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

package Encode;

$VERSION = 0.01;

require DynaLoader;
require Exporter;

@ISA = qw(Exporter DynaLoader);

@EXPORT_OK =
    qw(
       bytes_to_utf8
       utf8_to_bytes
       chars_to_utf8
       utf8_to_chars
       utf8_to_chars_check
       bytes_to_chars
       chars_to_bytes
       from_to
       is_utf8
       on_utf8
       off_utf8
       utf_to_utf
       encodings
      );

bootstrap Encode ();

=pod

=head1 NAME

Encode - character encodings

=head2 TERMINOLOGY

=over

=item *

I<char>: a character in the range 0..maxint (at least 2**32-1)

=item *

I<byte>: a character in the range 0..255

=back

The marker [INTERNAL] marks Internal Implementation Details, in
general meant only for those who think they know what they are doing,
and such details may change in future releases.

=head2 bytes

=over 4

=item *

        bytes_to_utf8(STRING [, FROM])

The bytes in STRING are recoded in-place into UTF-8.  If no FROM is
specified the bytes are expected to be encoded in US-ASCII or ISO
8859-1 (Latin 1).  Returns the new size of STRING, or C<undef> if
there's a failure.

[INTERNAL] Also the UTF-8 flag of STRING is turned on.

=item *

        utf8_to_bytes(STRING [, TO [, CHECK]])

The UTF-8 in STRING is decoded in-place into bytes.  If no TO encoding
is specified the bytes are expected to be encoded in US-ASCII or ISO
8859-1 (Latin 1).  Returns the new size of STRING, or C<undef> if
there's a failure.

What if there are characters > 255?  What if the UTF-8 in STRING is
malformed?  See L</"Handling Malformed Data">.

[INTERNAL] The UTF-8 flag of STRING is not checked.

=back

=head2 chars

=over 4

=item *

        chars_to_utf8(STRING)

The chars in STRING are encoded in-place into UTF-8.  Returns the new
size of STRING, or C<undef> if there's a failure.

No assumptions are made on the encoding of the chars.  If you want to
assume that the chars are Unicode and to trap illegal Unicode
characters, you must use C<from_to('Unicode', ...)>.

[INTERNAL] Also the UTF-8 flag of STRING is turned on.

=over 4

=item *

        utf8_to_chars(STRING)

The UTF-8 in STRING is decoded in-place into chars.  Returns the new
size of STRING, or C<undef> if there's a failure.

If the UTF-8 in STRING is malformed C<undef> is returned, and also an
optional lexical warning (category utf8) is given.

[INTERNAL] The UTF-8 flag of STRING is not checked.

=item *

        utf8_to_chars_check(STRING [, CHECK])

(Note that special naming of this interface since a two-argument
utf8_to_chars() has different semantics.)

The UTF-8 in STRING is decoded in-place into chars.  Returns the new
size of STRING, or C<undef> if there is a failure.

If the UTF-8 in STRING is malformed?  See L</"Handling Malformed Data">.

[INTERNAL] The UTF-8 flag of STRING is not checked.

=back

=head2 chars With Encoding

=over 4

=item *

        chars_to_utf8(STRING, FROM [, CHECK])

The chars in STRING encoded in FROM are recoded in-place into UTF-8.
Returns the new size of STRING, or C<undef> if there's a failure.

No assumptions are made on the encoding of the chars.  If you want to
assume that the chars are Unicode and to trap illegal Unicode
characters, you must use C<from_to('Unicode', ...)>.

[INTERNAL] Also the UTF-8 flag of STRING is turned on.

=item *

        utf8_to_chars(STRING, TO [, CHECK])

The UTF-8 in STRING is decoded in-place into chars encoded in TO.
Returns the new size of STRING, or C<undef> if there's a failure.

If the UTF-8 in STRING is malformed?  See L</"Handling Malformed Data">.

[INTERNAL] The UTF-8 flag of STRING is not checked.

