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PATCH: Encode.pm #11289

Closed p5pRT closed 13 years ago

p5pRT commented 13 years ago

Migrated from rt.perl.org#89640 (status was 'rejected')

Searchable as RT89640$

p5pRT commented 13 years ago

From tchrist@perl.com

Does anybody know anybody who really uses Encode​::ConfigLocal? The enc2xs manpage says​:

  7. If you want to add your encoding to Encode's demand-loading   list (so you don't have to "use Encode​::YourEncoding")\, run

  enc2xs -C

  to update Encode​::ConfigLocal\, a module that controls local   settings. After that\, "use Encode;" is enough to load your   encodings on demand.

But I can find nothing else on what that might be used for\, or how.

The patch below is virtually only doc changes. I'd appreciate it if other eyes than my own could please look it over to make sure I haven't accidentally swapped around something so much that it is no longer truthful.

Thank you.

--tom

p5pRT commented 13 years ago

From tchrist@perl.com

lib-Encode.patch ```diff --- lib/Encode.pm 2011-04-25 19:40:42.000000000 -0600 +++ /tmp/Encode.pm 2011-05-01 13:23:45.000000000 -0600 @@ -68,7 +68,7 @@ } else { %enc = %Encoding; - for my $mod ( map { m/::/o ? $_ : "Encode::$_" } @_ ) { + for my $mod ( map { m/::/ ? $_ : "Encode::$_" } @_ ) { DEBUG and warn $mod; for my $enc ( keys %ExtModule ) { $ExtModule{$enc} eq $mod and $enc{$enc} = $mod; @@ -334,8 +334,8 @@ $Encode::Encoding{utf8} = bless { Name => "utf8" } => "Encode::utf8"; $Encode::Encoding{"utf-8-strict"} = - bless { Name => "utf-8-strict", strict_utf8 => 1 } => - "Encode::utf8"; + bless { Name => "utf-8-strict", strict_utf8 => 1 } + => "Encode::utf8"; } } @@ -345,7 +345,7 @@ =head1 NAME -Encode - character encodings +Encode - character encodings in Perl =head1 SYNOPSIS @@ -353,10 +353,10 @@ =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 +Encode consists of a collection of modules whose details are too extensive +to fit in one document. This one itself explains the top-level APIs and general topics at a glance. For other topics and more details, -see the PODs below: +see the documentation for these modules: Name Description -------------------------------------------------------- @@ -371,26 +371,26 @@ =head1 DESCRIPTION -The C module provides the interfaces between Perl's strings +The C module provides the interface between Perl strings and the rest of the system. Perl strings are sequences of -B. +I. -The repertoire of characters that Perl can represent is at least that +The repertoire of characters that Perl can represent is a superset of those defined by the Unicode Consortium. On most platforms the ordinal -values of the characters (as returned by C) is the "Unicode -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). - -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 machine's representation of -numbers, pixels in an image - or just about anything. +values of a character as returned by C)> is the I for that character. The exceptions are platforms where +the legacy encoding is some variant of EBCDIC rather than a superset +of ASCII; see L. + +During recent history, data is moved around a computer in 8-bit chunks, +often called "bytes" but also known as "octets" in standards documents. +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. When Perl is processing "binary data", the programmer wants Perl to -process "sequences of bytes". This is not a problem for Perl - as a +process "sequences of bytes". This is not a problem for Perl: because a byte has 256 possible values, it easily fits in Perl's much larger "logical character". @@ -400,94 +400,95 @@ =item * -I: a character in the range 0..(2**32-1) (or more). -(What Perl's strings are made of.) +I: a character in the range 0 .. 2**32-1 (or more); +what Perl's strings are made of. =item * -I: a character in the range 0..255 -(A special case of a Perl character.) +I: a character in the range 0..255; +A special case of a Perl character. =item * -I: 8 bits of data, with ordinal values 0..255 -(Term for bytes passed to or from a non-Perl context, e.g. a disk file.) +I: 8 bits of data, with ordinal values 0..255; +Term for bytes passed to or from a non-Perl context, such as a disk file. =back -=head1 PERL ENCODING API +=head1 THE PERL ENCODING API =over 2 -=item $octets = encode(ENCODING, $string [, CHECK]) +=item $octets = encode(ENCODING, STRING[, CHECK]) -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. +Encodes the scalar value I from Perl's internal form into +I and returns a sequence of octets. I can be either a +canonical name or an alias. For encoding names and aliases, see +L. For CHECK, see L. -For example, to convert a string from Perl's internal format to -iso-8859-1 (also known as Latin1), +For example, to convert a string from Perl's internal format into +ISO-8859-1, also known as Latin1: $octets = encode("iso-8859-1", $string); B: When you run C<$octets = encode("utf8", $string)>, then -$octets B $string. 