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by Peaker 2961 days ago
That's the Maybe type. The Maybe monad is this:

  instance Monad Maybe where
    return = Just
    Nothing >>= _ = Nothing
    Just x >>= f = f x
(And is not really related to the discussion)
1 comments
pera 2960 days ago
Right! that definition was the type, thanks for the correction :) still, the Maybe monad is used for computations that may fail, which is often the purpose of the null pointer.
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