X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=ext%2FEncode%2FEncode.pm;h=b502e8fdc469a5a8570ac4f7af7e60ae9ce6499b;hb=7e19fb92789b07f9ae6ba1ee1b4f5fbb72612161;hp=808ae406f1b224646c6a8c239fa421957cd3df12;hpb=a67efb5be995bb44472ea9a442b3cdc2507c9899;p=p5sagit%2Fp5-mst-13.2.git diff --git a/ext/Encode/Encode.pm b/ext/Encode/Encode.pm index 808ae40..b502e8f 100644 --- a/ext/Encode/Encode.pm +++ b/ext/Encode/Encode.pm @@ -1,196 +1,82 @@ package Encode; use strict; -our $VERSION = '0.40'; +our $VERSION = do { my @r = (q$Revision: 1.61 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; +our $DEBUG = 0; +use XSLoader (); +XSLoader::load 'Encode'; -require DynaLoader; require Exporter; - -our @ISA = qw(Exporter DynaLoader); +use base qw/Exporter/; # Public, encouraged API is exported by default -our @EXPORT = qw ( - encode - decode - encode_utf8 - decode_utf8 - find_encoding - encodings + +our @EXPORT = qw( + decode decode_utf8 encode encode_utf8 + encodings find_encoding ); +our @FB_FLAGS = qw(DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC + PERLQQ HTMLCREF XMLCREF); +our @FB_CONSTS = qw(FB_DEFAULT FB_CROAK FB_QUIET FB_WARN + FB_PERLQQ FB_HTMLCREF FB_XMLCREF); + our @EXPORT_OK = - qw( - define_encoding - define_alias - from_to - is_utf8 - is_8bit - is_16bit - utf8_upgrade - utf8_downgrade - _utf8_on - _utf8_off - ); - -bootstrap Encode (); + ( + qw( + _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit + is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade + ), + @FB_FLAGS, @FB_CONSTS, + ); + +our %EXPORT_TAGS = + ( + all => [ @EXPORT, @EXPORT_OK ], + fallbacks => [ @FB_CONSTS ], + fallback_all => [ @FB_CONSTS, @FB_FLAGS ], + ); # Documentation moved after __END__ for speed - NI-S use Carp; -# Make a %encoding package variable to allow a certain amount of cheating -our %encoding; -my @alias; # ordered matching list -my %alias; # cached known aliases - - # 0 1 2 3 4 5 6 7 8 9 10 -our @latin2iso_num = ( 0, 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 ); - -our %winlatin2cp = ( - 'Latin1' => 1252, - 'Latin2' => 1250, - 'Cyrillic' => 1251, - 'Greek' => 1253, - 'Turkish' => 1254, - 'Hebrew' => 1255, - 'Arabic' => 1256, - 'Baltic' => 1257, - 'Vietnamese' => 1258, - ); +our $ON_EBCDIC = (ord("A") == 193); -sub encodings -{ - my ($class) = @_; - return - map { $_->[0] } - sort { $a->[1] cmp $b->[1] } - map { [$_, lc $_] } - grep { $_ ne 'Internal' } - keys %encoding; -} +use Encode::Alias; -sub findAlias +# Make a %Encoding package variable to allow a certain amount of cheating +our %Encoding; +our %ExtModule; +require Encode::Config; +eval { require Encode::ConfigLocal }; + +sub encodings { my $class = shift; - local $_ = shift; - # print "# findAlias $_\n"; - 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) - { - $new = eval $val; - } - elsif (ref($alias) eq 'CODE') - { - $new = &{$alias}($val) - } - elsif (lc($_) eq lc($alias)) - { - $new = $val; - } - if (defined($new)) - { - next if $new eq $_; # avoid (direct) recursion on bugs - my $enc = (ref($new)) ? $new : find_encoding($new); - if ($enc) - { - $alias{$_} = $enc; - last; - } - } - } + my @modules = (@_ and $_[0] eq ":all") ? values %ExtModule : @_; + for my $mod (@modules){ + $mod =~ s,::,/,g or $mod = "Encode/$mod"; + $mod .= '.pm'; + $DEBUG and warn "about to require $mod;"; + eval { require $mod; }; } - return $alias{$_}; + my %modules = map {$_ => 1} @modules; + return + sort { lc $a cmp lc $b } + grep {!/^(?:Internal|Unicode)$/o} keys %Encoding; } -sub define_alias -{ - while (@_) - { - my ($alias,$name) = splice(@_,0,2); - push(@alias, $alias => $name); - } +sub perlio_ok{ + my $obj = ref($_[0]) ? $_[0] : find_encoding($_[0]); + $obj->can("perlio_ok") and return $obj->perlio_ok(); + return 0; # safety net } -# Allow variants of iso-8859-1 etc. -define_alias( qr/^iso[-_]?(\d+)[-_](\d+)$/i => '"iso-$1-$2"' ); - -# At least HP-UX has these. -define_alias( qr/^iso8859(\d+)$/i => '"iso-8859-$1"' ); - -# More HP stuff. -define_alias( qr/^(?:hp-)?(arabic|greek|hebrew|kana|roman|thai|turkish)8$/i => '"${1}8"' ); - -# The Official name of ASCII. -define_alias( qr/^ANSI[-_]?X3\.4[-_]?1968$/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 => '"$1"' ); - -# Allow latin-1 style names as well -define_alias( qr/^(?:iso[-_]?)?latin[-_]?(\d+)$/i => '"iso-8859-$latin2iso_num[$1]"' ); - -# Allow winlatin1 style names as well -define_alias( qr/^win(latin[12]|cyrillic|baltic|greek|turkish|hebrew|arabic|baltic|vietnamese)$/i => '"cp$winlatin2cp{\u$1}"' ); - -# Common names for non-latin prefered MIME names -define_alias( 'ascii' => 'US-ascii', - 'cyrillic' => 'iso-8859-5', - 'arabic' => 'iso-8859-6', - 'greek' => 'iso-8859-7', - 'hebrew' => 'iso-8859-8', - 'thai' => 'iso-8859-11', - 'tis620' => 'iso-8859-11', - ); - -# At least AIX has IBM-NNN (surprisingly...) instead of cpNNN. -# And Microsoft has their own naming (again, surprisingly). -define_alias( qr/^(?:ibm|ms)[-_]?(\d\d\d\d?)$/i => '"cp$1"'); - -# Sometimes seen with a leading zero. -define_alias( qr/^cp037$/i => '"cp37"'); - -# Ououououou. -define_alias( qr/^macRomanian$/i => '"macRumanian"'); - -# Standardize on the dashed versions. -define_alias( qr/^utf8$/i => 'utf-8' ); -define_alias( qr/^koi8r$/i => 'koi8-r' ); -define_alias( qr/^koi8u$/i => 'koi8-u' ); - -# Seen in some Linuxes. -define_alias( qr/^ujis$/i => 'euc-jp' ); - -# TODO: HP-UX '8' encodings arabic8 greek8 hebrew8 kana8 thai8 turkish8 -# TODO: HP-UX '15' encodings japanese15 korean15 roi15 -# TODO: Cyrillic encoding ISO-IR-111 (useful?) -# TODO: Chinese encodings GB18030 EUC-TW HZ -# TODO: Armenian encoding ARMSCII-8 -# TODO: Hebrew encoding ISO-8859-8-1 -# TODO: Thai encoding TCVN -# TODO: Korean encoding Johab -# TODO: Vietnamese encodings VPS -# TODO: Japanese encoding JIS (not the same as SJIS) -# TODO: Mac Asian+African encodings: Arabic Armenian Bengali Burmese -# ChineseSimp ChineseTrad Devanagari Ethiopic ExtArabic -# Farsi Georgian Gujarati Gurmukhi Hebrew Japanese -# Kannada Khmer Korean Laotian Malayalam Mongolian -# Oriya Sinhalese Symbol Tamil Telugu Tibetan Vietnamese - -# Map white space and _ to '-' -define_alias( qr/^(\S+)[\s_]+(.