Typeable
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| Language | Haskell |
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| Owner | homam |
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| Visibility | Public |
{-# LANGUAGE ScopedTypeVariables #-}
import Data.Typeable
askQuestion :: (Typeable a, Typeable b) => b -> a -> b
askQuestion b a = case cast a of
(Just x) -> x
Nothing -> b
main = getLine >>= (print . askQuestion "Error")
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