X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcEnv.lhs;h=96dc2614e359dfce4fc437d6df51b62ace923c5d;hb=d9b111819b066157ca8bca296add7a7359c68170;hp=b69163cf66158b795c691a90db03d55201fd3104;hpb=a6f2d598e1e7760d334d1b5ea0b7745e66835e11;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcEnv.lhs b/compiler/typecheck/TcEnv.lhs
index b69163c..96dc261 100644
--- a/compiler/typecheck/TcEnv.lhs
+++ b/compiler/typecheck/TcEnv.lhs
@@ -203,6 +203,7 @@ tcLookupFamInst tycon tys
   = do { env <- getGblEnv
        ; eps <- getEps
        ; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
+       ; traceTc "lookupFamInst" ((ppr tycon <+> ppr tys) $$ ppr instEnv)
        ; case lookupFamInstEnv instEnv tycon tys of
 	   []                      -> return Nothing
 	   ((fam_inst, rep_tys):_) 
@@ -210,7 +211,7 @@ tcLookupFamInst tycon tys
        }
 
 tcLookupDataFamInst :: TyCon -> [Type] -> TcM (TyCon, [Type])
--- Find the instance of a data famliy
+-- Find the instance of a data family
 -- Note [Looking up family instances for deriving]
 tcLookupDataFamInst tycon tys
   | not (isFamilyTyCon tycon)
@@ -460,7 +461,7 @@ tcExtendGlobalTyVars gtv_var extra_global_tvs
 \begin{code}
 tcExtendRules :: [LRuleDecl Id] -> TcM a -> TcM a
 	-- Just pop the new rules into the EPS and envt resp
-	-- All the rules come from an interface file, not soruce
+	-- All the rules come from an interface file, not source
 	-- Nevertheless, some may be for this module, if we read
 	-- its interface instead of its source code
 tcExtendRules lcl_rules thing_inside
@@ -606,8 +607,8 @@ as well as explicit user written ones.
 \begin{code}
 data InstInfo a
   = InstInfo {
-      iSpec  :: Instance,		-- Includes the dfun id.  Its forall'd type 
-      iBinds :: InstBindings a		-- variables scope over the stuff in InstBindings!
+      iSpec   :: Instance,        -- Includes the dfun id.  Its forall'd type
+      iBinds  :: InstBindings a   -- variables scope over the stuff in InstBindings!
     }
 
 iDFunId :: InstInfo a -> DFunId
@@ -625,7 +626,7 @@ data InstBindings a
 			-- witness dictionary is identical to the argument 
 			-- dictionary.  Hence no bindings, no pragmas.
 
-	CoercionI	-- The coercion maps from newtype to the representation type
+	Coercion	-- The coercion maps from newtype to the representation type
 			-- (mentioning type variables bound by the forall'd iSpec variables)
 			-- E.g.   newtype instance N [a] = N1 (Tree a)
 			-- 	  co : N [a] ~ Tree a
@@ -637,7 +638,13 @@ data InstBindings a
                         -- in TcDeriv
 
 pprInstInfo :: InstInfo a -> SDoc
-pprInstInfo info = vcat [ptext (sLit "InstInfo:") <+> ppr (idType (iDFunId info))]
+pprInstInfo info = hang (ptext (sLit "instance"))
+                      2 (sep [ ifPprDebug (pprForAll tvs)
+                             , pprThetaArrowTy theta, ppr tau
+                             , ptext (sLit "where")])
+  where
+    (tvs, theta, tau) = tcSplitSigmaTy (idType (iDFunId info))
+
 
 pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc
 pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
@@ -674,7 +681,7 @@ newDFunName clas tys loc
 \end{code}
 
 Make a name for the representation tycon of a family instance.  It's an
-*external* name, like otber top-level names, and hence must be made with
+*external* name, like other top-level names, and hence must be made with
 newGlobalBinder.
 
 \begin{code}