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. - -If the $string is C then C is returned. - -=item $string = decode(ENCODING, $octets [, CHECK]) - -Decodes a sequence of octets assumed to be in I into Perl's -internal form and returns the resulting string. As in encode(), -ENCODING can be either a canonical name or an alias. For encoding names -and aliases, see L. For CHECK, see -L. +$octets I $string. Though both contain the +same data, the UTF8 flag for $octets is I off. When you +encode anything, the UTF8 flag on the result is always off, even when it +contains a completely valid utf8 string. See L below. + +If the $string is C, then C is returned. + +=item $string = decode(ENCODING, OCTETS[, CHECK]) + +This function returns the string that results from decoding the scalar +value I, assumed to be a sequence of octets in I, into +Perl's internal form. The returns the resulting string. As with encode(), +I can be either a canonical name or an alias. For encoding names +and aliases, see L; for I, see L. -For example, to convert ISO-8859-1 data to a string in Perl's internal format: +For example, to convert ISO-8859-1 data into a string in Perl's +internal format: $string = decode("iso-8859-1", $octets); B: When you run C<$string = decode("utf8", $octets)>, then $string -B $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 +I $octets. Though both contain the same data, the +UTF8 flag for $string is on unless $octets consists entirely of ASCII data +on ASCII machines or EBCDIC on EBCDIC machines. See L below. -If the $string is C then C is returned. +If the $string is C, then C is returned. =item [$obj =] find_encoding(ENCODING) -Returns the I corresponding to ENCODING. Returns -undef if no matching ENCODING is find. - -This object is what actually does the actual (en|de)coding. +Returns the I corresponding to I. Returns +C if no matching I is find. The returned object is +what does the actual encoding or decoding. $utf8 = decode($name, $bytes); is in fact - $utf8 = do{ - $obj = find_encoding($name); - croak qq(encoding "$name" not found) unless ref $obj; - $obj->decode($bytes) - }; + $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; +You can therefore 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; - } + my $enc = find_encoding("iso-8859-1"); + while(<>) { + my $utf8 = $enc->decode($_); + ... # now do something with $utf8; + } Besides C<< ->decode >> and C<< ->encode >>, other methods are -available as well. For instance, C<< -> name >> returns the canonical +available as well. For instance, C<< ->name >> returns the canonical name of the encoding object. find_encoding("latin1")->name; # iso-8859-1 @@ -496,9 +497,9 @@ =item [$length =] from_to($octets, FROM_ENC, TO_ENC [, CHECK]) -Converts B 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 +Converts I data between two encodings. The data in $octets +must be encoded as octets and I as characters in Perl's internal +format. For example, to convert ISO-8859-1 data into Microsoft's CP1250 encoding: from_to($octets, "iso-8859-1", "cp1250"); @@ -507,54 +508,53 @@ from_to($octets, "cp1250", "iso-8859-1"); -Note that because the conversion happens in place, the data to be -converted cannot be a string constant; it must be a scalar variable. +Because the conversion happens in place, the data to be +converted cannot be a string constant: it must be a scalar variable. -from_to() returns the length of the converted string in octets on -success, I on error. +from_to() returns the length of the converted string in octets on success, +and C on error. -B: The following operations look the same but are not quite so; +B: The following operations may look the same, but are not: from_to($data, "iso-8859-1", "utf8"); #1 $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 +Both #1 and #2 make $data consist of a completely valid UTF-8 string, +but only #2 turns the UTF8 flag on. #1 is equivalent to: $data = encode("utf8", decode("iso-8859-1", $data)); See L below. -Also note that +Also note that: from_to($octets, $from, $to, $check); -is equivalent to +is equivalent t:o $octets = encode($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 -then C as follows; +Yes, it does I respect the $check during decoding. It is +deliberately done that way. If you need minute control, use C +followed by C as follows: $octets = encode($to, decode($from, $octets, $check_from), $check_to); =item $octets = encode_utf8($string); -Equivalent to C<$octets = encode("utf8", $string);> The characters -that comprise $string are encoded in Perl's internal format and the -result is returned as a sequence of octets. All possible -characters have a UTF-8 representation so this function cannot fail. - +Equivalent to C<$octets = encode("utf8", $string)>. The characters in +$string are encoded in Perl's internal format, and the result is returned +as a sequence of octets. Because all possible characters in Perl have a +(loose, not strict) UTF-8 representation, this function cannot fail. =item $string = decode_utf8($octets [, CHECK]); -equivalent to C<$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. +Equivalent to C<$string = decode("utf8", $octets [, CHECK])>. +The sequence of octets represented by $octets is decoded +from UTF-8 into a sequence of logical characters. +Because not all sequences of octets are valid UTF-8, +it is quite possible for this function to fail. +For CHECK, see L. =back @@ -563,17 +563,17 @@ use Encode; @list = Encode->encodings(); -Returns a list of the canonical names of the available encodings that -are loaded. To get a list of all available encodings including the -ones that are not loaded yet, say +Returns a list of canonical names of available encodings that have already +been loaded. To get a list of all available encodings including those that +have not yet been loaded, say: @all_encodings = Encode->encodings(":all"); -Or you can give the name of a specific module. +Or you can give the name of a specific module: @with_jp = Encode->encodings("Encode::JP"); -When "::" is not in the