=item *

	bytes_to_chars(STRING, FROM [, CHECK])

The bytes in STRING encoded in FROM are recoded in-place into chars.
Returns the new size of STRING in bytes, or C<undef> if there's a
failure.

If the mapping is impossible?  See L</"Handling Malformed Data">.

=item *

	chars_to_bytes(STRING, TO [, CHECK])

The chars in STRING are recoded in-place to bytes encoded in TO.
Returns the new size of STRING in bytes, or C<undef> if there's a
failure.

If the mapping is impossible?  See L</"Handling Malformed Data">.

=item *

        from_to(STRING, FROM, TO [, CHECK])

The chars in STRING encoded in FROM are recoded in-place into TO.
Returns the new size of STRING, or C<undef> if there's a failure.

If mapping between the encodings is impossible?
See L</"Handling Malformed Data">.

[INTERNAL] If TO is UTF-8, also the UTF-8 flag of STRING is turned on.

=back

=head2 Testing For UTF-8

=over 4

=item *

        is_utf8(STRING [, CHECK])

[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
If CHECK is true, also checks the data in STRING for being
well-formed UTF-8.  Returns true if successful, false otherwise.

=back

=head2 Toggling UTF-8-ness

=over 4

=item *

        on_utf8(STRING)

[INTERNAL] Turn on the UTF-8 flag in STRING.  The data in STRING is
B<not> checked for being well-formed UTF-8.  Do not use unless you
B<know> that the STRING is well-formed UTF-8.  Returns the previous
state of the UTF-8 flag (so please don't test the return value as
I<not> success or failure), or C<undef> if STRING is not a string.

=item *

        off_utf8(STRING)

[INTERNAL] Turn off the UTF-8 flag in STRING.  Do not use frivolously.
Returns the previous state of the UTF-8 flag (so please don't test the
return value as I<not> success or failure), or C<undef> if STRING is
not a string.

=back

=head2 UTF-16 and UTF-32 Encodings

=over 4

=item *

        utf_to_utf(STRING, FROM, TO [, CHECK])

The data in STRING is converted from Unicode Transfer Encoding FROM to
Unicode Transfer Encoding TO.  Both FROM and TO may be any of the
following tags (case-insensitive, with or without 'utf' or 'utf-' prefix):

        tag             meaning

        '7'             UTF-7
        '8'             UTF-8
        '16be'          UTF-16 big-endian
        '16le'          UTF-16 little-endian
        '16'            UTF-16 native-endian
        '32be'          UTF-32 big-endian
        '32le'          UTF-32 little-endian
        '32'            UTF-32 native-endian

UTF-16 is also known as UCS-2, 16 bit or 2-byte chunks, and UTF-32 as
UCS-4, 32-bit or 4-byte chunks.  Returns the new size of STRING, or
C<undef> is there's a failure.

If FROM is UTF-8 and the UTF-8 in STRING is malformed?  See
L</"Handling Malformed Data">.

[INTERNAL] Even if CHECK is true and FROM is UTF-8, the UTF-8 flag of
STRING is not checked.  If TO is UTF-8, also the UTF-8 flag of STRING is
turned on.  Identical FROM and TO are fine.

=back

=head2 Handling Malformed Data

If CHECK is not set, C<undef> is returned.  If the data is supposed to
be UTF-8, an optional lexical warning (category utf8) is given.  If
CHECK is true but not a code reference, dies.  If CHECK is a code
reference, it is called with the arguments

	(MALFORMED_STRING, STRING_FROM_SO_FAR, STRING_TO_SO_FAR)

Two return values are expected from the call: the string to be used in
the result string in place of the malformed section, and the length of
the malformed section in bytes.

