LIE, emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE,
plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
- Inst, OverloadedLit(..),
+ Inst,
pprInst, pprInsts, pprInstsInFull, tidyInst, tidyInsts,
- InstanceMapper,
-
- newDictFromOld, newDicts, newClassDicts, newDictsAtLoc,
+ newDictsFromOld, newDicts, newClassDicts,
newMethod, newMethodWithGivenTy, newOverloadedLit,
- newIPDict, instOverloadedFun,
- instantiateFdClassTys, instFunDeps, instFunDepsOfTheta,
- newFunDepFromDict,
+ newIPDict, tcInstId,
tyVarsOfInst, tyVarsOfInsts, tyVarsOfLIE, instLoc, getDictClassTys,
- getDictPred_maybe, getMethodTheta_maybe,
- getFunDeps, getFunDepsOfLIE,
- getIPs, getIPsOfLIE,
- getAllFunDeps, getAllFunDepsOfLIE,
+ getIPs,
+ predsOfInsts,
lookupInst, lookupSimpleInst, LookupInstResult(..),
- isDict, isClassDict, isMethod,
- isTyVarDict, isStdClassTyVarDict, isMethodFor, notFunDep,
+ isDict, isClassDict, isMethod, instMentionsIPs,
+ isTyVarDict, isStdClassTyVarDict, isMethodFor,
instBindingRequired, instCanBeGeneralised,
- zonkInst, zonkInsts, zonkFunDeps, zonkTvFunDeps,
- instToId, instToIdBndr, ipToId,
+ zonkInst, zonkInsts,
+ instToId,
InstOrigin(..), InstLoc, pprInstLoc
) where
#include "HsVersions.h"
-import HsSyn ( HsLit(..), HsExpr(..) )
-import RnHsSyn ( RenamedArithSeqInfo, RenamedHsExpr, RenamedPat )
+import CmdLineOpts ( opt_NoMethodSharing )
+import HsSyn ( HsLit(..), HsOverLit(..), HsExpr(..) )
import TcHsSyn ( TcExpr, TcId,
mkHsTyApp, mkHsDictApp, mkHsConApp, zonkId
)
import TcMonad
-import TcEnv ( TcIdSet, tcLookupValueByKey, tcLookupTyConByKey )
-import TcType ( TcThetaType,
+import TcEnv ( TcIdSet, tcGetInstEnv, tcLookupSyntaxId )
+import InstEnv ( InstLookupResult(..), lookupInstEnv )
+import TcType ( TcThetaType, TcClassContext,
TcType, TcTauType, TcTyVarSet,
- zonkTcTyVars, zonkTcType, zonkTcTypes,
- zonkTcThetaType
+ zonkTcType, zonkTcTypes,
+ zonkTcThetaType, tcInstTyVar, tcInstType
)
-import Bag
-import Class ( classInstEnv, Class, FunDep )
-import FunDeps ( instantiateFdClassTys )
-import Id ( Id, idFreeTyVars, idType, mkUserLocal, mkSysLocal )
+import CoreFVs ( idFreeTyVars )
+import Class ( Class )
+import Id ( Id, idType, mkUserLocal, mkSysLocal, mkLocalId )
import PrelInfo ( isStandardClass, isCcallishClass, isNoDictClass )
-import Name ( OccName, Name, mkDictOcc, mkMethodOcc, mkIPOcc,
- getOccName, nameUnique )
+import Name ( mkDictOcc, mkMethodOcc, getOccName, mkLocalName )
+import NameSet ( NameSet )
import PprType ( pprPred )
-import InstEnv ( InstEnv, lookupInstEnv, InstEnvResult(..) )
-import SrcLoc ( SrcLoc )
-import Type ( Type, PredType(..), ThetaType,
- mkTyVarTy, isTyVarTy, mkDictTy, mkPredTy,
- splitForAllTys, splitSigmaTy,
- splitRhoTy, tyVarsOfType, tyVarsOfTypes, tyVarsOfPred,
- mkSynTy, tidyOpenType, tidyOpenTypes
+import Type ( Type, PredType(..),
+ isTyVarTy, mkPredTy, mkTyVarTy, mkTyVarTys,
+ splitForAllTys, splitSigmaTy, funArgTy,
+ splitMethodTy, splitRhoTy, classesOfPreds,
+ tyVarsOfType, tyVarsOfTypes, tyVarsOfPred,
+ tidyOpenType, tidyOpenTypes, predMentionsIPs
)
-import InstEnv ( InstEnv )
-import Subst ( emptyInScopeSet, mkSubst,
+import Subst ( emptyInScopeSet, mkSubst,
substTy, substClasses, mkTyVarSubst, mkTopTyVarSubst
)
-import TyCon ( TyCon )
import Literal ( inIntRange )
-import Var ( TyVar )
-import VarEnv ( lookupVarEnv, TidyEnv,
- lookupSubstEnv, SubstResult(..)