*)$/i => '"$1-$2"' ); - sub define_encoding { my $obj = shift; my $name = shift; - $encoding{$name} = $obj; + $Encoding{$name} = $obj; my $lc = lc($name); define_alias($lc => $obj) unless $lc eq $name; while (@_) @@ -203,38 +89,55 @@ sub define_encoding sub getEncoding { - my ($class,$name) = @_; + my ($class,$name,$skip_external) = @_; my $enc; if (ref($name) && $name->can('new_sequence')) { return $name; } my $lc = lc $name; - if (exists $encoding{$name}) + if (exists $Encoding{$name}) { - return $encoding{$name}; + return $Encoding{$name}; } - if (exists $encoding{$lc}) + if (exists $Encoding{$lc}) { - return $encoding{$lc}; + return $Encoding{$lc}; } - my $oc = $class->findAlias($name); + my $oc = $class->find_alias($name); return $oc if defined $oc; - return $class->findAlias($lc) if $lc ne $name; + $oc = $class->find_alias($lc) if $lc ne $name; + return $oc if defined $oc; + + unless ($skip_external) + { + if (my $mod = $ExtModule{$name} || $ExtModule{$lc}){ + $mod =~ s,::,/,g ; $mod .= '.pm'; + eval{ require $mod; }; + return $Encoding{$name} if exists $Encoding{$name}; + } + } return; } sub find_encoding { - my ($name) = @_; - return __PACKAGE__->getEncoding($name); + my ($name,$skip_external) = @_; + return __PACKAGE__->getEncoding($name,$skip_external); } -sub encode +sub resolve_alias { + my $obj = find_encoding(shift); + defined $obj and return $obj->name; + return; +} + +sub encode($$;$) { my ($name,$string,$check) = @_; + $check ||=0; my $enc = find_encoding($name); croak("Unknown encoding '$name'") unless defined $enc; my $octets = $enc->encode($string,$check); @@ -242,9 +145,10 @@ sub encode return $octets; } -sub decode +sub decode($$;$) { my ($name,$octets,$check) = @_; + $check ||=0; my $enc = find_encoding($name); croak("Unknown encoding '$name'") unless defined $enc; my $string = $enc->decode($octets,$check); @@ -252,41 +156,123 @@ sub decode return $string; } -sub from_to +sub from_to($$$;$) { my ($string,$from,$to,$check) = @_; + $check ||=0; my $f = find_encoding($from); croak("Unknown encoding '$from'") unless defined $f; my $t = find_encoding($to); croak("Unknown encoding '$to'") unless defined $t; my $uni = $f->decode($string,$check); return undef if ($check && length($string)); - $string = $t->encode($uni,$check); + $string = $t->encode($uni,$check); return undef if ($check && length($uni)); - return length($_[0] = $string); + return defined($_[0] = $string) ? length($string) : undef ; } -sub encode_utf8 +sub encode_utf8($) { my ($str) = @_; - utf8::encode($str); + utf8::encode($str); return $str; } -sub decode_utf8 +sub decode_utf8($) { my ($str) = @_; return undef unless utf8::decode($str); return $str; } -require Encode::Encoding; -require Encode::XS; -require Encode::Internal; -require Encode::Unicode; -require Encode::utf8; -require Encode::iso10646_1; -require Encode::ucs2_le; +predefine_encodings(); + +# +# This is to restore %Encoding if really needed; +# +sub predefine_encodings{ + if ($ON_EBCDIC) { + # was in Encode::UTF_EBCDIC + package Encode::UTF_EBCDIC; + *name = sub{ shift->{'Name'} }; + *new_sequence = sub{ return $_[0] }; + *needs_lines = sub{ 0 }; + *perlio_ok = sub { + eval{ require PerlIO::encoding }; + return $@ ? 0 : 1; + }; + *decode = sub{ + my ($obj,$str,$chk) = @_; + my $res = ''; + for (my $i = 0; $i < length($str); $i++) { + $res .= + chr(utf8::unicode_to_native(ord(substr($str,$i,1)))); + } + $_[1] = '' if $chk; + return $res; + }; + *encode = sub{ + my ($obj,$str,$chk) = @_; + my $res = ''; + for (my $i = 0; $i < length($str); $i++) { + $res .= + chr(utf8::native_to_unicode(ord(substr($str,$i,1)))); + } + $_[1] = '' if $chk; + return $res; + }; + $Encode::Encoding{Unicode} = + bless {Name => "UTF_EBCDIC"} => "Encode::UTF_EBCDIC"; + } else { + # was in Encode::UTF_EBCDIC + package Encode::Internal; + *name = sub{ shift->{'Name'} }; + *new_sequence = sub{ return $_[0] }; + *needs_lines = sub{ 0 }; + *perlio_ok = sub { + eval{ require PerlIO::encoding }; + return $@ ? 0 : 1; + }; + *decode = sub{ + my ($obj,$str,$chk) = @_; + utf8::upgrade($str); + $_[1] = '' if $chk; + return $str; + }; + *encode = \&decode; + $Encode::Encoding{Unicode} = + bless {Name => "Internal"} => "Encode::Internal"; + } + + { + # was in Encode::utf8 + package Encode::utf8; + *name = sub{ shift->{'Name'} }; + *new_sequence = sub{ return $_[0] }; + *needs_lines = sub{ 0 }; + *perlio_ok = sub { + eval{ require PerlIO::encoding }; + return $@ ? 0 : 1; + }; + *decode = sub{ + my ($obj,$octets,$chk) = @_; + my $str = Encode::decode_utf8($octets); + if (defined $str) { + $_[1] = '' if $chk; + return $str; + } + return undef; + }; + *encode = sub { + my ($obj,$string,$chk) = @_; + my $octets = Encode::encode_utf8($string); + $_[1] = '' if $chk; + return $octets; + }; + $Encode::Encoding{utf8} = + bless {Name => "utf8"} => "Encode::utf8"; + } +} 1; @@ -300,15 +286,29 @@ Encode - character encodings use Encode; - use Encode::TW; # for Taiwan-based Chinese encodings - use Encode::CN; # for China-based Chinese encodings - use Encode::JP; # for Japanese encodings - use Encode::KR; # for Korean encodings +=head2 Table of Contents + +Encode consists of a collection of modules whose details are too big +to fit in one document. This POD itself explains the top-level APIs +and general topics at a glance. For other topics and more details, +see the PODs below: + + Name