=cut

sub bytes_to_utf8 {
    &_bytes_to_utf8;
}

sub utf8_to_bytes {
    &_utf8_to_bytes;
}

sub chars_to_utf8 {
    &C_to_utf8;
}

sub utf8_to_chars {
    &_utf8_to_chars;
}

sub utf8_to_chars_check {
    &_utf8_to_chars_check;
}

sub bytes_to_chars {
    &_bytes_to_chars;
}

sub chars_to_bytes {
    &_chars_to_bytes;
}

sub is_utf8 {
    &_is_utf8;
}

sub on_utf8 {
    &_on_utf8;
}

sub off_utf8 {
    &_off_utf8;
}

sub utf_to_utf {
    &_utf_to_utf;
}

use Carp;

sub from_to
{
 my ($string,$from,$to,$check) = @_;
 my $f = __PACKAGE__->getEncoding($from);
 croak("Unknown encoding '$from'") unless $f;
 my $t = __PACKAGE__->getEncoding($to);
 croak("Unknown encoding '$to'") unless $t;
 my $uni = $f->toUnicode($string,$check);
 return undef if ($check && length($string));
 $string = $t->fromUnicode($uni,$check);
 return undef if ($check && length($uni));
 return length($_[0] = $string);
}

my %encoding = ( Unicode      => bless({},'Encode::Unicode'),
                 'iso10646-1' => bless({},'Encode::iso10646_1'),
               );

sub encodings
{
 my ($class) = @_;
 foreach my $dir (@INC)
  {
   if (opendir(my $dh,"$dir/Encode"))
    {
     while (defined(my $name = readdir($dh)))
      {
       if ($name =~ /^(.*)\.enc$/)
        {
         next if exists $encoding{$1};
         $encoding{$1} = "$dir/$name";
        }
      }
     closedir($dh);
    }
  }
 return keys %encoding;
}

sub loadEncoding
{
 my ($class,$name,$file) = @_;
 if (open(my $fh,$file))
  {
   my $type;
   while (1)
    {
     my $line = <$fh>;
     $type = substr($line,0,1);
     last unless $type eq '#';
    }
   $class .= ('::'.(($type eq 'E') ? 'Escape' : 'Table'));
   return $class->read($fh,$name,$type);
  }
 else
  {
   return undef;
  }
}

sub getEncoding
{
 my ($class,$name) = @_;
 my $enc;
 unless (ref($enc = $encoding{$name}))
  {
   $enc = $class->loadEncoding($name,$enc) if defined $enc;
   unless (ref($enc))
    {
     foreach my $dir (@INC)
      {
       last if ($enc = $class->loadEncoding($name,"$dir/Encode/$name.enc"));
      }
    }
   $encoding{$name} = $enc;
  }
 return $enc;
}

package Encode::Unicode;

# Dummy package that provides the encode interface

sub name { 'Unicode' }

sub toUnicode   { $_[1] }

sub fromUnicode { $_[1] }

package Encode::Table;

sub read
{
 my ($class,$fh,$name,$type) = @_;
 my $rep = $class->can("rep_$type");
 my ($def,$sym,$pages) = split(/\s+/,scalar(<$fh>));
 my @touni;
 my %fmuni;
 my $count = 0;
 $def = hex($def);
 while ($pages--)
  {
   my $line = <$fh>;
   chomp($line);
   my $page = hex($line);
   my @page;
   my $ch = $page * 256;
   for (my $i = 0; $i < 16; $i++)
    {
     my $line = <$fh>;
     for (my $j = 0; $j < 16; $j++)
      {
       my $val = hex(substr($line,0,4,''));
       if ($val || !$ch)
        {
         my $uch = chr($val);
         push(@page,$uch);
         $fmuni{$uch} = $ch;
         $count++;
        }
       else
        {
         push(@page,undef);
        }
       $ch++;
      }
    }
   $touni[$page] = \@page;
  }

 return bless {Name  => $name,
               Rep   => $rep,
               ToUni => \@touni,
               FmUni => \%fmuni,
               Def   => $def,
               Num   => $count,
              },$class;
}

sub name { shift->{'Name'} }

sub rep_S { 'C' }

sub rep_D { 'n' }

sub rep_M { ($_[0] > 255) ? 'n' : 'C' }

sub representation
{
 my ($obj,$ch) = @_;
 $ch = 0 unless @_ > 1;
 $obj-{'Rep'}->($ch);
}

