In my recent unsuccessful attempt to convert junctions into sets with their own container, perhaps the strongest argument against could be paraphrased as follows:
Everything about junctions or sets can be represented fully as an object, and objects are nicely stored in scalars, because it's simply one instance of a given class, in this case C<Junction>.
My question comes down to: so what makes Arrays and Hashes so special? As many pure-OO languages demonstrate, both can be fully represented as an object, and objects belong in Scalars. The obvious statement I expect to here is "Perl's always had Arrays and Hashes". While I'm not sure if they were there for Perl 1.0 (I started w/ Perl 4.xx), I do know that they certainly predate P5's objects and references. Therefore, there was no other way to create an array or hash. That is no longer the case.
In P6, we've even gone so far as to say that you can access an element in an array ref with C<$ref[1]>. I'm fairly sure you can call all the methods of the Array class on the $ref, letting you do C<$ref.pop> and all the other fun things we do with arrays. Similar things hold for hashes.
So I'm interested in hearing what pushes Arrays and Hashes over the edge for needing their own container and sigil, whereas Junctions/Sets do not.
-- Rod Adams