Description + -------------------------------------------------------- + Encode::Alias Alias definitions to encodings + Encode::Encoding Encode Implementation Base Class + Encode::Supported List of Supported Encodings + Encode::CN Simplified Chinese Encodings + Encode::JP Japanese Encodings + Encode::KR Korean Encodings + Encode::TW Traditional Chinese Encodings + -------------------------------------------------------- =head1 DESCRIPTION The C module provides the interfaces between Perl's strings -and the rest of the system. Perl strings are sequences of B. +and the rest of the system. Perl strings are sequences of +B. The repertoire of characters that Perl can represent is at least that defined by the Unicode Consortium. On most platforms the ordinal @@ -317,24 +317,21 @@ codepoint" for the character (the exceptions are those platforms where the legacy encoding is some variant of EBCDIC rather than a super-set of ASCII - see L). -Traditionaly computer data has been moved around in 8-bit chunks +Traditionally, computer data has been moved around in 8-bit chunks often called "bytes". These chunks are also known as "octets" in -networking standards. Perl is widely used to manipulate data of -many types - not only strings of characters representing human or -computer languages but also "binary" data being the machines representation -of numbers, pixels in an image - or just about anything. - -When Perl is processing "binary data" the programmer wants Perl to process -"sequences of bytes". This is not a problem for Perl - as a byte has 256 -possible values it easily fits in Perl's much larger "logical character". +networking standards. Perl is widely used to manipulate data of many +types - not only strings of characters representing human or computer +languages but also "binary" data being the machine's representation of +numbers, pixels in an image - or just about anything. -Due to size concerns, before using B (Chinese, Japanese & Korean) -encodings, you have to C the corresponding -B(B|B|B|B) modules first. +When Perl is processing "binary data", the programmer wants Perl to +process "sequences of bytes". This is not a problem for Perl - as a +byte has 256 possible values, it easily fits in Perl's much larger +"logical character". =head2 TERMINOLOGY -=over 4 +=over 2 =item * @@ -349,7 +346,7 @@ I: a character in the range 0..255 =item * I: 8 bits of data, with ordinal values 0..255 -(Term for bytes passed to or from a non-Perl context, e.g. disk file.) +(Term for bytes passed to or from a non-Perl context, e.g. a disk file.) =back @@ -357,708 +354,393 @@ 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. -=head1 ENCODINGS - -=head2 Characteristics of an Encoding - -An encoding has a "repertoire" of characters that it can represent, -and for each representable character there is at least one sequence of -octets that represents it. - -=head2 Types of Encodings - -Encodings can be divided into the following types: - -=over 4 - -=item * Fixed length 8-bit (or less) encodings. - -Each character is a single octet so may have a repertoire of up to -256 characters. ASCII and iso-8859-* are typical examples. - -=item * Fixed length 16-bit encodings - -Each character is two octets so may have a repertoire of up to -65 536 characters. Unicode's UCS-2 is an example. Also used for -encodings for East Asian languages. - -=item * Fixed length 32-bit encodings. - -Not really very "encoded" encodings. The Unicode code points -are just represented as 4-octet integers. None the less because -different architectures use different representations of integers -(so called "endian") there at least two disctinct encodings. - -=item * Multi-byte encodings - -The number of octets needed to represent a character varies. -UTF-8 is a particularly complex but regular case of a multi-byte -encoding. Several East Asian countries use a multi-byte encoding -where 1-octet is used to cover western roman characters and Asian -characters get 2-octets. -(UTF-16 is strictly a multi-byte encoding taking either 2 or 4 octets -to represent a Unicode code point.) - -=item * "Escape" encodings. - -These encodings embed "escape sequences" into the octet sequence -which describe how the following octets are to be interpreted. -The iso-2022-* family is typical. Following the escape sequence -octets are encoded by an "embedded" encoding (which will be one -of the above types) until another escape sequence switches to -a different "embedded" encoding. - -These schemes are very flexible and can handle mixed languages but are -very complex to process (and have state). No escape encodings are -implemented for Perl yet. - -=back - -=head2 Specifying Encodings - -Encodings can be specified to the API described below in two ways: - -=over 4 - -=item 1. By name - -Encoding names are strings with characters taken from a restricted -repertoire. See L. - -=item 2. As an object - -Encoding objects are returned by C. - -=back - -=head2 Encoding Names - -Encoding names are case insensitive. White space in names is ignored. -In addition an encoding may have aliases. Each encoding has one -"canonical" name. The "canonical" name is chosen from the names of -the encoding by picking the first in the following sequence: - -=over 4 - -=item * The MIME name as defined in IETF RFCs. - -=item * The name in the IANA registry. - -=item * The name used by the organization that defined it. - -=back - -Because of all the alias issues, and because in the general case -encodings have state C uses the encoding object internally -once an operation is in progress. - -As of Perl 5.8.0, at least the following encodings are recognized -(the => marks aliases): - - ASCII - - US-ASCII => ASCII - -The Unicode: +=head1 PERL ENCODING API - UTF-8 - UTF-16 - UCS-2 +=over 2 - ISO 10646-1 => UCS-2 +=item $octets = encode(ENCODING, $string[, CHECK]) -The ISO 8859 and KOI: +Encodes a string from Perl's internal form into I and returns +a sequence of octets. ENCODING can be either a canonical name or +an alias. For encoding names and aliases, see L. +For CHECK, see L. - ISO 8859-1 ISO 8859-6 ISO 8859-11 KOI8-F - ISO 8859-2 ISO 8859-7 (12 doesn't exist) KOI8-R - ISO 8859-3 ISO 8859-8 ISO 8859-13 KOI8-U - ISO 8859-4 ISO 8859-9 ISO 8859-14 - ISO 8859-5 ISO 8859-10 ISO 8859-15 - ISO 8859-16 +For example, to convert (internally UTF-8 encoded) Unicode string to +iso-8859-1 (also known as Latin1), - Latin1 => 8859-1 Latin6 => 8859-10 - Latin2 => 8859-2 Latin7 => 8859-13 - Latin3 => 8859-3 Latin8 => 8859-14 - Latin4 => 8859-4 Latin9 => 8859-15 - Latin5 => 8859-9 Latin10 => 8859-16 + $octets = encode("iso-8859-1", $utf8); - Cyrillic => 8859-5 - Arabic => 8859-6 - Greek => 8859-7 - Hebrew => 8859-8 - Thai => 8859-11 - TIS620 => 8859-11 +B: When you C<$octets = encode("utf8", $utf8)>, then $octets +B $utf8. Though they both contain the same data, the utf8 flag +for $octets is B off. When you encode anything, utf8 flag of +the result is always off, even when it contains completely valid utf8 +string. See L below. -The CJKV: Chinese, Japanese, Korean, Vietnamese: +=item $string = decode(ENCODING, $octets[, CHECK]) - ISO 2022 ISO 2022 JP-1 JIS 0201 GB 1988 Big5 EUC-CN - ISO 2022 CN ISO 2022 JP-2 JIS 0208 GB 2312 HZ EUC-JP - ISO 2022 JP ISO 2022 KR JIS 0210 GB 12345 CNS 11643 EUC-JP-0212 - Shift-JIS GBK Big5-HKSCS EUC-KR - VISCII ISO-IR-165 +Decodes a sequence of octets assumed to be in I into Perl's +internal form and returns the resulting string. As in encode(), +ENCODING can be either a canonical name or an alias. For encoding names +and aliases, see L. For CHECK, see +L. -(Due to size concerns, additional Chinese encodings including C, -C and C are distributed separately on CPAN, under the name -L.) +For example, to convert ISO-8859-1 data to UTF-8: -The PC codepages: + $utf8 = decode("iso-8859-1", $latin1); - CP37 CP852 CP861 CP866 CP949 CP1251 CP1256 - CP424 CP855 CP862 CP869 CP950 CP1252 CP1257 - CP737 CP856 CP863 CP874 CP1006 CP1253 CP1258 - CP775 CP857 CP864 CP932 CP1047 CP1254 - CP850 CP860 CP865 CP936 CP1250 CP1255 +B: When you C<$utf8 = encode("utf8", $octets)>, then $utf8 +B $utf8. Though they both contain the same data, +the utf8 flag for $utf8 is on unless $octets entirely conststs of +ASCII data (or EBCDIC on EBCDIC machines). See L +below. - WinLatin1 => CP1252 - WinLatin2 => CP1250 - WinCyrillic => CP1251 - WinGreek => CP1253 - WinTurkiskh => CP1254 - WinHebrew => CP1255 - WinArabic => CP1256 - WinBaltic => CP1257 - WinVietnamese => CP1258 +=item [$length =] from_to($string, FROM_ENC, TO_ENC [, CHECK]) -(All the CPI are available also as IBMI.) +Converts B data between two encodings. For example, to +convert ISO-8859-1 data to UTF-8: -The Mac codepages: + from_to($data, "iso-8859-1", "utf8"); - MacCentralEuropean MacJapanese - MacCroatian MacRoman - MacCyrillic MacRomanian - MacDingbats MacSami - MacGreek MacThai - MacIcelandic MacTurkish - MacUkraine +and to convert it back: -Miscellaneous: + from_to($data, "utf8", "iso-8859-1"); - 7bit-greek IR-197 - 7bit-kana NeXTstep - 7bit-latin1 POSIX-BC - DingBats Roman8 - GSM 0338 Symbol +Note that because the conversion happens in place, the data to be +converted cannot be a string constant; it must be a scalar variable. -=head1 PERL ENCODING API +from_to() returns the length of the converted string on success, undef +otherwise. -=head2 Generic Encoding Interface +B: The following operations look the same but not quite so; -=over 4 + from_to($data, "iso-8859-1", "utf8"); #1 + $data = decode("iso-8859-1", $data); #2 -=item * +Both #1 and #2 makes $data consists of completely valid UTF-8 string +but only #2 turns utf8 flag on. #1 is equivalent to - $bytes = encode(ENCODING, $string[, CHECK]) + $data = encode("utf8", decode("iso-8859-1", $data)); -Encodes string from Perl's internal form into I and returns -a sequence of octets. For CHECK see L. +See L below. -For example to convert (internally UTF-8 encoded) Unicode data -to octets: +=item $octets = encode_utf8($string); - $octets = encode("utf8", $unicode); +Equivalent to C<$octets = encode("utf8", $string);> The characters +that comprise $string are encoded in Perl's superset of UTF-8 and the +resulting octets are returned as a sequence of bytes. All possible +characters have a UTF-8 representation so this function cannot fail. -=item * - $string = decode(ENCODING, $bytes[, CHECK]) +=item $string = decode_utf8($octets [, CHECK]); -Decode sequence of octets assumed to be in I into Perl's -internal form and returns the resulting string. For CHECK see +equivalent to C<$string = decode("utf8", $octets [, CHECK])>. +decode_utf8($octets [, CHECK]); The sequence of octets represented by +$octets is decoded from UTF-8 into a sequence of logical +characters. Not all sequences of octets form valid UTF-8 encodings, so +it is possible for this call to fail. For CHECK, see L. -For example to convert ISO 8859-1 data to UTF-8: - - $utf8 = decode("latin1", $latin1); - -=item * - - from_to($string, FROM_ENCODING, TO_ENCODING[, CHECK]) - -Convert B the data between two encodings. How did the data -in $string originally get to be in FROM_ENCODING? Either using -encode() or through PerlIO: See L. For CHECK -see L. - -For example to convert ISO 8859-1 data to UTF-8: - - from_to($data, "iso-8859-1", "utf-8"); - -and to convert it back: - - from_to($data, "utf-8", "iso-8859-1"); - -Note that because the conversion happens in place, the data to be -converted cannot be a string constant, it must be a scalar variable. - =back -=head2 Handling Malformed Data - -If CHECK is not set, C 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. - -It would desirable to have a way to indicate that transform should use -the encodings "replacement character" - no such mechanism is defined yet. - -It is also planned to allow I to be a code reference. - -This is not yet implemented as there are design issues with what its -arguments should be and how it returns its results. +=head2 Listing available encodings -=over 4 + use Encode; + @list = Encode->encodings(); -=item Scheme 1 +Returns a list of the canonical names of the available encodings that +are loaded. To get a list of all available encodings including the +ones that are not loaded yet, say -Passed remaining fragment of string being processed. -Modifies it in place to remove bytes/characters it can understand -and returns a string used to represent them. -e.g. + @all_encodings = Encode->encodings(":all"); - sub fixup { - my $ch = substr($_[0],0,1,''); - return sprintf("\x{%02X}",ord($ch); - } +Or you can give the name of a specific module. -This scheme is close to how underlying C code for Encode works, but gives -the fixup routine very little context. + @with_jp = Encode->encodings("Encode::JP"); -=item Scheme 2 +When "::" is not in the name, "Encode::" is assumed. -Passed original string, and an index into it of the problem area, and -output string so far. Appends what it will to output string and -returns new index into original string. For example: + @ebcdic = Encode->encodings("EBCDIC"); - sub fixup { - # my ($s,$i,$d) = @_; - my $ch = substr($_[0],$_[1],1); - $_[2] .= sprintf("\x{%02X}",ord($ch); - return $_[1]+1; - } +To find out in detail which encodings are supported by this package, +see L. -This scheme gives maximal control to the fixup routine but is more -complicated to code, and may need internals of Encode to be tweaked to -keep original string intact. +=head2 Defining Aliases -=item Other Schemes +To add a new alias to a given encoding, use: -Hybrids of above. + use Encode; + use Encode::Alias; + define_alias(newName => ENCODING); -Multiple return values rather than in-place modifications. +After that, newName can be used as an alias for ENCODING. +ENCODING may be either the name of an encoding or an +I -Index into the string could be pos($str) allowing s/\G...//. +But before you do so, make sure the alias is nonexistent with +C, which returns the canonical name thereof. +i.e. -=back + Encode::resolve_alias("latin1") eq "iso-8859-1" # true + Encode::resolve_alias("iso-8859-12") # false; nonexistent + Encode::resolve_alias($name) eq $name # true if $name is canonical -=head2 UTF-8 / utf8 +resolve_alias() does not need C; it can be +exported via C. -The Unicode consortium defines the UTF-8 standard as a way of encoding -the entire Unicode repertiore as sequences of octets. This encoding is -expected to become very widespread. Perl can use this form internaly -to represent strings, so conversions to and from this form are -particularly efficient (as octets in memory do not have to change, -just the meta-data that tells Perl how to treat them). +See L for details. -=over 4 +=head1 Encoding via PerlIO -=item * +If your perl supports I, you can use a PerlIO layer to decode +and encode directly via a filehandle. The following two examples +are totally identical in their functionality. - $bytes = encode_utf8($string); + # via PerlIO + open my $in, "<:encoding(shiftjis)", $infile or die; + open my $out, ">:encoding(euc-jp)", $outfile or die; + while(<>){ print; } -The characters that comprise string are encoded in Perl's superset of UTF-8 -and the resulting octets returned as a sequence of bytes. All possible -characters have a UTF-8 representation so this function cannot fail. + # via from_to + open my $in, "<", $infile or die; + open my $out, ">", $outfile or die; + while(<>){ + from_to($_, "shiftjis", "euc-jp", 1); + } -=item * +Unfortunately, there may be encodings are PerlIO-savvy. You can check +if your encoding is supported by PerlIO by calling the C +method. - $string = decode_utf8($bytes [,CHECK]); + Encode::perlio_ok("hz"); # False + find_encoding("euc-cn")->perlio_ok; # True where PerlIO is available -The sequence of octets represented by $bytes is decoded from UTF-8 -into a sequence of logical characters. Not all sequences of octets -form valid UTF-8 encodings, so it is possible for this call to fail. -For CHECK see L. + use Encode qw(perlio_ok); # exported upon request + perlio_ok("euc-jp") -=back +Fortunately, all encodings that come with Encode core are PerlIO-savvy +except for hz and ISO-2022-kr. See L for details. -=head2 Other Encodings of Unicode +For gory details, see L. -UTF-16 is similar to UCS-2, 16 bit or 2-byte chunks. UCS-2 can only -represent 0..0xFFFF, while UTF-16 has a I scheme which -allows it to cover the whole Unicode range. +=head1 Handling Malformed Data -Surrogates are code points set aside to encode the 0x01000..0x10FFFF -range of Unicode code points in pairs of 16-bit units. The I are the range 0xD800..0xDBFF, and the I -are the range 0xDC00..0xDFFFF. The surrogate encoding is +=over 2 - $hi = ($uni - 0x10000) / 0x400 + 0xD800; - $lo = ($uni - 0x10000) % 0x400 + 0xDC00; +The I argument is used as follows. When you omit it, +the behaviour is the same as if you had passed a value of 0 for +I. -and the decoding is +=item I = Encode::FB_DEFAULT ( == 0) - $uni = 0x10000 + ($hi - 0xD8000) * 0x400 + ($lo - 0xDC00); +If I is 0, (en|de)code will put a I +in place of a malformed character. For UCM-based encodings, +EsubcharE will be used. For Unicode, "\x{FFFD}" is used. +If the data is supposed to be UTF-8, an optional lexical warning +(category utf8) is given. -Encode implements big-endian UCS-2 aliased to "iso-10646-1" as that -happens to