sub toUnicode
{
 my ($obj,$str,$chk) = @_;
 my $rep   = $obj->{'Rep'};
 my $touni = $obj->{'ToUni'};
 my $uni   = '';
 while (length($str))
  {
   my $ch = ord(substr($str,0,1,''));
   my $x;
   if (&$rep($ch) eq 'C')
    {
     $x = $touni->[0][$ch];
    }
   else
    {
     $x = $touni->[$ch][ord(substr($str,0,1,''))];
    }
   unless (defined $x)
    {
     last if $chk;
     # What do we do here ?
     $x = '';
    }
   $uni .= $x;
  }
 $_[1] = $str if $chk;
 return $uni;
}

sub fromUnicode
{
 my ($obj,$uni,$chk) = @_;
 my $fmuni = $obj->{'FmUni'};
 my $str   = '';
 my $def   = $obj->{'Def'};
 my $rep   = $obj->{'Rep'};
 while (length($uni))
  {
   my $ch = substr($uni,0,1,'');
   my $x  = $fmuni->{chr(ord($ch))};
   unless (defined $x)
    {
     last if ($chk);
     $x = $def;
    }
   $str .= pack(&$rep($x),$x);
  }
 $_[1] = $uni if $chk;
 return $str;
}

package Encode::iso10646_1;#

sub name { 'iso10646-1' }

sub toUnicode
{
 my ($obj,$str,$chk) = @_;
 my $uni   = '';
 while (length($str))
  {
   my $code = unpack('n',substr($str,0,2,'')) & 0xffff;
   $uni .= chr($code);
  }
 $_[1] = $str if $chk;
 return $uni;
}

sub fromUnicode
{
 my ($obj,$uni,$chk) = @_;
 my $str   = '';
 while (length($uni))
  {
   my $ch = substr($uni,0,1,'');
   my $x  = ord($ch);
   unless ($x < 32768)
    {
     last if ($chk);
     $x = 0;
    }
   $str .= pack('n',$x);
  }
 $_[1] = $uni if $chk;
 return $str;
}

package Encode::Escape;
use Carp;

sub read
{
 my ($class,$fh,$name) = @_;
 my %self = (Name => $name, Num => 0);
 while (<$fh>)
  {
   my ($key,$val) = /^(\S+)\s+(.*)$/;
   $val =~ s/^\{(.*?)\}/$1/g;
   $val =~ s/\\x([0-9a-f]{2})/chr(hex($1))/ge;
   $self{$key} = $val;
  }
 return bless \%self,$class;
}

sub name { shift->{'Name'} }

sub toUnicode
{
 croak("Not implemented yet");
}

sub fromUnicode
{
 croak("Not implemented yet");
}

1;

