constant::boolean(3) User Contributed Perl Documentation constant::boolean(3)NAMEconstant::boolean - Define TRUE and FALSE constants.
SYNOPSIS
use constant::boolean;
use File::Spec;
sub is_package_exist {
my ($package) = @_;
return FALSE unless defined $package;
foreach my $inc (@INC) {
my $filename = File::Spec->catfile(
split( /\//, $inc ), split( /\::/, $package )
) . '.pm';
return TRUE if -f $filename;
};
return FALSE;
};
no constant::boolean;
DESCRIPTION
Defines "TRUE" and "FALSE" constants in caller's namespace. You could
use simple values like empty string or zero for false, or any non-empty
and non-zero string value as true, but the "TRUE" and "FALSE" constants
are more descriptive.
It is virtually the same as:
# double "not" operator is used for converting scalar to boolean value
use constant TRUE => !! 1;
use constant FALSE => !! '';
The constants exported by "constant::boolean" are not reported by
Test::Pod::Coverage, so it is more convenient to use this module than
to define "TRUE" and "FALSE" constants by yourself.
The constants can be removed from class API with "no constant::boolean"
pragma or some universal tool like namespace::clean.
BUGS
If you find the bug or want to implement new features, please report it
at http://rt.cpan.org/NoAuth/Bugs.html?Dist=constant-boolean
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=constant-boolean>
AUTHOR
Piotr Roszatycki <dexter@cpan.org>
LICENSE
Copyright 2008, 2009 by Piotr Roszatycki <dexter@cpan.org>.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See <http://www.perl.com/perl/misc/Artistic.html>
perl v5.14.0 2011-06-17 constant::boolean(3)