name, "Encode::" is assumed. +When "C<::>" is not in the name, "C" is assumed. @ebcdic = Encode->encodings("EBCDIC"); @@ -586,36 +586,36 @@ use Encode; use Encode::Alias; - define_alias(newName => ENCODING); + define_alias(NEWNAME => ENCODING); -After that, newName can be used as an alias for ENCODING. -ENCODING may be either the name of an encoding or an -I +After that, I can be used as an alias for I. + may be either the name of an encoding or an +I. -But before you do so, make sure the alias is nonexistent with +Before you do that, first make sure the alias is nonexistent using C, which returns the canonical name thereof. -i.e. +For example: Encode::resolve_alias("latin1") eq "iso-8859-1" # true Encode::resolve_alias("iso-8859-12") # false; nonexistent Encode::resolve_alias($name) eq $name # true if $name is canonical resolve_alias() does not need C; it can be -exported via C. +imported via C. See L 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 >>. For most cases canonical names -work but sometimes it does not (notably 'utf-8-strict'). +IANA Character Set Registry, commonly seen as C<< Content-Type: +text/plain; charset=I >>. For most cases, the canonical name +works, but sometimes it does not, most notably with "utf-8-strict". -Therefore as of Encode version 2.21, a new method C is added. +As of C version 2.21, a new method C is thereforeadded. use Encode; - my $enc = find_encoding('UTF-8'); + my $enc = find_encoding("UTF-8"); warn $enc->name; # utf-8-strict warn $enc->mime_name; # UTF-8 @@ -623,51 +623,67 @@ =head1 Encoding via PerlIO -If your perl supports I (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; - open my $out, ">:encoding(euc-jp)", $outfile or die; - while(<$in>){ print $out $_; } - - # via from_to - open my $in, "<", $infile or die; - open my $out, ">", $outfile or die; - while(<$in>){ - from_to($_, "shiftjis", "euc-jp", 1); - print $out $_; - } - -Unfortunately, it may be that encodings are PerlIO-savvy. You can check -if your encoding is supported by PerlIO by calling the C -method. +If your perl supports C (which is the default), you can use a +C layer to decode and encode directly via a filehandle. The +following two examples are fully identical in functionality: + + ### Version 1 via PerlIO + open(INPUT, "< :encoding(shiftjis)", $infile) + || die "Can't open < $infile for reading: $!"; + open(OUTPUT, "> :encoding(euc-jp)", $outfile) + || die "Can't open > $output for writing: $!"; + while () { # auto decodes $_ + print OUTPUT; # auto encodes $_ + } + close(INPUT) || die "can't close $infile: $!"; + close(OUTPUT) || die "can't close $outfile: $!"; + + ### Version 2 via from_to() + open(INPUT, "< :raw", $infile) + || die "Can't open < $infile for reading: $!"; + open(OUTPUT, "> :raw", $outfile) + || die "Can't open > $output for writing: $!"; + + while () { + from_to($_, "shiftjis", "euc-jp", 1); # switch encoding + print OUTPUT; # emit raw (but properly encoded) data + } + close(INPUT) || die "can't close $infile: $!"; + close(OUTPUT) || die "can't close $outfile: $!"; + +In the first version above, you let the appropriate encoding layer +handle the conversion. In the second, you explicitly translate +from one encoding to the other. + +Unfortunately, it may be that encodings are C-savvy. You can check +to see whether your encoding is supported by C by invoking the +C method on it: - Encode::perlio_ok("hz"); # False - find_encoding("euc-cn")->perlio_ok; # True where PerlIO is available + Encode::perlio_ok("hz"); # false + find_encoding("euc-cn")->perlio_ok; # true wherever PerlIO is available - use Encode qw(perlio_ok); # exported upon request + use Encode qw(perlio_ok); # imported upon request 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 +Fortunately, all encodings that come with C core are C-savvy +except for "hz" and "ISO-2022-kr". For the gory details, see L and L. =head1 Handling Malformed Data -The optional I argument tells Encode what to do when it -encounters malformed data. Without CHECK, Encode::FB_DEFAULT ( == 0 ) -is assumed. +The optional I argument tells C what to do when +encountering malformed data. Without I, C +(== 0) is assumed. -As of version 2.12 Encode supports coderef values for CHECK. See below. +As of version 2.12, C supports coderef values for C; +see below. =over 2 -=item B Not all encoding support this feature +=item B Not all encoding support this feature! -Some encodings ignore I argument. For example, -L ignores I and it always croaks on error. +Some encodings ignore the I argument. For example, +L ignores I and always Is on error. =back @@ -677,39 +693,39 @@ =item I = Encode::FB_DEFAULT ( == 0) -If I is 0, (en|de)code will put a I in -place of a malformed character. When you encode, EsubcharE -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. +If I is 0, encoding and decoding replace any malformed character +with a I. When you encode, I is used. +When you decode, the Unicode REPLACEMENT CHARACTER, code point U+FFFD, is +used. If the data is supposed to be UTF-8, an optional lexical warning of +warning category C<"utf8"> is given. =item I = Encode::FB_CROAK ( == 1) -If I is 1, methods will die on error immediately with an error -message. Therefore, when I is set to 1, you should trap the -error with eval{} unless you really want to let it die. +If I is 1, methods immediately die with an error +message. Therefore, when I is 1, you should trap +exceptions with C, unless you really want to let it C. =item I = Encode::FB_QUIET -If I is set to Encode::FB_QUIET, (en|de)code will immediately +If I is set to C, encoding and decoding 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 +error occurs. The data argument is overwritten with everything +after that point; that is, the unprocessed portion of the data. This is +handy when you have to call C 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: +(that is, you are reading with a fixed-width buffer). Here's some sample +code to do exactly that: - my $buffer = ''; my $string = ''; - while(read $fh, $buffer, 256, length($buffer)){ - $string .