\section[Inst]{The @Inst@ type: dictionaries or method instances}
\begin{code}
-module Inst (
+module Inst (
LIE, emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE,
- plusLIEs, mkLIE, isEmptyLIE,
+ plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
- Inst, OverloadedLit(..),
+ Inst,
pprInst, pprInsts, pprInstsInFull, tidyInst, tidyInsts,
- InstanceMapper,
-
- newDictFromOld, newDicts, newDictsAtLoc,
+ newDictFromOld, newDicts, newClassDicts, newDictsAtLoc,
newMethod, newMethodWithGivenTy, newOverloadedLit,
+ newIPDict, instOverloadedFun,
+ instantiateFdClassTys, instFunDeps, instFunDepsOfTheta,
+ newFunDepFromDict,
- 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(..), pprOrigin
+ InstOrigin(..), InstLoc, pprInstLoc
) where
#include "HsVersions.h"
-import HsSyn ( HsLit(..), HsExpr(..) )
-import RnHsSyn ( RenamedArithSeqInfo, RenamedHsExpr, RenamedPat )
+import HsSyn ( HsLit(..), HsOverLit(..), HsExpr(..) )
+import RnHsSyn ( RenamedHsOverLit )
import TcHsSyn ( TcExpr, TcId,
- mkHsTyApp, mkHsDictApp, zonkId
+ mkHsTyApp, mkHsDictApp, mkHsConApp, zonkId
)
import TcMonad
-import TcEnv ( TcIdSet, tcLookupValueByKey, tcLookupTyConByKey )
+import TcEnv ( TcIdSet, tcGetInstEnv, tcLookupGlobalId )
+import InstEnv ( InstLookupResult(..), lookupInstEnv )
import TcType ( TcThetaType,
TcType, TcTauType, TcTyVarSet,
- zonkTcType, zonkTcTypes,
+ zonkTcTyVars, zonkTcType, zonkTcTypes,
zonkTcThetaType
)
-import Bag
-import Class ( classInstEnv,
- Class, ClassInstEnv
- )
-import Id ( Id, idFreeTyVars, idType, mkUserLocal, mkSysLocal )
-import VarSet ( elemVarSet )
+import CoreFVs ( idFreeTyVars )
+import Class ( Class, FunDep )
+import FunDeps ( instantiateFdClassTys )
+import Id ( Id, idType, mkUserLocal, mkSysLocal )
import PrelInfo ( isStandardClass, isCcallishClass, isNoDictClass )
-import Name ( OccName, Name, mkDictOcc, mkMethodOcc, getOccName )
-import PprType ( pprConstraint )
-import SpecEnv ( SpecEnv, lookupSpecEnv )
-import SrcLoc ( SrcLoc )
-import Type ( Type, ThetaType, substTy,
- isTyVarTy, mkDictTy, splitForAllTys, splitSigmaTy,
- splitRhoTy, tyVarsOfType, tyVarsOfTypes,
- mkSynTy, substTopTy, substTopTheta,
+import Name ( mkDictOcc, mkMethodOcc, mkIPOcc, getOccName, nameUnique )
+import PprType ( pprPred )
+import Type ( Type, PredType(..),
+ isTyVarTy, mkDictTy, mkPredTy,
+ splitForAllTys, splitSigmaTy, funArgTy,
+ splitRhoTy, tyVarsOfType, tyVarsOfTypes, tyVarsOfPred,
tidyOpenType, tidyOpenTypes
)
-import TyCon ( TyCon )
-import VarEnv ( zipVarEnv, lookupVarEnv, TidyEnv )
-import VarSet ( unionVarSet )
-import TysPrim ( intPrimTy, floatPrimTy, doublePrimTy )
-import TysWiredIn ( intDataCon, isIntTy, inIntRange,
+import Subst ( emptyInScopeSet, mkSubst, mkInScopeSet,
+ substTy, substClasses, mkTyVarSubst, mkTopTyVarSubst
+ )
+import Literal ( inIntRange )
+import VarEnv ( TidyEnv, lookupSubstEnv, SubstResult(..) )
+import VarSet ( elemVarSet, emptyVarSet, unionVarSet )
+import TysWiredIn ( isIntTy,
floatDataCon, isFloatTy,
doubleDataCon, isDoubleTy,
- integerTy, isIntegerTy
+ isIntegerTy, voidTy
)
-import Unique ( fromRationalClassOpKey, rationalTyConKey,
- fromIntClassOpKey, fromIntegerClassOpKey, Unique
- )
-import Maybes ( expectJust )
+import PrelNames( Unique, hasKey, fromIntName, fromIntegerClassOpKey )
+import Maybe ( catMaybes )
import Util ( thenCmp, zipWithEqual, mapAccumL )
+import Bag
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 -> NF_TcM LIE
zonkLIE lie = mapBagNF_Tc zonkInst lie
pprInsts :: [Inst] -> SDoc
-pprInsts insts = parens (hsep (punctuate comma (map pprInst insts)))
