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

package Encode::Alias;
use strict;
use Encode;
our $VERSION = do { my @r = (q$Revision: 1.2 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
our $DEBUG = 0;
require Exporter;

our @ISA = 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 $Alias{$_})
    {
	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();
    # 'C' => 'US-ascii' so you can feed default locale directly.
    define_alias('C' => 'US-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+)$/i 
		  => '"iso-8859-$Encode::Alias::Latin2iso[$1]"' );

    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(?:ibm|ms|windows)[-_]?(\d\d\d\d?)$/i => '"cp$1"');

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

    # Mac Mappings
    define_alias( qr/\bmacIcelandic$/i => '"macIceland"');
    define_alias( qr/^mac_(.*)$/i => '"mac$1"');
    # Ououououou.
    define_alias( qr/\bmacRomanian$/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$/i		  => '"big5"' );
	define_alias( qr/\bbig5-hk(?:scs)?$/i	  => '"big5-hkscs"' );
    }

    # 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 defintions 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 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 quote inside the single quote.

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().
New alias is always evaluated first and when neccessary define_alias()
flushes internal cache to make 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

  Encode::Alias->undef_aliases;

to do so.  And

  Encode::Alias->init_aliases;

gets factory setting back.


=head1 SEE ALSO

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

=cut
Commit	Line	Data
5d030b67	1	package Encode::Alias;
5d030b67	2	use strict;
5129552c	3	use Encode;
3ef515df	4	our $VERSION = do { my @r = (q$Revision: 1.2 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
5d030b67	5	our $DEBUG = 0;
	6	require Exporter;
	7
	8	our @ISA = qw(Exporter);
	9
	10	# Public, encouraged API is exported by default
5129552c	11
	12	our @EXPORT =
	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	{
	23	my $class = shift;
	24	local $_ = shift;
	25	unless (exists $Alias{$_})
	26	{
	27	for (my $i=0; $i < @Alias; $i += 2)
	28	{
	29	my $alias = $Alias[$i];
	30	my $val = $Alias[$i+1];
	31	my $new;
	32	if (ref($alias) eq 'Regexp' && $_ =~ $alias)
	33	{
a63c962f	34	$DEBUG and warn "eval $val";
5d030b67	35	$new = eval $val;
	36	# $@ and warn "$val, $@";
	37	}
	38	elsif (ref($alias) eq 'CODE')
	39	{
a63c962f	40	$DEBUG and warn "$alias", "->", "($val)";
5d030b67	41	$new = $alias->($val);
	42	}
	43	elsif (lc($_) eq lc($alias))
	44	{
	45	$new = $val;
	46	}
	47	if (defined($new))
	48	{
	49	next if $new eq $_; # avoid (direct) recursion on bugs
a63c962f	50	$DEBUG and warn "$alias, $new";
5d030b67	51	my $enc = (ref($new)) ? $new : Encode::find_encoding($new);
	52	if ($enc)
	53	{
	54	$Alias{$_} = $enc;
	55	last;
	56	}
	57	}
	58	}
	59	}
a63c962f	60	if ($DEBUG){
	61	my $name;
	62	if (my $e = $Alias{$_}){
	63	$name = $e->name;
	64	}else{
	65	$name = "";
	66	}
	67	warn "find_alias($class, $_)->name = $name";
	68	}
5d030b67	69	return $Alias{$_};
	70	}
	71
	72	sub define_alias
	73	{
	74	while (@_)
	75	{
	76	my ($alias,$name) = splice(@_,0,2);
	77	unshift(@Alias, $alias => $name); # newer one has precedence
	78	# clear %Alias cache to allow overrides
	79	if (ref($alias)){
5129552c	80	my @a = keys %Alias;
5129552c	81	for my $k (@a){
5d030b67	82	if (ref($alias) eq 'Regexp' && $k =~ $alias)
5d030b67	83	{
a63c962f	84	$DEBUG and warn "delete \$Alias\{$k\}";
5d030b67	85	delete $Alias{$k};
	86	}
	87	elsif (ref($alias) eq 'CODE')
	88	{
a63c962f	89	$DEBUG and warn "delete \$Alias\{$k\}";
5d030b67	90	delete $Alias{$alias->($name)};
	91	}
	92	}
	93	}else{
a63c962f	94	$DEBUG and warn "delete \$Alias\{$alias\}";
5d030b67	95	delete $Alias{$alias};
	96	}
