Re^3: From test harness to CPAN

[GrandFather]

Most likely the 'load it if we need it' failed for a second object because PDL was already loaded. I was thinking more in terms of "use it if it's available" in any case. The following code implements that:

use strict;
use warnings;

package TestPDL;

my $PDLLoaded = eval {
    require 'PDL.pm';
    PDL->import ();
    1;
};


sub new {
    my ($class, %params) = @_;

    $params{havePDL} = $PDLLoaded;
    return bless \%params, $class;
}


package main;

my $obj  = TestPDL->new ();
my $obj2 = TestPDL->new ();

print $obj2->{havePDL}
    ? "Have PDL available"
    : "PDL not present or object create failed";

I'd write one basic object that does common stuff then derive from that to specialise for additional capabilities. Following that thought, I'd arrange the name space as Sport::Analytics::SRS for the basic module then Sport::Analytics::SRS::Cricket for the Cricket specialisation.

This technique allows a PDL only implementation for tricky or computationally expensive stuff with a pure Perl implementation provided either in the module or in a derived class at some point in the future if there is a need for it.