Hello List!
I have function a -> IO a. How to get function:
Maybe a -> IO (Maybe a) ?
I found in Haskell mails archive such thing:
class IFunctor f where
imap :: Idiom i => (s -> i t) -> f s -> i (f t)
which looks similar, but I didn't find any helpfull instances of
`IFunctor` class in its package (and unfortunately I don't know what are
the indexed types: IMonad, IFunctor, etc). Sure, there is the primitive
solution like:
myfunc :: a -> IO a
...
f x = case x of Nothing -> return Nothing
Just x' -> Just <$> myfunc x'
but more interesting is to know more standard and Haskelish solution
(like lift's, etc). May be I miss something very obvious..
===
Best regards, Paul
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