diff options
| -rw-r--r-- | gnu/usr.bin/perl/ext/Encode/Encode.pm | 699 |
1 files changed, 460 insertions, 239 deletions
diff --git a/gnu/usr.bin/perl/ext/Encode/Encode.pm b/gnu/usr.bin/perl/ext/Encode/Encode.pm index 635de301a2d..af5527ed3fc 100644 --- a/gnu/usr.bin/perl/ext/Encode/Encode.pm +++ b/gnu/usr.bin/perl/ext/Encode/Encode.pm @@ -1,12 +1,13 @@ # -# $Id: Encode.pm,v 1.75 2002/06/01 18:07:42 dankogai Exp $ +# $Id: Encode.pm,v 2.35 2009/07/13 00:49:38 dankogai Exp $ # package Encode; use strict; -our $VERSION = do { my @r = (q$Revision: 1.75 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; -our $DEBUG = 0; +use warnings; +our $VERSION = sprintf "%d.%02d", q$Revision: 2.35 $ =~ /(\d+)/g; +sub DEBUG () { 0 } use XSLoader (); -XSLoader::load(__PACKAGE__, $VERSION); +XSLoader::load( __PACKAGE__, $VERSION ); require Exporter; use base qw/Exporter/; @@ -14,34 +15,35 @@ use base qw/Exporter/; # Public, encouraged API is exported by default our @EXPORT = qw( - decode decode_utf8 encode encode_utf8 - encodings find_encoding + decode decode_utf8 encode encode_utf8 str2bytes bytes2str + encodings find_encoding clone_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( - _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit - is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade +our @FB_FLAGS = qw( + DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC + PERLQQ HTMLCREF XMLCREF STOP_AT_PARTIAL +); +our @FB_CONSTS = qw( + FB_DEFAULT FB_CROAK FB_QUIET FB_WARN + FB_PERLQQ FB_HTMLCREF FB_XMLCREF +); +our @EXPORT_OK = ( + 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, - ); + @FB_FLAGS, @FB_CONSTS, +); -our %EXPORT_TAGS = - ( - all => [ @EXPORT, @EXPORT_OK ], - fallbacks => [ @FB_CONSTS ], - fallback_all => [ @FB_CONSTS, @FB_FLAGS ], - ); +our %EXPORT_TAGS = ( + all => [ @EXPORT, @EXPORT_OK ], + default => [ @EXPORT ], + fallbacks => [ @FB_CONSTS ], + fallback_all => [ @FB_CONSTS, @FB_FLAGS ], +); # Documentation moved after __END__ for speed - NI-S -our $ON_EBCDIC = (ord("A") == 193); +our $ON_EBCDIC = ( ord("A") == 193 ); use Encode::Alias; @@ -49,53 +51,57 @@ use Encode::Alias; our %Encoding; our %ExtModule; require Encode::Config; -eval { require Encode::ConfigLocal }; - -sub encodings -{ +# See +# https://bugzilla.redhat.com/show_bug.cgi?id=435505#c2 +# to find why sig handers inside eval{} are disabled. +eval { + local $SIG{__DIE__}; + local $SIG{__WARN__}; + require Encode::ConfigLocal; +}; + +sub encodings { my $class = shift; my %enc; - if (@_ and $_[0] eq ":all"){ - %enc = ( %Encoding, %ExtModule ); - }else{ - %enc = %Encoding; - for my $mod (map {m/::/o ? $_ : "Encode::$_" } @_){ - $DEBUG and warn $mod; - for my $enc (keys %ExtModule){ - $ExtModule{$enc} eq $mod and $enc{$enc} = $mod; - } - } + if ( @_ and $_[0] eq ":all" ) { + %enc = ( %Encoding, %ExtModule ); } - return - sort { lc $a cmp lc $b } - grep {!/^(?:Internal|Unicode|Guess)$/o} keys %enc; + else { + %enc = %Encoding; + for my $mod ( map { m/::/o ? $_ : "Encode::$_" } @_ ) { + DEBUG and warn $mod; + for my $enc ( keys %ExtModule ) { + $ExtModule{$enc} eq $mod and $enc{$enc} = $mod; + } + } + } + return sort { lc $a cmp lc $b } + grep { !/^(?:Internal|Unicode|Guess)$/o } keys %enc; } -sub perlio_ok{ - my $obj = ref($_[0]) ? $_[0] : find_encoding($_[0]); +sub perlio_ok { + my $obj = ref( $_[0] ) ? $_[0] : find_encoding( $_[0] ); $obj->can("perlio_ok") and return $obj->perlio_ok(); - return 0; # safety net + return 0; # safety net } -sub define_encoding -{ +sub define_encoding { my $obj = shift; my $name = shift; $Encoding{$name} = $obj; my $lc = lc($name); - define_alias($lc => $obj) unless $lc eq $name; - while (@_){ - my $alias = shift; - define_alias($alias, $obj); + define_alias( $lc => $obj ) unless $lc eq $name; + while (@_) { + my $alias = shift; + define_alias( $alias, $obj ); } return $obj; } -sub getEncoding -{ - my ($class, $name, $skip_external) = @_; +sub getEncoding { + my ( $class, $name, $skip_external ) = @_; - ref($name) && $name->can('new_sequence') and return $name; + ref($name) && $name->can('renew') and return $name; exists $Encoding{$name} and return $Encoding{$name}; my $lc = lc $name; exists $Encoding{$lc} and return $Encoding{$lc}; @@ -105,161 +111,217 @@ sub getEncoding $lc ne $name and $oc = $class->find_alias($lc); defined($oc) and return $oc; - unless ($skip_external) - { - if (my $mod = $ExtModule{$name} || $ExtModule{$lc}){ - $mod =~ s,::,/,g ; $mod .= '.pm'; - eval{ require $mod; }; - exists $Encoding{$name} and return $Encoding{$name}; - } + unless ($skip_external) { + if ( my $mod = $ExtModule{$name} || $ExtModule{$lc} ) { + $mod =~ s,::,/,g; + $mod .= '.pm'; + eval { require $mod; }; + exists $Encoding{$name} and return $Encoding{$name}; + } } return; } -sub find_encoding -{ - my ($name, $skip_external) = @_; - return __PACKAGE__->getEncoding($name,$skip_external); +sub find_encoding($;$) { + my ( $name, $skip_external ) = @_; + return __PACKAGE__->getEncoding( $name, $skip_external ); } -sub resolve_alias { +sub resolve_alias($) { my $obj = find_encoding(shift); defined $obj and return $obj->name; return; } -sub encode($$;$) -{ - my ($name, $string, $check) = @_; - $check ||=0; +sub clone_encoding($) { + my $obj = find_encoding(shift); + ref $obj or return; + eval { require Storable }; + $@ and return; + return Storable::dclone($obj); +} + +sub encode($$;$) { + my ( $name, $string, $check ) = @_; + return undef unless defined $string; + $string .= '' if ref $string; # stringify; + $check ||= 0; + unless ( defined $name ) { + require Carp; + Carp::croak("Encoding name should not be undef"); + } my $enc = find_encoding($name); - unless(defined $enc){ - require Carp; - Carp::croak("Unknown encoding '$name'"); + unless ( defined $enc ) { + require Carp; + Carp::croak("Unknown encoding '$name'"); } - my $octets = $enc->encode($string,$check); - return undef if ($check && length($string)); + my $octets = $enc->encode( $string, $check ); + $_[1] = $string if $check and !ref $check and !( $check & LEAVE_SRC() ); return $octets; } +*str2bytes = \&encode; -sub decode($$;$) -{ - my ($name,$octets,$check) = @_; - $check ||=0; +sub decode($$;$) { + my ( $name, $octets, $check ) = @_; + return undef unless defined $octets; + $octets .= '' if ref $octets; + $check ||= 0; my $enc = find_encoding($name); - unless(defined $enc){ - require Carp; - Carp::croak("Unknown encoding '$name'"); + unless ( defined $enc ) { + require Carp; + Carp::croak("Unknown encoding '$name'"); } - my $string = $enc->decode($octets,$check); - $_[1] = $octets if $check; + my $string = $enc->decode( $octets, $check ); + $_[1] = $octets if $check and !ref $check and !( $check & LEAVE_SRC() ); return $string; } +*bytes2str = \&decode; -sub from_to($$$;$) -{ - my ($string,$from,$to,$check) = @_; - $check ||=0; +sub from_to($$$;$) { + my ( $string, $from, $to, $check ) = @_; + return undef unless defined $string; + $check ||= 0; my $f = find_encoding($from); - unless (defined $f){ - require Carp; - Carp::croak("Unknown encoding '$from'"); + unless ( defined $f ) { + require Carp; + Carp::croak("Unknown encoding '$from'"); } my $t = find_encoding($to); - unless (defined $t){ - require Carp; - Carp::croak("Unknown encoding '$to'"); + unless ( defined $t ) { + require Carp; + Carp::croak("Unknown encoding '$to'"); } - my $uni = $f->decode($string,$check); - return undef if ($check && length($string)); - $string = $t->encode($uni,$check); - return undef if ($check && length($uni)); - return defined($_[0] = $string) ? length($string) : undef ; + my $uni = $f->decode($string); + $_[0] = $string = $t->encode( $uni, $check ); + return undef if ( $check && length($uni) ); + return defined( $_[0] ) ? length($string) : undef; } -sub encode_utf8($) -{ +sub encode_utf8($) { my ($str) = @_; utf8::encode($str); return $str; } -sub decode_utf8($) -{ - my ($str) = @_; - return undef unless utf8::decode($str); - return $str; +sub decode_utf8($;$) { + my ( $str, $check ) = @_; + return $str if is_utf8($str); + if ($check) { + return decode( "utf8", $str, $check ); + } + else { + return decode( "utf8", $str ); + return $str; + } } -predefine_encodings(); +predefine_encodings(1); # # This is to restore %Encoding if really needed; # -sub predefine_encodings{ - use Encode::Encoding; +sub predefine_encodings { + require Encode::Encoding; + no warnings 'redefine'; + my $use_xs = shift; if ($ON_EBCDIC) { - # was in Encode::UTF_EBCDIC - package Encode::UTF_EBCDIC; - push @Encode::UTF_EBCDIC::ISA, 'Encode::Encoding'; - *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; - }; - $Encode::Encoding{Unicode} = - bless {Name => "UTF_EBCDIC"} => "Encode::UTF_EBCDIC"; - } else { - package Encode::Internal; - push @Encode::Internal::ISA, 'Encode::Encoding'; - *decode = sub{ - my ($obj,$str,$chk) = @_; - utf8::upgrade($str); - $_[1] = '' if $chk; - return $str; - }; - *encode = \&decode; - $Encode::Encoding{Unicode} = - bless {Name => "Internal"} => "Encode::Internal"; + + # was in Encode::UTF_EBCDIC + package Encode::UTF_EBCDIC; + push @Encode::UTF_EBCDIC::ISA, 'Encode::Encoding'; + *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 { + + package Encode::Internal; + push @Encode::Internal::ISA, 'Encode::Encoding'; + *decode = sub { + my ( $obj, $str, $chk ) = @_; + utf8::upgrade($str); + $_[1] = '' if $chk; + return $str; + }; + *encode = \&decode; + $Encode::Encoding{Unicode} = + bless { Name => "Internal" } => "Encode::Internal"; } { - # was in Encode::utf8 - package Encode::utf8; - push @Encode::utf8::ISA, 'Encode::Encoding'; - *decode = sub{ - my ($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; - }; - $Encode::Encoding{utf8} = - bless {Name => "utf8"} => "Encode::utf8"; + + # was in Encode::utf8 + package Encode::utf8; + push @Encode::utf8::ISA, 'Encode::Encoding'; + + # + if ($use_xs) { + Encode::DEBUG and warn __PACKAGE__, " XS on"; + *decode = \&decode_xs; + *encode = \&encode_xs; + } + else { + Encode::DEBUG and warn __PACKAGE__, " XS off"; + *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 $octets; + }; + } + *cat_decode = sub { # ($obj, $dst, $src, $pos, $trm, $chk) + # currently ignores $chk + my ( $obj, undef, undef, $pos, $trm ) = @_; + my ( $rdst, $rsrc, $rpos ) = \@_[ 1, 2, 3 ]; + use bytes; + if ( ( my $npos = index( $$rsrc, $trm, $pos ) ) >= 0 ) { + $$rdst .= + substr( $$rsrc, $pos, $npos - $pos + length($trm) ); + $$rpos = $npos + length($trm); + return 1; + } + $$rdst .= substr( $$rsrc, $pos ); + $$rpos = length($$rsrc); + return ''; + }; + $Encode::Encoding{utf8} = + bless { Name => "utf8" } => "Encode::utf8"; + $Encode::Encoding{"utf-8-strict"} = + bless { Name => "utf-8-strict", strict_utf8 => 1 } => + "Encode::utf8"; } } @@ -355,15 +417,13 @@ iso-8859-1 (also known as Latin1), $octets = encode("iso-8859-1", $string); -B<CAVEAT>: When you run C<$octets = encode("utf8", $string)>, then $octets -B<may not be equal to> $string. Though they both contain the same data, the utf8 flag -for $octets is B<always> off. When you encode anything, utf8 flag of -the result is always off, even when it contains completely valid utf8 -string. See L</"The UTF-8 flag"> below. +B<CAVEAT>: When you run C<$octets = encode("utf8", $string)>, then +$octets B<may not be equal to> $string. Though they both contain the +same data, the UTF8 flag for $octets is B<always> off. When you +encode anything, UTF8 flag of the result is