\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
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 Subst ( mkTyVarSubst )
+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}
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
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
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
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
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
\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}
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
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
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]
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 ->
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}
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 ->
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}
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)
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 "-}")
%************************************************************************
\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
-- 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)
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
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.
| 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 ->
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}
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}
+
+
projects / ghc-hetmet.git / blobdiff