19 lines
534 B
Haskell
19 lines
534 B
Haskell
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import Data.Maybe
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maybeRead :: Read a => String -> Maybe a
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maybeRead s = case reads s of
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[(x,"")] -> Just x
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_ -> Nothing
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getListFromString :: String -> Maybe [Integer]
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getListFromString str = maybeRead $ "[" ++ str ++ "]"
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main :: IO ()
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main = do
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putStrLn "Enter a list of numbers (separated by comma):"
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input <- getLine
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let maybeList = getListFromString input in
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case maybeList of
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Just l -> print (sum l)
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Nothing -> putStrLn "Bad format. Good Bye."
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