NAME

vars::i - Perl pragma to declare and simultaneously initialize global variables.

SYNOPSIS

use Data::Dumper;
$Data::Dumper::Deparse = 1;

use vars::i '$VERSION' => 3.44;
use vars::i '@BORG' => 6 .. 6;
use vars::i '%BORD' => 1 .. 10;
use vars::i '&VERSION' => sub(){rand 20};
use vars::i '*SOUTH' => *STDOUT;

BEGIN {
    print SOUTH Dumper [
        $VERSION, \@BORG, \%BORD, \&VERSION
    ];
}

use vars::i [ # has the same effect as the 5 use statements above
    '$VERSION' => 3.66,
    '@BORG' => [6 .. 6],
    '%BORD' => {1 .. 10},
    '&VERSION' => sub(){rand 20},
    '*SOUTH' => *STDOUT,
];

print SOUTH Dumper [ $VERSION, \@BORG, \%BORD, \&VERSION ];

DESCRIPTION

For whatever reason, I once had to write something like

BEGIN {
    use vars '$VERSION';
    $VERSION = 3;
}

or

our $VERSION;
BEGIN { $VERSION = 3; }

and I really didn't like typing that much. With this package, I can say:

use vars::i '$VERSION' => 3;

and get the same effect.

Also, I like being able to say

use vars::i '$VERSION' => sprintf("%d.%02d", q$Revision: 1.3 $ =~ /: (\d+)\.(\d+)/);

use vars::i [
 '$VERSION' => sprintf("%d.%02d", q$Revision: 1.3 $ =~ /: (\d+)\.(\d+)/),
 '$REVISION'=> '$Id: GENERIC.pm,v 1.3 2002/06/02 11:12:38 _ Exp $',
];

Like with use vars;, there is no need to fully qualify the variable name. However, you may if you wish.

NOTES

• Specifying a variable but not a value will succeed silently, and will not create the variable. E.g., use vars::i '$foo'; is a no-op.

  Now, you might expect that use vars::i '$foo'; would behave the same way as use vars '$foo';. That would not be an unreasonable expectation. However, use vars::i qw($foo $bar); has a very different effect than does use vars qw($foo $bar);! In order to avoid subtle errors in the two-parameter case, vars::i also rejects the one-parameter case.

• Trying to create a special variable is fatal. E.g., use vars::i '$@', 1; will die at compile time.

• The sigil is taken into account (context sensitivity!) So:

    use vars::i '$foo' => [1,2,3];  # now $foo is an arrayref
    use vars::i '@bar' => [1,2,3];  # now @bar is a three-element list
  

SEE ALSO

See vars, "our" in perldoc, "Pragmatic Modules" in perlmodlib.

VERSIONING

Since version 1.900000, this module is numbered using Semantic Versioning 2.0.0, packed in the compatibility format of vX.Y.Z -> X.00Y00Z.

This version supports Perl 5.6.1+. If you are running an earlier Perl:

• Perl 5.6:

  Use version 1.10 of this module (CXW/vars-i-1.10).

• Pre-5.6:

  Use version 1.01 of this module (PODMASTER/vars-i-1.01).

DEVELOPMENT

This module uses Minilla for release management. When developing, you can use normal prove -l for testing based on the files in lib/. Before submitting a pull request, please:

• make sure all tests pass under minil test
• add brief descriptions to the Changes file, under the {{$NEXT}} line.
• update the .mailmap file to list your PAUSE user ID if you have one, and if your git commits are not under your @cpan.org email. That way you will be properly listed as a contributor in MetaCPAN.

AUTHORS

D.H. podmaster@cpan.org

Christopher White cxw@cpan.org

Thanks

Thanks to everyone who has worked on vars, which served as the basis for this module.

SUPPORT

Please report any bugs at https://github.com/cxw42/Perl-vars-i/issues.

You can also see the old bugtracker at http://rt.cpan.org/NoAuth/Bugs.html?Dist=vars-i for older bugs.

LICENSE

Copyright (c) 2003--2019 by D.H. aka PodMaster, and contributors. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.