- )
+import VarEnv ( TidyEnv, lookupSubstEnv, SubstResult(..) )
import VarSet ( elemVarSet, emptyVarSet, unionVarSet )
-import TysPrim ( intPrimTy, floatPrimTy, doublePrimTy )
-import TysWiredIn ( intDataCon, isIntTy,
+import TysWiredIn ( isIntTy,
floatDataCon, isFloatTy,
doubleDataCon, isDoubleTy,
- integerTy, isIntegerTy,
- voidTy
+ isIntegerTy
)
-import Unique ( fromRationalClassOpKey, rationalTyConKey,
- fromIntClassOpKey, fromIntegerClassOpKey, Unique
- )
-import Maybes ( expectJust )
-import Maybe ( catMaybes )
+import PrelNames( fromIntegerName, fromRationalName )
import Util ( thenCmp, zipWithEqual, mapAccumL )
+import Bag
import Outputable
\end{code}
lieToList = bagToList
listToLIE = listToBag
-zonkLIE :: LIE -> NF_TcM s LIE
+zonkLIE :: LIE -> NF_TcM LIE
zonkLIE lie = mapBagNF_Tc zonkInst lie
pprInsts :: [Inst] -> SDoc
\begin{code}
data Inst
= Dict
- Unique
+ Id
TcPredType
InstLoc
| Method
- Unique
+ Id
TcId -- The overloaded function
-- This function will be a global, local, or ClassOpId;
-- type of (f tys dicts(from theta)) = tau
| LitInst
- Unique
- OverloadedLit
+ Id
+ HsOverLit -- The literal from the occurrence site
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
\end{code}
Ordering
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 _ lit1 ty1 _) (LitInst _ lit2 ty2 _) = (lit1 `compare` 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
-cmpOverLit (OverloadedIntegral _) (OverloadedFractional _) = LT
-cmpOverLit (OverloadedFractional _) (OverloadedIntegral _) = GT
+-- and they can only have HsInt or HsFracs in them.
\end{code}
Selection
~~~~~~~~~
\begin{code}
-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)
-
-getFunDeps (FunDep _ clas fds _) = Just (clas, fds)
-getFunDeps _ = Nothing
+instToId :: Inst -> TcId
+instToId (Dict id _ _) = id
+instToId (Method id _ _ _ _ _) = id
+instToId (LitInst id _ _ _) = id
-getFunDepsOfLIE lie = catMaybes (map getFunDeps (lieToList lie))
+instLoc (Dict _ _ loc) = loc
+instLoc (Method _ _ _ _ _ loc) = loc
+instLoc (LitInst _ _ _ loc) = loc
-getIPsOfPred (IParam n ty) = [(n, ty)]
-getIPsOfPred _ = []
-getIPsOfTheta theta = concatMap getIPsOfPred theta
+getDictClassTys (Dict _ (Class clas tys) _) = (clas, tys)
-getIPs (Dict u (IParam n ty) loc) = [(n, ty)]
-getIPs (Method u id _ theta t loc) = getIPsOfTheta theta
-getIPs _ = []
+predsOfInsts :: [Inst] -> [PredType]
+predsOfInsts insts = concatMap predsOfInst insts
-getIPsOfLIE lie = concatMap getIPs (lieToList lie)
+predsOfInst (Dict _ pred _) = [pred]
+predsOfInst (Method _ _ _ theta _ _) = theta
+predsOfInst (LitInst _ _ _ _) = []
+ -- The last case is is really a big cheat
+ -- LitInsts to give rise to a (Num a) or (Fractional a) predicate
+ -- But Num and Fractional have only one parameter and no functional
+ -- dependencies, so I think no caller of predsOfInst will care.
