3 Jan
2016
3 Jan
'16
3:01 p.m.
Prelude> let f g = g . g Prelude> let sum x y = x + y Prelude> let sum' = f sum Occurs check: cannot construct the infinite type: a ~ a -> a If f and sum were defined in a module, given a signature, I suppose this would compile. Similarly, sometimes valid functions defined within function body without signatures sometimes make compiler complain. Once such functions are moved to top (module) level and given a signature, compiler is happy.