$utf8::hint_bits = 0x00800000;
-our $VERSION = '1.00';
+our $VERSION = '1.01';
sub import {
$^H |= $utf8::hint_bits;
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. On EBCDIC platforms characters
-in the Latin 1 character set are treated as being part of a literal
-UTF-EBCDIC character.
+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
=head2 Utility functions
-The following functions are defined in the C<utf8::> package by the perl core.
+The following functions are defined in the C<utf8::> package by the
+Perl core. You do not need to say C<use utf8> to use these and in fact
+you should not unless you really want to have UTF-8 source code.
=over 4
=item * $num_octets = utf8::upgrade($string);
-Converts (in-place) internal representation of string to Perl's internal
-I<UTF-X> form. Returns the number of octets necessary to represent
-the string as I<UTF-X>. Can be used to make sure that the
+Converts (in-place) internal representation of string to Perl's
+internal I<UTF-X> form. Returns the number of octets necessary to
+represent the string as I<UTF-X>. Can be used to make sure that the
UTF-8 flag is on, so that C<\w> or C<lc()> work as expected on strings
-containing characters in the range 0x80-0xFF. Note that this should
-not be used to convert
-a legacy byte encoding to Unicode: use Encode for that. Affected
-by the encoding pragma.
+containing characters in the range 0x80-0xFF (oon ASCII and
+derivatives). 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($string[, FAIL_OK])
-Converts (in-place) internal representation of string to be un-encoded bytes.
-Returns true on success. On failure dies or, if the value of
-FAIL_OK is true, returns false. Can be used to make sure that the
+Converts (in-place) internal representation of string to be un-encoded
+bytes. Returns true on success. On failure dies or, if the value of
+FAIL_OK is true, returns false. Can be used to make sure that the
UTF-8 flag is off, e.g. when you want to make sure that the substr()
or length() function works with the usually faster byte algorithm.
Note that this should not be used to convert Unicode back to a legacy
=item * utf8::encode($string)
Converts (in-place) I<$string> from logical characters to octet
-sequence representing it in Perl's I<UTF-X> encoding. Same as
-Encode::encode_utf8(). Note that this
-should not be used to convert a legacy byte encoding to Unicode: use
-Encode for that.
+sequence representing it in Perl's I<UTF-X> encoding. Returns
+nothing. Same as Encode::encode_utf8(). 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. Same as Encode::decode_utf8(). Note that this should not be used to convert
-Unicode back to a legacy byte encoding: use Encode for that.
+into logical characters. Returns nothing. Same as Encode::decode_utf8().
+Note that this should not be used to convert Unicode back to a legacy
+byte encoding: use Encode for that.
+
+=item * $flag = utf8::is_utf8(STRING)
+
+Test whether STRING is in UTF-8. Same as Encode::is_utf8().
=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.
+[INTERNAL] Test whether STRING is in a consistent state regarding
+UTF-8. Will return true is well-formed UTF-8 and has the UTF-8 flag
+on B<or> if string is held as bytes (both these states are 'consistent').
+Main reason for this routine is to allow Perl's testsuite to check
+that operations have left strings in a consistent state. You most
+probably want to use 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>,
+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>. The functions utf8::valid, utf8::encode,
-utf8::decode, utf8::upgrade, and utf8::downgrade are always available,
-without a C<require utf8> statement.
+C<utf8::decode>. Note that in the Perl 5.8.0 implementation the
+functions utf8::is_utf8, utf8::valid, utf8::encode, utf8::decode,
+utf8::upgrade, and utf8::downgrade are always available, without a
+C<require utf8> statement-- this may change in future releases.
+
+=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.
=head1 SEE ALSO
projects / p5sagit/p5-mst-13.2.git / blobdiff