constant::boolean - Define TRUE and FALSE constants.
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;
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.
TRUE
FALSE
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.
constant::boolean
The constants can be removed from class API with no constant::boolean pragma or some universal tool like namespace::clean.
no constant::boolean
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
Piotr Roszatycki <dexter@cpan.org>
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
To install constant::boolean, copy and paste the appropriate command in to your terminal.
cpanm
cpanm constant::boolean
CPAN shell
perl -MCPAN -e shell install constant::boolean
For more information on module installation, please visit the detailed CPAN module installation guide.