diff options
author | Karl Berry <karl@freefriends.org> | 2017-04-18 23:10:57 +0000 |
---|---|---|
committer | Karl Berry <karl@freefriends.org> | 2017-04-18 23:10:57 +0000 |
commit | 40b4b6e177c62a14c166dbba6adf3abc415af4b2 (patch) | |
tree | 2996bf29509c806bd8064fb6cf38092c1b375ff8 /Master/tlpkg/tlperl/lib/utf8.pm | |
parent | 8e743c86b6872f30b7a35c72aa944455157d4b3f (diff) |
tlperl 5.24.1 from siep
git-svn-id: svn://tug.org/texlive/trunk@43914 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/tlpkg/tlperl/lib/utf8.pm')
-rw-r--r-- | Master/tlpkg/tlperl/lib/utf8.pm | 127 |
1 files changed, 57 insertions, 70 deletions
diff --git a/Master/tlpkg/tlperl/lib/utf8.pm b/Master/tlpkg/tlperl/lib/utf8.pm index 23fbfac4a24..324cb87c869 100644 --- a/Master/tlpkg/tlperl/lib/utf8.pm +++ b/Master/tlpkg/tlperl/lib/utf8.pm @@ -2,7 +2,7 @@ package utf8; $utf8::hint_bits = 0x00800000; -our $VERSION = '1.17'; +our $VERSION = '1.19'; sub import { $^H |= $utf8::hint_bits; @@ -47,8 +47,9 @@ utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code $unicode = utf8::native_to_unicode(ord('A')); # returns 65 on both # ASCII and EBCDIC # platforms - $native = utf8::unicode_to_native(65); # returns 65 on ASCII - # platforms; 193 on EBCDIC + $native = utf8::unicode_to_native(65); # returns 65 on ASCII + # platforms; 193 on + # EBCDIC $flag = utf8::is_utf8($string); # since Perl 5.8.1 $flag = utf8::valid($string); @@ -56,9 +57,11 @@ utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code =head1 DESCRIPTION The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the -program text in the current lexical scope (allow UTF-EBCDIC on EBCDIC based -platforms). The C<no utf8> pragma tells Perl to switch back to treating -the source text as literal bytes in the current lexical scope. +program text in the current lexical scope. The C<no utf8> pragma tells Perl +to switch back to treating the source text as literal bytes in the current +lexical scope. (On EBCDIC platforms, technically it is allowing UTF-EBCDIC, +and not UTF-8, but this distinction is academic, so in this document the term +UTF-8 is used to mean both). B<Do not use this pragma for anything else than telling Perl that your script is written in UTF-8.> The utility functions described below are @@ -69,9 +72,7 @@ encodings, you need either a Byte Order Mark at the beginning of your source code, or C<use utf8;>, to instruct perl. When UTF-8 becomes the standard source format, this pragma will -effectively become a no-op. For convenience in what follows the term -I<UTF-X> is used to refer to UTF-8 on ASCII and ISO Latin based -platforms and UTF-EBCDIC on EBCDIC based platforms. +effectively become a no-op. See also the effects of the C<-C> switch and its cousin, the C<PERL_UNICODE> environment variable, in L<perlrun>. @@ -82,22 +83,17 @@ Enabling the C<utf8> pragma has the following effect: =item * -Bytes in the source text that have their high-bit set will be treated -as being part of a literal UTF-X sequence. This includes most +Bytes in the source text that are not in the ASCII character set will be +treated as being part of a literal UTF-8 sequence. This includes most literals such as identifier names, string constants, and constant regular expression patterns. -On EBCDIC platforms characters in the Latin 1 character set are -treated as being part of a literal UTF-EBCDIC character. - =back -Note that if you have bytes with the eighth bit on in your script -(for example embedded Latin-1 in your string literals), C<use utf8> -will be unhappy since the bytes are most probably not well-formed -UTF-X. If you want to have such bytes under C<use utf8>, you can disable -this pragma until the end the block (or file, if at top level) by -C<no utf8;>. +Note that if you have non-ASCII, non-UTF-8 bytes in your script (for example +embedded Latin-1 in your