+pprInsts insts = parens (sep (punctuate comma (map pprInst insts)))
pprInstsInFull insts
= vcat (map go insts)
where
- go inst = quotes (ppr inst) <+> pprOrigin inst
+ go inst = quotes (ppr inst) <+> pprInstLoc (instLoc inst)
\end{code}
%************************************************************************
data Inst
= Dict
Unique
- Class -- The type of the dict is (c ts), where
- [TcType] -- c is the class and ts the types;
- InstOrigin
- SrcLoc
+ TcPredType
+ InstLoc
| Method
Unique
TcTauType -- The type of the method
- InstOrigin
- SrcLoc
+ InstLoc
-- INVARIANT: in (Method u f tys theta tau loc)
-- type of (f tys dicts(from theta)) = tau
| LitInst
Unique
- OverloadedLit
- TcType -- The type at which the literal is used
- InstOrigin -- Always a literal; but more convenient to carry this around
- SrcLoc
-
-data OverloadedLit
- = OverloadedIntegral Integer -- The number
- | OverloadedFractional Rational -- The number
+ RenamedHsOverLit -- 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
\end{code}
Ordering
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 `compare` 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
-cmpOverLit (OverloadedIntegral _) (OverloadedFractional _) = LT
-cmpOverLit (OverloadedFractional _) (OverloadedIntegral _) = GT
+-- and they can only have HsInt or HsFracs in them.
\end{code}
Selection
~~~~~~~~~
\begin{code}
-instOrigin (Dict u clas tys origin loc) = origin
-instOrigin (Method u clas ty _ _ origin loc) = origin
-instOrigin (LitInst u lit ty origin loc) = origin
+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
-instLoc (Dict u clas tys origin loc) = loc
-instLoc (Method u clas ty _ _ origin loc) = loc
-instLoc (LitInst u lit ty origin loc) = loc
+getFunDepsOfLIE lie = catMaybes (map getFunDeps (lieToList lie))
-getDictClassTys (Dict u clas tys _ _) = (clas, tys)
+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 (Method _ id tys _ _ _ _) = tyVarsOfTypes tys `unionVarSet` idFreeTyVars id
+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 (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 _ _ orig 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}
\begin{code}
newDicts :: InstOrigin
-> TcThetaType
- -> NF_TcM s (LIE, [TcId])
+ -> NF_TcM (LIE, [TcId])
newDicts orig theta
- = tcGetSrcLoc `thenNF_Tc` \ loc ->
- newDictsAtLoc orig loc theta `thenNF_Tc` \ (dicts, ids) ->
+ = tcGetInstLoc orig `thenNF_Tc` \ loc ->
+ newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, ids) ->
returnNF_Tc (listToBag dicts, ids)
+newClassDicts :: InstOrigin
+ -> [(Class,[TcType])]
+ -> NF_TcM (LIE, [TcId])
+newClassDicts orig theta
+ = newDicts orig (map (uncurry Class) theta)
+
-- Local function, similar to newDicts,
-- but with slightly different interface
-newDictsAtLoc :: InstOrigin
- -> SrcLoc
+newDictsAtLoc :: InstLoc
-> TcThetaType
- -> NF_TcM s ([Inst], [TcId])
-newDictsAtLoc orig loc theta =
+ -> NF_TcM ([Inst], [TcId])
+newDictsAtLoc loc theta =
tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs ->
let
- mk_dict u (clas, tys) = Dict u clas tys orig 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 _ _ _ orig loc) clas tys
+newDictFromOld :: Inst -> Class -> [TcType] -> NF_TcM Inst
+newDictFromOld (Dict _ _ loc) clas tys
= tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (Dict uniq clas tys orig loc)
+ returnNF_Tc (Dict uniq (Class clas tys) loc)
newMethod :: InstOrigin
-> TcId
-> [TcType]
- -> NF_TcM s (LIE, TcId)
+ -> NF_TcM (LIE, TcId)
newMethod orig id tys
= -- Get the Id type and instantiate it at the specified types
let
