On 3 September 2010 22:23, John Lato
1) How should I name the kind * versions? For example, the kind * version of Functor is currently called Mappable with a class method of rigidMap. What should I call the kind * version of Foldable and its corresponding methods? Is there a valid system I can use for these?
You could prefix (or postfix) classes with an 'R' similar to RMonad, but that would conflict with the rmonad package. For just Foldable, maybe Reduceable?
Well, I wanted the kind * -> * versions to have the same names as the ones in base so that they're kinda drop-in.
Do you have a kind * implementation of Foldable? I'd be interested in seeing it, because I was unable to create a usable implementation (based upon the RMonad scheme) on my last attempt.
I was going to make it a subset of Foldable: fold, foldr, foldl, etc.
2) How far should I go? Should I restrict myself to the "data-oriented" classes such as Functor, Traversable, etc. or should I try to make restricted versions of Applicative and Monad? Assuming I should:
I don't have a strong opinion either way, but could you re-use RMonad and RFunctor from the rmonad package?
Well, I could except that I didn't want the `R' prefix. Also, if I end up putting in the Applicative constraint, etc. for Monad then I obviously can't re-use RMonad.
2c) Should I keep the classes as-is, or should I explicitly put in the constraints mentioned in the Typeclassopedia (e.g. make Applicative an explicit superclass of Monad, and define return = pure for compatability reasons)? If so, should I bring over Pointed, etc. from category-extras to round out the set or just stick with classes that are already in base?
+1 for using the proper constraints, and especially for bringing over Pointed (and anything else that applies).
That's one vote for...
3) Am I wasting my time with this?
I would find it useful, and I appreciate all the care you're putting into the design.
Oh, good, so I'm not going to be the only user of this library... -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com