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|
{-# LANGUAGE ParallelListComp,
TransformListComp,
RecordWildCards #-}
{-# LANGUAGE MonadComprehensions #-}
-- From https://ocharles.org.uk/blog/guest-posts/2014-12-07-list-comprehensions.html
import GHC.Exts
import qualified Data.Map as M
import Data.Ord (comparing)
import Data.List (sortBy)
-- Monad Comprehensions
sqrts :: M.Map Int Int
sqrts = M.fromList $ [ (x, sx)
| x <- map (^2) [1..100]
| sx <- [1..100]
]
sumIntSqrts :: Int -> Int -> Maybe Int
sumIntSqrts a b = [ x + y
| x <- M.lookup a sqrts
, y <- M.lookup b sqrts
]
greet :: IO String
greet = [ name
| name <- getLine
, _ <- putStrLn $ unwords ["Hello, ", name, "!"]
]
|
