package Encode::Alias;

use strict;

use warnings;

our $VERSION = do { my @r = ( q$Revision: 2.24 $ =~ /\d+/g ); sprintf "%d." . "%02d" x $#r, @r };

use constant DEBUG => !!$ENV{PERL_ENCODE_DEBUG};

use Exporter 'import';

# 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;

}

}

}

# case insensitive search when canonical is not in all lowercase

# RT ticket #7835

unless ( $Alias{$find} ) {

my $lcfind = lc($find);

for my $name ( keys %Encode::Encoding, keys %Encode::ExtModule )

{

$lcfind eq lc($name) or next;

$Alias{$find} = Encode::find_encoding($name);

DEBUG and warn "$find => $name";

}

}

}

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 = shift;

my $name = shift;

unshift( @Alias, $alias => $name ) # newer one has precedence

if defined $alias;

if ( ref($alias) ) {

# clear %Alias cache to allow overrides

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' && $alias->($k) ) {

DEBUG and warn "delete \$Alias\{$k\}";

delete $Alias{$k};

}

}

}

elsif (defined $alias) {

DEBUG and warn "delete \$Alias\{$alias\}";

delete $Alias{$alias};

}

elsif (DEBUG) {

require Carp;

Carp::croak("undef \$alias");

}

}

}

# HACK: Encode must be used after define_alias is declarated as Encode calls define_alias

use Encode ();

# 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/^(unicode-1-1-)?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/\b(?:ISO[-_]?)?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 preferred 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',

);

# RT #20781

define_alias(qr/\btis-?620\b/i => '"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/^(?:x[_-])?mac[_-](.*)$/i => '"mac$1"' );

# http://rt.cpan.org/Ticket/Display.html?id=36326

define_alias( qr/^macintosh$/i => '"MacRoman"' );

# https://rt.cpan.org/Ticket/Display.html?id=78125

define_alias( qr/^macce$/i => '"MacCentralEurRoman"' );

# Ououououou. gone. They are different!

# define_alias( qr/\bmacRomanian$/i => '"macRumanian"');

# Standardize on the dashed versions.

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"' );

define_alias( qr/\bwindows-31j$/i => '"cp932"' );

# 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"' );

}

# https://github.com/dankogai/p5-encode/issues/37

define_alias(qr/cp65000/i => '"UTF-7"');

define_alias(qr/cp65001/i => '"utf-8-strict"');

# utf8 is blessed :)

define_alias( qr/\bUTF-8$/i => '"utf-8-strict"' );

# At last, Map white space and _ to '-'

define_alias( qr/^([^\s_]+)[\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);

define_alias( qr/.../ => ENCODING);

define_alias( sub { return ENCODING if ...; } );

=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 the first argument to define_alias() 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 ignored if provided.

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 this 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 necessary,

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.

Note that define_alias() will not be able to override the canonical name

of encodings. Encodings are first looked up by canonical name before

potential aliases are tried.

=head1 SEE ALSO

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

=cut