On Thu, Jul 02, 2009 at 04:36:37PM -0400, Stevan Little wrote:
> Very good point actually.
>
> I think we should split the categories by their intentions ...
>
> Structural - ArrayRef, HashRef, Number, etc ...
>
> Behavioral - Counter, Queue, Stack, Buffer, etc ...
>
> Now, you could easily argue all around this and blah blah blah (I WANT
> TO PAINT THE BIKESHED RED!). But what I am proposing is that we draw
> *our own* distinctions, complete with reasoning to support. And let me
> start the first wave of bullshit here ...
>
> Structural items are ones for whom the underlying value type is the key
> focus. ArrayRef describes the actual data structure used and Number the
> actual value type used. The operations supplied for these Structural
> items are basically the core operations that perl supports out of the box
> (with maybe a few additions for convenience).
>
> Behavioral items are one for whom the behavior of the item is the key
> focus. Counter is obvious. The Stack item is less obvious unless you
> look at it as an ADT (Abstract Data Type) and realize that it really
> describes a data structure whose internal implementation is irrelevant
> as long as it provides an expected set of behaviors.
>
> Yes, these lines are blurry. Yes, you could easily argue that ArrayRef
> fits the Behavioral definition and Stack fits the Structural. But who
> cares, I think we can make our own distinctions and as long as we remain
> consistent then all the haters can just f*ck off ;)
So... why stop there? Since we're redoing API anyway, what about this
idea: the Structural items described here get their methods stored
directly on the associated TypeConstraint object, and handles just looks
things up from there. This would make extending quite easy, doing
something like
subtype 'Matrix', as 'ArrayRef[ArrayRef]',
where { ... },
with { lookup => sub {
my ($mat, $i, $j) = @_;
$mat->[$i][$j]
} };
which would make this valid:
has matrix => (
isa => 'Matrix',
handles => ['lookup'],
);
This would simplify the interface too, since users wouldn't have to
think about including traits and whatnot, things would just work.
Thoughts?
-doy
