtArabic
	246	# Farsi Georgian Gujarati Gurmukhi Hebrew Japanese
	247	# Kannada Khmer Korean Laotian Malayalam Mongolian
	248	# Oriya Sinhalese Symbol Tamil Telugu Tibetan Vietnamese
	249
5d030b67	250	=head1 NAME
5d030b67	251
ce912cd4	252	Encode::Alias - alias definitions to encodings
5d030b67	253
	254	=head1 SYNOPSIS
	255
5129552c	256	use Encode;
5129552c	257	use Encode::Alias;
5d030b67	258	define_alias( newName => ENCODING);
	259
	260	=head1 DESCRIPTION
	261
3ef515df	262	Allows newName to be used as an alias for ENCODING. ENCODING may be
fcb875d4	263	either the name of an encoding or an encoding object (as described
3ef515df	264	in L<Encode>).
5d030b67	265
	266	Currently I<newName> can be specified in the following ways:
	267
	268	=over 4
	269
	270	=item As a simple string.
	271
	272	=item As a qr// compiled regular expression, e.g.:
	273
	274	define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' );
	275
0ab8f81e	276	In this case, if I<ENCODING> is not a reference, it is C<eval>-ed
	277	in order to allow C<$1> etc. to be substituted. The example is one
	278	way to alias names as used in X11 fonts to the MIME names for the
	279	iso-8859-* family. Note the double quotes inside the single quotes.
5d030b67	280
151b5d36	281	(or, you don't have to do this yourself because this example is predefined)
151b5d36	282
3ef515df	283	If you are using a regex here, you have to use the quotes as shown or
3ef515df	284	it won't work. Also note that regex handling is tricky even for the
151b5d36	285	experienced. Use this feature with caution.
5d030b67	286
	287	=item As a code reference, e.g.:
	288
151b5d36	289	define_alias( sub {shift =~ /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } );
5d030b67	290
151b5d36	291	The same effect as the example above in a different way. The coderef
	292	takes the alias name as an argument and returns a canonical name on
	293	success or undef if not. Note the second argument is not required.
	294	Use this with even more caution than the regex version.
5d030b67	295
5129552c	296	=back
5129552c	297
151b5d36	298	=head3 Changes in code reference aliasing
	299
	300	As of Encode 1.87, the older form
	301
	302	define_alias( sub { return /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } );
	303
	304	no longer works.
	305
	306	Encode up to 1.86 internally used "local $_" to implement ths older
	307	form. But consider the code below;
	308
	309	use Encode;
	310	$_ = "eeeee" ;
	311	while (/(e)/g) {
	312	my $utf = decode('aliased-encoding-name', $1);
	313	print "position:",pos,"\n";
	314	}
	315
	316	Prior to Encode 1.86 this fails because of "local $_".
	317
0ab8f81e	318	=head2 Alias overloading
5d030b67	319
3ef515df	320	You can override predefined aliases by simply applying define_alias().
0ab8f81e	321	The new alias is always evaluated first, and when neccessary,
	322	define_alias() flushes the internal cache to make the new definition
	323	available.
5d030b67	324
0ab8f81e	325	# redirect SHIFT_JIS to MS/IBM Code Page 932, which is a
5d030b67	326	# superset of SHIFT_JIS
5d030b67	327
5129552c	328	define_alias( qr/shift.*jis$/i => '"cp932"' );
	329	define_alias( qr/sjis$/i => '"cp932"' );
	330
0ab8f81e	331	If you want to zap all predefined aliases, you can use
5129552c	332
	333	Encode::Alias->undef_aliases;
	334
	335	to do so. And
	336
	337	Encode::Alias->init_aliases;
	338
0ab8f81e	339	gets the factory settings back.
5d030b67	340
	341	=head1 SEE ALSO
	342
	343	L<Encode>, L<Encode::Supported>
	344
5129552c	345	=cut
5d030b67	346