After reading Differention of Datastructures, I think I finally understand what is meant by “types as functions”, and immediately I can see one direction in which to go from what is presented there. If we take integration to be the logical inverse of differentiation (which is defined in the article as ‘removal of an element [...]
There you go: comp [] _ = False comp _ [] = True comp (_s) (_:ys) = comp xs ys
I’ve noticed that when reading rather deeply-nested functional code in Haskell, the process taking place in reading the code seems to resemble trying to decipher APL more than anything else. This seems to be because functions which operate over lists are easily concatenated (possibly using the $ operator), because they operate on lists in their [...]
