Working on examples/exercises of snoyberg/conduit README

a.md

$cat app/Main.hs
module Main where

{-# LANGUAGE ExtendedDefaultRules #-}

import Control.Monad.Trans.List
import Conduit
import Control.Applicative

-- mapMC :: Monad m => (a -> m b) -> Conduit a m b

iterMC' :: Monad m => (a -> m ()) -> Conduit a m a
iterMC' f = mapMC (\a -> (f a) >> return a)


--  (<*>) :: f (a -> b) -> f a -> f b
-- liftA :: Applicative f => (a -> b) -> f a -> f b
sink' :: Monad m => ConduitM Int o m (String, Int)
sink' = liftA2 (,) a b
  where
   a = takeC 5 .| mapC show .| foldC
   b = sumC