__END__
Commit	Line	Data
22d4bb9c	1	package Encode;
	2
	3	$VERSION = 0.01;
	4
	5	require DynaLoader;
	6	require Exporter;
	7
	8	@ISA = qw(Exporter DynaLoader);
	9
	10	@EXPORT_OK =
	11	qw(
	12	bytes_to_utf8
	13	utf8_to_bytes
	14	chars_to_utf8
	15	utf8_to_chars
	16	utf8_to_chars_check
	17	bytes_to_chars
	18	chars_to_bytes
	19	from_to
	20	is_utf8
	21	on_utf8
	22	off_utf8
	23	utf_to_utf
	24	encodings
	25	);
	26
	27	bootstrap Encode ();
	28
	29	=pod
	30
	31	=head1 NAME
	32
	33	Encode - character encodings
	34
	35	=head2 TERMINOLOGY
	36
	37	=over
	38
	39	=item *
	40
	41	I<char>: a character in the range 0..maxint (at least 2**32-1)
	42
	43	=item *
	44
	45	I<byte>: a character in the range 0..255
	46
	47	=back
	48
	49	The marker [INTERNAL] marks Internal Implementation Details, in
	50	general meant only for those who think they know what they are doing,
	51	and such details may change in future releases.
	52
	53	=head2 bytes
	54
	55	=over 4
	56
	57	=item *
	58
	59	bytes_to_utf8(STRING [, FROM])
	60
	61	The bytes in STRING are recoded in-place into UTF-8. If no FROM is
	62	specified the bytes are expected to be encoded in US-ASCII or ISO
	63	8859-1 (Latin 1). Returns the new size of STRING, or C<undef> if
	64	there's a failure.
65
66	[INTERNAL] Also the UTF-8 flag of STRING is turned on.
67
68	=item *
69
70	utf8_to_bytes(STRING [, TO [, CHECK]])
71
72	The UTF-8 in STRING is decoded in-place into bytes. If no TO encoding
73	is specified the bytes are expected to be encoded in US-ASCII or ISO
74	8859-1 (Latin 1). Returns the new size of STRING, or C<undef> if
75	there's a failure.
76
77	What if there are characters > 255? What if the UTF-8 in STRING is
78	malformed? See L</"Handling Malformed Data">.
79
80	[INTERNAL] The UTF-8 flag of STRING is not checked.
81
82	=back
83
84	=head2 chars
85
86	=over 4
87
88	=item *
89
90	chars_to_utf8(STRING)
91
92	The chars in STRING are encoded in-place into UTF-8. Returns the new
93	size of STRING, or C<undef> if there's a failure.
94
95	No assumptions are made on the encoding of the chars. If you want to
96	assume that the chars are Unicode and to trap illegal Unicode
97	characters, you must use C<from_to('Unicode', ...)>.
98
99	[INTERNAL] Also the UTF-8 flag of STRING is turned on.
100
101	=over 4
102
103	=item *
104
105	utf8_to_chars(STRING)
106
107	The UTF-8 in STRING is decoded in-place into chars. Returns the new
108	size of STRING, or C<undef> if there's a failure.
109
110	If the UTF-8 in STRING is malformed C<undef> is returned, and also an
111	optional lexical warning (category utf8) is given.
112
113	[INTERNAL] The UTF-8 flag of STRING is not checked.
114
115	=item *
116
117	utf8_to_chars_check(STRING [, CHECK])
118
119	(Note that special naming of this interface since a two-argument
120	utf8_to_chars() has different semantics.)
121
122	The UTF-8 in STRING is decoded in-place into chars. Returns the new
123	size of STRING, or C<undef> if there is a failure.
124
125	If the UTF-8 in STRING is malformed? See L</"Handling Malformed Data">.
126
127	[INTERNAL] The UTF-8 flag of STRING is not checked.
128
129	=back
130
131	=head2 chars With Encoding
132
133	=over 4
134
135	=item *
136
137	chars_to_utf8(STRING, FROM [, CHECK])
138
139	The chars in STRING encoded in FROM are recoded in-place into UTF-8.
140	Returns the new size of STRING, or C<undef> if there's a failure.
141
