diff options
Diffstat (limited to 'ext/Encode/Encode.pm')
| -rw-r--r-- | ext/Encode/Encode.pm | 215 |
1 files changed, 104 insertions, 111 deletions
diff --git a/ext/Encode/Encode.pm b/ext/Encode/Encode.pm index fb80200d2c..dbd7934f87 100644 --- a/ext/Encode/Encode.pm +++ b/ext/Encode/Encode.pm @@ -1,6 +1,6 @@ package Encode; use strict; -our $VERSION = do { my @r = (q$Revision: 1.52 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; +our $VERSION = do { my @r = (q$Revision: 1.56 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; our $DEBUG = 0; use XSLoader (); XSLoader::load 'Encode'; @@ -66,9 +66,9 @@ sub encodings sub perlio_ok{ exists $INC{"PerlIO/encoding.pm"} or return 0; - my $stash = ref($_[0]); - $stash ||= ref(find_encoding($_[0])); - return ($stash eq "Encode::XS" || $stash eq "Encode::Unicode"); + my $obj = ref($_[0]) ? $_[0] : find_encoding($_[0]); + $obj->can("perlio_ok") and return $obj->perlio_ok() unless $@; + return 0; # safety net } sub define_encoding @@ -253,26 +253,11 @@ sub predefine_encodings{ $_[1] = '' if $chk; return $octets; }; - $Encode::Encoding{utf8} = + $Encode::Encoding{utf8} = bless {Name => "utf8"} => "Encode::utf8"; } } -require Encode::Encoding; -@Encode::XS::ISA = qw(Encode::Encoding); - -# This is very dodgy - PerlIO::encoding does "use Encode" and _BEFORE_ it gets a -# chance to set its VERSION we potentially delete it from %INC so it will be re-loaded -# NI-S -eval { - require PerlIO::encoding; - unless (PerlIO::encoding->VERSION >= 0.02){ - delete $INC{"PerlIO/encoding.pm"}; - } -}; -# warn $@ if $@; -@Encode::XS::ISA = qw(Encode::Encoding); - 1; __END__ @@ -285,13 +270,12 @@ Encode - character encodings use Encode; - =head2 Table of Contents -Encode consists of a collection of modules which details are too big +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; +see the PODs below: Name Description -------------------------------------------------------- @@ -317,16 +301,16 @@ 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<perlebcdic>). -Traditionally 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 +languages but also "binary" data being the machine's representation of numbers, pixels in an image - or just about anything. -When Perl is processing "binary data" the programmer wants Perl to +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 +byte has 256 possible values, it easily fits in Perl's much larger "logical character". =head2 TERMINOLOGY @@ -346,7 +330,7 @@ I<byte>: a character in the range 0..255 =item * I<octet>: 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 @@ -360,32 +344,32 @@ and such details may change in future releases. =item $octets = encode(ENCODING, $string[, CHECK]) -Encodes string from Perl's internal form into I<ENCODING> and returns +Encodes a string from Perl's internal form into I<ENCODING> and returns a sequence of octets. ENCODING can be either a canonical name or -alias. For encoding names and aliases, see L</"Defining Aliases">. -For CHECK see L</"Handling Malformed Data">. +an alias. For encoding names and aliases, see L</"Defining Aliases">. +For CHECK, see L</"Handling Malformed Data">. -For example to convert (internally UTF-8 encoded) Unicode string to +For example, to convert (internally UTF-8 encoded) Unicode string to iso-8859-1 (also known as Latin1), $octets = encode("iso-8859-1", $unicode); =item $string = decode(ENCODING, $octets[, CHECK]) -Decode sequence of octets assumed to be in I<ENCODING> into Perl's -internal form and returns the resulting string. as in encode(), -ENCODING can be either a canonical name or alias. For encoding names -and aliases, see L</"Defining Aliases">. For CHECK see +Decodes a sequence of octets assumed to be in I<ENCODING> 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</"Defining Aliases">. For CHECK, see L</"Handling Malformed Data">. -For example to convert ISO-8859-1 data to UTF-8: +For example, to convert ISO-8859-1 data to UTF-8: $utf8 = decode("iso-8859-1", $latin1); =item [$length =] from_to($string, FROM_ENCODING, TO_ENCODING [,CHECK]) -Convert B<in-place> the data between two encodings. -For example to convert ISO-8859-1 data to UTF-8: +Converts B<in-place> data between two encodings. +For example, to convert ISO-8859-1 data to UTF-8: from_to($data, "iso-8859-1", "utf-8"); @@ -394,36 +378,37 @@ 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. +converted cannot be a string constant; it must