[Haskell-cafe] Monadic correctness

Andrew Coppin andrewcoppin at btinternet.com
Sat Oct 17 17:15:47 EDT 2009

Derek Elkins wrote:
> On Sat, Oct 17, 2009 at 3:24 PM, Andrew Coppin
> <andrewcoppin at btinternet.com> wrote:
>> I'm reasonably confident it works, but not 100% sure...
>> newtype Foo x = Foo (M -> IO x)
> In this case it is trivial, Foo = ReaderT M IO which is a monad.

Ah yes, of course... I keep forgetting that the Reader monad doesn't do 
what it sounds like it does!

Oh well. ;-)

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