Revise implementation of overlapping type family instances.

This commit changes the syntax and story around overlapping type
family instances. Before, we had "unbranched" instances and
"branched" instances. Now, we have closed type families and
open ones.

The behavior of open families is completely unchanged. In particular,
coincident overlap of open type family instances still works, despite
emails to the contrary.

A closed type family is declared like this:
> type family F a where
>   F Int = Bool
>   F a   = Char
The equations are tried in order, from top to bottom, subject to
certain constraints, as described in the user manual. It is not
allowed to declare an instance of a closed family.

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs
index 391de5a42f..635c194a92 100644
--- a/compiler/main/InteractiveEval.hs
+++ b/compiler/main/InteractiveEval.hs
@@ -45,7 +45,7 @@ import HscMain
 import HsSyn
 import HscTypes
 import InstEnv
-import FamInstEnv ( FamInst, Branched, orphNamesOfFamInst )
+import FamInstEnv ( FamInst, orphNamesOfFamInst )
 import TyCon
 import Type     hiding( typeKind )
 import TcType           hiding( typeKind )
@@ -890,7 +890,7 @@ moduleIsInterpreted modl = withSession $ \h ->
 -- are in scope (qualified or otherwise).  Otherwise we list a whole lot too many!
 -- The exact choice of which ones to show, and which to hide, is a judgement call.
 --      (see Trac #1581)
-getInfo :: GhcMonad m => Bool -> Name -> m (Maybe (TyThing,Fixity,[ClsInst],[FamInst Branched]))
+getInfo :: GhcMonad m => Bool -> Name -> m (Maybe (TyThing,Fixity,[ClsInst],[FamInst]))
 getInfo allInfo name
   = withSession $ \hsc_env ->
     do mb_stuff <- liftIO $ hscTcRnGetInfo hsc_env name