giokoguashvili / haskell

Functional Programming problem solutions for Certificate

HaskellSamples

• Functors, Applicatives, And Monads In Pictures

Monads:

f :: a -> m b
f :: a -> Maybe b            -- m = Maybe
f :: a -> [] b               -- m = []
f :: a -> (Either s) b       -- m = Either s
f :: a -> ((,) s) b          -- m = ((,) s)
f :: a -> ((->) e) b         -- m = ((->) e)
f :: a -> (State s) b        -- m = State s
f :: a -> IO b               -- m = IO

class Applicative m => Monad (m :: * -> *) where
    return :: a -> m a
    (>>=) :: m a -> (a -> m b) -> m b
    (>>) :: m a -> m b -> m b
    x >> y = x >>= (\_ -> y)
    fail :: String -> m a

1. return a >>= k == k a
2. m >>= return == m
3. (m >>= k) >>= k' == m >>= (k >>= k') -- m >>= (\x -> k x >>= k')

Courses:

• Денис Николаевич Москвин - twitter @deniok
  • Функциональное программирование на языке Haskell - Часть 1 (see also: Certificate, Solutions) - stepik.org
  • Функциональное программирование (Практические задания) - youtube.com