型クラスとカインドの関係性

Hoge.hs

module Hoge (Hoge, Fuga) where

-- > :k Applicative
-- Applicative :: (* -> *) -> Constraint
-- > :k Hoge
-- Hoge :: (* -> *) -> Constraint
class (Applicative h) => Hoge h where
    hoge :: h a

-- > :k Show
-- Show :: * -> Constraint
-- > :k Fuga
-- Fuga :: * -> Constraint
class (Show f) => Fuga f where
    fuga :: f