always off, even when it +contains completely valid utf8 string. See L</"The UTF8 flag"> below. -encode($valid_encoding, undef) is harmless but warns you for -C<Use of uninitialized value in subroutine entry>. -encode($valid_encoding, '') is harmless and warnless. +If the $string is C<undef> then C<undef> is returned. =item $string = decode(ENCODING, $octets [, CHECK]) @@ -379,19 +439,53 @@ For example, to convert ISO-8859-1 data to a string in Perl's internal format: B<CAVEAT>: When you run C<$string = decode("utf8", $octets)>, then $string B<may not be equal to> $octets. Though they both contain the same data, -the utf8 flag for $string is on unless $octets entirely consists of -ASCII data (or EBCDIC on EBCDIC machines). See L</"The UTF-8 flag"> +the UTF8 flag for $string is on unless $octets entirely consists of +ASCII data (or EBCDIC on EBCDIC machines). See L</"The UTF8 flag"> below. -decode($valid_encoding, undef) is harmless but warns you for -C<Use of uninitialized value in subroutine entry>. -decode($valid_encoding, '') is harmless and warnless. +If the $string is C<undef> then C<undef> is returned. + +=item [$obj =] find_encoding(ENCODING) + +Returns the I<encoding object> corresponding to ENCODING. Returns +undef if no matching ENCODING is find. + +This object is what actually does the actual (en|de)coding. + + $utf8 = decode($name, $bytes); + +is in fact + + $utf8 = do{ + $obj = find_encoding($name); + croak qq(encoding "$name" not found) unless ref $obj; + $obj->decode($bytes) + }; + +with more error checking. + +Therefore you can save time by reusing this object as follows; + + my $enc = find_encoding("iso-8859-1"); + while(<>){ + my $utf8 = $enc->decode($_); + # and do someting with $utf8; + } + +Besides C<< ->decode >> and C<< ->encode >>, other methods are +available as well. For instance, C<< -> name >> returns the canonical +name of the encoding object. + + find_encoding("latin1")->name; # iso-8859-1 + +See L<Encode::Encoding> for details. =item [$length =] from_to($octets, FROM_ENC, TO_ENC [, CHECK]) Converts B<in-place> data between two encodings. The data in $octets must be encoded as octets and not as characters in Perl's internal -format. For example, to convert ISO-8859-1 data to Microsoft's CP1250 encoding: +format. For example, to convert ISO-8859-1 data to Microsoft's CP1250 +encoding: from_to($octets, "iso-8859-1", "cp1250"); @@ -402,8 +496,8 @@ and to convert it back: Note that because the conversion happens in place, the data to be converted cannot be a string constant; it must be a scalar variable. -from_to() returns the length of the converted string in octets on success, undef -otherwise. +from_to() returns the length of the converted string in octets on +success, I<undef> on error. B<CAVEAT>: The following operations look the same but are not quite so; @@ -411,11 +505,25 @@ B<CAVEAT>: The following operations look the same but are not quite so; $data = decode("iso-8859-1", $data); #2 Both #1 and #2 make $data consist of a completely valid UTF-8 string -but only #2 turns utf8 flag on. #1 is equivalent to +but only #2 turns UTF8 flag on. #1 is equivalent to $data = encode("utf8", decode("iso-8859-1", $data)); -See L</"The UTF-8 flag"> below. +See L</"The UTF8 flag"> below. + +Also note that + + from_to($octets, $from, $to, $check); + +is equivalent to + + $octets = encode($to, decode($from, $octets), $check); + +Yes, it does not respect the $check during decoding. It is +deliberately done that way. If you need minute control, C<decode> +then C<encode> as follows; + + $octets = encode($to, decode($from, $octets, $check_from), $check_to); =item $octets = encode_utf8($string); @@ -483,11 +591,27 @@ exported via C<use Encode qw(resolve_alias)>. See L<Encode::Alias> for details. +=head2 Finding IANA Character