142	No assumptions are made on the encoding of the chars. If you want to
143	assume that the chars are Unicode and to trap illegal Unicode
144	characters, you must use C<from_to('Unicode', ...)>.
145
146	[INTERNAL] Also the UTF-8 flag of STRING is turned on.
147
148	=item *
149
150	utf8_to_chars(STRING, TO [, CHECK])
151
152	The UTF-8 in STRING is decoded in-place into chars encoded in TO.
153	Returns the new size of STRING, or C<undef> if there's a failure.
154
155	If the UTF-8 in STRING is malformed? See L</"Handling Malformed Data">.
156
157	[INTERNAL] The UTF-8 flag of STRING is not checked.
158
159	=item *
160
161	bytes_to_chars(STRING, FROM [, CHECK])
162
163	The bytes in STRING encoded in FROM are recoded in-place into chars.
164	Returns the new size of STRING in bytes, or C<undef> if there's a
165	failure.
166
167	If the mapping is impossible? See L</"Handling Malformed Data">.
168
169	=item *
170
171	chars_to_bytes(STRING, TO [, CHECK])
172
173	The chars in STRING are recoded in-place to bytes encoded in TO.
174	Returns the new size of STRING in bytes, or C<undef> if there's a
175	failure.
176
177	If the mapping is impossible? See L</"Handling Malformed Data">.
178
179	=item *
180
181	from_to(STRING, FROM, TO [, CHECK])
182
183	The chars in STRING encoded in FROM are recoded in-place into TO.
184	Returns the new size of STRING, or C<undef> if there's a failure.
185
186	If mapping between the encodings is impossible?
187	See L</"Handling Malformed Data">.
188
189	[INTERNAL] If TO is UTF-8, also the UTF-8 flag of STRING is turned on.
190
191	=back
192
193	=head2 Testing For UTF-8
194
195	=over 4
196
197	=item *
198
199	is_utf8(STRING [, CHECK])
200
201	[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING.
202	If CHECK is true, also checks the data in STRING for being
203	well-formed UTF-8. Returns true if successful, false otherwise.
204
205	=back
206
207	=head2 Toggling UTF-8-ness
208
209	=over 4
210
211	=item *
212
213	on_utf8(STRING)
214
215	[INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is
216	B<not> checked for being well-formed UTF-8. Do not use unless you
217	B<know> that the STRING is well-formed UTF-8. Returns the previous
218	state of the UTF-8 flag (so please don't test the return value as
219	I<not> success or failure), or C<undef> if STRING is not a string.
220
221	=item *
222
223	off_utf8(STRING)
224
225	[INTERNAL] Turn off the UTF-8 flag in STRING. Do not use frivolously.
226	Returns the previous state of the UTF-8 flag (so please don't test the
227	return value as I<not> success or failure), or C<undef> if STRING is
228	not a string.
229
230	=back
231
232	=head2 UTF-16 and UTF-32 Encodings
233
234	=over 4
235
236	=item *
237
238	utf_to_utf(STRING, FROM, TO [, CHECK])
239
240	The data in STRING is converted from Unicode Transfer Encoding FROM to
241	Unicode Transfer Encoding TO. Both FROM and TO may be any of the
242	following tags (case-insensitive, with or without 'utf' or 'utf-' prefix):
243
244	tag meaning
245
246	'7' UTF-7
247	'8' UTF-8
248	'16be' UTF-16 big-endian
249	'16le' UTF-16 little-endian
250	'16' UTF-16 native-endian
251	'32be' UTF-32 big-endian
252	'32le' UTF-32 little-endian
253	'32' UTF-32 native-endian
254
255	UTF-16 is also known as UCS-2, 16 bit or 2-byte chunks, and UTF-32 as
256	UCS-4, 32-bit or 4-byte chunks. Returns the new size of STRING, or