= decode($encoding, $buffer, Encode::FB_QUIET); - # $buffer now contains the unprocessed partial character - } + my($buffer, $string) = ("", ""); + while (read($fh, $buffer, 256, length($buffer))) { + $string .= decode($encoding, $buffer, Encode::FB_QUIET); + # $buffer now contains the unprocessed partial character + } =item I = Encode::FB_WARN -This is the same as above, except that it warns on error. Handy when -you are debugging the mode above. +This is the same as C above, except that instead of being silent +on errors, it issues a warning. This is handy for when you are debugging. =item perlqq mode (I = Encode::FB_PERLQQ) @@ -717,26 +733,26 @@ =item XML charref mode (I = Encode::FB_XMLCREF) -For encodings that are implemented by Encode::XS, CHECK == -Encode::FB_PERLQQ turns (en|de)code into C fallback mode. +For encodings that are implemented by the C module, C C<==> +C puts C and C into C fallback mode. -When you decode, C<\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, C<\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. +When you decode, C<\xI> is inserted for a malformed character, where +I is the hex representation of the octet that could not be decoded to +utf8. When you encode, C<\x{I}> will be inserted, where I is +the Unicode code point (in any number of hex digits) 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}>, HTML uses C<&#I;> where I is a decimal number and +The HTML/XML character reference modes are about the same. In place of +C<\x{I}>, HTML uses C<&#I;> where I is a decimal number, and XML uses C<&#xI;> where I is the hexadecimal number. -In Encode 2.10 or later, C is also implied. +In C 2.10 or later, C is also implied. =item The bitmask -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 +These modes are all actually set via a bitmask. Here is how the C> +constants are laid out. You can import the C> constants via +C, and you can import the generic bitmask constants via C. FB_DEFAULT FB_CROAK FB_QUIET FB_WARN FB_PERLQQ @@ -754,44 +770,43 @@ =item Encode::LEAVE_SRC -If the C bit is not set, but I is, then the second -argument to C or C may be assigned to by the functions. If -you're not interested in this, then bitwise-or the bitmask with it. +If the C bit is I set but I is set, then the +second argument to encode() or decode() will be overwritten in place. +If you're not interested in this, then bitwise-OR it with the bitmask. =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, +As of C 2.12, C can also be a code reference which takes the +ordinal value of the unmapped caharacter as an argument and returns a string +that represents the fallback character. For instance: $ascii = encode("ascii", $utf8, sub{ sprintf "", shift }); -Acts like FB_PERLQQ but EU+IE is used instead of -\x{I}. +Acts like C but U+I is used instead of C<\x{I}>. =head1 Defining Encodings To define a new encoding, use: use Encode qw(define_encoding); - define_encoding($object, 'canonicalName' [, alias...]); + define_encoding($object, CANONICAL_NAME [, alias...]); -I will be associated with I<$object>. The object +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>. +If more than two arguments are provided, additional +arguments are considered aliases for I<$object>. -See L for more details. +See L for details. =head1 The UTF8 flag -Before the introduction of Unicode support in perl, The C operator +Before the introduction of Unicode support in Perl, The C operator just compared the strings represented by two scalars. Beginning with -perl 5.8, C compares two strings with simultaneous consideration of -I. To explain why we made it so, I will quote page 402 of -C +Perl 5.8, C compares two strings with simultaneous consideration of +I. To explain why we made it so, I quote from page 402 of +I =over 2 @@ -817,28 +832,27 @@ =back -Back when C was written, not even Perl 5.6.0 -was born and many features documented in the book remained -unimplemented for a long time. Perl 5.8 corrected this and the introduction -of the UTF8 flag is one of them. You can think of this perl notion as of a -byte-oriented mode (UTF8 flag off) and a character-oriented mode (UTF8 -flag on). +When I was written, not even Perl 5.6.0 had been +born yet, many features documented in the book remained unimplemented for a +long time. Perl 5.8 corrected much of this, and the introduction of the +UTF8 flag is one of them. You can think of there being two fundamentally +different kinds of strings and string-operations in Perl: one a +byte-oriented mode for when the internal UTF8 flag is off, and the other a +character-oriented mode for when the internal UTF8 flag is on. -Here is how Encode takes care of the UTF8 flag. +Here is how C handles the UTF8 flag. =over 2 =item * -When you encode, the resulting UTF8 flag is always off. +When you I, the resulting UTF8 flag is always B. =item * -When you decode, the resulting UTF8 flag is on unless you can -unambiguously represent data. Here is the definition of -dis-ambiguity. - -After C<$utf8 = decode('foo', $octet);>, +When you I, the resulting UTF8 flag is B--I you can +unambiguously represent data. Here is what we mean by "unambiguously". +After C<$utf8 = decode("foo", $octet)>, When $octet is... The UTF8 flag in $utf8 is --------------------------------------------- @@ -847,50 +861,53 @@ In any other Encoding ON --------------------------------------------- -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 paragraphs. - -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. +As you see, there is one exception: in ASCII. That way you can assume +Goal #1. And with C, Goal #2 is assumed but you still have to be +careful in the cases mentioned in the B paragraphs above. + +This UTF8 flag is not visible in Perl scripts, exactly for the same reason +you cannot (or rather, you I) see whether a scalar contains +a string, an integer, or a floating-point number. But you can still peek +and poke these if you will. See the next section. =back =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 in a future +release. =over 2 =item is_utf8(STRING [, CHECK]) -[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 +[INTERNAL] Tests whether the UTF8 flag is turned on in the I. +If I is true, also checks whether I contains well-formed UTF-8. Returns true if successful, false otherwise. -As of perl 5.8.1, L also has utf8::is_utf8(). +As of Perl 5.8.1, L also has the C function. =item _utf8_on(STRING) -[INTERNAL] Turns on the UTF8 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 UTF8 flag (so please don't treat the return value as -indicating success or failure), or C if STRING is not a string. +[INTERNAL] Turns the I's internal UTF8 flag B. The I +is I checked for containing only well-formed UTF-8. Do not use this +unless you I that the STRING holds only +well-formed UTF-8. Returns the previous state of the UTF8 flag (so please +don't treat the return value as indicating success or failure), or C +if I is not a string. -This function does not work on tainted values. +B: For security reasons, this function does not work on tainted values. =item _utf8_off(STRING) -[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 if STRING is -not a string. +[INTERNAL] Turns the I's internal UTF8 flag B. Do not use +frivolously. Returns the previous state of the UTF8 flag, or C if +I is not a string. Do not treat the return value as indicative of +success or failure, because that isn't what it means: it is only the +previous setting. -This function does not work on tainted values. +B: For security reasons, this function does not work on tainted values. =back @@ -900,49 +917,57 @@ 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). +That has historically been Perl's notion of UTF-8, as that is how UTF-8 was +first conceived by Ken Thompson when he invented it. However, thanks to +later revisions to the applicable standards, official UTF-8 is now rather +stricter than that. For example, its range is much narrower (0 .. 0x10_FFFF +to cover only 21 bits instead of 32 or 64 bits) and some sequences +are not allowed, like those used in surrogate pairs, the 31 non-character +code points 0xFDD0 .. 0xFDEF, the last two code points in I plane +(0xI_FFFE and 0xI_FFFF), all non-shortest encodings, etc. -Now that is overruled by Larry Wall himself. +The former default in which Perl would always use a loose interpretation of +UTF-8 has now been overruled: From: Larry Wall 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 means strict, official UTF-8 -while B means liberal, lax, version thereof. And Encode version -2.10 or later thus groks the difference between C and C"utf8". +Got that? As of Perl 5.8.7, B<"UTF-8"> means UTF-8 in its current +sense, which is conservative and strict and security-conscious, whereas +B<"utf8"> means UTF-8 in its former sense, which was liberal and loose and +lax. C version 2.10 or later thus groks this subtle but critically +important distinction between C<"UTF-8"> and C<"utf8">. encode("utf8", "\x{FFFF_FFFF}", 1); # okay encode("UTF-8", "\x{FFFF_FFFF}", 1); # croaks -C in Encode is actually a canonical name for C. -Yes, the hyphen between "UTF" and "8" is important. Without it Encode -goes "liberal" +In the C module, C<"UTF-8"> is actually a canonical name for +C<"utf-8-strict">. That hyphen between the C<"UTF"> and the C<"8"> is +critical; without it, C goes "liberal" and (perhaps overly-)permissive: 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("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. +Perl's internal UTF8 flag is called "UTF8", without a hyphen. It indicates +whether a string is internally encoded as "utf8", also without a hyphen. =head1 SEE ALSO @@ -958,18 +983,18 @@ =head1 MAINTAINER -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. - -While Dan Kogai retains the copyright as a maintainer, the credit -should go to all those involoved. See AUTHORS for those submitted -codes. +This project was originated by the late Nick Ing-Simmons and later +maintained by Dan Kogai I<< >>. See AUTHORS +for a full list of people involved. For any questions, send mail to +I<< >> so that we can all share. + +While Dan Kogai retains the copyright as a maintainer, credit +should go to all those involved. See AUTHORS for a list of those +who submitted code to the project. =head1 COPYRIGHT -Copyright 2002-2006 Dan Kogai Edankogai@dan.co.jpE +Copyright 2002-2011 Dan Kogai I<< >>. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. ```
p5pRT commented 13 years ago

