Curry: An Integrated Functional Logic Language

putStr [] = done
putStr (c:cs) = putChar c >> putStr cs
putStrLn :: String -> IO ()
putStrLn cs = putStr cs >> putChar ’\n’
getLine :: IO String
getLine = do c IO ()
doSolve constraint | constraint = done
-- IO monad auxiliary functions:
-- Execute a sequence of I/O actions and collect all results in a list:
sequenceIO :: [IO a] -> IO [a]
sequenceIO [] = return []
sequenceIO (c:cs) = do x >) done
-- Map an I/O action function on a list of elements.
-- The results of all I/O actions are collected in a list.
mapIO :: (a -> IO b) -> [a] -> IO [b]
mapIO f = sequenceIO . map f
-- Map an I/O action function on a list of elements.
-- The results of all I/O actions are ignored.
mapIO_ :: (a -> IO _) -> [a] -> IO ()
mapIO_ f = sequenceIO_ . map f
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