Set Registry names + +The canonical name of a given encoding does not necessarily agree with +IANA IANA Character Set Registry, commonly seen as C<< Content-Type: +text/plain; charset=I<whatever> >>. For most cases canonical names +work but sometimes it does not (notably 'utf-8-strict'). + +Therefore as of Encode version 2.21, a new method C<mime_name()> is added. + + use Encode; + my $enc = find_encoding('UTF-8'); + warn $enc->name; # utf-8-strict + warn $enc->mime_name; # UTF-8 + +See also: L<Encode::Encoding> + =head1 Encoding via PerlIO -If your perl supports I<PerlIO> (which is the default), you can use a PerlIO layer to decode -and encode directly via a filehandle. The following two examples -are totally identical in their functionality. +If your perl supports I<PerlIO> (which is the default), you can use a +PerlIO layer to decode and encode directly via a filehandle. The +following two examples are totally identical in their functionality. # via PerlIO open my $in, "<:encoding(shiftjis)", $infile or die; @@ -513,47 +637,59 @@ method. perlio_ok("euc-jp") Fortunately, all encodings that come with Encode core are PerlIO-savvy -except for hz and ISO-2022-kr. For gory details, see L<Encode::Encoding> and L<Encode::PerlIO>. +except for hz and ISO-2022-kr. For gory details, see +L<Encode::Encoding> and L<Encode::PerlIO>. =head1 Handling Malformed Data +The optional I<CHECK> argument tells Encode what to do when it +encounters malformed data. Without CHECK, Encode::FB_DEFAULT ( == 0 ) +is assumed. + +As of version 2.12 Encode supports coderef values for CHECK. See below. + =over 2 -The I<CHECK> 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<CHECK>. +=item B<NOTE:> Not all encoding support this feature + +Some encodings ignore I<CHECK> argument. For example, +L<Encode::Unicode> ignores I<CHECK> and it always croaks on error. + +=back + +Now here is the list of I<CHECK> values available + +=over 2 =item I<CHECK> = Encode::FB_DEFAULT ( == 0) -If I<CHECK> is 0, (en|de)code will put a I<substitution character> -in place of a malformed character. For UCM-based encodings, -E<lt>subcharE<gt> will be used. For Unicode, the code point C<0xFFFD> is used. -If the data is supposed to be UTF-8, an optional lexical warning +If I<CHECK> is 0, (en|de)code will put a I<substitution character> in +place of a malformed character. When you encode, E<lt>subcharE<gt> +will be used. When you decode the code point C<0xFFFD> is used. If +the data is supposed to be UTF-8, an optional lexical warning (category utf8) is given. =item I<CHECK> = Encode::FB_CROAK ( == 1) If I<CHECK> is 1, methods will die on error immediately with an error message. Therefore, when I<CHECK> is set to 1, you should trap the -fatal error with eval{} unless you really want to let it die on error. +error with eval{} unless you really want to let it die. =item I<CHECK> = Encode::FB_QUIET If I<CHECK> 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: - - my $data = ''; my $utf8 = ''; - 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 +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, +(i.e. you are reading with a fixed-width buffer). Here is a sample +code that does exactly this: + + my $buffer = ''; my $string = ''; + while(read $fh, $buffer, 256, length($buffer)){ + $string .