	97	}
	98	}
	99
5d030b67	100	# Allow latin-1 style names as well
	101	# 0 1 2 3 4 5 6 7 8 9 10
	102	our @Latin2iso = ( 0, 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 );
5d030b67	103	# Allow winlatin1 style names as well
	104	our %Winlatin2cp = (
	105	'latin1' => 1252,
	106	'latin2' => 1250,
	107	'cyrillic' => 1251,
	108	'greek' => 1253,
	109	'turkish' => 1254,
	110	'hebrew' => 1255,
	111	'arabic' => 1256,
	112	'baltic' => 1257,
	113	'vietnamese' => 1258,
	114	);
	115
5129552c	116	init_aliases();
	117
	118	sub undef_aliases{
	119	@Alias = ();
	120	%Alias = ();
	121	}
	122
	123	sub init_aliases
	124	{
	125	undef_aliases();
67d7b5ef	126	# 'C' => 'US-ascii' so you can feed default locale directly.
	127	define_alias('C' => 'US-ascii');
	128	# Allow variants of iso-8859-1 etc.
	129	define_alias( qr/\biso[-_]?(\d+)[-_](\d+)$/i => '"iso-$1-$2"' );
5129552c	130
67d7b5ef	131	# At least HP-UX has these.
67d7b5ef	132	define_alias( qr/\biso8859(\d+)$/i => '"iso-8859-$1"' );
5129552c	133
67d7b5ef	134	# More HP stuff.
67d7b5ef	135	define_alias( qr/\b(?:hp-)?(arabic\|greek\|hebrew\|kana\|roman\|thai\|turkish)8$/i => '"${1}8"' );
5129552c	136
67d7b5ef	137	# The Official name of ASCII.
67d7b5ef	138	define_alias( qr/\bANSI[-_]?X3\.4[-_]?1968$/i => '"ascii"' );
5129552c	139
67d7b5ef	140	# This is a font issue, not an encoding issue.
	141	# (The currency symbol of the Latin 1 upper half
	142	# has been redefined as the euro symbol.)
5129552c	143	define_alias( qr/^(.+)\@euro$/i => '"$1"' );
5129552c	144
67d7b5ef	145	define_alias( qr/\b(?:iso[-_]?)?latin[-_]?(\d+)$/i
5129552c	146	=> '"iso-8859-$Encode::Alias::Latin2iso[$1]"' );
5129552c	147
67d7b5ef	148	define_alias( qr/\bwin(latin[12]\|cyrillic\|baltic\|greek\|turkish\|
5129552c	149	hebrew\|arabic\|baltic\|vietnamese)$/ix =>
5129552c	150	'"cp" . $Encode::Alias::Winlatin2cp{lc($1)}' );
5d030b67	151
67d7b5ef	152	# Common names for non-latin prefered MIME names
5129552c	153	define_alias( 'ascii' => 'US-ascii',
	154	'cyrillic' => 'iso-8859-5',
	155	'arabic' => 'iso-8859-6',
	156	'greek' => 'iso-8859-7',
	157	'hebrew' => 'iso-8859-8',
	158	'thai' => 'iso-8859-11',
	159	'tis620' => 'iso-8859-11',
	160	);
5d030b67	161
67d7b5ef	162	# At least AIX has IBM-NNN (surprisingly...) instead of cpNNN.
	163	# And Microsoft has their own naming (again, surprisingly).
	164	# And windows-* is registered in IANA!
	165	define_alias( qr/\b(?:ibm\|ms\|windows)[-_]?(\d\d\d\d?)$/i => '"cp$1"');
5d030b67	166
67d7b5ef	167	# Sometimes seen with a leading zero.
67d7b5ef	168	define_alias( qr/\bcp037\b/i => '"cp37"');
5d030b67	169
3ef515df	170	# Mac Mappings
	171	define_alias( qr/\bmacIcelandic$/i => '"macIceland"');
	172	define_alias( qr/^mac_(.*)$/i => '"mac$1"');
67d7b5ef	173	# Ououououou.
67d7b5ef	174	define_alias( qr/\bmacRomanian$/i => '"macRumanian"');
5d030b67	175
5d030b67	176	# Standardize on the dashed versions.
67d7b5ef	177	# define_alias( qr/\butf8$/i => 'utf-8' );
	178	define_alias( qr/\bkoi8r$/i => 'koi8-r' );
	179	define_alias( qr/\bkoi8u$/i => 'koi8-u' );
5129552c	180
a63c962f	181	unless ($Encode::ON_EBCDIC){
a63c962f	182	# for Encode::CN
67d7b5ef	183	define_alias( qr/\beuc.*cn$/i => '"euc-cn"' );
	184	define_alias( qr/\bcn.*euc$/i => '"euc-cn"' );
	185	# define_alias( qr/\bGB[- ]?(\d+)$/i => '"euc-cn"' )
	186	# CP936 doesn't have vendor-addon for GBK, so they're identical.
	187	define_alias( qr/^gbk$/i => '"cp936"');
	188	# This fixes gb2312 vs. euc-cn confusion, practically
	189	define_alias( qr/\bGB[-_ ]?2312(?:\D.*$\|$)/i => '"euc-cn"' );
	190	# for Encode::JP
	191	define_alias( qr/\bjis$/i => '"7bit-jis"' );
	192	define_alias( qr/\beuc.*jp$/i => '"euc-jp"' );
	193	define_alias( qr/\bjp.*euc$/i => '"euc-jp"' );
	194	define_alias( qr/\bujis$/i => '"euc-jp"' );
	195	define_alias( qr/\bshift.*jis$/i => '"shiftjis"' );
	196	define_alias( qr/\bsjis$/i => '"shiftjis"' );