-getAllFunDeps (FunDep _ clas fds _) = fds
-getAllFunDeps inst = map (\(n,ty) -> ([], [ty])) (getIPs inst)
+ipsOfPreds theta = [(n,ty) | IParam n ty <- theta]
-getAllFunDepsOfLIE lie = concat (map getAllFunDeps (lieToList lie))
+getIPs inst = ipsOfPreds (predsOfInst inst)
tyVarsOfInst :: Inst -> TcTyVarSet
+tyVarsOfInst (LitInst _ _ ty _) = tyVarsOfType ty
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
+tyVarsOfInsts insts = foldr (unionVarSet . tyVarsOfInst) emptyVarSet insts
+tyVarsOfLIE lie = tyVarsOfInsts (lieToList lie)
\end{code}
Predicates
isDict :: Inst -> Bool
isDict (Dict _ _ _) = True
isDict other = False
+
isClassDict :: Inst -> Bool
isClassDict (Dict _ (Class _ _) _) = True
isClassDict other = False
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
+
+instMentionsIPs :: Inst -> NameSet -> Bool
+ -- True if the Inst mentions any of the implicit
+ -- parameters in the supplied set of names
+instMentionsIPs (Dict _ pred _) ip_names = pred `predMentionsIPs` ip_names
+instMentionsIPs (Method _ _ _ theta _ _) ip_names = any (`predMentionsIPs` ip_names) theta
+instMentionsIPs other ip_names = False
isTyVarDict :: Inst -> Bool
isTyVarDict (Dict _ (Class _ tys) _) = all isTyVarTy tys
= 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
\end{code}
-Construction
-~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Building dictionaries}
+%* *
+%************************************************************************
\begin{code}
newDicts :: InstOrigin
-> TcThetaType
- -> NF_TcM s (LIE, [TcId])
+ -> NF_TcM [Inst]
newDicts orig theta
= tcGetInstLoc orig `thenNF_Tc` \ loc ->
- newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, ids) ->
- returnNF_Tc (listToBag dicts, ids)
+ newDictsAtLoc loc theta
newClassDicts :: InstOrigin
- -> [(Class,[TcType])]
- -> NF_TcM s (LIE, [TcId])
-newClassDicts orig theta
- = newDicts orig (map (uncurry Class) theta)
+ -> TcClassContext
+ -> NF_TcM [Inst]
+newClassDicts orig theta = newDicts orig (map (uncurry Class) theta)
+
+newDictsFromOld :: Inst -> TcClassContext -> NF_TcM [Inst]
+newDictsFromOld (Dict _ _ loc) theta = newDictsAtLoc loc (map (uncurry Class) theta)
-- Local function, similar to newDicts,
-- but with slightly different interface
newDictsAtLoc :: InstLoc
-> TcThetaType
- -> NF_TcM s ([Inst], [TcId])
-newDictsAtLoc loc theta =
- tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs ->
- let
- mk_dict u pred = Dict u pred loc
- dicts = zipWithEqual "newDictsAtLoc" mk_dict new_uniqs theta
- in
- returnNF_Tc (dicts, map instToId dicts)
+ -> NF_TcM [Inst]
+newDictsAtLoc inst_loc@(_,loc,_) theta
+ = tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs ->
+ returnNF_Tc (zipWithEqual "newDictsAtLoc" mk_dict new_uniqs theta)
+ where
+ mk_dict uniq pred = Dict (mkLocalId (mk_dict_name uniq pred) (mkPredTy pred)) pred inst_loc
+
+ mk_dict_name uniq (Class cls tys) = mkLocalName uniq (mkDictOcc (getOccName cls)) loc
+ mk_dict_name uniq (IParam name ty) = name
+
+newIPDict orig name ty
+ = tcGetInstLoc orig `thenNF_Tc` \ inst_loc ->
+ returnNF_Tc (Dict (mkLocalId name ty) (IParam name ty) inst_loc)
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Building methods (calls of overloaded functions)}
+%* *
+%************************************************************************
+
+tcInstId instantiates an occurrence of an Id.
