X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FInst.lhs;h=6b8a7afbe2a35b662ffd32ae56d589240df88ece;hb=f7ecf7234c224489be8a5e63fced903b655d92ee;hp=d0615f6bf6f3bf6590ba177f6f6e1304fe123c72;hpb=a77abe6a30ea2763cfa1c0ca83cdce9b7200ced2;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/Inst.lhs b/ghc/compiler/typecheck/Inst.lhs index d0615f6..6b8a7af 100644 --- a/ghc/compiler/typecheck/Inst.lhs +++ b/ghc/compiler/typecheck/Inst.lhs @@ -10,59 +10,67 @@ module Inst ( Inst(..), -- Visible only to TcSimplify InstOrigin(..), OverloadedLit(..), - LIE(..), emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE, plusLIEs, + SYN_IE(LIE), emptyLIE, unitLIE, plusLIE, consLIE, zonkLIE, plusLIEs, - InstanceMapper(..), + SYN_IE(InstanceMapper), newDicts, newDictsAtLoc, newMethod, newMethodWithGivenTy, newOverloadedLit, - instType, tyVarsOfInst, lookupInst, + instType, tyVarsOfInst, lookupInst, lookupSimpleInst, isDict, isTyVarDict, zonkInst, instToId, matchesInst, - instBindingRequired, instCanBeGeneralised - + instBindingRequired, instCanBeGeneralised, + + pprInst ) where -import Ubiq +IMP_Ubiq() +IMPORT_1_3(Ratio(Rational)) import HsSyn ( HsLit(..), HsExpr(..), HsBinds, - InPat, OutPat, Stmt, Qual, Match, + InPat, OutPat, Stmt, Qualifier, Match, ArithSeqInfo, PolyType, Fake ) -import RnHsSyn ( RenamedArithSeqInfo(..), RenamedHsExpr(..) ) -import TcHsSyn ( TcIdOcc(..), TcExpr(..), TcIdBndr(..), - mkHsTyApp, mkHsDictApp ) +import RnHsSyn ( SYN_IE(RenamedArithSeqInfo), SYN_IE(RenamedHsExpr), + RnName{-instance NamedThing-} + ) +import TcHsSyn ( TcIdOcc(..), SYN_IE(TcExpr), SYN_IE(TcIdBndr), + mkHsTyApp, mkHsDictApp, tcIdTyVars ) -import TcMonad -import TcEnv ( tcLookupGlobalValueByKey ) -import TcType ( TcType(..), TcRhoType(..), TcMaybe, TcTyVarSet(..), - tcInstType, tcInstTcType, zonkTcType ) +import TcMonad hiding ( rnMtoTcM ) +import TcEnv ( tcLookupGlobalValueByKey, tcLookupTyConByKey ) +import TcType ( SYN_IE(TcType), SYN_IE(TcRhoType), TcMaybe, SYN_IE(TcTyVarSet), + tcInstType, zonkTcType ) import Bag ( emptyBag, unitBag, unionBags, unionManyBags, listToBag, consBag ) -import Class ( Class(..), GenClass, ClassInstEnv(..), classInstEnv ) +import Class ( isCcallishClass, isNoDictClass, classInstEnv, + SYN_IE(Class), GenClass, SYN_IE(ClassInstEnv), SYN_IE(ClassOp) + ) +import ErrUtils ( addErrLoc, SYN_IE(Error) ) import Id ( GenId, idType, mkInstId ) import MatchEnv ( lookupMEnv, insertMEnv ) import Name ( mkLocalName, getLocalName, Name ) import Outputable -import PprType ( GenClass, TyCon, GenType, GenTyVar ) +import PprType ( GenClass, TyCon, GenType, GenTyVar, pprParendGenType ) import PprStyle ( PprStyle(..) ) import Pretty -import RnHsSyn ( RnName{-instance NamedThing-} ) -import SpecEnv ( SpecEnv(..) ) +import SpecEnv ( SpecEnv ) import SrcLoc ( SrcLoc, mkUnknownSrcLoc ) -import Type ( GenType, eqSimpleTy, +import Type ( GenType, eqSimpleTy, instantiateTy, isTyVarTy, mkDictTy, splitForAllTy, splitSigmaTy, - splitRhoTy, matchTy, tyVarsOfType, tyVarsOfTypes ) -import TyVar ( GenTyVar ) + splitRhoTy, matchTy, tyVarsOfType, tyVarsOfTypes, + mkSynTy + ) +import TyVar ( unionTyVarSets, GenTyVar ) import