Library with some useful functions on the Maybe datatype
Author: Frank Huch (source from the corresponding Hugs module)
Bernd Brassel (sequence, mapM)
Version: April 2005
Functions:
>>-
| catMaybes
| fromJust
| fromMaybe
| isJust
| isNothing
| listToMaybe
| mapMaybe
| mapMMaybe
| maybeToList
| sequenceMaybe
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Summary of exported functions:
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mapMaybe :: (a -> Maybe b) -> [a] -> [b] 
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(>>-) :: Maybe a -> (a -> Maybe b) -> Maybe b 
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Monadic bind for Maybe.
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sequenceMaybe :: [Maybe a] -> Maybe [a]
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monadic sequence for maybe
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mapMMaybe :: (a -> Maybe b) -> [a] -> Maybe [b]
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monadic map for maybe
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Prelude
isJust :: Maybe a -> Bool
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Further infos:
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solution complete, i.e., able to compute all solutions
isNothing :: Maybe a -> Bool
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Further infos:
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solution complete, i.e., able to compute all solutions
fromJust :: Maybe a -> a
fromMaybe :: a -> Maybe a -> a
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Further infos:
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solution complete, i.e., able to compute all solutions
maybeToList :: Maybe a -> [a]
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Further infos:
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solution complete, i.e., able to compute all solutions
listToMaybe :: [a] -> Maybe a
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Further infos:
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solution complete, i.e., able to compute all solutions
catMaybes :: [Maybe a] -> [a]
mapMaybe :: (a -> Maybe b) -> [a] -> [b]
(>>-) :: Maybe a -> (a -> Maybe b) -> Maybe b
Monadic bind for Maybe.
Maybe can be interpreted as a monad where Nothing is interpreted
as the error case by this monadic binding.
Example call: (maybeValue >>- f)
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Parameters:
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maybeValue
- Nothing or Just x
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f
- function to be applied to x
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Returns:
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Nothing if maybeValue is Nothing,
otherwise f is applied to x
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Further infos:
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defined as left-associative infix operator with precedence 1
sequenceMaybe :: [Maybe a] -> Maybe [a]
monadic sequence for maybe
mapMMaybe :: (a -> Maybe b) -> [a] -> Maybe [b]
monadic map for maybe
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