be the name used by that representation when used with X11 -fonts. +=item I = Encode::FB_CROAK ( == 1) -UTF-32 or UCS-4 is 32-bit or 4-byte chunks. Perl's logical characters -can be considered as being in this form without encoding. An encoding -to transfer strings in this form (e.g. to write them to a file) would -need to +If I is 1, methods will die immediately with an error +message. Therefore, when I is set to 1, you should trap the +fatal error with eval{} unless you really want to let it die on error. - pack('L*', unpack('U*', $string)); # native - or - pack('V*', unpack('U*', $string)); # little-endian - or - pack('N*', unpack('U*', $string)); # big-endian +=item I = Encode::FB_QUIET -depending on the endianness required. +If I is set to Encode::FB_QUIET, (en|de)code will immediately +return the portion of the data that has been processed so far when +an error occurs. The data argument will be overwritten with +everything after that point (that is, the unprocessed part of data). +This is handy when you have to call decode repeatedly in the case +where your source data may contain partial multi-byte character +sequences, for example because you are reading with a fixed-width +buffer. Here is some sample code that does exactly this: -No UTF-32 encodings are implemented yet. + my $data = ''; + while(defined(read $fh, $buffer, 256)){ + # buffer may end in a partial character so we append + $data .= $buffer; + $utf8 .= decode($encoding, $data, ENCODE::FB_QUIET); + # $data now contains the unprocessed partial character + } -Both UCS-2 and UCS-4 style encodings can have "byte order marks" by -representing the code point 0xFFFE as the very first thing in a file. +=item I = Encode::FB_WARN -=head2 Listing available encodings +This is the same as above, except that it warns on error. Handy when +you are debugging the mode above. - use Encode qw(encodings); - @list = encodings(); +=item perlqq mode (I = Encode::FB_PERLQQ) -Returns a list of the canonical names of the available encodings. +=item HTML charref mode (I = Encode::FB_HTMLCREF) -=head2 Defining Aliases +=item XML charref mode (I = Encode::FB_XMLCREF) - use Encode qw(define_alias); - define_alias( newName => ENCODING); +For encodings that are implemented by Encode::XS, CHECK == +Encode::FB_PERLQQ turns (en|de)code into C fallback mode. -Allows newName to be used as am alias for ENCODING. ENCODING may be -either the name of an encoding or and encoding object (as above). +When you decode, '\xI' will be inserted for a malformed character, +where I is the hex representation of the octet that could not be +decoded to utf8. And when you encode, '\x{I}' will be inserted, +where I is the Unicode ID of the character that cannot be found +in the character repertoire of the encoding. -Currently I can be specified in the following ways: +HTML/XML character reference modes are about the same, in place of +\x{I}, HTML uses &#I<1234>; where I<1234> is a decimal digit and +XML uses &#xI; where I is the hexadecimal digit. -=over 4 +=item The bitmask -=item As a simple string. +These modes are actually set via a bitmask. Here is how the FB_XX +constants are laid out. You can import the FB_XX constants via +C; you can import the generic bitmask +constants via C. -=item As a qr// compiled regular expression, e.g.: + FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ + DIE_ON_ERR 0x0001 X + WARN_ON_ER 0x0002 X + RETURN_ON_ERR 0x0004 X X + LEAVE_SRC 0x0008 + PERLQQ 0x0100 X + HTMLCREF 0x0200 + XMLCREF 0x0400 - define_alias( qr/^iso8859-(\d+)$/i => '"iso-8859-$1"' ); +=head2 Unimplemented fallback schemes -In this case if I is not a reference it is C-ed to -allow C<$1> etc. to be subsituted. The example is one way to names as -used in X11 font names to alias the MIME names for the iso-8859-* -family. +In the future, you will be able to use a code reference to a callback +function for the value of I but its API is still undecided. -=item As a code reference, e.g.: +=head1 Defining Encodings - define_alias( sub { return /^iso8859-(\d+)$/i ? "iso-8859-$1" : undef } , ''); - -In this case C<$_> will be set to the name that is being looked up and -I is passed to the sub as its first argument. The example -is another way to names as used in X11 font names to alias the MIME -names for the iso-8859-* family. - -=back - -=head2 Defining Encodings +To define a new encoding, use: use Encode qw(define_alias); - define_encoding( $object, 'canonicalName' [,alias...]); + define_encoding($object, 'canonicalName' [, alias...]); -Causes I to be associated with I<$object>. The object -should provide the interface described in L -below. If more than two arguments are provided then additional -arguments are taken as aliases for I<$object> as for C. +I will be associated with I<$object>. The object +should provide the interface described in L. +If more than two arguments are provided then additional +arguments are taken as aliases for I<$object>, as for C. -=head1 Encoding and IO +See L for more details. -It is very common to want to do encoding transformations when -reading or writing files, network connections, pipes etc. -If Perl is configured to use the new 'perlio' IO system then -C provides a "layer" (See L) which can transform -data as it is read or written. +=head1 The UTF-8 flag -Here is how the blind poet would modernise the encoding: +Before the introduction of utf8 support in perl, The C operator +just compares internal data of the scalars. Now C means internal +data equality AND I. To explain why we made it so, I +will quote page 402 of C - use Encode; - open(my $iliad,'<:encoding(iso-8859-7)','iliad.greek'); - open(my $utf8,'>:utf8','iliad.utf8'); - my @epic = <$iliad>; - print $utf8 @epic; - close($utf8); - close($illiad); +=over 2 -In