package utf8;
-if (ord('A') != 193) { # make things more pragmatic for EBCDIC folk
-
$utf8::hint_bits = 0x00800000;
our $VERSION = '1.00';
Carp::croak("Undefined subroutine $AUTOLOAD called");
}
-}
-
1;
__END__
=head1 NAME
-utf8 - Perl pragma to enable/disable UTF-8 in source code
+utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code
=head1 SYNOPSIS
=head1 DESCRIPTION
-WARNING: The implementation of Unicode support in Perl is incomplete.
-See L<perlunicode> for the exact details.
-
The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the
-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.
+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.
This pragma is primarily a compatibility device. Perl versions
earlier than 5.6 allowed arbitrary bytes in source code, whereas
source text. Until UTF-8 becomes the default format for source
text, this pragma should be used to recognize UTF-8 in the source.
When UTF-8 becomes the standard source format, this pragma will
-effectively become a no-op. This pragma already is a no-op on
-EBCDIC platforms (where it is alright to code perl in EBCDIC
-rather than UTF-8).
+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.
-Enabling the C<utf8> pragma has the following effects:
+Enabling the C<utf8> pragma has the following effect:
-=over
+=over 4
=item *
Bytes in the source text that have their high-bit set will be treated
-as being part of a literal UTF-8 character. This includes most literals
-such as identifiers, string constants, constant regular expression patterns
-and package names.
+as being part of a literal UTF-8 character. This includes most
+literals such as identifiers, string constants, constant regular
+expression patterns and package names. On EBCDIC platforms characters
+in the Latin 1 character set are treated as being part of a literal
+UTF-EBCDIC character.
-=item *
+=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-8. If you want to have such bytes and use utf8, you can disable
+utf8 until the end the block (or file, if at top level) by C<no utf8;>.
+
+=head2 Utility functions
+
+The following functions are defined in the C<utf8::> package by the perl core.
+
+=over 4
+
+=item * $num_octets = utf8::upgrade($string);
+
+Converts internal representation of string to the Perl's internal
+I<UTF-X> form. Returns the number of octets necessary to represent
+the string as I<UTF-X>. Note that this should not be used to convert
+a legacy byte encoding to Unicode: use Encode for that. Affected
+by the encoding pragma.
+
+=item * utf8::downgrade($string[, CHECK])
+
+Converts internal representation of string to be un-encoded bytes.
+Note that this should not be used to convert Unicode back to a legacy
+byte encoding: use Encode for that. B<Not> affected by the encoding
+pragma.
+
+=item * utf8::encode($string)
+
+Converts (in-place) I<$string> from logical characters to octet
+sequence representing it in Perl's I<UTF-X> encoding. Note that this
+should not be used to convert a legacy byte encoding to Unicode: use
+Encode for that.
+
+=item * $flag = utf8::decode($string)
+
+Attempts to convert I<$string> in-place from Perl's I<UTF-X> encoding
+into logical characters. Note that this should not be used to convert
+Unicode back to a legacy byte encoding: use Encode for that.
+
+=item * $flag = utf8::valid(STRING)
+
+[INTERNAL] Test whether STRING is in a consistent state. Will return
+true if string is held as bytes, or is well-formed UTF-8 and has the
+UTF-8 flag on. Main reason for this routine is to allow Perl's
+testsuite to check that operations have left strings in a consistent
+state.
-In the absence of inputs marked as UTF-8, regular expressions within the
-scope of this pragma will default to using character semantics instead
-of byte semantics.
+=back
- @bytes_or_chars = split //, $data; # may split to bytes if data
- # $data isn't UTF-8
- {
- use utf8; # force char semantics
- @chars = split //, $data; # splits characters
- }
+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
+C<utf8::upgrade>, C<utf8::downgrade>, C<utf8::encode> and
+C<utf8::decode>.
=head1 SEE ALSO