On 12/2/10 4:38 PM, Tyson Whitehead wrote:
On November 30, 2010 00:32:18 wren ng thornton wrote:
Not all functors are pointed therefore Pointed=>Functor is invalid.
but, as I think your email argued, this may be equally pedantic to not all pointed things are functors as so Functor=>Pointed must also be invalid?
Some folks on this thread have argued for that interpretation. Personally, I question whether the "pointed" notion of functors should really be conflated with the "canonical value" notion of non-functors. But then I don't particularly care whether the new hierarchy has Functor=>Pointed so long as it does have (Functor,Pointed)=>Applicative and Applicative=>Monad.
Personally, I think something like an embedded DSL might have reason to want to let embed values (i.e., be pointed) but not lift functions to functions over embed values (i.e., be functorial). I think these should be separate.
That does seem like a good reason to ban Functor=>Pointed. Far better than the bloomfilter argument. -- Live well, ~wren