Hidden features of Haskell [closed]

Answer 1

Avoiding parentheses

The (.) and ($) functions in Prelude have very convenient fixities, letting you avoid parentheses in many places. The following are equivalent:

f (g (h x))
f $ g $ h x
f . g $ h x
f . g . h $ x

flip helps too, the following are equivalent:

map (\a -> {- some long expression -}) list
flip map list $ \a ->
    {- some long expression -}