+The instantiate_it loop runs round instantiating the Id.
+It has to be a loop because we are now prepared to entertain
+types like
+ f:: forall a. Eq a => forall b. Baz b => tau
+We want to instantiate this to
+ f2::tau {f2 = f1 b (Baz b), f1 = f a (Eq a)}
+
+The -fno-method-sharing flag controls what happens so far as the LIE
+is concerned. The default case is that for an overloaded function we
+generate a "method" Id, and add the Method Inst to the LIE. So you get
+something like
+ f :: Num a => a -> a
+ f = /\a (d:Num a) -> let m = (+) a d in \ (x:a) -> m x x
+If you specify -fno-method-sharing, the dictionary application
+isn't shared, so we get
+ f :: Num a => a -> a
+ f = /\a (d:Num a) (x:a) -> (+) a d x x
+This gets a bit less sharing, but
+ a) it's better for RULEs involving overloaded functions
+ b) perhaps fewer separated lambdas
-newDictFromOld :: Inst -> Class -> [TcType] -> NF_TcM s Inst
-newDictFromOld (Dict _ _ loc) clas tys
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (Dict uniq (Class clas tys) loc)
+
+\begin{code}
+tcInstId :: Id -> NF_TcM (TcExpr, LIE, TcType)
+tcInstId fun
+ | opt_NoMethodSharing = loop_noshare (HsVar fun) (idType fun)
+ | otherwise = loop_share fun
+ where
+ orig = OccurrenceOf fun
+ loop_noshare fun fun_ty
+ = tcInstType fun_ty `thenNF_Tc` \ (tyvars, theta, tau) ->
+ let
+ ty_app = mkHsTyApp fun (mkTyVarTys tyvars)
+ in
+ if null theta then -- Is it overloaded?
+ returnNF_Tc (ty_app, emptyLIE, tau)
+ else
+ newDicts orig theta `thenNF_Tc` \ dicts ->
+ loop_noshare (mkHsDictApp ty_app (map instToId dicts)) tau `thenNF_Tc` \ (expr, lie, final_tau) ->
+ returnNF_Tc (expr, mkLIE dicts `plusLIE` lie, final_tau)
+
+ loop_share fun
+ = tcInstType (idType fun) `thenNF_Tc` \ (tyvars, theta, tau) ->
+ let
+ arg_tys = mkTyVarTys tyvars
+ in
+ if null theta then -- Is it overloaded?
+ returnNF_Tc (mkHsTyApp (HsVar fun) arg_tys, emptyLIE, tau)
+ else
+ -- Yes, it's overloaded
+ newMethodWithGivenTy orig fun arg_tys theta tau `thenNF_Tc` \ meth ->
+ loop_share (instToId meth) `thenNF_Tc` \ (expr, lie, final_tau) ->
+ returnNF_Tc (expr, unitLIE meth `plusLIE` lie, final_tau)
newMethod :: InstOrigin
-> TcId
-> [TcType]
- -> NF_TcM s (LIE, TcId)
+ -> NF_TcM Inst
newMethod orig id tys
= -- Get the Id type and instantiate it at the specified types
let
(tyvars, rho) = splitForAllTys (idType id)
rho_ty = substTy (mkTyVarSubst tyvars tys) rho
- (theta, tau) = splitRhoTy rho_ty
+ (pred, tau) = splitMethodTy rho_ty
in
- newMethodWithGivenTy orig id tys theta tau `thenNF_Tc` \ meth_inst ->
- returnNF_Tc (unitLIE meth_inst, instToId meth_inst)
-
-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 ->
- 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 [pred] tau
newMethodWithGivenTy orig id tys theta tau
= tcGetInstLoc orig `thenNF_Tc` \ loc ->
- newMethodWith id tys theta tau loc
+ newMethodWith loc id tys theta tau
-newMethodWith id tys theta tau loc
+newMethodWith inst_loc@(_,loc,_) id tys theta tau
= tcGetUnique `thenNF_Tc` \ new_uniq ->
- returnNF_Tc (Method new_uniq id tys theta tau loc)
+ let
+ meth_id = mkUserLocal (mkMethodOcc (getOccName id)) new_uniq tau loc
+ in
+ returnNF_Tc (Method meth_id id tys theta tau inst_loc)
newMethodAtLoc :: InstLoc
-> Id -> [TcType]
- -> NF_TcM s (Inst, TcId)
-newMethodAtLoc loc real_id tys -- Local function, similar to newMethod but with
- -- slightly different interface