257	C<undef> is there's a failure.
258
259	If FROM is UTF-8 and the UTF-8 in STRING is malformed? See
260	L</"Handling Malformed Data">.
261
262	[INTERNAL] Even if CHECK is true and FROM is UTF-8, the UTF-8 flag of
263	STRING is not checked. If TO is UTF-8, also the UTF-8 flag of STRING is
264	turned on. Identical FROM and TO are fine.
265
266	=back
267
268	=head2 Handling Malformed Data
269
270	If CHECK is not set, C<undef> is returned. If the data is supposed to
271	be UTF-8, an optional lexical warning (category utf8) is given. If
272	CHECK is true but not a code reference, dies. If CHECK is a code
273	reference, it is called with the arguments
274
275	(MALFORMED_STRING, STRING_FROM_SO_FAR, STRING_TO_SO_FAR)
276
277	Two return values are expected from the call: the string to be used in
278	the result string in place of the malformed section, and the length of
279	the malformed section in bytes.
280
281	=cut
282
283	sub bytes_to_utf8 {
284	&_bytes_to_utf8;
285	}
286
287	sub utf8_to_bytes {
288	&_utf8_to_bytes;
289	}
290
291	sub chars_to_utf8 {
292	&C_to_utf8;
293	}
294
295	sub utf8_to_chars {
296	&_utf8_to_chars;
297	}
298
299	sub utf8_to_chars_check {
300	&_utf8_to_chars_check;
301	}
302
303	sub bytes_to_chars {
304	&_bytes_to_chars;
305	}
306
307	sub chars_to_bytes {
308	&_chars_to_bytes;
309	}
310
311	sub is_utf8 {
312	&_is_utf8;
313	}
314
315	sub on_utf8 {
316	&_on_utf8;
317	}
318
319	sub off_utf8 {
320	&_off_utf8;
321	}
322
323	sub utf_to_utf {
324	&_utf_to_utf;
325	}
326
327	use Carp;
328
329	sub from_to
330	{
331	my ($string,$from,$to,$check) = @_;
332	my $f = __PACKAGE__->getEncoding($from);
333	croak("Unknown encoding '$from'") unless $f;
334	my $t = __PACKAGE__->getEncoding($to);
335	croak("Unknown encoding '$to'") unless $t;
336	my $uni = $f->toUnicode($string,$check);
337	return undef if ($check && length($string));
338	$string = $t->fromUnicode($uni,$check);
339	return undef if ($check && length($uni));
340	return length($_[0] = $string);
341	}
342
343	my %encoding = ( Unicode => bless({},'Encode::Unicode'),
344	'iso10646-1' => bless({},'Encode::iso10646_1'),
345	);
346
347	sub encodings
348	{
349	my ($class) = @_;
350	foreach my $dir (@INC)
351	{
352	if (opendir(my $dh,"$dir/Encode"))
353	{
354	while (defined(my $name = readdir($dh)))
355	{
356	if ($name =~ /^(.*)\.enc$/)
357	{
358	next if exists $encoding{$1};
359	$encoding{$1} = "$dir/$name";
360	}
361	}
362	closedir($dh);
363	}
364	}
365	return keys %encoding;
366	}
367
368	sub loadEncoding
369	{
370	my ($class,$name,$file) = @_;
371	if (open(my $fh,$file))
372	{
373	my $type;
374	while (1)
375	{
376	my $line = <$fh>;
377	$type = substr($line,0,1);
378	last unless $type eq '#';
379	}
380	$class .= ('::'.(($type eq 'E') ? 'Escape' : 'Table'));
381	return $class->read($fh,$name,$type);
382	}
383	else
384	{
385	return undef;
386	}
387	}
388
389	sub getEncoding
390	{
391	my ($class,$name) = @_;
392	my $enc;
393	unless (ref($enc = $encoding{$name}))
394	{
395	$enc = $class->loadEncoding($name,$enc) if defined $enc;
396	unless (ref($enc))
397	{
398	foreach my $dir (@INC)
399	{
400	last if ($enc = $class->loadEncoding($name,"$dir/Encode/$name.enc"));
401	}
402	}
403	$encoding{$name} = $enc;
404	}
405	return $enc;
406	}
407
408	package Encode::Unicode;
409
410	# Dummy package that provides the encode interface
411
412	sub name { 'Unicode' }
