X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FInst.lhs;h=1e99572c5e8b809c5cf3a70a23c463d3b3fc4443;hb=7bb069508f094825ca136ed97606651f3e093123;hp=5968b1ee0ee7877f59c5c48a66e65744b40eb253;hpb=cb5f88f09f87208fa74a424e4da7141fb5204aa2;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/Inst.lhs b/ghc/compiler/typecheck/Inst.lhs index 5968b1e..1e99572 100644 --- a/ghc/compiler/typecheck/Inst.lhs +++ b/ghc/compiler/typecheck/Inst.lhs @@ -6,24 +6,31 @@ \begin{code} module Inst ( LIE, emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE, - plusLIEs, mkLIE, isEmptyLIE, + plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE, Inst, OverloadedLit(..), pprInst, pprInsts, pprInstsInFull, tidyInst, tidyInsts, - InstanceMapper, + newDictFromOld, newDicts, newClassDicts, newDictsAtLoc, + newMethod, newMethodWithGivenTy, newOverloadedLit, + newIPDict, instOverloadedFun, + instantiateFdClassTys, instFunDeps, instFunDepsOfTheta, + newFunDepFromDict, - newDictFromOld, newDicts, newDictsAtLoc, - newMethod, newMethodWithGivenTy, newOverloadedLit, instOverloadedFun, - - tyVarsOfInst, instLoc, getDictClassTys, + tyVarsOfInst, tyVarsOfInsts, tyVarsOfLIE, instLoc, getDictClassTys, + getDictPred_maybe, getMethodTheta_maybe, + getFunDeps, getFunDepsOfLIE, + getIPs, getIPsOfLIE, + getAllFunDeps, getAllFunDepsOfLIE, lookupInst, lookupSimpleInst, LookupInstResult(..), - isDict, isTyVarDict, isStdClassTyVarDict, isMethodFor, + isDict, isClassDict, isMethod, + isTyVarDict, isStdClassTyVarDict, isMethodFor, notFunDep, instBindingRequired, instCanBeGeneralised, - zonkInst, instToId, instToIdBndr, + zonkInst, zonkInsts, zonkFunDeps, zonkTvFunDeps, + instToId, instToIdBndr, ipToId, InstOrigin(..), InstLoc, pprInstLoc ) where @@ -33,48 +40,54 @@ module Inst ( import HsSyn ( HsLit(..), HsExpr(..) ) import RnHsSyn ( RenamedArithSeqInfo, RenamedHsExpr, RenamedPat ) import TcHsSyn ( TcExpr, TcId, - mkHsTyApp, mkHsDictApp, zonkId + mkHsTyApp, mkHsDictApp, mkHsConApp, zonkId ) import TcMonad -import TcEnv ( TcIdSet, tcLookupValueByKey, tcLookupTyConByKey ) +import TcEnv ( TcIdSet, InstEnv, tcGetInstEnv, lookupInstEnv, InstLookupResult(..), + tcLookupValueByKey, tcLookupTyConByKey + ) import TcType ( TcThetaType, TcType, TcTauType, TcTyVarSet, - zonkTcType, zonkTcTypes, + zonkTcTyVars, zonkTcType, zonkTcTypes, zonkTcThetaType ) import Bag -import Class ( classInstEnv, Class ) +import Class ( Class, FunDep ) +import FunDeps ( instantiateFdClassTys ) import Id ( Id, idFreeTyVars, idType, mkUserLocal, mkSysLocal ) -import VarSet ( elemVarSet ) import PrelInfo ( isStandardClass, isCcallishClass, isNoDictClass ) -import Name ( OccName, Name, mkDictOcc, mkMethodOcc, getOccName ) -import PprType ( pprConstraint ) -import InstEnv ( InstEnv, lookupInstEnv ) +import Name ( OccName, Name, mkDictOcc, mkMethodOcc, mkIPOcc, + getOccName, nameUnique ) +import PprType ( pprPred ) import SrcLoc ( SrcLoc ) -import Type ( Type, ThetaType, - mkTyVarTy, isTyVarTy, mkDictTy, splitForAllTys, splitSigmaTy, - splitRhoTy, tyVarsOfType, tyVarsOfTypes, +import