monad transformer library

Simon Peyton-Jones
Fri, 6 Jun 2003 10:40:12 +0100

| > That is, deriving works for arbitrary classes for newtypes, just
| > the instance
| > for the representation type.  This greatly alleviates the pain you
| > to.  It's documented in the GHC user manual.
| I recall that you came across a glitch with the specification of this
| feature -- is that all sorted out now?

Hmm.  I've forgotten a glitch.  I'm not aware of any problem though.