= decode($encoding, $buffer, Encode::FB_QUIET); + # $buffer now contains the unprocessed partial character } =item I<CHECK> = Encode::FB_WARN @@ -577,8 +713,10 @@ where I<HHHH> is the Unicode ID of the character that cannot be found in the character repertoire of the encoding. HTML/XML character reference modes are about the same, in place of -C<\x{I<HHHH>}>, HTML uses C<&#I<NNNN>>; where I<NNNN> is a decimal digit and -XML uses C<&#xI<HHHH>>; where I<HHHH> is the hexadecimal digit. +C<\x{I<HHHH>}>, HTML uses C<&#I<NNN>;> where I<NNN> is a decimal number and +XML uses C<&#xI<HHHH>;> where I<HHHH> is the hexadecimal number. + +In Encode 2.10 or later, C<LEAVE_SRC> is also implied. =item The bitmask @@ -591,17 +729,33 @@ constants via C<use Encode qw(:fallback_all)>. DIE_ON_ERR 0x0001 X WARN_ON_ERR 0x0002 X RETURN_ON_ERR 0x0004 X X - LEAVE_SRC 0x0008 + LEAVE_SRC 0x0008 X PERLQQ 0x0100 X HTMLCREF 0x0200 XMLCREF 0x0400 -=head2 Unimplemented fallback schemes +=back + +=over 2 + +=item Encode::LEAVE_SRC + +If the C<Encode::LEAVE_SRC> bit is not set, but I<CHECK> is, then the second +argument to C<encode()> or C<decode()> may be assigned to by the functions. If +you're not interested in this, then bitwise-or the bitmask with it. + +=back + +=head2 coderef for CHECK + +As of Encode 2.12 CHECK can also be a code reference which takes the +ord value of unmapped caharacter as an argument and returns a string +that represents the fallback character. For instance, -In the future, you will be able to use a code reference to a callback -function for the value of I<CHECK> but its API is still undecided. + $ascii = encode("ascii", $utf8, sub{ sprintf "<U+%04X>", shift }); -The fallback scheme does not work on EBCDIC platforms. +Acts like FB_PERLQQ but E<lt>U+I<XXXX>E<gt> is used instead of +\x{I<XXXX>}. =head1 Defining Encodings @@ -617,13 +771,13 @@ arguments are taken as aliases for I<$object>. See L<Encode::Encoding> for more details. -=head1 The UTF-8 flag +=head1 The UTF8 flag -Before the introduction of utf8 support in perl, The C<eq> operator +Before the introduction of Unicode support in perl, The C<eq> operator just compared the strings represented by two scalars. Beginning with -perl 5.8, C<eq> compares two strings with simultaneous consideration -of I<the utf8 flag>. To explain why we made it so, I will quote page -402 of C<Programming Perl, 3rd ed.> +perl 5.8, C<eq> compares two strings with simultaneous consideration of +I<the UTF8 flag>. To explain why we made it so, I will quote page 402 of +C<Programming Perl, 3rd ed.> =over 2 @@ -652,38 +806,38 @@ byte-oriented Perl and a character-oriented Perl. Back when C<Programming Perl, 3rd ed.> was written, not even Perl 5.6.0 was born and many features documented in the book remained unimplemented for a long time. Perl 5.8 corrected this and the introduction -of the UTF-8 flag is one of them. You can think of this perl notion as of a -byte-oriented mode (utf8 flag off) and a character-oriented mode (utf8 +of the UTF8 flag is one of them. You can think of this perl notion as of a +byte-oriented mode (UTF8 flag off) and a character-oriented mode (UTF8 flag on). -Here is how Encode takes care of the utf8 flag. +Here is how Encode takes care of the UTF8 flag. =over 2 =item * -When you encode, the resulting utf8 flag is always off. +When you encode, the resulting UTF8 flag is always off. -=item +=item * -When you decode, the resulting utf8 flag is on unless you can +When you decode, the resulting UTF8 flag is on unless you can unambiguously represent data. Here is the definition of dis-ambiguity. After C<$utf8 = decode('foo', $octet);>, - When $octet is... The utf8 flag in $utf8 is + 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 --------------------------------------------- -As you see, there is one exception, In ASCII. That way you can assue +As you see, there is one exception, In ASCII. That way you can assume Goal #1. And with Encode Goal #2 is assumed but you still have to be careful in such cases mentioned in B<CAVEAT> paragraphs. -This utf8 flag is not visible in perl scripts, exactly for the same +This UTF8 flag is not visible in perl scripts, exactly for the same reason you cannot (or you I<don't have to>) 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. @@ -699,27 +853,83 @@ implementation. As such, they are efficient but may change. =item is_utf8(STRING [, CHECK]) -[INTERNAL] Tests whether the UTF-8 flag is turned on in the STRING. +[INTERNAL] Tests whether the UTF8 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. +As of perl 5.8.1, L<utf8> also has utf8::is_utf8(). + =item _utf8_on(STRING) -[INTERNAL] Turns on the UTF-8 flag in STRING. The data in STRING is +[INTERNAL] Turns on the UTF8 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 treat the return value as +state of the UTF8 flag (so please don't treat the return value as indicating success or failure), or C<undef> if STRING is not a string. +This function does not work on tainted values. + =item _utf8_off(STRING) -[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 +[INTERNAL] Turns off the UTF8 flag in STRING. Do not use frivolously. +Returns the previous state of the UTF8 flag (so please don't treat the return value as indicating success or failure), or C<undef> if STRING is not a string. +This function does not work on tainted values. + =back +=head1 UTF-8 vs. utf8 vs. UTF8 + + ....We now view strings not as sequences of bytes, but as sequences + of numbers in the range 0 .. 2**32-1 (or in the case of 64-bit + computers, 0 .. 2**64-1) -- Programming Perl, 3rd ed. + +That has been the perl's notion of UTF-8 but official UTF-8 is more +strict; Its ranges is much narrower (0 .. 10FFFF), some sequences are +not allowed (i.e. Those used in the surrogate pair, 0xFFFE, et al). + +Now that is overruled by Larry Wall himself. + + From: Larry Wall <larry@wall.org> + Date: December 04, 2004 11:51:58 JST + To: perl-unicode@perl.org + Subject: Re: Make Encode.pm support the real UTF-8 + Message-Id: <20041204025158.GA28754@wall.org> + + On Fri, Dec 03, 2004 at 10:12:12PM +0000, Tim Bunce wrote: + : I've no problem with 'utf8' being perl's unrestricted uft8 encoding, + : but "UTF-8" is the name of the standard and should give the + : corresponding behaviour. + + For what it's worth, that's how I've always kept them straight in my + head. + + Also for what it's worth, Perl 6 will mostly default to strict but + make it easy to switch back to lax. + + Larry + +Do you copy? As of Perl 5.8.7, B<UTF-8> means strict, official UTF-8 +while B<utf8> means liberal, lax, version thereof. And Encode version +2.10 or later thus groks the difference between C<UTF-8> and C<utf8>. + + encode("utf8", "\x{FFFF_FFFF}", 1); # okay + encode("UTF-8", "\x{FFFF_FFFF}", 1); # croaks + +C<UTF-8> in Encode is actually a canonical name for C<utf-8-strict>. +Yes, the hyphen between "UTF" and "8" is important. Without it Encode +goes "liberal" + + find_encoding("UTF-8")->name # is 'utf-8-strict' + find_encoding("utf-8")->name # ditto. names are case insensitive + find_encoding("utf_8")->name # ditto. "_" are treated as "-" + find_encoding("UTF8")->name # is 'utf8'. + +The UTF8 flag is internally called UTF8, without a hyphen. It indicates +whether a string is internally encoded as utf8, also without a hypen. + =head1 SEE ALSO L<Encode::Encoding>, @@ -728,7 +938,7 @@ L<Encode::PerlIO>, L<encoding>, L<perlebcdic>, L<perlfunc/open>, -L<perlunicode>, +L<perlunicode>, L<perluniintro>, L<perlunifaq>, L<perlunitut> L<utf8>, the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt> @@ -739,4 +949,15 @@ by Dan Kogai E<lt>dankogai@dan.co.jpE<gt>. See AUTHORS for a full list of people involved. For any questions, use E<lt>perl-unicode@perl.orgE<gt> so we can all share. +While Dan Kogai retains the copyright as a maintainer, the credit +should go to all those involoved. See AUTHORS for those submitted +codes. + +=head1 COPYRIGHT + +Copyright 2002-2006 Dan Kogai E<lt>dankogai@dan.co.jpE<gt> + +This library is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + =cut |