The final batch of changes for the new coercion representation

[ghc-hetmet.git] / compiler / typecheck / TcEnv.lhs

diff --git a/compiler/typecheck/TcEnv.lhs b/compiler/typecheck/TcEnv.lhs
index d6177b4..a087059 100644 (file)
--- 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):_) 
@@ -548,9 +549,9 @@ tcGetDefaultTys :: Bool             -- True <=> interactive context
                          Bool)) -- True <=> Use extended defaulting rules
 tcGetDefaultTys interactive
   = do { dflags <- getDOpts
-        ; let ovl_strings = dopt Opt_OverloadedStrings dflags
+        ; let ovl_strings = xopt Opt_OverloadedStrings dflags
               extended_defaults = interactive
-                               || dopt Opt_ExtendedDefaultRules dflags
+                               || xopt Opt_ExtendedDefaultRules dflags
                                        -- See also Trac #1974 
               flags = (ovl_strings, extended_defaults)
     
@@ -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))