[Haskell-cafe] Why no IO transformer monad?

[Keean Schupke]

I thought you would get the following if you have a transformer 'M':
   
    runM :: M IO a -> IO a

to run 'M'...

    Keean.

Udo Stenzel wrote:

>Keean Schupke <k.schupke at imperial.ac.uk> schrieb am 20.12.04 10:25:36:
>  
>
>>What about:
>>
>>    runIOT :: Monad m => IOT m a -> IO (m a)
>>    
>>
>
>I have a gut feeling that this is unimplementable.  However, IO (m a) is
>what you get using the transformer version of m over IO.  
>
>
>Udo.
>
>
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