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TOBYINK / PerlX-Define-0.101 / lib / PerlX / Define.pm 

            

              
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use v5.12;
use strict;
use warnings FATAL => 'all';
no warnings qw(void once uninitialized numeric);
package PerlX::Define;
our $AUTHORITY = 'cpan:TOBYINK';
our $VERSION   = '0.101';
use B ();
use Keyword::Simple ();
use namespace::clean ();
sub import
{
        shift;
         
        my ($caller, $file, $line) = caller;
         
        if (@_)
        {
                my ($name, $value) = @_;
                 
                local $@;
                ref($value)
                        ? eval qq[
                                package $caller;\n#line $line ${\ B::perlstring($file) }
                                sub $name () { \$value };
                                1;
                        ]
                        : eval qq[
                                package $caller;\n#line $line ${\ B::perlstring($file) }
                                sub $name () { ${\ B::perlstring($value) } };
                                1;
                        ];
                 
                $@ ? die($@) : return;
        }
         
        Keyword::Simple::define('define' => sub
        {
                my $line = shift;
                my ($whitespace1, $name, $whitespace2, $equals) =
                        ( $$line =~ m{\A([\n\s]*)(\w+)([\n\s]*)(=\>?)}s )
                        or Carp::croak("Syntax error near 'define'");
                my $len = length($whitespace1. $name. $whitespace2. $equals);
                substr($$line, 0, $len) = "; use PerlX::Define $name => ";
        });
         
        'namespace::clean'->import(
                -cleanee => $caller,
                'define',
        );
}
1;
__END__
=pod
=encoding utf-8
=head1 NAME
PerlX::Define - cute syntax for defining constants
=head1 SYNOPSIS
   use v5.12;
   use strict;
   use warnings;
    
   package MyMaths {
      use PerlX::Define;
      define PI = 3.2;
   }
=head1 DESCRIPTION
PerlX::Define is a yet another module for defining constants.
Differences from L<constant.pm|constant>:
=over
=item *
Cute syntax.
Like constant.pm, constants get defined at compile time, not run time.
=item *
Requires Perl 5.12 or above.
If you're lucky enough to be able to free yourself from the shackles of
supporting decade-old versions of Perl, PerlX::Define is your friend.
=item *
Only supports scalar constants.
List constants are rarely useful.
Your constant can of course be a reference to an array or hash, but this
module doesn't attempt to make the referred-to structure read only.
=item *
Doesn't try to handle some of the things constant.pm does like declaring
constants using fully-qualified names, or defining constants pointing at
magic scalars.
=back
Prior to version 0.100, PerlX::Define was bundled with L<Moops>.
=head1 BUGS
Please report any bugs to
L<http://rt.cpan.org/Dist/Display.html?Queue=PerlX-Define>.
=head1 SEE ALSO
L<constant>.
L<Moops>.
=head1 AUTHOR
Toby Inkster E<lt>tobyink@cpan.orgE<gt>.
=head1 COPYRIGHT AND LICENCE
This software is copyright (c) 2013-2014, 2018 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=head1 DISCLAIMER OF WARRANTIES
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.