be a scalar variable. -from_to() return the length of the converted string on success, undef +from_to() returns the length of the converted string on success, undef otherwise. =back =head2 UTF-8 / utf8 -The Unicode consortium defines the UTF-8 standard as a way of encoding -the entire Unicode repertoire as sequences of octets. This encoding is -expected to become very widespread. Perl can use this form internally -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). +The Unicode Consortium defines the UTF-8 transformation format as a +way of encoding the entire Unicode repertoire as sequences of octets. +This encoding is expected to become very widespread. Perl can use this +form internally 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). =over 4 =item $octets = encode_utf8($string); -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. +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 $string = decode_utf8($octets [, CHECK]); The sequence of octets represented by $octets is decoded from UTF-8 into a sequence of logical characters. Not all sequences of octets form valid UTF-8 encodings, so it is possible for this call to fail. -For CHECK see L</"Handling Malformed Data">. +For CHECK, see L</"Handling Malformed Data">. =back @@ -438,7 +423,7 @@ ones that are not loaded yet, say @all_encodings = Encode->encodings(":all"); -Or you can give the name of specific module. +Or you can give the name of a specific module. @with_jp = Encode->encodings("Encode::JP"); @@ -446,12 +431,12 @@ When "::" is not in the name, "Encode::" is assumed. @ebcdic = Encode->encodings("EBCDIC"); -To find which encodings are supported by this package in details, +To find out in detail which encodings are supported by this package, see L<Encode::Supported>. =head2 Defining Aliases -To add new alias to a given encoding, Use; +To add a new alias to a given encoding, use: use Encode; use Encode::Alias; @@ -469,16 +454,16 @@ i.e. Encode::resolve_alias("iso-8859-12") # false; nonexistent Encode::resolve_alias($name) eq $name # true if $name is canonical -This resolve_alias() does not need C<use Encode::Alias> and is -exported via C<use encode qw(resolve_alias)>. +resolve_alias() does not need C<use Encode::Alias>; it can be +exported via C<use Encode qw(resolve_alias)>. -See L<Encode::Alias> on details. +See L<Encode::Alias> for details. =head1 Encoding via PerlIO -If your perl supports I<PerlIO>, you can use PerlIO layer to directly -decode and encode via filehandle. The following two examples are -totally identical by functionality. +If your perl supports I<PerlIO>, 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; @@ -486,82 +471,90 @@ totally identical by functionality. while(<>){ print; } # via from_to - open my $in, $infile or die; - open my $out, $outfile or die; + open my $in, "<", $infile or die; + open my $out, ">", $outfile or die; while(<>){ - from_to($_, "shiftjis", "euc", 1); + from_to($_, "shiftjis", "euc-jp", 1); } -Unfortunately, not all encodings are PerlIO-savvy. You can check if -your encoding is supported by PerlIO by C<perlio_ok> method. +Unfortunately, there may be encodings are PerlIO-savvy. You can check +if your encoding is supported by PerlIO by calling the C<perlio_ok> +method. + + Encode::perlio_ok("hz"); # False + find_encoding("euc-cn")->perlio_ok; # True where PerlIO is available + + use Encode qw(perlio_ok); # exported upon request + perlio_ok("euc-jp") - Encode::perlio_ok("iso-20220jp"); # false - find_encoding("iso-2022-jp")->perlio_ok; # false - use Encode qw(perlio_ok); # exported upon request - perlio_ok("euc-jp") # true if PerlIO is enabled +Fortunately, all encodings that come with Encode core are PerlIO-savvy +except for hz and ISO-2022-kr. See L<Encode::Encoding> for details. -For gory details, see L<Encode::PerlIO>; +For gory details, see L<Encode::PerlIO>. =head1 Handling Malformed Data =over 4 -THE I<CHECK> argument is used as follows. When you omit it, it is -identical to I<CHECK> = 0. +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 I<CHECK> = Encode::FB_DEFAULT ( == 0) -If I<CHECK> is 0, (en|de)code will put I<substitution character> in -place of the malformed character. for UCM-based encodings, -E<lt>subcharE<gt> will be used. For Unicode, \xFFFD is used. If the -data is supposed to be UTF-8, an optional lexical warning (category -utf8) is given. +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, "\x{FFFD}" is