Hello Monks,

I am attempting to create a class hierarchy which, when new is called for the base class, the first parameter will allow a run time decision as to which derived class is required and instantiate that. Kind of like how DBI works. I would prefer to not specify all the classes required. Something like this:

use Astro::Observation;
my $obs = Astro::Observation->new( "simple", ... );
my $obc = Astro::Observation->new( "complex", ... );

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rather than this:
use Astro::Observation::Simple;
use Astro::Observation::Complex;
my $obs = Astro::Observation::Simple->new( ... );
my $obc = Astro::Observation::Complex->new( ... );

[download]
I don't have a clue how to go about doing this. I have Conway's book, but cannot figure out from there.

Can anyone suggest somewhere to look, or a pure perl module which uses this? I looked at DBI, but couldn't figure out how they accomplished this.

As you might be able to infer, this is my first attempt at using objects in Perl, and I'm barely treading water...

Thanks,
Rob

In reply to Runtime instantiation decisions by LogicalChaos

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