Ah, that worked perfectly! Thanks!
On Sep 16, 2010, at 11:45 AM, Simon Peyton-Jones wrote:
> For reasons explained in “Let should not be generalised” GHC isn’t going to
> generalise local let-bindings, at least not when you switch on GADTs , which
> you have.
>
> So unBM is monomorphic, hen
For reasons explained in "Let should not be generalised" GHC isn't going to
generalise local let-bindings, at least not when you switch on GADTs , which
you have.
So unBM is monomorphic, hence the error.
Give it a type signature, or make it top-level. Either works fine.
Simon
From: cvs-ghc-b