used. +If the data is supposed to be UTF-8, an optional lexical warning +(category utf8) is given. =item I<CHECK> = Encode::DIE_ON_ERROR (== 1) -If I<CHECK> is 1, methods will die immediately with an error -message. so when I<CHECK> is set, you should trap the fatal error -with eval{} unless you really want to let it die on error. +If I<CHECK> is 1, methods will die 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. =item I<CHECK> = Encode::FB_QUIET If I<CHECK> is set to Encode::FB_QUIET, (en|de)code will immediately -return processed part on error, with data passed via argument -overwritten with unprocessed part. This is handy when have to -repeatedly call because the source data is chopped in the middle for -some reasons, such as fixed-width buffer. Here is a sample code that -just does this. +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 = ''; while(defined(read $fh, $buffer, 256)){ - # buffer may end in partial character so we append + # buffer may end in a partial character so we append $data .= $buffer; $utf8 .= decode($encoding, $data, ENCODE::FB_QUIET); - # $data now contains unprocessed partial character + # $data now contains the unprocessed partial character } =item I<CHECK> = Encode::FB_WARN -This is the same as above, except it warns on error. Handy when you -are debugging the mode above. +This is the same as above, except that it warns on error. Handy when +you are debugging the mode above. =item perlqq mode (I<CHECK> = Encode::FB_PERLQQ) For encodings that are implemented by Encode::XS, CHECK == Encode::FB_PERLQQ turns (en|de)code into C<perlqq> fallback mode. -When you decode, '\xI<XX>' will be placed where I<XX> is the hex -representation of the octet that could not be decoded to utf8. And -when you encode, '\x{I<xxxx>}' will be placed where I<xxxx> is the -Unicode ID of the character that cannot be found in the character -repertoire of the encoding. +When you decode, '\xI<XX>' will be inserted for a malformed character, +where I<XX> is the hex representation of the octet that could not be +decoded to utf8. And when you encode, '\x{I<xxxx>}' will be inserted, +where I<xxxx> is the Unicode ID of the character that cannot be found +in the character repertoire of the encoding. =item The bitmask -These modes are actually set via bitmask. here is how FB_XX are laid -out. for FB_XX you can import via C<use Encode qw(:fallbacks)> for -generic bitmask constants, you can import via - C<use Encode qw(:fallback_all)>. +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<use Encode qw(:fallbacks)>; you can import the generic bitmask +constants via C<use Encode qw(:fallback_all)>. FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ DIE_ON_ERR 0x0001 X @@ -570,9 +563,9 @@ generic bitmask constants, you can import via LEAVE_SRC 0x0008 PERLQQ 0x0100 X -=head2 Unemplemented fallback schemes +=head2 Unimplemented fallback schemes -In future you will be able to use a code reference to a callback +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. =head1 Defining Encodings @@ -583,38 +576,38 @@ To define a new encoding, use: define_encoding($object, 'canonicalName' [, alias...]); I<canonicalName> will be associated with I<$object>. The object -should provide the interface described in L<Encode::Encoding> +should provide the interface described in L<Encode::Encoding>. If more than two arguments are provided then additional -arguments are taken as aliases for I<$object> as for C<define_alias>. +arguments are taken as aliases for I<$object>, as for C<define_alias>. See L<Encode::Encoding> for more details. =head1 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 =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 _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<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. +state of the UTF-8 flag (so please don't treat the return value as +indicating success or failure), or C<undef> if STRING is not a 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<not> success or failure), or C<undef> 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<undef> if STRING is not a string. =back @@ -634,7 +627,7 @@ the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt> =head1 MAINTAINER This project was originated by Nick Ing-Simmons and later maintained -by Dan Kogai E<lt>dankogai@dan.co.jpE<gt>. See AUTHORS for full list +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 others can share. |