Re: 2014 Applicative => Monad proposal
On 5/24/13 11:20 AM, Edward Kmett wrote:
For the record I'm actually -1 on including Pointed.
My experience is that there are very few uses for the class that permit you to reason about your code without one-off ad hoc reasoning based on the particular instance you are given. Now, the Apply and Bind classes on the other hand... =) Though, to be fair, I couldn't seriously propose including either of those, either. Even I can't be bothered to instantiate them all the time!
FWIW, as things stand, I'm also -1 for Pointed. Pointed doesn't really have much meaning on its own, so I think it's more helpful to invert the hierarchy as Kmett has done and have Apply/Bind classes as the generalization of Applicative/Monad. More to the point, the Pointed proposal doesn't meet the AMP goals of gentility and compatibility. And the controversy renders it dubious for inclusion in the proposal to make a unified compatibility-breaking change to clean up the long-standing complaints. -- Live well, ~wren
On 2013-05-24 23:59, wren ng thornton wrote:
FWIW, as things stand, I'm also -1 for Pointed. Pointed doesn't really have much meaning on its own, so I think it's more helpful to invert the hierarchy as Kmett has done and have Apply/Bind classes as the generalization of Applicative/Monad.
More to the point, the Pointed proposal doesn't meet the AMP goals of gentility and compatibility. And the controversy renders it dubious for inclusion in the proposal to make a unified compatibility-breaking change to clean up the long-standing complaints.
I'd also vote -1 for Pointed. For one Applicative and Monad are widely used, can't say that of Pointed. Compatibility is another big thing: the AMP connects things that are already there, while Pointed would mean introducing the typeclass in Base in the first place. On the other hand, I think the AMP can also serve as a model for similar proposals in the future. Should it turn out in five years that Pointed is amazing and we all need it, its inclusion won't be much different from the AMP right now, except that we'll all know what to expect beforehand. David
participants (2)
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David Luposchainsky -
wren ng thornton