413
414	sub toUnicode { $_[1] }
415
416	sub fromUnicode { $_[1] }
417
418	package Encode::Table;
419
420	sub read
421	{
422	my ($class,$fh,$name,$type) = @_;
423	my $rep = $class->can("rep_$type");
424	my ($def,$sym,$pages) = split(/\s+/,scalar(<$fh>));
425	my @touni;
426	my %fmuni;
427	my $count = 0;
428	$def = hex($def);
429	while ($pages--)
430	{
431	my $line = <$fh>;
432	chomp($line);
433	my $page = hex($line);
434	my @page;
435	my $ch = $page * 256;
436	for (my $i = 0; $i < 16; $i++)
437	{
438	my $line = <$fh>;
439	for (my $j = 0; $j < 16; $j++)
440	{
441	my $val = hex(substr($line,0,4,''));
442	if ($val \|\| !$ch)
443	{
444	my $uch = chr($val);
445	push(@page,$uch);
446	$fmuni{$uch} = $ch;
447	$count++;
448	}
449	else
450	{
451	push(@page,undef);
452	}
453	$ch++;
454	}
455	}
456	$touni[$page] = \@page;
457	}
458
459	return bless {Name => $name,
460	Rep => $rep,
461	ToUni => \@touni,
462	FmUni => \%fmuni,
463	Def => $def,
464	Num => $count,
465	},$class;
466	}
467
468	sub name { shift->{'Name'} }
469
470	sub rep_S { 'C' }
471
472	sub rep_D { 'n' }
473
474	sub rep_M { ($_[0] > 255) ? 'n' : 'C' }
475
476	sub representation
477	{
478	my ($obj,$ch) = @_;
479	$ch = 0 unless @_ > 1;
480	$obj-{'Rep'}->($ch);
481	}
482
483	sub toUnicode
484	{
485	my ($obj,$str,$chk) = @_;
486	my $rep = $obj->{'Rep'};
487	my $touni = $obj->{'ToUni'};
488	my $uni = '';
489	while (length($str))
490	{
491	my $ch = ord(substr($str,0,1,''));
492	my $x;
493	if (&$rep($ch) eq 'C')
494	{
495	$x = $touni->[0][$ch];
496	}
497	else
498	{
499	$x = $touni->[$ch][ord(substr($str,0,1,''))];
500	}
501	unless (defined $x)
502	{
503	last if $chk;
504	# What do we do here ?
505	$x = '';
506	}
507	$uni .= $x;
508	}
509	$_[1] = $str if $chk;
510	return $uni;
511	}
512
513	sub fromUnicode
514	{
515	my ($obj,$uni,$chk) = @_;
516	my $fmuni = $obj->{'FmUni'};
517	my $str = '';
518	my $def = $obj->{'Def'};
519	my $rep = $obj->{'Rep'};
520	while (length($uni))
521	{
522	my $ch = substr($uni,0,1,'');
523	my $x = $fmuni->{chr(ord($ch))};
524	unless (defined $x)
525	{
526	last if ($chk);
527	$x = $def;
528	}
529	$str .= pack(&$rep($x),$x);
530	}
531	$_[1] = $uni if $chk;
532	return $str;
533	}
534
535	package Encode::iso10646_1;#
536
537	sub name { 'iso10646-1' }
538
539	sub toUnicode
540	{
541	my ($obj,$str,$chk) = @_;
542	my $uni = '';
543	while (length($str))
544	{
545	my $code = unpack('n',substr($str,0,2,'')) & 0xffff;
546	$uni .= chr($code);
547	}
548	$_[1] = $str if $chk;
549	return $uni;
550	}
551
552	sub fromUnicode
553	{
554	my ($obj,$uni,$chk) = @_;
555	my $str = '';
556	while (length($uni))
557	{
558	my $ch = substr($uni,0,1,'');
559	my $x = ord($ch);
560	unless ($x < 32768)
561	{
562	last if ($chk);
563	$x = 0;
564	}
565	$str .= pack('n',$x);
566	}
567	$_[1] = $uni if $chk;
568	return $str;
569	}
570
571	package Encode::Escape;
572	use Carp;
573
574	sub read
575	{
576	my ($class,$fh,$name) = @_;
577	my %self = (Name => $name, Num => 0);
578	while (<$fh>)
579	{
580	my ($key,$val) = /^(\S+)\s+(.*)$/;
581	$val =~ s/^\{(.*?)\}/$1/g;
582	$val =~ s/\\x([0-9a-f]{2})/chr(hex($1))/ge;
583	$self{$key} = $val;
584	}
585	return bless \%self,$class;
586	}
587
588	sub name { shift->{'Name'} }
589
590	sub toUnicode
591	{
592	croak("Not implemented yet");
593	}
594
595	sub fromUnicode
596	{
597	croak("Not implemented yet");
598	}
599
600	1;
601
602	__END__