-
Simon Peyton Jones authored
In standalone deriving, we now do *not* check side conditions. We simply generate the code and typecheck it. If there's a type error, it's the programmer's problem. This means that you can do 'deriving instance Show (T a)', where T is a GADT, for example, provided of course that the boilerplate code does in fact typecheck. I put some work into getting a decent error message. In particular if there's a type error in a method, GHC will show the entire code for that method (since, after all, the user did not write it). Most of the changes are to achieve that goal. Still to come: changes in the documentation.
aa0c0de9