Typechecking class declarations
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module TcClassDcl ( tcClassSigs, tcClassDecl2,
getGenericInstances,
MethodSpec, tcMethodBind, mkMethId,
import TcType
import TcRnMonad
import Generics
-import PrelInfo
import Class
import TyCon
import Type
import MkId
import Id
import Name
+import Var
import NameEnv
import NameSet
import OccName
; mapM (tcClassSig dm_env) op_sigs }
where
op_sigs = [sig | sig@(L _ (TypeSig _ _)) <- sigs]
- op_names = [n | sig@(L _ (TypeSig (L _ n) _)) <- op_sigs]
+ op_names = [n | (L _ (TypeSig (L _ n) _)) <- op_sigs]
checkDefaultBinds :: Name -> [Name] -> LHsBinds Name -> TcM (NameEnv Bool)
= do dm_infos <- mapM (addLocM (checkDefaultBind clas ops)) (bagToList binds)
return (mkNameEnv dm_infos)
+checkDefaultBind :: Name -> [Name] -> HsBindLR Name Name -> TcM (Name, Bool)
checkDefaultBind clas ops (FunBind {fun_id = L _ op, fun_matches = MatchGroup matches _ })
= do { -- Check that the op is from this class
checkTc (op `elem` ops) (badMethodErr clas op)
n_generic = count (isJust . maybeGenericMatch) matches
none_generic = n_generic == 0
all_generic = matches `lengthIs` n_generic
+checkDefaultBind _ _ b = pprPanic "checkDefaultBind" (ppr b)
tcClassSig :: NameEnv Bool -- Info about default methods;
Just False -> DefMeth
Just True -> GenDefMeth
; return (op_name, dm, op_ty) }
+tcClassSig _ s = pprPanic "tcClassSig" (ppr s)
\end{code}
(defm_binds, dm_ids_s) <- mapAndUnzipM tc_dm dm_sel_ids
return (listToBag defm_binds, concat dm_ids_s)
+tcClassDecl2 d = pprPanic "tcClassDecl2" (ppr d)
+tcDefMeth :: InstOrigin -> Class -> [TyVar] -> LHsBinds Name
+ -> TcSigFun -> TcPragFun -> Id
+ -> TcM (LHsBindLR Id Var, [Id])
tcDefMeth origin clas tyvars binds_in sig_fn prag_fn sel_id
= do { dm_name <- lookupTopBndrRn (mkDefMethRdrName sel_id)
; let inst_tys = mkTyVarTys tyvars
---------------------------
+tc_method_bind :: [TyVar] -> TcThetaType -> [Inst] -> (Name -> Maybe [Name])
+ -> (Name -> [LSig Name]) -> Id -> Id -> LHsBind Name
+ -> TcRn (LHsBindsLR Id Var)
tc_method_bind inst_tyvars inst_theta avail_insts sig_fn prag_fn
sel_id meth_id meth_bind
= recoverM (return emptyLHsBinds) $
---------------------------
-mkMethId :: InstOrigin -> Class
+mkMethId :: InstOrigin -> Class
-> Id -> [TcType] -- Selector, and instance types
-> TcM (Maybe Inst, Id)
-- where C is the class in question
ASSERT( not (null preds) &&
case getClassPredTys_maybe first_pred of
- { Just (clas1,tys) -> clas == clas1 ; Nothing -> False }
+ { Just (clas1, _tys) -> clas == clas1 ; Nothing -> False }
)
if isSingleton preds then do
-- If it's the only one, make a 'method'
f _other = Nothing
---------------------------
+mkGenericDefMethBind :: Class -> [Type] -> Id -> Name -> TcM (LHsBind Name)
mkGenericDefMethBind clas inst_tys sel_id meth_name
= -- A generic default method
-- If the method is defined generically, we can only do the job if the
maybe_tycon = case inst_tys of
[ty] -> case tcSplitTyConApp_maybe ty of
Just (tycon, arg_tys) | all tcIsTyVarTy arg_tys -> Just tycon
- other -> Nothing
- other -> Nothing
+ _ -> Nothing
+ _ -> Nothing
+isInstDecl :: InstOrigin -> Bool
isInstDecl (SigOrigin InstSkol) = True
isInstDecl (SigOrigin (ClsSkol _)) = False
+isInstDecl o = pprPanic "isInstDecl" (ppr o)
\end{code}
\begin{code}
-getGenericInstances :: [LTyClDecl Name] -> TcM [InstInfo]
+getGenericInstances :: [LTyClDecl Name] -> TcM [InstInfo Name]
getGenericInstances class_decls
= do { gen_inst_infos <- mapM (addLocM get_generics) class_decls
; let { gen_inst_info = concat gen_inst_infos }
(vcat (map pprInstInfoDetails gen_inst_info)))
; return gen_inst_info }}
+get_generics :: TyClDecl Name -> TcM [InstInfo Name]
get_generics decl@(ClassDecl {tcdLName = class_name, tcdMeths = def_methods})
| null generic_binds
= return [] -- The comon case: no generic default methods
--
-- The class should be unary, which is why simpleInstInfoTyCon should be ok
let
- tc_inst_infos :: [(TyCon, InstInfo)]
+ tc_inst_infos :: [(TyCon, InstInfo Name)]
tc_inst_infos = [(simpleInstInfoTyCon i, i) | i <- inst_infos]
bad_groups = [group | group <- equivClassesByUniq get_uniq tc_inst_infos,
where
generic_binds :: [(HsType Name, LHsBind Name)]
generic_binds = getGenericBinds def_methods
+get_generics decl = pprPanic "get_generics" (ppr decl)
---------------------------------
-- them in finite map indexed by the type parameter in the definition.