From @cpansprout

On Sun May 01 12​:37​:33 2011\, tom christiansen wrote​:

Does anybody know anybody who really uses Encode​::ConfigLocal? The enc2xs manpage says​:

7. If you want to add your encoding to Encode's demand-loading list (so you don't have to "use Encode​::YourEncoding")\, run

       enc2xs \-C

   to update Encode&#8203;::ConfigLocal\, a module that controls local
   settings\.  After that\, "use Encode;" is enough to load your
   encodings on demand\.

But I can find nothing else on what that might be used for\, or how.

The patch below is virtually only doc changes. I'd appreciate it if other eyes than my own could please look it over to make sure I haven't accidentally swapped around something so much that it is no longer truthful.

I scanned through it very quickly\, but did not find any errors\, except for a minor capitalisation problem​:

+I\​: 8 bits of data\, with ordinal values 0..255; +Term for bytes passed to or from a non-Perl context\, such as a disk file.

Shouldnā€™t Term be lc?

Could you resubmit this to Encodeā€™s CPAN queue? (bug-Encode@​rt.cpan.org)

CPAN is upstream.

p5pRT commented 13 years ago

The RT System itself - Status changed from 'new' to 'open'

p5pRT commented 13 years ago

From @obra

Like everything that's in cpan/ in an unbuilt source tree\, Encode's upstream is cpan - Patches for Encode should go to Dan Kogai.

-j

p5pRT commented 13 years ago

@iabyn - Status changed from 'open' to 'rejected'