string literals), C<use utf8> will be unhappy. If +you want to have such bytes under C<use utf8>, you can disable this pragma +until the end the block (or file, if at top level) by C<no utf8;>. =head2 Utility functions @@ -109,23 +105,24 @@ you should not say that unless you really want to have UTF-8 source code. =item * C<$num_octets = utf8::upgrade($string)> +(Since Perl v5.8.0) Converts in-place the internal representation of the string from an octet -sequence in the native encoding (Latin-1 or EBCDIC) to I<UTF-X>. The +sequence in the native encoding (Latin-1 or EBCDIC) to UTF-8. The logical character sequence itself is unchanged. If I<$string> is already -stored as I<UTF-X>, then this is a no-op. Returns the -number of octets necessary to represent the string as I<UTF-X>. Can be +stored as UTF-8, then this is a no-op. Returns the +number of octets necessary to represent the string as UTF-8. Can be used to make sure that the UTF-8 flag is on, so that C<\w> or C<lc()> -work as Unicode on strings containing characters in the range 0x80-0xFF -(on ASCII and derivatives). +work as Unicode on strings containing non-ASCII characters whose code points +are below 256. -B<Note that this function does not handle arbitrary encodings.> -Therefore Encode is recommended for the general purposes; see also -L<Encode>. +B<Note that this function does not handle arbitrary encodings>; +use L<Encode> instead. =item * C<$success = utf8::downgrade($string[, $fail_ok])> +(Since Perl v5.8.0) Converts in-place the internal representation of the string from -I<UTF-X> to the equivalent octet sequence in the native encoding (Latin-1 +UTF-8 to the equivalent octet sequence in the native encoding (Latin-1 or EBCDIC). The logical character sequence itself is unchanged. If I<$string> is already stored as native 8 bit, then this is a no-op. Can be used to @@ -133,56 +130,52 @@ make sure that the UTF-8 flag is off, e.g. when you want to make sure that the substr() or length() function works with the usually faster byte algorithm. -Fails if the original I<UTF-X> sequence cannot be represented in the +Fails if the original UTF-8 sequence cannot be represented in the native 8 bit encoding. On failure dies or, if the value of I<$fail_ok> is true, returns false. Returns true on success. -B<Note that this function does not handle arbitrary encodings.> -Therefore Encode is recommended for the general purposes; see also -L<Encode>. +B<Note that this function does not handle arbitrary encodings>; +use L<Encode> instead. =item * C<utf8::encode($string)> +(Since Perl v5.8.0) Converts in-place the character sequence to the corresponding octet -sequence in I<UTF-X>. That is, every (possibly wide) character gets +sequence in UTF-8. That is, every (possibly wide) character gets replaced with a sequence of one or more characters that represent the -individual I<UTF-X> bytes of the character. The UTF8 flag is turned off. +individual UTF-8 bytes of the character. The UTF8 flag is turned off. Returns nothing. my $a = "\x{100}"; # $a contains one character, with ord 0x100 utf8::encode($a); # $a contains two characters, with ords (on - # ASCII platforms) 0xc4 and 0x80 + # ASCII platforms) 0xc4 and 0x80. On EBCDIC + # 1047, this would instead be 0x8C and 0x41. -B<Note that this function does not handle arbitrary encodings.