¤ mapfilter, plookup, et al

Types

mapfilter :: (a -> Maybe b) -> [a] -> [b]
plookup :: (a -> Bool) -> [(a, b)] -> Maybe b
maybe :: ??
mapMaybe :: (a -> b) -> Maybe a -> Maybe b
stripMaybe :: Maybe a -> a
stripMaybeDef :: a -> Maybe a -> a
isM :: Maybe a -> Bool

type Maybe = ??

Description