Why Haskell is cool

simple-composition.hs

-- Taken from https://www.youtube.com/watch?v=6KkF5-_erns#t=1154
-- Original code taken from https://github.com/haskelllive/haskelllive/blob/episode-1/Chess.hs
module Chess where


-- This call reads in a string grid of a chessboard with each row separated by a newline
-- and returns an encoded board where each position could be Nothing or an encoded piece
-- type (returned from readSquare).
-- 
readBoard :: String -> Maybe Board
readBoard = mapM readRows . lines
  where readRows = mapM readSquare

-- This does the exact same thing, only using function composition to eliminate
-- unnecessary inner definitions.
readBoard = (mapM . mapM) readSquare . lines

-- Gotta love function compositions!