> Koen Claessen wrote:
>> I think you can "encode", or "mimick" every monad by the following type,
>> which is the monad of continuations:
>>
>> type M a = (a -> Action) -> Action
>>
>> unit :: a -> M a
>> unit a = \cont -> cont a
>>
>> bind :: M a -> (a -> M b) -> M b
>> m `bind` k = \cont -> m (\a -> k a cont)
>>
>> As you see, the type Action is not mentioned in these definitions, so we
>> can choose any structure on Action we want, to encode the "features" of
>> the monad.
Hans> I do not think it is possible to write every monad on this form.
Sure it is. See my paper, `The essence of functional programming'.
Also see Filinski's work. -- P
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