(tyvars, rho) = splitForAllTys (idType id)
- rho_ty = substTy (zipVarEnv tyvars tys) rho
- (theta, tau) = splitRhoTy rho_ty
+ rho_ty = substTy (mkTyVarSubst tyvars tys) rho
+ (theta, tau) = splitRhoTy 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 theta tau
- = tcGetSrcLoc `thenNF_Tc` \ loc ->
- tcGetUnique `thenNF_Tc` \ new_uniq ->
- let
- meth_inst = Method new_uniq id tys theta tau orig loc
- in
- returnNF_Tc meth_inst
+ = tcGetInstLoc orig `thenNF_Tc` \ loc ->
+ 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 :: InstOrigin -> SrcLoc
+newMethodAtLoc :: InstLoc
-> Id -> [TcType]
- -> NF_TcM s (Inst, TcId)
-newMethodAtLoc orig loc real_id tys -- Local function, similar to newMethod but with
+ -> NF_TcM (Inst, TcId)
+newMethodAtLoc loc real_id tys -- Local function, similar to newMethod but with
-- slightly different interface
= -- 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 )
- substTopTy (zipVarEnv tyvars tys) rho
+ substTy (mkTopTyVarSubst tyvars tys) rho
(theta, tau) = splitRhoTy rho_ty
- meth_inst = Method new_uniq real_id tys theta tau orig loc
+ meth_inst = Method new_uniq real_id tys theta tau loc
in
returnNF_Tc (meth_inst, instToId meth_inst)
\end{code}
\begin{code}
newOverloadedLit :: InstOrigin
- -> OverloadedLit
+ -> RenamedHsOverLit
-> 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 = HsCon intDataCon [] [intprim_lit]
+ int_lit = HsLit (HsInt i)
+ integer_lit = HsLit (HsInteger i)
newOverloadedLit orig lit ty -- The general case
- = tcGetSrcLoc `thenNF_Tc` \ loc ->
+ = tcGetInstLoc orig `thenNF_Tc` \ loc ->
tcGetUnique `thenNF_Tc` \ new_uniq ->
let
- lit_inst = LitInst new_uniq lit ty orig loc
+ lit_inst = LitInst new_uniq lit ty loc
in
returnNF_Tc (HsVar (instToId lit_inst), unitLIE lit_inst)
\end{code}
+\begin{code}
+newFunDepFromDict dict
+ | isClassDict 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)
+ | otherwise
+ = returnNF_Tc Nothing
+\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 orig 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 orig loc)
+instToIdBndr (Method u id tys theta tau (_,loc,_))
= mkUserLocal (mkMethodOcc (getOccName id)) u tau loc
-
-instToIdBndr (LitInst u list ty orig 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}
-zonkInst :: Inst -> NF_TcM s Inst
-zonkInst (Dict u clas tys orig loc)
- = zonkTcTypes tys `thenNF_Tc` \ new_tys ->
- returnNF_Tc (Dict u clas new_tys orig loc)
+zonkPred :: TcPredType -> NF_TcM 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 Inst
+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 orig loc)
+zonkInst (Method u 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 orig loc)
+ returnNF_Tc (Method u new_id new_tys new_theta new_tau loc)
-zonkInst (LitInst u lit ty orig loc)
+zonkInst (LitInst u lit ty loc)
= zonkTcType ty `thenNF_Tc` \ new_ty ->
- returnNF_Tc (LitInst u lit new_ty orig loc)
+ 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)
+
+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}
instance Outputable Inst where
ppr inst = pprInst inst
-pprInst (LitInst u lit ty orig loc)
- = hsep [case lit of
- OverloadedIntegral i -> integer i
- OverloadedFractional f -> rational f,
- ptext SLIT("at"),
- ppr ty,
- show_uniq u]
+pprInst (LitInst u lit ty loc)
+ = hsep [ppr lit, ptext SLIT("at"), ppr ty, show_uniq u]
-pprInst (Dict u clas tys orig loc) = pprConstraint clas tys <+> show_uniq u
+pprInst (Dict u pred loc) = pprPred pred <+> show_uniq u
-pprInst (Method u id tys _ _ orig 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 orig loc)
- = (env', LitInst u lit ty' orig loc)