TysPrim ( intPrimTy ) -import TysWiredIn ( intDataCon ) -import Unique ( Unique, showUnique, - fromRationalClassOpKey, fromIntClassOpKey, fromIntegerClassOpKey ) -import Util ( panic, zipEqual, zipWithEqual, assoc, assertPanic ) - +import TysWiredIn ( intDataCon, integerTy ) +import Unique ( showUnique, fromRationalClassOpKey, rationalTyConKey, + fromIntClassOpKey, fromIntegerClassOpKey, Unique + ) +import Util ( panic, zipEqual, zipWithEqual, assoc, assertPanic, pprTrace{-ToDo:rm-} ) \end{code} %************************************************************************ @@ -158,7 +166,7 @@ newDicts orig theta tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs -> let mk_dict u (clas, ty) = Dict u clas ty orig loc - dicts = zipWithEqual mk_dict new_uniqs theta + dicts = zipWithEqual "newDicts" mk_dict new_uniqs theta in returnNF_Tc (listToBag dicts, map instToId dicts) @@ -167,7 +175,7 @@ newDictsAtLoc orig loc theta -- Local function, similar to newDicts, = tcGetUniques (length theta) `thenNF_Tc` \ new_uniqs -> let mk_dict u (clas, ty) = Dict u clas ty orig loc - dicts = zipWithEqual mk_dict new_uniqs theta + dicts = zipWithEqual "newDictsAtLoc" mk_dict new_uniqs theta in returnNF_Tc (dicts, map instToId dicts) @@ -179,9 +187,11 @@ newMethod orig id tys = -- Get the Id type and instantiate it at the specified types (case id of RealId id -> let (tyvars, rho) = splitForAllTy (idType id) - in tcInstType (tyvars `zipEqual` tys) rho + in + (if length tyvars /= length tys then pprTrace "newMethod" (ppr PprDebug (idType id)) else \x->x) $ + tcInstType (zip{-Equal "newMethod"-} tyvars tys) rho TcId id -> let (tyvars, rho) = splitForAllTy (idType id) - in tcInstTcType (tyvars `zipEqual` tys) rho + in returnNF_Tc (instantiateTy (zipEqual "newMethod(2)" tyvars tys) rho) ) `thenNF_Tc` \ rho_ty -> -- Our friend does the rest newMethodWithGivenTy orig id tys rho_ty @@ -202,8 +212,8 @@ newMethodAtLoc orig loc real_id tys -- Local function, similar to newMethod but let (tyvars,rho) = splitForAllTy (idType real_id) in - tcInstType (tyvars `zipEqual` tys) rho `thenNF_Tc` \ rho_ty -> - tcGetUnique `thenNF_Tc` \ new_uniq -> + tcInstType (zipEqual "newMethodAtLoc" tyvars tys) rho `thenNF_Tc` \ rho_ty -> + tcGetUnique `thenNF_Tc` \ new_uniq -> let meth_inst = Method new_uniq (RealId real_id) tys rho_ty orig loc in @@ -226,13 +236,17 @@ newOverloadedLit orig lit ty \begin{code} instToId :: Inst s -> TcIdOcc s instToId (Dict u clas ty orig loc) - = TcId (mkInstId u (mkDictTy clas ty) (mkLocalName u SLIT("dict") loc)) + = TcId (mkInstId u (mkDictTy clas ty) (mkLocalName u str False{-emph name-} loc)) + where + str = SLIT("d.") _APPEND_ (getLocalName clas) instToId (Method u id tys rho_ty orig loc) - = TcId (mkInstId u tau_ty (mkLocalName u (getLocalName id) loc)) + = TcId (mkInstId u tau_ty (mkLocalName u str False{-emph name-} loc)) where (_, tau_ty) = splitRhoTy rho_ty -- NB The method Id has just the tau type + str = SLIT("m.") _APPEND_ (getLocalName id) + instToId (LitInst u list ty orig loc) - = TcId (mkInstId u ty (mkLocalName u SLIT("lit") loc)) + = TcId (mkInstId u ty (mkLocalName u SLIT("lit") True{-emph