Hi,
What are some interesting, idiomatic ways of writing something similar
to the following, using
a) Only standard utilities
b) Non-standard utilities
getValidatedInteger = do
maybeInt <- maybeGet
case maybeInt of
Just int -> return int
Nothing -> do putStrLn "That doesn't seem to be an integer. Try
again."
getValidatedInteger
maybeGet :: (Read r) => IO (Maybe r)
maybeGet = getLine >>= return . maybeReadS
maybeReadS text =
case reads text of
[(int, rest)] | all (== ' ') rest -> Just int
_ -> Nothing
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