On Wed, 11 Sep 2013, Greg Fitzgerald wrote:

I'd prefer something more like:

   mux :: Enum b => [a] -> b -> a
   mux xs x = xs !! fromEnum x

so then 'bool' could be implemented as:

   bool :: a -> a -> Bool -> a
   bool f t = mux [f, t]

but 'mux' needs a stronger type signature.  The size of the enum is
known at compile-time.  Is there any way to constrain the input list

I don't like a total function to be implemented using a non-total function (!!). Additionally your implementation relies on fromEnum True == 1, which is a bad thing.

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