a63c962f	197	# for Encode::KR
67d7b5ef	198	define_alias( qr/\beuc.*kr$/i => '"euc-kr"' );
	199	define_alias( qr/\bkr.*euc$/i => '"euc-kr"' );
	200	# This fixes ksc5601 vs. euc-kr confusion, practically
	201	define_alias( qr/(?:x-)?uhc$/i => '"cp949"' );
	202	define_alias( qr/(?:x-)?windows-949$/i => '"cp949"' );
	203	define_alias( qr/\bks_c_5601-1987$/i => '"cp949"' );
a63c962f	204	# for Encode::TW
67d7b5ef	205	define_alias( qr/\bbig-?5$/i => '"big5"' );
67d7b5ef	206	define_alias( qr/\bbig5-hk(?:scs)?$/i => '"big5-hkscs"' );
a63c962f	207	}
5129552c	208
67d7b5ef	209	# At last, Map white space and _ to '-'
5129552c	210	define_alias( qr/^(\S+)[\s_]+(.*)$/i => '"$1-$2"' );
	211	}
	212
	213	1;
	214	__END__
5d030b67	215
	216	# TODO: HP-UX '8' encodings arabic8 greek8 hebrew8 kana8 thai8 turkish8
	217	# TODO: HP-UX '15' encodings japanese15 korean15 roi15
	218	# TODO: Cyrillic encoding ISO-IR-111 (useful?)
	219	# TODO: Armenian encoding ARMSCII-8
	220	# TODO: Hebrew encoding ISO-8859-8-1
	221	# TODO: Thai encoding TCVN
5d030b67	222	# TODO: Vietnamese encodings VPS
	223	# TODO: Mac Asian+African encodings: Arabic Armenian Bengali Burmese
	224	# ChineseSimp ChineseTrad Devanagari Ethiopic ExtArabic
	225	# Farsi Georgian Gujarati Gurmukhi Hebrew Japanese
	226	# Kannada Khmer Korean Laotian Malayalam Mongolian
	227	# Oriya Sinhalese Symbol Tamil Telugu Tibetan Vietnamese
	228
5d030b67	229	=head1 NAME
	230
	231	Encode::Alias - alias defintions to encodings
	232
	233	=head1 SYNOPSIS
	234
5129552c	235	use Encode;
5129552c	236	use Encode::Alias;
5d030b67	237	define_alias( newName => ENCODING);
	238
	239	=head1 DESCRIPTION
	240
3ef515df	241	Allows newName to be used as an alias for ENCODING. ENCODING may be
	242	either the name of an encoding or an encoding object (as described
	243	in L<Encode>).
5d030b67	244
	245	Currently I<newName> can be specified in the following ways:
	246
	247	=over 4
	248
	249	=item As a simple string.
	250
	251	=item As a qr// compiled regular expression, e.g.:
	252
	253	define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' );
	254
	255	In this case if I<ENCODING> is not a reference it is C<eval>-ed to
3ef515df	256	allow C<$1> etc. to be substituted. The example is one way to alias
	257	names as used in X11 fonts to the MIME names for the iso-8859-*
	258	family. Note the double quote inside the single quote.
5d030b67	259
3ef515df	260	If you are using a regex here, you have to use the quotes as shown or
	261	it won't work. Also note that regex handling is tricky even for the
	262	experienced. Use it with caution.
5d030b67	263
	264	=item As a code reference, e.g.:
	265
	266	define_alias( sub { return /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } , '');
	267
3ef515df	268
5d030b67	269	In this case C<$_> will be set to the name that is being looked up and
5d030b67	270	I<ENCODING> is passed to the sub as its first argument. The example
3ef515df	271	is another way to alias names as used in X11 fonts to the MIME names
3ef515df	272	for the iso-8859-* family.
5d030b67	273
5129552c	274	=back
	275
	276	=head2 Alias overloading
5d030b67	277
3ef515df	278	You can override predefined aliases by simply applying define_alias().
5d030b67	279	New alias is always evaluated first and when neccessary define_alias()
	280	flushes internal cache to make new definition available.
	281
	282	# redirect SHIFT_JIS to MS/IBM Code Page 932, which is a
	283	# superset of SHIFT_JIS
	284
5129552c	285	define_alias( qr/shift.*jis$/i => '"cp932"' );
	286	define_alias( qr/sjis$/i => '"cp932"' );
	287
	288	If you want to zap all predefined aliases, you can
	289
	290	Encode::Alias->undef_aliases;
	291
	292	to do so. And
	293
	294	Encode::Alias->init_aliases;
	295
	296	gets factory setting back.
	297
5d030b67	298
	299	=head1 SEE ALSO
	300
	301	L<Encode>, L<Encode::Supported>
	302
5129552c	303	=cut
5d030b67	304