> -Therefore Encode is recommended for the general purposes; see also -L<Encode>. +B<Note that this function does not handle arbitrary encodings>; +use L<Encode> instead. =item * C<$success = utf8::decode($string)> -Attempts to convert in-place the octet sequence encoded as I<UTF-X> to the +(Since Perl v5.8.0) +Attempts to convert in-place the octet sequence encoded as UTF-8 to the corresponding character sequence. That is, it replaces each sequence of -characters in the string whose ords represent a valid UTF-X byte +characters in the string whose ords represent a valid UTF-8 byte sequence, with the corresponding single character. The UTF-8 flag is -turned on only if the source string contains multiple-byte I<UTF-X> -characters. If I<$string> is invalid as I<UTF-X>, returns false; +turned on only if the source string contains multiple-byte UTF-8 +characters. If I<$string> is invalid as UTF-8, returns false; otherwise returns true. my $a = "\xc4\x80"; # $a contains two characters, with ords # 0xc4 and 0x80 utf8::decode($a); # On ASCII platforms, $a contains one char, - # with ord 0x100. On EBCDIC platforms, $a - # is unchanged and the function returns FALSE. - -(C<"\xc4\x80"> is not a valid sequence of bytes in any UTF-8-encoded -character(s) in the EBCDIC code pages that Perl supports, which is why the -above example returns failure on them. What does decode into C<\x{100}> -depends on the platform. It is C<"\x8C\x41"> in IBM-1047.) + # with ord 0x100. Since these bytes aren't + # legal UTF-EBCDIC, on EBCDIC platforms, $a is + # unchanged and the function returns FALSE. -B<Note that this function does not handle arbitrary encodings.> -Therefore Encode is recommended for the general purposes; see also -L<Encode>. +B<Note that this function does not handle arbitrary encodings>; +use L<Encode> instead. =item * C<$unicode = utf8::native_to_unicode($code_point)> @@ -215,7 +208,7 @@ platforms, so there is no performance hit in using it there. =item * C<$flag = utf8::is_utf8($string)> (Since Perl 5.8.1) Test whether I<$string> is marked internally as encoded in -UTF-8. Functionally the same as Encode::is_utf8(). +UTF-8. Functionally the same as C<Encode::is_utf8()>. =item * C<$flag = utf8::valid($string)> @@ -224,32 +217,26 @@ UTF-8. Will return true if it is well-formed UTF-8 and has the UTF-8 flag on B<or> if I<$string> is held as bytes (both these states are 'consistent'). Main reason for this routine is to allow Perl's test suite to check that operations have left strings in a consistent state. You most -probably want to use utf8::is_utf8() instead. +probably want to use C<utf8::is_utf8()> instead. =back C<utf8::encode> is like C<utf8::upgrade>, but the UTF8 flag is -cleared. See L<perlunicode> for more on the UTF8 flag and the C API -functions C<sv_utf8_upgrade>, C<sv_utf8_downgrade>, C<sv_utf8_encode>, -and C<sv_utf8_decode>, which are wrapped by the Perl functions +cleared. See L<perlunicode>, and the C API +functions C<L<sv_utf8_upgrade|perlapi/sv_utf8_upgrade>>, +C<L<perlapi/sv_utf8_downgrade>>, C<L<perlapi/sv_utf8_encode>>, +and C<L<perlapi/sv_utf8_decode>>, which are wrapped by the Perl functions C<utf8::upgrade>, C<utf8::downgrade>, C<utf8::encode> and -C<utf8::decode>. Also, the functions utf8::is_utf8, utf8::valid, -utf8::encode, utf8::decode, utf8::upgrade, and utf8::downgrade are +C<utf8::decode>. Also, the functions C<utf8::is_utf8>, C<utf8::valid>, +C<utf8::encode>, C<utf8::decode>, C<utf8::upgrade>, and C<utf8::downgrade> are actually internal, and thus always available, without a C<require utf8> statement. =head1 BUGS -One can have Unicode in identifier names, but not in package/class or -subroutine names. While some limited functionality towards this does -exist as of Perl 5.8.0, that is more accidental than designed; use of -Unicode for the said purposes is unsupported. - -One reason of this unfinishedness is its (currently) inherent -unportability: since both package names and subroutine names may need -to be mapped to file and directory names, the Unicode capability of -the filesystem becomes important-- and there unfortunately aren't -portable answers. +Some filesystems may not support UTF-8 file names, or they may be supported +incompatibly with Perl. Therefore UTF-8 names that are visible to the +filesystem, such as module names may not work. =head1 SEE ALSO |