BooleanEval - Boolean expression parser.

An example of its use:

    use Math::BooleanEval;
    my $bool = Math::BooleanEval->new('yes|no');

    # evaluate each defined item in the expression to 1 or 0
    foreach my $item (@{$bool->{'arr'}}){
       next unless defined $item;
       $item = ($item =~ m/^no|off|false|null$/i) ? 1 : 0;
    }

    # evaluate the expression
    print $bool->eval();

To install, do the usual make routine:

  perl Makefile.PL
  make
  make test
  make install

... or you could just copy BooleanEval.pm into the Math/ subdirectory 
or your Perl include path.  