+tidyInst env (LitInst u lit ty loc)
+ = (env', LitInst u lit ty' loc)
where
(env', ty') = tidyOpenType env ty
-tidyInst env (Dict u clas tys orig loc)
- = (env', Dict u clas tys' orig 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 orig loc)
- = (env', Method u id tys' theta tau orig loc)
+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 -> ClassInstEnv
-\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 _ clas tys orig loc)
- = case lookupSpecEnv (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 (mkInScopeSet (tyVarsOfTypes tys)) tenv
(tyvars, rho) = splitForAllTys (idType dfun_id)
- ty_args = map (expectJust "Inst" . lookupVarEnv tenv) tyvars
- -- tenv should bind all the tyvars
- dfun_rho = substTopTy tenv rho
- (theta, tau) = splitRhoTy dfun_rho
+ ty_args = map subst_tv tyvars
+ dfun_rho = substTy subst 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 orig loc theta `thenNF_Tc` \ (dicts, dict_ids) ->
+ newDictsAtLoc loc theta `thenNF_Tc` \ (dicts, dict_ids) ->
let
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
-lookupInst inst@(Method _ id tys theta _ orig loc)
- = newDictsAtLoc orig loc theta `thenNF_Tc` \ (dicts, dict_ids) ->
+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))
-- Literals
-lookupInst inst@(LitInst u (OverloadedIntegral i) ty orig loc)
+lookupInst inst@(LitInst u (HsIntegral i from_integer_name) 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 orig loc from_int [ty] `thenNF_Tc` \ (method_inst, method_id) ->
+ | in_int_range -- It's overloaded but small enough to fit into an Int
+ && from_integer_name `hasKey` fromIntegerClassOpKey -- And it's the built-in prelude fromInteger
+ -- (i.e. no funny business with user-defined
+ -- packages of numeric classes)
+ = -- So we can use the Prelude fromInt
+ tcLookupGlobalId fromIntName `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 ->
- newMethodAtLoc orig loc from_integer [ty] `thenNF_Tc` \ (method_inst, method_id) ->
+ = tcLookupGlobalId from_integer_name `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 = HsCon 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 orig loc)
+lookupInst inst@(LitInst u (HsFractional f from_rat_name) 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 ->
+ = tcLookupGlobalId from_rat_name `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 orig 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
- float_lit = HsCon floatDataCon [] [floatprim_lit]
- doubleprim_lit = HsLitOut (HsDoublePrim f) doublePrimTy
- double_lit = HsCon doubleDataCon [] [doubleprim_lit]
+ floatprim_lit = HsLit (HsFloatPrim f)
+ float_lit = mkHsConApp floatDataCon [] [floatprim_lit]
+ 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}
ambiguous dictionaries.
\begin{code}
-lookupSimpleInst :: ClassInstEnv
- -> 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 lookupSpecEnv (ppr clas) class_inst_env tys of
- Nothing -> returnNF_Tc Nothing
-
- Just (tenv, dfun)
- -> returnNF_Tc (Just (substTopTheta tenv theta))
+lookupSimpleInst :: Class
+ -> [Type] -- Look up (c,t)
+ -> NF_TcM (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)
-\end{code}
-
-
-
-%************************************************************************
-%* *
-\subsection[Inst-origin]{The @InstOrigin@ type}
-%* *
-%************************************************************************
-
-The @InstOrigin@ type gives information about where a dictionary came from.
-This is important for decent error message reporting because dictionaries
-don't appear in the original source code. Doubtless this type will evolve...
