The Other Prelude

import Prelude ()    -- hide everything
 
-- the idea is to remove 'fmap' 
-- and map :: (a -> b) -> [a] -> [b] to be a special case
-- as well as having (.) :: (a -> b) -> (e -> a) -> (e -> b) as a
-- special case from the Functor instance for ((->) e)
-- Both notations can be provided to allow for clarity in different situations.
class Functor f where
  map :: (a -> b) -> f a -> f b
  (.) :: (a -> b) -> f a -> f b
  map = (.)
  (.) = map
 
-- should the Functor hierarchy proposal be adopted?
--
-- NO --
class Monad m where
  (>>=) :: m a -> (a -> m b) -> m b
  (>>) :: m a -> m b -> m b
  join :: m (m a) -> m a
  return :: a -> m a
 
  join x = x >>= id
  x >>= f = join (map f x)
 
--
-- YES --
-- the following has been shamelessly copied 
-- from the functor hierarchy proposal wiki page
class Functor f => Applicative f where
  return :: a -> f a
  (<*>) :: f (a -> b) -> f a -> f b   -- or should this be named 'ap'? 
                                      -- or something even better?
                                      -- could this nice looking function
                                      -- refactor the liftM* idioms?
 
 
-- my undestanding is that this is the default for monad
(>>) :: Applicative f => f a -> f b -> f b
  fa >> fb = (map (const id) fa) <*> fb
 
-- this leaves little left for the actual Monad class
class (Applicative f) => Monad f where
  (>>=) :: f a -> (a -> f b) -> f b
  join :: f (f a) -> f a
 
  x >>= f = join (map f x)
  join x = x >>= id
 
-- end of Functor hierarchy dilemma
 
-- zero will be used when pattern matching against refutable patterns in
-- do-notation as well as to provide support for monad comprehensions.
class (Monad m) => MonadZero m where
  zero :: m a
 
class (MonadZero m) => MonadPlus m where
  (++) :: m a -> m a -> m a
 
class (MonadZero m) => MonadOr m where
  orElse :: m a -> m a -> m a

import Prelude ()                                    -- hide everything
import TheOtherPrelude                               -- get everything
import qualified TheOtherPrelude.Monad.Kleisli as M  -- standard convention