Is there a visual modeling language or style for the functional programming paradigm?

Question

UML is a standard aimed at the modeling of software which will be written in OO languages, and goes hand in hand with Java. Still, could it possibly be used to model softwar

Answer 1

In Haskell, you model by types.

Just begin with writing your function-, class- and data signatures without any implementation and try to make the types fit. Next step is QuickCheck.

E.g. to model a sort:

class Ord a where
    compare :: a -> a -> Ordering

sort :: Ord a => [a] -> [a]
sort = undefined

then tests

prop_preservesLength l = (length l) == (length $ sort l)
...

and finally the implementation ...