+ -> NF_TcM (Inst, TcId)
+newMethodAtLoc inst_loc real_id tys
+ -- This actually builds the Inst
= -- Get the Id type and instantiate it at the specified types
- tcGetUnique `thenNF_Tc` \ new_uniq ->
let
(tyvars,rho) = splitForAllTys (idType real_id)
rho_ty = ASSERT( length tyvars == length tys )
substTy (mkTopTyVarSubst tyvars tys) rho
(theta, tau) = splitRhoTy rho_ty
- meth_inst = Method new_uniq real_id tys theta tau loc
in
+ newMethodWith inst_loc real_id tys theta tau `thenNF_Tc` \ meth_inst ->
returnNF_Tc (meth_inst, instToId meth_inst)
\end{code}
\begin{code}
newOverloadedLit :: InstOrigin
- -> OverloadedLit
+ -> HsOverLit
-> TcType
- -> NF_TcM s (TcExpr, LIE)
-newOverloadedLit orig (OverloadedIntegral i) ty
+ -> NF_TcM (TcExpr, LIE)
+newOverloadedLit orig (HsIntegral i) ty
| isIntTy ty && inIntRange i -- Short cut for Int
= returnNF_Tc (int_lit, emptyLIE)
= returnNF_Tc (integer_lit, emptyLIE)
where
- intprim_lit = HsLitOut (HsIntPrim i) intPrimTy
- integer_lit = HsLitOut (HsInt i) integerTy
- int_lit = mkHsConApp intDataCon [] [intprim_lit]
+ int_lit = HsLit (HsInt i)
+ integer_lit = HsLit (HsInteger i)
newOverloadedLit orig lit ty -- The general case
= tcGetInstLoc orig `thenNF_Tc` \ loc ->
tcGetUnique `thenNF_Tc` \ new_uniq ->
let
- lit_inst = LitInst new_uniq lit ty loc
+ lit_inst = LitInst lit_id lit ty loc
+ lit_id = mkSysLocal SLIT("lit") new_uniq ty
in
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 (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}
+%************************************************************************
+%* *
+\subsection{Zonking}
+%* *
+%************************************************************************
-Zonking
-~~~~~~~
Zonking makes sure that the instance types are fully zonked,
-but doesn't do the same for the Id in a Method. There's no
+but doesn't do the same for any of the Ids in an Inst. There's no
need, and it's a lot of extra work.
\begin{code}
-zonkPred :: TcPredType -> NF_TcM s TcPredType
+zonkPred :: TcPredType -> NF_TcM TcPredType
zonkPred (Class clas tys)
= zonkTcTypes tys `thenNF_Tc` \ new_tys ->
returnNF_Tc (Class clas new_tys)
= zonkTcType ty `thenNF_Tc` \ new_ty ->
returnNF_Tc (IParam n new_ty)
-zonkInst :: Inst -> NF_TcM s Inst
-zonkInst (Dict u pred loc)
+zonkInst :: Inst -> NF_TcM Inst
+zonkInst (Dict id pred loc)
= zonkPred pred `thenNF_Tc` \ new_pred ->
- returnNF_Tc (Dict u new_pred loc)
+ returnNF_Tc (Dict id new_pred loc)
-zonkInst (Method u id tys theta tau loc)
+zonkInst (Method m id tys theta tau loc)
= zonkId id `thenNF_Tc` \ new_id ->
-- Essential to zonk the id in case it's a local variable
-- Can't use zonkIdOcc because the id might itself be
zonkTcTypes tys `thenNF_Tc` \ new_tys ->
zonkTcThetaType theta `thenNF_Tc` \ new_theta ->
zonkTcType tau `thenNF_Tc` \ new_tau ->
- returnNF_Tc (Method u new_id new_tys new_theta new_tau loc)
+ returnNF_Tc (Method m new_id new_tys new_theta new_tau loc)
-zonkInst (LitInst u lit ty loc)
+zonkInst (LitInst id 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)
+ returnNF_Tc (LitInst id lit new_ty 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}
-Printing
-~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Printing}
+%* *
+%************************************************************************
+
ToDo: improve these pretty-printing things. The ``origin'' is really only
relevant in error messages.
