Complete the evidence generation for GADTs

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

diff --git a/compiler/typecheck/TcEnv.lhs b/compiler/typecheck/TcEnv.lhs
index 19deca9..1d093e2 100644 (file)
--- a/compiler/typecheck/TcEnv.lhs
+++ b/compiler/typecheck/TcEnv.lhs
@@ -45,19 +45,19 @@ module TcEnv(
 
 import HsSyn           ( LRuleDecl, LHsBinds, LSig, 
                          LHsTyVarBndr, HsTyVarBndr(..), pprLHsBinds,
-                         ExprCoFn(..), idCoercion, (<.>) )
+                         idCoercion, (<.>) )
 import TcIface         ( tcImportDecl )
 import IfaceEnv                ( newGlobalBinder )
 import TcRnMonad
 import TcMType         ( zonkTcType, zonkTcTyVarsAndFV )
-import TcType          ( Type, TcKind, TcTyVar, TcTyVarSet, TcType, TvSubst,
-                         substTy, substTyVar, tyVarsOfType, tcTyVarsOfTypes, mkTyConApp,
+import TcType          ( Type, TcKind, TcTyVar, TcTyVarSet, TcType, 
+                         substTy, tyVarsOfType, tcTyVarsOfTypes, mkTyConApp,
                          getDFunTyKey, tcTyConAppTyCon, tcGetTyVar, mkTyVarTy,
                          tidyOpenType, isRefineableTy
                        )
 import TcGadt          ( Refinement, refineType )
 import qualified Type  ( getTyVar_maybe )
-import Id              ( idName, isLocalId, setIdType )
+import Id              ( idName, isLocalId )
 import Var             ( TyVar, Id, idType, tyVarName )
 import VarSet
 import VarEnv
@@ -565,7 +565,9 @@ data InstBindings
        [LSig Name]             -- User pragmas recorded for generating 
                                -- specialised instances
 
-  | NewTypeDerived             -- Used for deriving instances of newtypes, where the
+  | NewTypeDerived             
+        TyCon                   -- tycon for the newtype
+                                -- Used for deriving instances of newtypes, where the
        [Type]                  -- witness dictionary is identical to the argument 
                                -- dictionary.  Hence no bindings, no pragmas
        -- The [Type] are the representation types
@@ -576,7 +578,7 @@ pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))
 pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
   where
     details (VanillaInst b _)  = pprLHsBinds b
-    details (NewTypeDerived _) = text "Derived from the representation type"
+    details (NewTypeDerived _  _) = text "Derived from the representation type"
 
 simpleInstInfoClsTy :: InstInfo -> (Class, Type)
 simpleInstInfoClsTy info = case instanceHead (iSpec info) of