X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcInstDcls.lhs;h=d314e1e21f0b5e479bb5cccf5ed72e2ae554847f;hb=b99310f05faee2abec850da4349fcd5c0498f7ca;hp=0be77242e3e7f6bc29beabc1d8e319b96c8e42cb;hpb=0aa1d46a1e5c19553c410dc6ff65b29594a2499f;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcInstDcls.lhs b/compiler/typecheck/TcInstDcls.lhs
index 0be7724..d314e1e 100644
--- a/compiler/typecheck/TcInstDcls.lhs
+++ b/compiler/typecheck/TcInstDcls.lhs
@@ -147,9 +147,8 @@ tcInstDecls1 tycl_decls inst_decls deriv_decls
 		-- (they recover, so that we get more than one error each
 		-- round) 
 
-		-- (1) Do class instance declarations and instances of indexed
-		--     types 
-       ; let { idxty_decls = filter (isIdxTyDecl . unLoc) tycl_decls }
+		-- (1) Do class and family instance declarations
+       ; let { idxty_decls = filter (isFamInstDecl . unLoc) tycl_decls }
        ; local_info_tycons <- mappM tcLocalInstDecl1  inst_decls
        ; idx_tycons        <- mappM tcIdxTyInstDeclTL idxty_decls
 
@@ -180,7 +179,10 @@ tcInstDecls1 tycl_decls inst_decls deriv_decls
 	        -- (4) Compute instances from "deriving" clauses; 
 		-- This stuff computes a context for the derived instance
 		-- decl, so it needs to know about all the instances possible
-       ; (deriv_inst_info, deriv_binds) <- tcDeriving tycl_decls deriv_decls
+                -- NB: class instance declarations can contain derivings as
+                --     part of associated data type declarations
+       ; (deriv_inst_info, deriv_binds) <- tcDeriving tycl_decls inst_decls 
+                                                      deriv_decls
        ; addInsts deriv_inst_info   $ do {
 
        ; gbl_env <- getGblEnv
@@ -193,7 +195,7 @@ tcInstDecls1 tycl_decls inst_decls deriv_decls
     -- !!!TODO: Need to perform this check for the TyThing of type functions,
     --		too.
     tcIdxTyInstDeclTL ldecl@(L loc decl) =
-      do { tything <- tcIdxTyInstDecl ldecl
+      do { tything <- tcFamInstDecl ldecl
 	 ; setSrcSpan loc $
 	     when (isAssocFamily tything) $
 	       addErr $ assocInClassErr (tcdName decl)
@@ -240,14 +242,10 @@ tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
 	; checkTc (not is_boot || (isEmptyLHsBinds binds && null uprags))
 		  badBootDeclErr
 
-	-- Typecheck the instance type itself.  We can't use 
-	-- tcHsSigType, because it's not a valid user type.
-	; kinded_ty <- kcHsSigType poly_ty
-	; poly_ty'  <- tcHsKindedType kinded_ty
-	; let (tyvars, theta, tau) = tcSplitSigmaTy poly_ty'
+	; (tyvars, theta, tau) <- tcHsInstHead poly_ty
 	
 	-- Next, process any associated types.
-	; idx_tycons <- mappM tcIdxTyInstDecl ats
+	; idx_tycons <- mappM tcFamInstDecl ats
 
 	-- Now, check the validity of the instance.
 	; (clas, inst_tys) <- checkValidInstHead tau
@@ -257,7 +255,7 @@ tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
 
 	-- Finally, construct the Core representation of the instance.
 	-- (This no longer includes the associated types.)
-	; dfun_name <- newDFunName clas inst_tys (srcSpanStart loc)
+	; dfun_name <- newDFunName clas inst_tys loc
 	; overlap_flag <- getOverlapFlag
 	; let dfun           = mkDictFunId dfun_name tyvars theta clas inst_tys
 	      ispec          = mkLocalInstance dfun overlap_flag
@@ -278,11 +276,11 @@ tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags ats))
     checkValidAndMissingATs clas inst_tys ats
       = do { -- Issue a warning for each class AT that is not defined in this
 	     -- instance.
-	   ; let classDefATs = listToNameSet . map tyConName . classATs $ clas
-                 definedATs  = listToNameSet . map (tcdName.unLoc.fst)  $ ats
-		 omitted     = classDefATs `minusNameSet` definedATs
+	   ; let class_ats   = map tyConName (classATs clas)
+                 defined_ats = listToNameSet . map (tcdName.unLoc.fst)  $ ats
+		 omitted     = filterOut (`elemNameSet` defined_ats) class_ats
 	   ; warn <- doptM Opt_WarnMissingMethods
-	   ; mapM_ (warnTc warn . omittedATWarn) (nameSetToList omitted)
+	   ; mapM_ (warnTc warn . omittedATWarn) omitted
 	   
 	     -- Ensure that all AT indexes that correspond to class parameters
 	     -- coincide with the types in the instance head.  All remaining
@@ -587,10 +585,11 @@ tcInstDecl2 (InstInfo { iSpec = ispec, iBinds = VanillaInst monobinds uprags })
 	dfun_id    = instanceDFunId ispec
 	rigid_info = InstSkol
 	inst_ty    = idType dfun_id
+	loc   	   = srcLocSpan (getSrcLoc dfun_id)
     in
 	 -- Prime error recovery
     recoverM (returnM emptyLHsBinds)		$
-    setSrcSpan (srcLocSpan (getSrcLoc dfun_id))	$
+    setSrcSpan loc				$
     addErrCtxt (instDeclCtxt2 (idType dfun_id))	$
 
 	-- Instantiate the instance decl with skolem constants 
@@ -643,7 +642,7 @@ tcInstDecl2 (InstInfo { iSpec = ispec, iBinds = VanillaInst monobinds uprags })
 	scs_and_meths = map instToId sc_dicts ++ meth_ids
 	this_dict_id  = instToId this_dict
 	inline_prag | null dfun_arg_dicts = []
-		    | otherwise	= [InlinePrag (Inline AlwaysActive True)]
+		    | otherwise	= [L loc (InlinePrag (Inline AlwaysActive True))]
 		-- Always inline the dfun; this is an experimental decision
 		-- because it makes a big performance difference sometimes.
 		-- Often it means we can do the method selection, and then