ppr inst = pprInst inst
pprInst (LitInst u lit ty loc)
- = hsep [case lit of
- OverloadedIntegral i -> integer i
- OverloadedFractional f -> rational f,
- ptext SLIT("at"),
- ppr ty,
- show_uniq u]
+ = hsep [ppr lit, ptext SLIT("at"), ppr ty, show_uniq u]
pprInst (Dict u pred loc) = pprPred pred <+> show_uniq u
pprInst m@(Method u id tys theta tau loc)
= hsep [ppr id, ptext SLIT("at"),
brackets (interppSP tys) {- ,
- ppr theta, ppr tau,
+ ptext SLIT("theta"), ppr theta,
+ ptext SLIT("tau"), 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
--- 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 "-}")
%************************************************************************
%* *
-\subsection[InstEnv-types]{Type declarations}
+\subsection{Looking up Insts}
%* *
%************************************************************************
\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
| GenInst [Inst] TcExpr -- The expression and its needed insts
lookupInst :: Inst
- -> NF_TcM s (LookupInstResult s)
+ -> NF_TcM (LookupInstResult s)
-- Dictionaries
lookupInst dict@(Dict _ (Class clas tys) loc)
- = case lookupInstEnv (classInstEnv clas) tys of
+ = tcGetInstEnv `thenNF_Tc` \ inst_env ->
+ case lookupInstEnv inst_env clas tys of
FoundInst tenv dfun_id
-> let
- subst = mkSubst (tyVarsOfTypes tys) tenv
(tyvars, rho) = splitForAllTys (idType dfun_id)
- ty_args = map subst_tv tyvars
+ mk_ty_arg tv = case lookupSubstEnv tenv tv of
+ Just (DoneTy ty) -> returnNF_Tc ty
+ Nothing -> tcInstTyVar tv `thenNF_Tc` \ tc_tv ->
+ returnTc (mkTyVarTy tc_tv)
+ in
+ mapNF_Tc mk_ty_arg tyvars `thenNF_Tc` \ ty_args ->
+ let
+ subst = mkTyVarSubst tyvars ty_args
dfun_rho = substTy subst rho
- (theta, tau) = splitRhoTy dfun_rho
+ (theta, _) = splitRhoTy dfun_rho
ty_app = mkHsTyApp (HsVar dfun_id) ty_args
- subst_tv tv = case lookupSubstEnv tenv tv of
- Just (DoneTy ty) -> ty
- -- tenv should bind all the tyvars
in
if null theta then
returnNF_Tc (SimpleInst ty_app)
else
- newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, dict_ids) ->
+ newDictsAtLoc loc theta `thenNF_Tc` \ dicts ->
let
- rhs = mkHsDictApp ty_app dict_ids
+ rhs = mkHsDictApp ty_app (map instToId dicts)
in
returnNF_Tc (GenInst dicts rhs)
other -> returnNF_Tc NoInstance
+
lookupInst dict@(Dict _ _ loc) = returnNF_Tc NoInstance
-- Methods
lookupInst inst@(Method _ id tys theta _ loc)
- = newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, dict_ids) ->
- returnNF_Tc (GenInst dicts (mkHsDictApp (mkHsTyApp (HsVar id) tys) dict_ids))
+ = newDictsAtLoc loc theta `thenNF_Tc` \ dicts ->
+ returnNF_Tc (GenInst dicts (mkHsDictApp (mkHsTyApp (HsVar id) tys) (map instToId dicts)))
-- Literals
-lookupInst inst@(LitInst u (OverloadedIntegral i) ty loc)
+lookupInst inst@(LitInst u (HsIntegral i) ty loc)
| isIntTy ty && in_int_range -- Short cut for Int
= returnNF_Tc (GenInst [] int_lit)
-- GenInst, not SimpleInst, because int_lit is actually a constructor application
| isIntegerTy ty -- Short cut for Integer
= returnNF_Tc (GenInst [] integer_lit)
- | in_int_range -- It's overloaded but small enough to fit into an Int
- = tcLookupValueByKey fromIntClassOpKey `thenNF_Tc` \ from_int ->
- newMethodAtLoc loc from_int [ty] `thenNF_Tc` \ (method_inst, method_id) ->
- returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) int_lit))
-
| otherwise -- Alas, it is overloaded and a big literal!