-
-\begin{code}
-data InstOrigin
- = OccurrenceOf TcId -- Occurrence of an overloaded identifier
- | OccurrenceOfCon Id -- Occurrence of a data constructor
-
- | RecordUpdOrigin
-
- | DataDeclOrigin -- Typechecking a data declaration
-
- | InstanceDeclOrigin -- Typechecking an instance decl
-
- | LiteralOrigin HsLit -- Occurrence of a literal
-
- | PatOrigin RenamedPat
-
- | ArithSeqOrigin RenamedArithSeqInfo -- [x..], [x..y] etc
-
- | SignatureOrigin -- A dict created from a type signature
- | Rank2Origin -- A dict created when typechecking the argument
- -- of a rank-2 typed function
-
- | DoOrigin -- The monad for a do expression
+ theta' = map (\(Class clas tys) -> (clas,tys)) theta
- | ClassDeclOrigin -- Manufactured during a class decl
-
- | InstanceSpecOrigin Class -- in a SPECIALIZE instance pragma
- Type
-
- -- When specialising instances the instance info attached to
- -- each class is not yet ready, so we record it inside the
- -- origin information. This is a bit of a hack, but it works
- -- fine. (Patrick is to blame [WDP].)
-
- | ValSpecOrigin Name -- in a SPECIALIZE pragma for a value
-
- -- Argument or result of a ccall
- -- Dictionaries with this origin aren't actually mentioned in the
- -- translated term, and so need not be bound. Nor should they
- -- be abstracted over.
-
- | CCallOrigin String -- CCall label
- (Maybe RenamedHsExpr) -- Nothing if it's the result
- -- Just arg, for an argument
-
- | LitLitOrigin String -- the litlit
-
- | UnknownOrigin -- Help! I give up...
+ other -> returnNF_Tc Nothing
\end{code}
-\begin{code}
-pprOrigin :: Inst -> SDoc
-pprOrigin inst
- = hsep [text "arising from", pp_orig orig, text "at", ppr locn]
- where
- (orig, locn) = case inst of
- Dict _ _ _ orig loc -> (orig,loc)
- Method _ _ _ _ _ orig loc -> (orig,loc)
- LitInst _ _ _ orig loc -> (orig,loc)
-
- pp_orig (OccurrenceOf id)
- = hsep [ptext SLIT("use of"), quotes (ppr id)]
- pp_orig (OccurrenceOfCon id)
- = hsep [ptext SLIT("use of"), quotes (ppr id)]
- pp_orig (LiteralOrigin lit)
- = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
- pp_orig (PatOrigin pat)
- = hsep [ptext SLIT("the pattern"), quotes (ppr pat)]
- pp_orig (InstanceDeclOrigin)
- = ptext SLIT("an instance declaration")
- pp_orig (ArithSeqOrigin seq)
- = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
- pp_orig (SignatureOrigin)
- = ptext SLIT("a type signature")
- pp_orig (Rank2Origin)
- = ptext SLIT("a function with an overloaded argument type")
- pp_orig (DoOrigin)
- = ptext SLIT("a do statement")
- pp_orig (ClassDeclOrigin)
- = ptext SLIT("a class declaration")
- pp_orig (InstanceSpecOrigin clas ty)
- = hsep [text "a SPECIALIZE instance pragma; class",
- quotes (ppr clas), text "type:", ppr ty]
- pp_orig (ValSpecOrigin name)
- = hsep [ptext SLIT("a SPECIALIZE user-pragma for"), quotes (ppr name)]
- pp_orig (CCallOrigin clabel Nothing{-ccall result-})
- = hsep [ptext SLIT("the result of the _ccall_ to"), quotes (text clabel)]
- pp_orig (CCallOrigin clabel (Just arg_expr))
- = hsep [ptext SLIT("an argument in the _ccall_ to"), quotes (text clabel) <> comma,
- text "namely", quotes (ppr arg_expr)]
- pp_orig (LitLitOrigin s)
- = hsep [ptext SLIT("the ``literal-literal''"), quotes (text s)]
- pp_orig (UnknownOrigin)
- = ptext SLIT("...oops -- I don't know where the overloading came from!")
-\end{code}
+