uniq-} loc)) \end{code} \begin{code} @@ -269,7 +283,9 @@ zonkInst (LitInst u lit ty orig loc) \begin{code} tyVarsOfInst :: Inst s -> TcTyVarSet s tyVarsOfInst (Dict _ _ ty _ _) = tyVarsOfType ty -tyVarsOfInst (Method _ _ tys rho _ _) = tyVarsOfTypes tys +tyVarsOfInst (Method _ id tys rho _ _) = tyVarsOfTypes tys `unionTyVarSets` tcIdTyVars id + -- The id might not be a RealId; in the case of + -- locally-overloaded class methods, for example tyVarsOfInst (LitInst _ _ ty _ _) = tyVarsOfType ty \end{code} @@ -317,19 +333,12 @@ must be witnessed by an actual binding; the second tells whether an \begin{code} instBindingRequired :: Inst s -> Bool -instBindingRequired inst - = case getInstOrigin inst of - CCallOrigin _ _ -> False -- No binding required - LitLitOrigin _ -> False - OccurrenceOfCon _ -> False - other -> True +instBindingRequired (Dict _ clas _ _ _) = not (isNoDictClass clas) +instBindingRequired other = True instCanBeGeneralised :: Inst s -> Bool -instCanBeGeneralised inst - = case getInstOrigin inst of - CCallOrigin _ _ -> False -- Can't be generalised - LitLitOrigin _ -> False -- Can't be generalised - other -> True +instCanBeGeneralised (Dict _ clas _ _ _) = not (isCcallishClass clas) +instCanBeGeneralised other = True \end{code} @@ -340,36 +349,29 @@ relevant in error messages. \begin{code} instance Outputable (Inst s) where - ppr sty (LitInst uniq lit ty orig loc) - = ppHang (ppSep [case lit of - OverloadedIntegral i -> ppInteger i - OverloadedFractional f -> ppRational f, - ppStr "at", - ppr sty ty, - show_uniq sty uniq - ]) - 4 (show_origin sty orig) - - ppr sty (Dict uniq clas ty orig loc) - = ppHang (ppSep [ppr sty clas, - ppStr "at", - ppr sty ty, - show_uniq sty uniq - ]) - 4 (show_origin sty orig) - - ppr sty (Method uniq id tys rho orig loc) - = ppHang (ppSep [ppr sty id, - ppStr "at", - ppr sty tys, - show_uniq sty uniq - ]) - 4 (show_origin sty orig) - -show_uniq PprDebug uniq = ppr PprDebug uniq -show_uniq sty uniq = ppNil - -show_origin sty orig = ppBesides [ppLparen, pprOrigin sty orig, ppRparen] + ppr sty inst = ppr_inst sty ppNil (\ o l -> ppNil) inst + +pprInst sty hdr inst = ppr_inst sty hdr (\ o l -> pprOrigin hdr o l sty) inst + +ppr_inst sty hdr ppr_orig (LitInst u lit ty orig loc) + = ppHang (ppr_orig orig loc) + 4 (ppCat [case lit of + OverloadedIntegral i -> ppInteger i + OverloadedFractional f -> ppRational f, + ppStr "at", + ppr sty ty, + show_uniq sty u]) + +ppr_inst sty hdr ppr_orig (Dict u clas ty orig loc) + = ppHang (ppr_orig orig loc) + 4 (ppCat [ppr sty clas, pprParendGenType sty ty, show_uniq sty u]) + +ppr_inst sty hdr ppr_orig (Method u id tys rho orig loc) + = ppHang (ppr_orig orig loc) + 4 (ppCat [ppr sty id, ppStr "at", interppSP sty tys, show_uniq sty u]) + +show_uniq PprDebug u = ppr PprDebug u +show_uniq sty u = ppNil \end{code} Printing in error messages @@ -412,7 +414,9 @@ lookupInst :: Inst s lookupInst dict@(Dict _ clas ty orig loc) = case lookupMEnv matchTy (get_inst_env clas orig) ty of - Nothing -> failTc (noInstanceErr dict) + Nothing -> tcAddSrcLoc loc $ + tcAddErrCtxt (pprOrigin ""{-hdr-} orig loc) $ + failTc (noInstanceErr dict) Just (dfun_id, tenv) -> let @@ -452,15 +456,22 @@ lookupInst inst@(LitInst u (OverloadedIntegral i) ty orig loc) = -- Alas, it is overloaded and a big literal! tcLookupGlobalValueByKey fromIntegerClassOpKey `thenNF_Tc` \ from_integer -> newMethodAtLoc orig loc from_integer [ty] `thenNF_Tc` \ (method_inst, method_id) -> - returnTc ([method_inst], (instToId inst, HsApp (HsVar method_id) (HsLitOut (HsInt i) ty))) + returnTc ([method_inst], (instToId inst, HsApp (HsVar method_id) (HsLitOut (HsInt i) integerTy))) where intprim_lit = HsLitOut (HsIntPrim i) intPrimTy int_lit = HsApp (HsVar (RealId intDataCon)) intprim_lit lookupInst inst@(LitInst u (OverloadedFractional f) ty orig loc) = tcLookupGlobalValueByKey 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 -> + let + rational_ty = mkSynTy rational_tycon [] + rational_lit = HsLitOut (HsFrac f) rational_ty + in newMethodAtLoc orig loc from_rational [ty] `thenNF_Tc` \ (method_inst, method_id) -> - returnTc ([method_inst], (instToId inst, HsApp (HsVar method_id) (HsLitOut (HsFrac f) ty))) + returnTc ([method_inst], (instToId inst, HsApp (HsVar method_id) rational_lit)) \end{code} There is a second, simpler interface, when you want an instance of a @@ -469,15 +480,21 @@ appropriate dictionary if it exists. It is used only when resolving ambiguous dictionaries. \begin{code} -lookupClassInstAtSimpleType :: Class -> Type -> Maybe Id - -lookupClassInstAtSimpleType clas ty - = case (lookupMEnv matchTy (classInstEnv clas) ty) of - Nothing -> Nothing - Just (dfun,_) -> ASSERT( null tyvars && null theta ) - Just dfun - where - (tyvars, theta, _) = splitSigmaTy (idType dfun) +lookupSimpleInst :: ClassInstEnv + -> Class + -> Type -- Look up (c,t) + -> TcM s [(Class,Type)] -- Here are the needed (c,t)s + +lookupSimpleInst class_inst_env clas ty + = case (lookupMEnv matchTy class_inst_env ty) of + Nothing -> failTc (noSimpleInst clas ty) + Just (dfun,tenv) -> returnTc [(c,instantiateTy tenv t) | (c,t) <- theta] + where + (_, theta, _) = splitSigmaTy (idType dfun) + +noSimpleInst clas ty sty + = ppSep [ppStr "No instance for class", ppQuote (ppr sty clas), + ppStr "at type", ppQuote (ppr sty ty)] \end{code} @@ -553,9 +570,10 @@ data InstOrigin s | ClassDeclOrigin -- Manufactured during a class decl - | DerivingOrigin InstanceMapper - Class - TyCon +-- NO MORE! +-- | DerivingOrigin InstanceMapper +-- Class +-- TyCon -- During "deriving" operations we have an ever changing -- mapping of classes to instances, so we record it inside the @@ -571,7 +589,7 @@ data InstOrigin s -- origin information. This is a bit of a hack, but it works -- fine. (Patrick is to blame [WDP].) - | DefaultDeclOrigin -- Related to a `default' declaration +-- | DefaultDeclOrigin -- Related to a `default' declaration | ValSpecOrigin Name -- in a SPECIALIZE pragma for a value @@ -596,58 +614,50 @@ data InstOrigin s -- find a mapping from classes to envts inside the dict origin. get_inst_env :: Class -> InstOrigin s -> ClassInstEnv -get_inst_env clas (DerivingOrigin inst_mapper _ _) - = fst (inst_mapper clas) +-- get_inst_env clas (DerivingOrigin inst_mapper _ _) +-- = fst (inst_mapper clas) get_inst_env clas (InstanceSpecOrigin inst_mapper _ _) = fst (inst_mapper clas) get_inst_env clas other_orig = classInstEnv clas -pprOrigin :: PprStyle -> InstOrigin s -> Pretty +pprOrigin :: String -> InstOrigin s -> SrcLoc -> Error -pprOrigin sty (OccurrenceOf id) - = ppBesides [ppPStr SLIT("at a use of an overloaded identifier: `"), +pprOrigin hdr orig locn + = addErrLoc locn hdr $ \ sty -> + case orig of + OccurrenceOf id -> + ppBesides [ppPStr SLIT("at a use of an overloaded identifier: `"), ppr sty id, ppChar '\''] -pprOrigin sty (OccurrenceOfCon id) - = ppBesides [ppPStr SLIT("at a use of an overloaded constructor: `"), + OccurrenceOfCon id -> + ppBesides [ppPStr SLIT("at a use of an overloaded constructor: `"), ppr sty id, ppChar '\''] -pprOrigin sty (InstanceDeclOrigin) - = ppStr "in an instance declaration" -pprOrigin sty (LiteralOrigin lit) - = ppCat [ppStr "at an overloaded literal:", ppr sty lit] -pprOrigin sty (ArithSeqOrigin seq) - = ppCat [ppStr "at an arithmetic sequence:", ppr sty seq] -pprOrigin sty (SignatureOrigin) - = ppStr "in a type signature" -pprOrigin sty (DoOrigin) - = ppStr "in a do statement" -pprOrigin sty (ClassDeclOrigin) - = ppStr "in a class declaration" -pprOrigin sty (DerivingOrigin _ clas tycon) - = ppBesides [ppStr "in a `deriving' clause; class `", - ppr sty clas, - ppStr "'; offending type `", - ppr sty tycon, - ppStr "'"] -pprOrigin sty (InstanceSpecOrigin _ clas ty) - = ppBesides [ppStr "in a SPECIALIZE instance pragma; class \"", + InstanceDeclOrigin -> + ppStr "in an instance declaration" + LiteralOrigin lit -> + ppCat [ppStr "at an overloaded literal:", ppr sty lit] + ArithSeqOrigin seq -> + ppCat [ppStr "at an arithmetic sequence:", ppr sty seq] + SignatureOrigin -> + ppStr "in a type signature" + DoOrigin -> + ppStr "in a do statement" + ClassDeclOrigin -> + ppStr "in a class declaration" + InstanceSpecOrigin _ clas ty -> + ppBesides [ppStr "in a SPECIALIZE instance pragma; class \"", ppr sty clas, ppStr "\" type: ", ppr sty ty] -pprOrigin sty (DefaultDeclOrigin) - = ppStr "in a `default' declaration" -pprOrigin sty (ValSpecOrigin name) - = ppBesides [ppStr "in a SPECIALIZE user-pragma for `", + ValSpecOrigin name -> + ppBesides [ppStr "in a SPECIALIZE user-pragma for `", ppr sty name, ppStr "'"] -pprOrigin sty (CCallOrigin clabel Nothing{-ccall result-}) - = ppBesides [ppStr "in the result of the _ccall_ to `", + CCallOrigin clabel Nothing{-ccall result-} -> + ppBesides [ppStr "in the result of the _ccall_ to `", ppStr clabel, ppStr "'"] -pprOrigin sty (CCallOrigin clabel (Just arg_expr)) - = ppBesides [ppStr "in an argument in the _ccall_ to `", + CCallOrigin clabel (Just arg_expr) -> + ppBesides [ppStr "in an argument in the _ccall_ to `", ppStr clabel, ppStr "', namely: ", ppr sty arg_expr] -pprOrigin sty (LitLitOrigin s) - = ppBesides [ppStr "in this ``literal-literal'': ", ppStr s] -pprOrigin sty UnknownOrigin - = ppStr "in... oops -- I don't know where the overloading came from!" + LitLitOrigin s -> + ppBesides [ppStr "in this ``literal-literal'': ", ppStr s] + UnknownOrigin -> + ppStr "in... oops -- I don't know where the overloading came from!" \end{code} - - -