Type ( Type, PredType(..), ThetaType, + mkTyVarTy, isTyVarTy, mkDictTy, mkPredTy, + splitForAllTys, splitSigmaTy, + splitRhoTy, tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, mkSynTy, tidyOpenType, tidyOpenTypes ) -import InstEnv ( InstEnv ) import Subst ( emptyInScopeSet, mkSubst, - substTy, substTheta, mkTyVarSubst, mkTopTyVarSubst + substTy, substClasses, mkTyVarSubst, mkTopTyVarSubst ) import TyCon ( TyCon ) +import Literal ( inIntRange ) +import Var ( TyVar ) import VarEnv ( lookupVarEnv, TidyEnv, lookupSubstEnv, SubstResult(..) ) -import VarSet ( unionVarSet ) +import VarSet ( elemVarSet, emptyVarSet, unionVarSet ) import TysPrim ( intPrimTy, floatPrimTy, doublePrimTy ) -import TysWiredIn ( intDataCon, isIntTy, inIntRange, +import TysWiredIn ( intDataCon, isIntTy, floatDataCon, isFloatTy, doubleDataCon, isDoubleTy, - integerTy, isIntegerTy + integerTy, isIntegerTy, + voidTy ) import Unique ( fromRationalClassOpKey, rationalTyConKey, fromIntClassOpKey, fromIntegerClassOpKey, Unique ) import Maybes ( expectJust ) +import Maybe ( catMaybes ) import Util ( thenCmp, zipWithEqual, mapAccumL ) import Outputable \end{code} @@ -95,6 +108,8 @@ mkLIE insts = listToBag insts plusLIE lie1 lie2 = lie1 `unionBags` lie2 consLIE inst lie = inst `consBag` lie plusLIEs lies = unionManyBags lies +lieToList = bagToList +listToLIE = listToBag zonkLIE :: LIE -> NF_TcM s LIE zonkLIE lie = mapBagNF_Tc zonkInst lie @@ -127,8 +142,7 @@ type Int, represented by data Inst = Dict Unique - Class -- The type of the dict is (c ts), where - [TcType] -- c is the class and ts the types; + TcPredType InstLoc | Method @@ -161,6 +175,12 @@ data Inst TcType -- The type at which the literal is used InstLoc + | FunDep + Unique + Class -- the class from which this arises + [FunDep TcType] + InstLoc + data OverloadedLit = OverloadedIntegral Integer -- The number | OverloadedFractional Rational -- The number @@ -181,23 +201,19 @@ instance Eq Inst where EQ -> True other -> False -cmpInst (Dict _ clas1 tys1 _) (Dict _ clas2 tys2 _) - = (clas1 `compare` clas2) `thenCmp` (tys1 `compare` tys2) -cmpInst (Dict _ _ _ _) other - = LT +cmpInst (Dict _ pred1 _) (Dict _ pred2 _) = (pred1 `compare` pred2) +cmpInst (Dict _ _ _) other = LT +cmpInst (Method _ _ _ _ _ _) (Dict _ _ _) = GT +cmpInst (Method _ id1 tys1 _ _ _) (Method _ id2 tys2 _ _ _) = (id1 `compare` id2) `thenCmp` (tys1 `compare` tys2) +cmpInst (Method _ _ _ _ _ _) other = LT -cmpInst (Method _ _ _ _ _ _) (Dict _ _ _ _) - = GT -cmpInst (Method _ id1 tys1 _ _ _) (Method _ id2 tys2 _ _ _) - = (id1 `compare` id2) `thenCmp` (tys1 `compare` tys2) -cmpInst (Method _ _ _ _ _ _) other - = LT +cmpInst (LitInst _ lit1 ty1 _) (LitInst _ lit2 ty2 _) = (lit1 `cmpOverLit` lit2) `thenCmp` (ty1 `compare` ty2) +cmpInst (LitInst _ _ _ _) (FunDep _ _ _ _) = LT +cmpInst (LitInst _ _ _ _) other = GT -cmpInst (LitInst _ lit1 ty1 _) (LitInst _ lit2 ty2 _) - = (lit1 `cmpOverLit` lit2) `thenCmp` (ty1 `compare` ty2) -cmpInst (LitInst _ _ _ _) other - = GT +cmpInst (FunDep _ clas1 fds1 _) (FunDep _ clas2 fds2 _) = (clas1 `compare` clas2) `thenCmp` (fds1 `compare` fds2) +cmpInst (FunDep _ _ _ _) other = GT cmpOverLit (OverloadedIntegral i1) (OverloadedIntegral i2) = i1 `compare` i2 cmpOverLit (OverloadedFractional f1) (OverloadedFractional f2) = f1 `compare` f2 @@ -209,39 +225,89 @@ cmpOverLit (OverloadedFractional _) (OverloadedIntegral _) = GT Selection ~~~~~~~~~ \begin{code} -instLoc (Dict u clas tys loc) = loc +instLoc (Dict u pred loc) = loc instLoc (Method u _ _ _ _ loc) = loc instLoc (LitInst u lit ty loc) = loc +instLoc (FunDep _ _ _ loc) = loc + +getDictPred_maybe (Dict _ p _) = Just p +getDictPred_maybe _ = Nothing + +getMethodTheta_maybe (Method _ _ _ theta _ _) = Just theta +getMethodTheta_maybe _ = Nothing + +getDictClassTys (Dict u (Class clas tys) _) = (clas, tys) -getDictClassTys (Dict u clas tys _) = (clas, tys) +getFunDeps (FunDep _ clas fds _) = Just (clas, fds) +getFunDeps _ = Nothing + +getFunDepsOfLIE lie = catMaybes (map getFunDeps (lieToList lie)) + +getIPsOfPred (IParam n ty) = [(n, ty)] +getIPsOfPred _ = [] +getIPsOfTheta theta = concatMap getIPsOfPred theta + +getIPs (Dict u (IParam n ty) loc) = [(n, ty)] +getIPs (Method u id _ theta t loc) = getIPsOfTheta theta +getIPs _ = [] + +getIPsOfLIE lie = concatMap getIPs (lieToList lie) + +getAllFunDeps (FunDep _ clas fds _) = fds +getAllFunDeps inst = map (\(n,ty) -> ([], [ty])) (getIPs inst) + +getAllFunDepsOfLIE lie = concat (map getAllFunDeps (lieToList lie)) tyVarsOfInst :: Inst -> TcTyVarSet -tyVarsOfInst (Dict _ _ tys _) = tyVarsOfTypes tys +tyVarsOfInst (Dict _ pred _) = tyVarsOfPred pred tyVarsOfInst (Method _ id tys _ _ _) = tyVarsOfTypes tys `unionVarSet` idFreeTyVars id -- The id might have free type variables; in the case of -- locally-overloaded class methods, for example tyVarsOfInst (LitInst _ _ ty _) = tyVarsOfType ty +tyVarsOfInst (FunDep _ _ fds _) + = foldr unionVarSet emptyVarSet (map tyVarsOfFd fds) + where tyVarsOfFd (ts1, ts2) = + tyVarsOfTypes ts1 `unionVarSet` tyVarsOfTypes ts2 + +tyVarsOfInsts insts + = foldr unionVarSet emptyVarSet (map tyVarsOfInst insts) + +tyVarsOfLIE lie + = foldr unionVarSet emptyVarSet (map tyVarsOfInst insts) + where insts = lieToList lie \end{code} Predicates ~~~~~~~~~~ \begin{code} isDict :: Inst -> Bool -isDict (Dict _ _ _ _) = True -isDict other = False +isDict (Dict _ _ _) = True +isDict other = False + +isClassDict :: Inst -> Bool +isClassDict (Dict _ (Class _ _) _) = True +isClassDict other = False + +isMethod :: Inst -> Bool +isMethod (Method _ _ _ _ _ _) = True +isMethod other = False isMethodFor :: TcIdSet -> Inst -> Bool -isMethodFor ids (Method uniq id tys _ _ loc) - = id `elemVarSet` ids -isMethodFor ids inst - = False +isMethodFor ids (Method uniq id tys _ _ loc) = id `elemVarSet` ids +isMethodFor ids inst = False isTyVarDict :: Inst -> Bool -isTyVarDict (Dict _ _ tys _) = all isTyVarTy tys -isTyVarDict other = False +isTyVarDict (Dict _ (Class _ tys) _) = all isTyVarTy tys +isTyVarDict other = False + +isStdClassTyVarDict (Dict _ (Class clas [ty]) _) + = isStandardClass clas && isTyVarTy ty +isStdClassTyVarDict other + = False -isStdClassTyVarDict (Dict _ clas [ty] _) = isStandardClass clas && isTyVarTy ty -isStdClassTyVarDict other = False +notFunDep :: Inst -> Bool +notFunDep (FunDep _ _ _ _) = False +notFunDep other = True \end{code} Two predicates which deal with the case where class constraints don't @@ -251,12 +317,13 @@ must be witnessed by an actual binding; the second tells whether an \begin{code} instBindingRequired :: Inst -> Bool -instBindingRequired (Dict _ clas _ _) = not (isNoDictClass clas) -instBindingRequired other = True +instBindingRequired (Dict _ (Class clas _) _) = not (isNoDictClass clas) +instBindingRequired (Dict _ (IParam _ _) _) = False +instBindingRequired other = True instCanBeGeneralised :: Inst -> Bool -instCanBeGeneralised (Dict _ clas _ _) = not (isCcallishClass clas) -instCanBeGeneralised other = True +instCanBeGeneralised (Dict _ (Class clas _) _) = not (isCcallishClass clas) +instCanBeGeneralised other = True \end{code} @@ -272,6 +339,12 @@ newDicts orig theta newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, ids) -> returnNF_Tc (listToBag dicts, ids) +newClassDicts :: InstOrigin + -> [(Class,[TcType])] + -> NF_TcM s (LIE, [TcId]) +newClassDicts orig theta + = newDicts orig (map (uncurry Class) theta) + -- Local function, similar to newDicts, -- but with slightly different interface newDictsAtLoc :: InstLoc @@ -280,15 +353,15 @@ newDictsAtLoc :: InstLoc newDictsAtLoc loc theta = tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs -> let - mk_dict u (clas, tys) = Dict u clas tys loc + mk_dict u pred = Dict u pred loc dicts = zipWithEqual "newDictsAtLoc" mk_dict new_uniqs theta in returnNF_Tc (dicts, map instToId dicts) newDictFromOld :: Inst -> Class -> [TcType] -> NF_TcM s Inst -newDictFromOld (Dict _ _ _ loc) clas tys +newDictFromOld (Dict _ _ loc) clas tys = tcGetUnique `thenNF_Tc` \ uniq -> - returnNF_Tc (Dict uniq clas tys loc) + returnNF_Tc (Dict uniq (Class clas tys) loc) newMethod :: InstOrigin @@ -305,17 +378,33 @@ newMethod orig id tys newMethodWithGivenTy orig id tys theta tau `thenNF_Tc` \ meth_inst -> returnNF_Tc (unitLIE meth_inst, instToId meth_inst) -instOverloadedFun orig (HsVar v) arg_tys theta tau +instOverloadedFun orig v arg_tys theta tau +-- This is where we introduce new functional dependencies into the LIE = newMethodWithGivenTy orig v arg_tys theta tau `thenNF_Tc` \ inst -> - returnNF_Tc (HsVar (instToId inst), unitLIE inst) + instFunDeps orig theta `thenNF_Tc` \ fds -> + returnNF_Tc (instToId inst, mkLIE (inst : fds)) + +instFunDeps orig theta + = tcGetUnique `thenNF_Tc` \ uniq -> + tcGetInstLoc orig `thenNF_Tc` \ loc -> + let ifd (Class clas tys) = + let fds = instantiateFdClassTys clas tys in + if null fds then Nothing else Just (FunDep uniq clas fds loc) + ifd _ = Nothing + in returnNF_Tc (catMaybes (map ifd theta)) + +instFunDepsOfTheta theta + = let ifd (Class clas tys) = instantiateFdClassTys clas tys + ifd (IParam n ty) = [([], [ty])] + in concat (map ifd theta) newMethodWithGivenTy orig id tys theta tau = tcGetInstLoc orig `thenNF_Tc` \ loc -> - tcGetUnique `thenNF_Tc` \ new_uniq -> - let - meth_inst = Method new_uniq id tys theta tau loc - in - returnNF_Tc meth_inst + newMethodWith id tys theta tau loc + +newMethodWith id tys theta tau loc + = tcGetUnique `thenNF_Tc` \ new_uniq -> + returnNF_Tc (Method new_uniq id tys theta tau loc) newMethodAtLoc :: InstLoc -> Id -> [TcType] @@ -354,7 +443,7 @@ newOverloadedLit orig (OverloadedIntegral i) ty where intprim_lit = HsLitOut (HsIntPrim i) intPrimTy integer_lit = HsLitOut (HsInt i) integerTy - int_lit = HsCon intDataCon [] [intprim_lit] + int_lit = mkHsConApp intDataCon [] [intprim_lit] newOverloadedLit orig lit ty -- The general case = tcGetInstLoc orig `thenNF_Tc` \ loc -> @@ -365,20 +454,44 @@ newOverloadedLit orig lit ty -- The general case returnNF_Tc (HsVar (instToId lit_inst), unitLIE lit_inst) \end{code} +\begin{code} +newFunDepFromDict dict + = tcGetUnique `thenNF_Tc` \ uniq -> + let (clas, tys) = getDictClassTys dict + fds = instantiateFdClassTys clas tys + inst = FunDep uniq clas fds (instLoc dict) + in + if null fds then returnNF_Tc Nothing else returnNF_Tc (Just inst) +\end{code} + +\begin{code} +newIPDict name ty loc + = tcGetUnique `thenNF_Tc` \ new_uniq -> + let d = Dict new_uniq (IParam name ty) loc in + returnNF_Tc d +\end{code} \begin{code} instToId :: Inst -> TcId instToId inst = instToIdBndr inst instToIdBndr :: Inst -> TcId -instToIdBndr (Dict u clas ty (_,loc,_)) - = mkUserLocal (mkDictOcc (getOccName clas)) u (mkDictTy clas ty) loc +instToIdBndr (Dict u (Class clas tys) (_,loc,_)) + = mkUserLocal (mkDictOcc (getOccName clas)) u (mkDictTy clas tys) loc +instToIdBndr (Dict u (IParam n ty) (_,loc,_)) + = ipToId n ty loc instToIdBndr (Method u id tys theta tau (_,loc,_)) = mkUserLocal (mkMethodOcc (getOccName id)) u tau loc - + instToIdBndr (LitInst u list ty loc) = mkSysLocal SLIT("lit") u ty + +instToIdBndr (FunDep u clas fds _) + = mkSysLocal SLIT("FunDep") u voidTy + +ipToId n ty loc + = mkUserLocal (mkIPOcc (getOccName n)) (nameUnique n) (mkPredTy (IParam n ty)) loc \end{code} @@ -389,10 +502,18 @@ but doesn't do the same for the Id in a Method. There's no need, and it's a lot of extra work. \begin{code} +zonkPred :: TcPredType -> NF_TcM s TcPredType +zonkPred (Class clas tys) + = zonkTcTypes tys `thenNF_Tc` \ new_tys -> + returnNF_Tc (Class clas new_tys) +zonkPred (IParam n ty) + = zonkTcType ty `thenNF_Tc` \ new_ty -> + returnNF_Tc (IParam n new_ty) + zonkInst :: Inst -> NF_TcM s Inst -zonkInst (Dict u clas tys loc) - = zonkTcTypes tys `thenNF_Tc` \ new_tys -> - returnNF_Tc (Dict u clas new_tys loc) +zonkInst (Dict u pred loc) + = zonkPred pred `thenNF_Tc` \ new_pred -> + returnNF_Tc (Dict u new_pred loc) zonkInst (Method u id tys theta tau loc) = zonkId id `thenNF_Tc` \ new_id -> @@ -408,6 +529,27 @@ zonkInst (Method u id tys theta tau loc) zonkInst (LitInst u lit ty loc) = zonkTcType ty `thenNF_Tc` \ new_ty -> returnNF_Tc (LitInst u lit new_ty loc) + +zonkInst (FunDep u clas fds loc) + = zonkFunDeps fds `thenNF_Tc` \ fds' -> + returnNF_Tc (FunDep u clas fds' loc) + +zonkPreds preds = mapNF_Tc zonkPred preds +zonkInsts insts = mapNF_Tc zonkInst insts + +zonkFunDeps fds = mapNF_Tc zonkFd fds + where + zonkFd (ts1, ts2) + = zonkTcTypes ts1 `thenNF_Tc` \ ts1' -> + zonkTcTypes ts2 `thenNF_Tc` \ ts2' -> + returnNF_Tc (ts1', ts2') + +zonkTvFunDeps fds = mapNF_Tc zonkFd fds + where + zonkFd (tvs1, tvs2) + = zonkTcTyVars tvs1 `thenNF_Tc` \ tvs1' -> + zonkTcTyVars tvs2 `thenNF_Tc` \ tvs2' -> + returnNF_Tc (tvs1', tvs2') \end{code} @@ -428,12 +570,27 @@ pprInst (LitInst u lit ty loc) ppr ty, show_uniq u] -pprInst (Dict u clas tys loc) = pprConstraint clas tys <+> show_uniq u +pprInst (Dict u pred loc) = pprPred pred <+> show_uniq u -pprInst (Method u id tys _ _ loc) +pprInst m@(Method u id tys theta tau loc) = hsep [ppr id, ptext SLIT("at"), - brackets (interppSP tys), - show_uniq u] + brackets (interppSP tys) {- , + ppr theta, ppr tau, + show_uniq u, + ppr (instToId m) -}] + +pprInst (FunDep _ clas fds loc) + = hsep [ppr clas, ppr fds] + +tidyPred :: TidyEnv -> TcPredType -> (TidyEnv, TcPredType) +tidyPred env (Class clas tys) + = (env', Class clas tys') + where + (env', tys') = tidyOpenTypes env tys +tidyPred env (IParam n ty) + = (env', IParam n ty') + where + (env', ty') = tidyOpenType env ty tidyInst :: TidyEnv -> Inst -> (TidyEnv, Inst) tidyInst env (LitInst u lit ty loc) @@ -441,17 +598,21 @@ tidyInst env (LitInst u lit ty loc) where (env', ty') = tidyOpenType env ty -tidyInst env (Dict u clas tys loc) - = (env', Dict u clas tys' loc) +tidyInst env (Dict u pred loc) + = (env', Dict u pred' loc) where - (env', tys') = tidyOpenTypes env tys + (env', pred') = tidyPred env pred tidyInst env (Method u id tys theta tau loc) = (env', Method u id tys' theta tau loc) -- Leave theta, tau alone cos we don't print them where (env', tys') = tidyOpenTypes env tys - + +-- this case shouldn't arise... (we never print fundeps) +tidyInst env fd@(FunDep _ clas fds loc) + = (env, fd) + tidyInsts env insts = mapAccumL tidyInst env insts show_uniq u = ifPprDebug (text "{-" <> ppr u <> text "-}") @@ -465,25 +626,6 @@ show_uniq u = ifPprDebug (text "{-" <> ppr u <> text "-}") %************************************************************************ \begin{code} -type InstanceMapper = Class -> InstEnv -\end{code} - -A @ClassInstEnv@ lives inside a class, and identifies all the instances -of that class. The @Id@ inside a ClassInstEnv mapping is the dfun for -that instance. - -There is an important consistency constraint between the @MatchEnv@s -in and the dfun @Id@s inside them: the free type variables of the -@Type@ key in the @MatchEnv@ must be a subset of the universally-quantified -type variables of the dfun. Thus, the @ClassInstEnv@ for @Eq@ might -contain the following entry: -@ - [a] ===> dfun_Eq_List :: forall a. Eq a => Eq [a] -@ -The "a" in the pattern must be one of the forall'd variables in -the dfun type. - -\begin{code} data LookupInstResult s = NoInstance | SimpleInst TcExpr -- Just a variable, type application, or literal @@ -494,10 +636,11 @@ lookupInst :: Inst -- Dictionaries -lookupInst dict@(Dict _ clas tys loc) - = case lookupInstEnv (ppr clas) (classInstEnv clas) tys of +lookupInst dict@(Dict _ (Class clas tys) loc) + = tcGetInstEnv `thenNF_Tc` \ inst_env -> + case lookupInstEnv inst_env clas tys of - Just (tenv, dfun_id) + FoundInst tenv dfun_id -> let subst = mkSubst (tyVarsOfTypes tys) tenv (tyvars, rho) = splitForAllTys (idType dfun_id) @@ -517,8 +660,9 @@ lookupInst dict@(Dict _ clas tys loc) rhs = mkHsDictApp ty_app dict_ids in returnNF_Tc (GenInst dicts rhs) - - Nothing -> returnNF_Tc NoInstance + + other -> returnNF_Tc NoInstance +lookupInst dict@(Dict _ _ loc) = returnNF_Tc NoInstance -- Methods @@ -549,7 +693,7 @@ lookupInst inst@(LitInst u (OverloadedIntegral i) ty loc) in_int_range = inIntRange i intprim_lit = HsLitOut (HsIntPrim i) intPrimTy integer_lit = HsLitOut (HsInt i) integerTy - int_lit = HsCon intDataCon [] [intprim_lit] + int_lit = mkHsConApp intDataCon [] [intprim_lit] -- similar idea for overloaded floating point literals: if the literal is -- *definitely* a float or a double, generate the real thing here. @@ -560,7 +704,7 @@ lookupInst inst@(LitInst u (OverloadedFractional f) ty loc) | isDoubleTy ty = returnNF_Tc (GenInst [] double_lit) | otherwise - = tcLookupValueByKey fromRationalClassOpKey `thenNF_Tc` \ from_rational -> + = tcLookupValueByKey fromRationalClassOpKey `thenNF_Tc` \ from_rational -> -- The type Rational isn't wired in so we have to conjure it up tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon -> @@ -573,9 +717,13 @@ lookupInst inst@(LitInst u (OverloadedFractional f) ty loc) where floatprim_lit = HsLitOut (HsFloatPrim f) floatPrimTy - float_lit = HsCon floatDataCon [] [floatprim_lit] + float_lit = mkHsConApp floatDataCon [] [floatprim_lit] doubleprim_lit = HsLitOut (HsDoublePrim f) doublePrimTy - double_lit = HsCon doubleDataCon [] [doubleprim_lit] + double_lit = mkHsConApp doubleDataCon [] [doubleprim_lit] + +-- there are no `instances' of functional dependencies or implicit params + +lookupInst _ = returnNF_Tc NoInstance \end{code} @@ -585,17 +733,20 @@ appropriate dictionary if it exists. It is used only when resolving ambiguous dictionaries. \begin{code} -lookupSimpleInst :: InstEnv - -> Class - -> [Type] -- Look up (c,t) - -> NF_TcM s (Maybe ThetaType) -- Here are the needed (c,t)s - -lookupSimpleInst class_inst_env clas tys - = case lookupInstEnv (ppr clas) class_inst_env tys of - Nothing -> returnNF_Tc Nothing - - Just (tenv, dfun) - -> returnNF_Tc (Just (substTheta (mkSubst emptyInScopeSet tenv) theta)) +lookupSimpleInst :: Class + -> [Type] -- Look up (c,t) + -> NF_TcM s (Maybe [(Class,[Type])]) -- Here are the needed (c,t)s + +lookupSimpleInst clas tys + = tcGetInstEnv `thenNF_Tc` \ inst_env -> + case lookupInstEnv inst_env clas tys of + FoundInst tenv dfun + -> returnNF_Tc (Just (substClasses (mkSubst emptyInScopeSet tenv) theta')) where (_, theta, _) = splitSigmaTy (idType dfun) + theta' = map (\(Class clas tys) -> (clas,tys)) theta + + other -> returnNF_Tc Nothing \end{code} + +