[Haskell-cafe] category design approach for inconvenient concepts

Gábor Lehel illissius at gmail.com
Wed Dec 19 00:12:54 CET 2012


On Tue, Dec 18, 2012 at 11:03 PM, Christopher Howard
>
> The original link I gave
> <http://www.haskellforall.com/2012_08_01_archive.html> purposely skipped
> over any discussion of objects, morphisms, domains, and codomains. The
> author stated, in his first example, that "Haskell functions" are a
> category, and proceeded to describe function composition. But here I am
> confused: If "functions" are a category, this would seem to imply (by
> the phrasing) that functions are the objects of the category. However,
> since we compose functions, and only morphisms are composed, it would
> follow that functions are actually morphisms. So, in the "function"
> category, are functions objects or morphisms? If they are morphisms,
> then what are the objects of the category?

Types.


(P.S. Thanks Ertugrul, for giving me a way to latch onto the meaning
of profunctors - now I'll have to go back to that package again and
see if it makes more sense...)

-- 
Your ship was destroyed in a monadic eruption.



More information about the Haskell-Cafe mailing list