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45e4dedf45
This implements https://github.com/Perl/RFCs/pull/5/commits/2c5e4698d3aaf9114c631c819323e5b 719eaa328
72 lines
1.7 KiB
Perl
72 lines
1.7 KiB
Perl
package source::encoding;
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use v5.40;
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our $VERSION = '0.01';
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our $ascii_hint_bits = 0x00000010;
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sub import {
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unimport(); # Get rid of any 'use utf8'
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my (undef, $arg) = @_;
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if ($arg eq 'utf8') {
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require utf8;
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utf8->import;
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return;
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}
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elsif ($arg eq 'ascii') {
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$^H |= $ascii_hint_bits;
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return;
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}
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die "Bad argument for source::encoding: '$arg'";
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}
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sub unimport {
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$^H &= ~$ascii_hint_bits;
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utf8->unimport;
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}
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1;
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__END__
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=head1 NAME
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source::encoding -- Declare Perl source code encoding
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=head1 SYNOPSIS
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use source::encoding 'ascii';
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use source::encoding 'utf8';
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no source::encoding;
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=head1 DESCRIPTION
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These days, Perl code either generally contains only ASCII characters with
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C<\x{}> and similar escapes to represent non-ASCII, or C<S<use utf8>> is used
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to indicate that the source code itself contains characters encoded as UTF-8.
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That means that a character in the source code not meeting these criteria is
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often a typographical error. This pragma is used to tell Perl to raise an
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error when this happens.
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S<C<use source::encoding 'utf8'>> is a synonym for S<C<use utf8>>. They may
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be used interchangeably.
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S<C<use source::encoding 'ascii'>> turns off any UTF-8 expectations, and
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raises a fatal error if any character within its scope in the input source
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code is not ASCII (or ASCII-equivalent on EBCDIC systems).
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S<C<no source::encoding>> turns off any UTF-8/ASCII expectations for the
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remainder of its scope. The meaning of non-ASCII characters is then
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undefined.
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S<C<use source::encoding 'ascii'>> is automatically enabled within the
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lexical scope of a S<C<use v5.41.0>> or higher.
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=head1 SEE ALSO
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L<utf8>
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=cut
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