addition the new IO system can also be configured to read/write -UTF-8 encoded characters (as noted above this is efficient): +=item Goal #1: - open(my $fh,'>:utf8','anything'); - print $fh "Any \x{0021} string \N{SMILEY FACE}\n"; +Old byte-oriented programs should not spontaneously break on the old +byte-oriented data they used to work on. -Either of the above forms of "layer" specifications can be made the default -for a lexical scope with the C pragma. See L. +=item Goal #2: -Once a handle is open is layers can be altered using C. +Old byte-oriented programs should magically start working on the new +character-oriented data when appropriate. -Without any such configuration, or if Perl itself is built using -system's own IO, then write operations assume that file handle accepts -only I and will C if a character larger than 255 is -written to the handle. When reading, each octet from the handle -becomes a byte-in-a-character. Note that this default is the same -behaviour as bytes-only languages (including Perl before v5.6) would -have, and is sufficient to handle native 8-bit encodings -e.g. iso-8859-1, EBCDIC etc. and any legacy mechanisms for handling -other encodings and binary data. +=item Goal #3: -In other cases it is the programs responsibility to transform -characters into bytes using the API above before doing writes, and to -transform the bytes read from a handle into characters before doing -"character operations" (e.g. C, C, ...). +Programs should run just as fast in the new character-oriented mode +as in the old byte-oriented mode. -You can also use PerlIO to convert larger amounts of data you don't -want to bring into memory. For example to convert between ISO 8859-1 -(Latin 1) and UTF-8 (or UTF-EBCDIC in EBCDIC machines): +=item Goal #4: - open(F, "<:encoding(iso-8859-1)", "data.txt") or die $!; - open(G, ">:utf8", "data.utf") or die $!; - while () { print G } +Perl should remain one language, rather than forking into a +byte-oriented Perl and a character-oriented Perl. - # Could also do "print G " but that would pull - # the whole file into memory just to write it out again. +=back -More examples: +Back when C was written, not even Perl 5.6.0 +was born and many features documented in the book remained +unimplemented. Perl 5.8 hopefully correct this and the introduction +of UTF-8 flag is one of them. You can think this perl notion of +byte-oriented mode (utf8 flag off) and character-oriented mode (utf8 +flag on). - open(my $f, "<:encoding(cp1252)") - open(my $g, ">:encoding(iso-8859-2)") - open(my $h, ">:encoding(latin9)") # iso-8859-15 +Here is how Encode takes care of the utf8 flag. -See L for more information. +=over2 -See also L for how to change the default encoding of the -data in your script. +=item * -=head1 Encoding How to ... +When you encode, the resulting utf8 flag is always off. -To do: +=item -=over 4 +When you decode, the resuting utf8 flag is on unless you can +unambiguously represent data. Here is the definition of +dis-ambiguity. -=item * IO with mixed content (faking iso-2020-*) + After C<$utf8 = decode('foo', $octet);>, -=item * MIME's Content-Length: + When $octet is... The utf8 flag in $utf8 is + --------------------------------------------- + In ASCII only (or EBCDIC only) OFF + In ISO-8859-1 ON + In any other Encoding ON + --------------------------------------------- -=item * UTF-8 strings in binary data. +As you see, there is one exception, In ASCII. That way you can assue +Goal #1. And with Encode Goal #2 is assumed but you still have to be +careful in such cases mentioned in B paragraphs. -=item * Perl/Encode wrappers on non-Unicode XS modules. +This utf8 flag is not visible in perl scripts, exactly for the same +reason you cannot (or you I) see if a scalar contains a +string, integer, or floating point number. But you can still peek +and poke these if you will. See the section below. =back -=head1 Messing with Perl's Internals +=head2 Messing with Perl's Internals The following API uses parts of Perl's internals in the current -implementation. As such they are efficient, but may change. +implementation. As such, they are efficient but may change. -=over 4 +=over 2 -=item * is_utf8(STRING [, CHECK]) +=item is_utf8(STRING [, CHECK]) -[INTERNAL] Test whether the UTF-8 flag is turned on in the STRING. +[INTERNAL] Tests 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. -=item * valid_utf8(STRING) - -[INTERNAL] Test whether STRING is in a consistent state. Will return -true if string is held as bytes, or is well-formed UTF-8 and has the -UTF-8 flag on. Main reason for this routine is to allow Perl's -testsuite to check that operations have left strings in a consistent -state. +=item _utf8_on(STRING) -=item * - - _utf8_on(STRING) - -[INTERNAL] Turn on the UTF-8 flag in STRING. The data in STRING is +[INTERNAL] Turns on the UTF-8 flag in STRING. The data in STRING is B checked for being well-formed UTF-8. Do not use unless you B 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 success or failure), or C if STRING is not a string. - -=item * +state of the UTF-8 flag (so please don't treat the return value as +indicating success or failure), or C if STRING is not a string. - _utf8_off(STRING) +=item _utf8_off(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 success or failure), or C if STRING is +[INTERNAL] Turns off the UTF-8 flag in STRING. Do not use frivolously. +Returns the previous state of the UTF-8 flag (so please don't treat the +return value as indicating success or failure), or C if STRING is not a string. =back -=head1 IMPLEMENTATION CLASSES - -As mentioned above encodings are (in the current implementation at least) -defined by objects. The mapping of encoding name to object is via the -C<%encodings> hash. - -The