Re: Moose::Trait ?? Was: Announcement: Moose 2.0800 is released!

On Tue, 10 Sep 2013, Ovid wrote:

> Not having state in traits was a mistake and the trait researchers have experimented with ways
> of correcting this. The reason stateless traits was a mistake is

Sounds interesting, I haven't gone through all of their references or
formal paper yet, but I've already identified plenty of useful stateless
Traits so I can tackle state and subsequent observations and lessons
later.

When I get time I'll see if I can write up a Moose implementation guide
to Traits, after I've finished exploring it all myself and have
something that I'm happy with.

> to track something that is completely irrelevant to the calling code, but is nonetheless
> necessary for the trait to do its thing. A stateless trait would then need to implement "glue
> code" (as it was called in the papers) to glue the trait and class together. This glue code
> would be duplicated in every class consuming the trait. Oops! That's something traits were
> supposed to avoid.

Conceptually we'd need an equivalent alias|exclude mechanism for all
attributes, and flattening/consumption/override rules, right?

> If you would like to know more, email the researchers. They've been very helpful for me and
> their mailing list is at https://www.iam.unibe.ch/mailman/listinfo/traits.
> 
> See also:
>  *  "Stateful Traits": http://scg.unibe.ch/archive/papers/Berg07aStatefulTraits.pdf
>  *  "Stateful Traits and their
>     Formalization": http://ulir.ul.ie/bitstream/handle/10344/2107/2008_Bergel,A.pdf?sequence=2

Cheers Ovid!

--
Niall Young
[email protected]