CUSIP: Difference between revisions
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m (→{{header|Haskell}}: allMaybe is just sequence) |
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data Result = Valid | BadCheck | TooLong | TooShort | InvalidContent deriving Show |
data Result = Valid | BadCheck | TooLong | TooShort | InvalidContent deriving Show |
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prependMaybe :: Maybe a -> Maybe [a] -> Maybe [a] |
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prependMaybe (Just v) (Just vs) = Just (v:vs) |
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prependMaybe _ _ = Nothing |
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-- convert a list of Maybe to a Maybe list. |
-- convert a list of Maybe to a Maybe list. |
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-- result is Nothing if any of values from the original list are Nothing |
-- result is Nothing if any of values from the original list are Nothing |
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allMaybe :: [Maybe a] -> Maybe [a] |
allMaybe :: [Maybe a] -> Maybe [a] |
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allMaybe = |
allMaybe = sequence |
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toValue :: Char -> Maybe Int |
toValue :: Char -> Maybe Int |
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