[jhc] building transformers library, irrefutable patterns

[Henning Thielemann]

On Sat, 7 Aug 2010, Korcan Hussein wrote:

> Hello I can build all of transformers (http://hackage.haskell.org/package/transformers) but only when excluding the files:
>
> Control.Monad.Trans.RWS.Lazy,
> Control.Monad.Trans.State.Lazy,
> Control.Monad.Trans.Writer.Lazy
>
> Which use irrefutable patterns, I could probably make this work without 
> them but I just thought it was worth mentioning.

I remember I already complained about this issue and wrote a quick fix 
that replaces the ~ with let's.