Added Cyg-Win
This commit is contained in:
parent
82cbc206eb
commit
413c315806
10586 changed files with 3806249 additions and 0 deletions
109
Agent-Windows/OGP64/usr/share/perl5/5.40/bytes.pm
Normal file
109
Agent-Windows/OGP64/usr/share/perl5/5.40/bytes.pm
Normal file
|
|
@ -0,0 +1,109 @@
|
|||
package bytes 1.09;
|
||||
|
||||
use v5.38;
|
||||
|
||||
BEGIN { $bytes::hint_bits = 0x0000_0008 }
|
||||
|
||||
sub import { $^H |= $bytes::hint_bits }
|
||||
sub unimport { $^H &= ~$bytes::hint_bits }
|
||||
|
||||
sub chr :prototype(_) { BEGIN { import() } &CORE::chr }
|
||||
sub index :prototype($$;$) { BEGIN { import() } &CORE::index }
|
||||
sub length :prototype(_) { BEGIN { import() } &CORE::length }
|
||||
sub ord :prototype(_) { BEGIN { import() } &CORE::ord }
|
||||
sub rindex :prototype($$;$) { BEGIN { import() } &CORE::rindex }
|
||||
sub substr :prototype($$;$$) { BEGIN { import() } &CORE::substr }
|
||||
|
||||
__END__
|
||||
|
||||
=head1 NAME
|
||||
|
||||
bytes - Perl pragma to expose the individual bytes of characters
|
||||
|
||||
=head1 NOTICE
|
||||
|
||||
Because the bytes pragma breaks encapsulation (i.e. it exposes the innards of
|
||||
how the perl executable currently happens to store a string), the byte values
|
||||
that result are in an unspecified encoding.
|
||||
|
||||
B<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 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
|
||||
|
||||
Perl's characters are stored internally as sequences of one or more bytes.
|
||||
This pragma allows for the examination of the individual bytes that together
|
||||
comprise a character.
|
||||
|
||||
Originally the pragma was designed for the loftier goal of helping incorporate
|
||||
Unicode into Perl, but the approach that used it was found to be defective,
|
||||
and the one remaining legitimate use is for debugging when you need to
|
||||
non-destructively examine characters' individual bytes. Just insert this
|
||||
pragma temporarily, and remove it after the debugging is finished.
|
||||
|
||||
The original usage can be accomplished by explicit (rather than this pragma's
|
||||
implicit) encoding using the L<Encode> module:
|
||||
|
||||
use Encode qw/encode/;
|
||||
|
||||
my $utf8_byte_string = encode "UTF8", $string;
|
||||
my $latin1_byte_string = encode "Latin1", $string;
|
||||
|
||||
Or, if performance is needed and you are only interested in the UTF-8
|
||||
representation:
|
||||
|
||||
utf8::encode(my $utf8_byte_string = $string);
|
||||
|
||||
C<no bytes> can be used to reverse the effect of C<use bytes> within the
|
||||
current lexical scope.
|
||||
|
||||
As an example, when Perl sees C<$x = chr(400)>, it encodes the character
|
||||
in UTF-8 and stores it in C<$x>. Then it is marked as character data, so,
|
||||
for instance, C<length $x> returns C<1>. However, in the scope of the
|
||||
C<bytes> pragma, C<$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 (on
|
||||
# ASCII platforms)"
|
||||
}
|
||||
|
||||
C<chr()>, C<ord()>, C<substr()>, C<index()> and C<rindex()> behave similarly.
|
||||
|
||||
For more on the implications, see L<perluniintro> and L<perlunicode>.
|
||||
|
||||
C<bytes::length()> is admittedly handy if you need to know the
|
||||
B<byte length> of a Perl scalar. But a more modern way is:
|
||||
|
||||
use Encode 'encode';
|
||||
length(encode('UTF-8', $scalar))
|
||||
|
||||
=head1 LIMITATIONS
|
||||
|
||||
C<bytes::substr()> does not work as an I<lvalue()>.
|
||||
|
||||
=head1 SEE ALSO
|
||||
|
||||
L<perluniintro>, L<perlunicode>, L<utf8>, L<Encode>
|
||||
Loading…
Add table
Add a link
Reference in a new issue