Simplification of instances

[Simon Peyton-Jones]

Ahem.  DFuns (what you get from is_dfun of a ClsInst) now have some "silent" arguments, that are added by GHC and are not part of the original instance declaration. See
Note [Silent superclass arguments] in TcInstDcls.

But you don't want to print them.  Just do what InstEnv.pprInstanceHdr does (in InstEnv) to drop the silent arguments.

I've added some more comments (commit to come).

Simon

| -----Original Message-----
| From: glasgow-haskell-users-bounces at haskell.org [mailto:glasgow-haskell-
| users-bounces at haskell.org] On Behalf Of David Waern
| Sent: 28 September 2012 10:03
| To: glasgow-haskell-users at haskell.org
| Subject: Simplification of instances
| 
| Hi,
| 
| was there a change in how GHC simplifies instances sometime between
| 7.4.1 and 7.6.1? Haddock used to produce this:
| 
|   http://hackage.haskell.org/packages/archive/kan-
| extensions/2.7/doc/html/Data-Functor-Yoneda.html
| 
| but is now producing this:
| 
|   http://hackage.haskell.org/packages/archive/kan-
| extensions/3.1/doc/html/Data-Functor-Yoneda.html
| 
| Haddock uses tcRnGetInfo to get the instances.
| 
| Thanks,
| David
| 
| _______________________________________________
| Glasgow-haskell-users mailing list
| Glasgow-haskell-users at haskell.org
| http://www.haskell.org/mailman/listinfo/glasgow-haskell-users