- = tcLookupValueByKey fromIntegerClassOpKey `thenNF_Tc` \ from_integer ->
+ = tcLookupSyntaxId fromIntegerName `thenNF_Tc` \ from_integer ->
newMethodAtLoc loc from_integer [ty] `thenNF_Tc` \ (method_inst, method_id) ->
returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) integer_lit))
where
in_int_range = inIntRange i
- intprim_lit = HsLitOut (HsIntPrim i) intPrimTy
- integer_lit = HsLitOut (HsInt i) integerTy
- int_lit = mkHsConApp intDataCon [] [intprim_lit]
+ integer_lit = HsLit (HsInteger i)
+ int_lit = HsLit (HsInt i)
-- similar idea for overloaded floating point literals: if the literal is
-- *definitely* a float or a double, generate the real thing here.
-- This is essential (see nofib/spectral/nucleic).
-lookupInst inst@(LitInst u (OverloadedFractional f) ty loc)
+lookupInst inst@(LitInst u (HsFractional f) ty loc)
| isFloatTy ty = returnNF_Tc (GenInst [] float_lit)
| isDoubleTy ty = returnNF_Tc (GenInst [] double_lit)
| otherwise
- = 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 ->
+ = tcLookupSyntaxId fromRationalName `thenNF_Tc` \ from_rational ->
+ newMethodAtLoc loc from_rational [ty] `thenNF_Tc` \ (method_inst, method_id) ->
let
- rational_ty = mkSynTy rational_tycon []
- rational_lit = HsLitOut (HsFrac f) rational_ty
+ rational_ty = funArgTy (idType method_id)
+ rational_lit = HsLit (HsRat f rational_ty)
in
- newMethodAtLoc loc from_rational [ty] `thenNF_Tc` \ (method_inst, method_id) ->
returnNF_Tc (GenInst [method_inst] (HsApp (HsVar method_id) rational_lit))
where
- floatprim_lit = HsLitOut (HsFloatPrim f) floatPrimTy
+ floatprim_lit = HsLit (HsFloatPrim f)
float_lit = mkHsConApp floatDataCon [] [floatprim_lit]
- doubleprim_lit = HsLitOut (HsDoublePrim f) doublePrimTy
+ doubleprim_lit = HsLit (HsDoublePrim f)
double_lit = mkHsConApp doubleDataCon [] [doubleprim_lit]
-
--- there are no `instances' of functional dependencies or implicit params
-
-lookupInst _ = returnNF_Tc NoInstance
-
\end{code}
There is a second, simpler interface, when you want an instance of a
ambiguous dictionaries.
\begin{code}
-lookupSimpleInst :: InstEnv
- -> Class
+lookupSimpleInst :: Class
-> [Type] -- Look up (c,t)
- -> NF_TcM s (Maybe [(Class,[Type])]) -- Here are the needed (c,t)s
+ -> NF_TcM (Maybe [(Class,[Type])]) -- Here are the needed (c,t)s
-lookupSimpleInst class_inst_env clas tys
- = case lookupInstEnv class_inst_env tys of
+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
+ theta' = classesOfPreds theta
other -> returnNF_Tc Nothing
\end{code}
+
+
projects / ghc-hetmet.git / blobdiff