-package byte;
+package bytes;
+
+our $VERSION = '1.04';
+
+$bytes::hint_bits = 0x00000008;
sub import {
- $^H |= 0x00000008;
+ $^H |= $bytes::hint_bits;
}
sub unimport {
- $^H &= ~0x00000008;
+ $^H &= ~$bytes::hint_bits;
}
sub AUTOLOAD {
- require "byte_heavy.pl";
- goto &$AUTOLOAD;
+ require "bytes_heavy.pl";
+ goto &$AUTOLOAD if defined &$AUTOLOAD;
+ require Carp;
+ Carp::croak("Undefined subroutine $AUTOLOAD called");
}
-sub length ($);
+sub length (_);
+sub chr (_);
+sub ord (_);
+sub substr ($$;$$);
+sub index ($$;$);
+sub rindex ($$;$);
1;
__END__
=head1 NAME
-byte - Perl pragma to force byte semantics rather than character semantics
+bytes - Perl pragma to force byte semantics rather than character semantics
+
+=head1 NOTICE
+
+This pragma reflects early attempts to incorporate Unicode into perl and
+has since been superseded. It breaks encapsulation (i.e. it exposes the
+innards of how the perl executable currently happens to store a string),
+and use of this module for anything other than debugging purposes is
+strongly discouraged. If you feel that the functions here within might be
+useful for your application, this possibly indicates a mismatch between
+your mental model of Perl Unicode and the current reality. In that case,
+you may wish to read some of the perl Unicode documentation:
+L<perluniintro>, L<perlunitut>, L<perlunifaq> and L<perlunicode>.
=head1 SYNOPSIS
- use byte;
- no byte;
+ use bytes;
+ ... chr(...); # or bytes::chr
+ ... index(...); # or bytes::index
+ ... length(...); # or bytes::length
+ ... ord(...); # or bytes::ord
+ ... rindex(...); # or bytes::rindex
+ ... substr(...); # or bytes::substr
+ no bytes;
+
=head1 DESCRIPTION
-WARNING: The implementation of Unicode support in Perl is incomplete.
-Expect sudden and unannounced changes!
+The C<use bytes> pragma disables character semantics for the rest of the
+lexical scope in which it appears. C<no bytes> can be used to reverse
+the effect of C<use bytes> within the current lexical scope.
+
+Perl normally assumes character semantics in the presence of character
+data (i.e. data that has come from a source that has been marked as
+being of a particular character encoding). When C<use bytes> is in
+effect, the encoding is temporarily ignored, and each string is treated
+as a series of bytes.
+
+As an example, when Perl sees C<$x = chr(400)>, it encodes the character
+in UTF-8 and stores it in $x. Then it is marked as character data, so,
+for instance, C<length $x> returns C<1>. However, in the scope of the
+C<bytes> pragma, $x is treated as a series of bytes - the bytes that make
+up the UTF8 encoding - and C<length $x> returns C<2>:
+
+ $x = chr(400);
+ print "Length is ", length $x, "\n"; # "Length is 1"
+ printf "Contents are %vd\n", $x; # "Contents are 400"
+ {
+ use bytes; # or "require bytes; bytes::length()"
+ print "Length is ", length $x, "\n"; # "Length is 2"
+ printf "Contents are %vd\n", $x; # "Contents are 198.144"
+ }
+
+chr(), ord(), substr(), index() and rindex() behave similarly.
-The C<use byte> pragma disables character semantics for the rest of the
-lexical scope in which it appears. C<no byte> can be used to reverse
-the effect of C<use byte> within the current lexical scope.
+For more on the implications and differences between character
+semantics and byte semantics, see L<perluniintro> and L<perlunicode>.
-Perl normally assumes character semantics in the presence of
-character data (i.e. data that has come from a source that has
-been marked as being of a particular character encoding).
+=head1 LIMITATIONS
-To understand the implications and differences between character
-semantics and byte semantics, see L<perlunicode>.
+bytes::substr() does not work as an lvalue().
=head1 SEE ALSO
-L<perlunicode>, L<utf8>
+L<perluniintro>, L<perlunicode>, L<utf8>
=cut
https://perl5.git.perl.org / perl5.git / blobdiff