getGenericBinds binds = concat (map getGenericBind (bagToList binds))
+getGenericBind :: LHsBindLR Name Name -> [(HsType Name, LHsBindLR Name Name)]
getGenericBind (L loc bind@(FunBind { fun_matches = MatchGroup matches ty }))
= groupWith wrap (mapCatMaybes maybeGenericMatch matches)
where
= []
groupWith :: ([a] -> b) -> [(HsType Name, a)] -> [(HsType Name, b)]
-groupWith op [] = []
+groupWith _ [] = []
groupWith op ((t,v):prs) = (t, op (v:vs)) : groupWith op rest
where
- vs = map snd this
- (this,rest) = partition same_t prs
- same_t (t',v) = t `eqPatType` t'
+ vs = map snd this
+ (this,rest) = partition same_t prs
+ same_t (t', _v) = t `eqPatType` t'
eqPatLType :: LHsType Name -> LHsType Name -> Bool
eqPatLType t1 t2 = unLoc t1 `eqPatType` unLoc t2
---------------------------------
mkGenericInstance :: Class
-> (HsType Name, LHsBinds Name)
- -> TcM InstInfo
+ -> TcM (InstInfo Name)
mkGenericInstance clas (hs_ty, binds) = do
-- Make a generic instance declaration
%************************************************************************
\begin{code}
+tcAddDeclCtxt :: TyClDecl Name -> TcM a -> TcM a
tcAddDeclCtxt decl thing_inside
= addErrCtxt ctxt thing_inside
where
then "newtype" ++ maybeInst
else "data type" ++ maybeInst
| isFamilyDecl decl = "family"
+ | otherwise = panic "tcAddDeclCtxt/thing"
maybeInst | isFamInstDecl decl = " instance"
| otherwise = ""
ctxt = hsep [ptext (sLit "In the"), text thing,
ptext (sLit "declaration for"), quotes (ppr (tcdName decl))]
+defltMethCtxt :: Class -> SDoc
defltMethCtxt clas
= ptext (sLit "When checking the default methods for class") <+> quotes (ppr clas)
+methodCtxt :: Var -> SDoc
methodCtxt sel_id
= ptext (sLit "In the definition for method") <+> quotes (ppr sel_id)
+badMethodErr :: Outputable a => a -> Name -> SDoc
badMethodErr clas op
= hsep [ptext (sLit "Class"), quotes (ppr clas),
ptext (sLit "does not have a method"), quotes (ppr op)]
+badATErr :: Class -> Name -> SDoc
badATErr clas at
= hsep [ptext (sLit "Class"), quotes (ppr clas),
ptext (sLit "does not have an associated type"), quotes (ppr at)]
+omittedMethodWarn :: Id -> SDoc
omittedMethodWarn sel_id
= ptext (sLit "No explicit method nor default method for") <+> quotes (ppr sel_id)
+omittedATWarn :: Name -> SDoc
omittedATWarn at
= ptext (sLit "No explicit AT declaration for") <+> quotes (ppr at)
+badGenericInstance :: Var -> SDoc -> SDoc
badGenericInstance sel_id because
= sep [ptext (sLit "Can't derive generic code for") <+> quotes (ppr sel_id),
because]
+notSimple :: [Type] -> SDoc
notSimple inst_tys
= vcat [ptext (sLit "because the instance type(s)"),
nest 2 (ppr inst_tys),
ptext (sLit "is not a simple type of form (T a1 ... an)")]
+notGeneric :: TyCon -> SDoc
notGeneric tycon
= vcat [ptext (sLit "because the instance type constructor") <+> quotes (ppr tycon) <+>
- ptext (sLit "was not compiled with -fgenerics")]
+ ptext (sLit "was not compiled with -XGenerics")]
+badGenericInstanceType :: LHsBinds Name -> SDoc
badGenericInstanceType binds
= vcat [ptext (sLit "Illegal type pattern in the generic bindings"),
nest 4 (ppr binds)]
+missingGenericInstances :: [Name] -> SDoc
missingGenericInstances missing
= ptext (sLit "Missing type patterns for") <+> pprQuotedList missing
+dupGenericInsts :: [(TyCon, InstInfo a)] -> SDoc
dupGenericInsts tc_inst_infos
= vcat [ptext (sLit "More than one type pattern for a single generic type constructor:"),
nest 4 (vcat (map ppr_inst_ty tc_inst_infos)),
where
ppr_inst_ty (_,inst) = ppr (simpleInstInfoTy inst)
+mixedGenericErr :: Name -> SDoc
mixedGenericErr op
= ptext (sLit "Can't mix generic and non-generic equations for class method") <+> quotes (ppr op)
\end{code}
projects / ghc-hetmet.git / blobdiff