Logic-Kleene - README

NAME

Logic::Kleene - Kleene three-valued logic

REQUIREMENTS

This module requires Perl 5.6.0 or newer. Only core modules are used.

INSTALLATION

Installation can be done using the traditional Makefile.PL or the newer Build.PL method .

Using Makefile.PL:

      perl Makefile.PL
      make test
      make install

(On Windows platforms you should use nmake instead.)

Using Build.PL (if you have Moddule::Build installed):

      perl Build.PL
      perl Build test
      perl Build install

You may see warnings about undefined values during testing. This is normal.

SYNOPSIS

use Logic::Kleene;

$a = !kleene( somefunction() );

if ($a && $b) { ... }

DESCRIPTION

This module implements Kleene three-valued logic via overloading.

The third value is between true and false, and is equivalent to an undefined value (as when a program has not yet returned a value).

The significant different is that the negation of an undefined value is still undefined (and so treated as false). For example,

      my $status = kleene(somefunction());
      if (!$status) {
        print "somefunction failed";
      }

If the status value is false, then it will print the failure message, as expected. But if the status is undefined, then it will not print the message.

REVISION HISTORY

The following changes have been made since the last release:

0.05 Thu Jul 28 2005

added 'kleene' function (exported by default)
fixed typos in documentation
added additional information to the documentation

AUTHOR

Robert Rothenberg <rrwo at cpan.org>

Suggestions and Bug Reporting

Feedback is always welcome. Please use the CPAN Request Tracker at http://rt.cpan.org to submit bug reports.

LICENSE