values of the hash can currently be either strings or objects. -The string form may go away in the future. The string form occurs -when C has scanned C<@INC> for loadable encodings but has -not actually loaded the encoding in question. This is because the -current "loading" process is all Perl and a bit slow. - -Once an encoding is loaded then value of the hash is object which -implements the encoding. The object should provide the following -interface: - -=over 4 - -=item -Ename - -Should return the string representing the canonical name of the encoding. - -=item -Enew_sequence - -This is a placeholder for encodings with state. It should return an -object which implements this interface, all current implementations -return the original object. - -=item -Eencode($string,$check) - -Should return the octet sequence representing I<$string>. If I<$check> -is true it should modify I<$string> in place to remove the converted -part (i.e. the whole string unless there is an error). If an error -occurs it should return the octet sequence for the fragment of string -that has been converted, and modify $string in-place to remove the -converted part leaving it starting with the problem fragment. - -If check is is false then C should make a "best effort" to -convert the string - for example by using a replacement character. - -=item -Edecode($octets,$check) - -Should return the string that I<$octets> represents. If I<$check> is -true it should modify I<$octets> in place to remove the converted part -(i.e. the whole sequence unless there is an error). If an error -occurs it should return the fragment of string that has been -converted, and modify $octets in-place to remove the converted part -leaving it starting with the problem fragment. - -If check is is false then C should make a "best effort" to -convert the string - for example by using Unicode's "\x{FFFD}" as a -replacement character. - -=back - -It should be noted that the check behaviour is different from the -outer public API. The logic is that the "unchecked" case is useful -when encoding is part of a stream which may be reporting errors -(e.g. STDERR). In such cases it is desirable to get everything -through somehow without causing additional errors which obscure the -original one. Also the encoding is best placed to know what the -correct replacement character is, so if that is the desired behaviour -then letting low level code do it is the most efficient. - -In contrast if check is true, the scheme above allows the encoding to -do as much as it can and tell layer above how much that was. What is -lacking at present is a mechanism to report what went wrong. The most -likely interface will be an additional method call to the object, or -perhaps (to avoid forcing per-stream objects on otherwise stateless -encodings) and additional parameter. - -It is also highly desirable that encoding classes inherit from -C as a base class. This allows that class to define -additional behaviour for all encoding objects. For example built in -Unicode, UCS-2 and UTF-8 classes use : - - package Encode::MyEncoding; - use base qw(Encode::Encoding); - - __PACKAGE__->Define(qw(myCanonical myAlias)); - -To create an object with bless {Name => ...},$class, and call -define_encoding. They inherit their C method from -C. - -=head2 Compiled Encodings - -F provides a class C which provides the -interface described above. It calls a generic octet-sequence to -octet-sequence "engine" that is driven by tables (defined in -F). The same engine is used for both encode and -decode. C's C forces Perl's characters to their -UTF-8 form and then treats them as just another multibyte -encoding. C's C transforms the sequence and then -turns the UTF-8-ness flag as that is the form that the tables are -defined to produce. For details of the engine see the comments in -F. - -The tables are produced by the Perl script F (the name needs -to change so we can eventually install it somewhere). F can -currently read two formats: - -=over 4 - -=item *.enc - -This is a coined format used by Tcl. It is documented in -Encode/EncodeFormat.pod. - -=item *.ucm - -This is the semi-standard format used by IBM's ICU package. - -=back - -F can write the following forms: - -=over 4 - -=item *.ucm - -See above - the F files provided with the distribution have -been created from the original Tcl .enc files using this approach. - -=item *.c - -Produces tables as C data structures - this is used to build in encodings -into F/F. - -=item *.xs - -In theory this allows encodings to be stand-alone loadable Perl -extensions. The process has not yet been tested. The plan is to use -this approach for large East Asian encodings. - -=back - -The set of encodings built-in to F/F is -determined by F. The current set is as follows: - -=over 4 - -=item ascii and iso-8859-* - -That is all the common 8-bit "western" encodings. - -=item IBM-1047 and two other variants of EBCDIC. - -These are the same variants that are supported by EBCDIC Perl as -"native" encodings. They are included to prove "reversibility" of -some constructs in EBCDIC Perl. - -=item symbol and dingbats as used by Tk on X11. - -(The reason Encode got started was to support Perl/Tk.) +=head1 SEE ALSO -=back +L, +L, +L, +L, +L, +L, +L, +L, +the Perl Unicode Mailing List Eperl-unicode@perl.orgE -That set is rather ad hoc and has been driven by the needs of the -tests rather than the needs of typical applications. It is likely -to be rationalized. +=head1 MAINTAINER -=head1 SEE ALSO - -L, L, L, L, L +This project was originated by Nick Ing-Simmons and later maintained +by Dan Kogai Edankogai@dan.co.jpE. See AUTHORS for a full +list of people involved. For any questions, use +Eperl-unicode@perl.orgE so we can all share share. =cut -