X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FDataCon.lhs;h=9ce966ee7743dbbfff37e6288f352bd5f5d10374;hb=6758ba711a3f9f3100a9dba1818b131c32e62106;hp=a04f28f28e0587e498bfcd82b33ec44afae170fe;hpb=80c89b80c355b2aaebcd53330e6c6170c3f05aca;p=ghc-hetmet.git diff --git a/compiler/basicTypes/DataCon.lhs b/compiler/basicTypes/DataCon.lhs index a04f28f..9ce966e 100644 --- a/compiler/basicTypes/DataCon.lhs +++ b/compiler/basicTypes/DataCon.lhs @@ -1,4 +1,5 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1998 % \section[DataCon]{@DataCon@: Data Constructors} @@ -9,11 +10,10 @@ module DataCon ( ConTag, fIRST_TAG, mkDataCon, dataConRepType, dataConSig, dataConFullSig, - dataConName, dataConTag, dataConTyCon, dataConUserType, - dataConUnivTyVars, dataConExTyVars, dataConAllTyVars, dataConResTys, - dataConInstTys, + dataConName, dataConIdentity, dataConTag, dataConTyCon, dataConUserType, + dataConUnivTyVars, dataConExTyVars, dataConAllTyVars, dataConEqSpec, eqSpecPreds, dataConTheta, dataConStupidTheta, - dataConInstArgTys, dataConOrigArgTys, + dataConInstArgTys, dataConOrigArgTys, dataConOrigResTy, dataConInstOrigArgTys, dataConRepArgTys, dataConFieldLabels, dataConFieldType, dataConStrictMarks, dataConExStricts, @@ -30,28 +30,24 @@ module DataCon ( #include "HsVersions.h" -import Type ( Type, ThetaType, - substTyWith, substTyVar, mkTopTvSubst, - mkForAllTys, mkFunTys, mkTyConApp, mkTyVarTy, mkTyVarTys, - splitTyConApp_maybe, newTyConInstRhs, - mkPredTys, isStrictPred, pprType, mkPredTy - ) -import Coercion ( isEqPred, mkEqPred ) -import TyCon ( TyCon, FieldLabel, tyConDataCons, - isProductTyCon, isTupleTyCon, isUnboxedTupleTyCon, - isNewTyCon, isRecursiveTyCon, tyConFamily_maybe ) -import Class ( Class, classTyCon ) -import Name ( Name, NamedThing(..), nameUnique, mkSysTvName, mkSystemName ) -import Var ( TyVar, CoVar, Id, mkTyVar, tyVarKind, setVarUnique, - mkCoVar ) -import BasicTypes ( Arity, StrictnessMark(..) ) +import Type +import Coercion +import TyCon +import Class +import Name +import Var +import BasicTypes import Outputable -import Unique ( Unique, Uniquable(..) ) -import ListSetOps ( assoc, minusList ) -import Util ( zipEqual, zipWithEqual ) -import List ( partition ) -import Maybes ( expectJust ) +import Unique +import ListSetOps +import Util +import Maybes import FastString +import PackageConfig +import Module + +import Data.Char +import Data.Word \end{code} @@ -242,7 +238,7 @@ data DataCon -- dcEqSpec = [a:=:(x,y)] -- dcTheta = [Ord x] -- dcOrigArgTys = [a,List b] - -- dcTyCon = T + -- dcRepTyCon = T dcVanilla :: Bool, -- True <=> This is a vanilla Haskell 98 data constructor -- Its type is of form @@ -255,6 +251,8 @@ data DataCon -- The declaration format is held in the TyCon (algTcGadtSyntax) dcUnivTyVars :: [TyVar], -- Universally-quantified type vars + -- INVARIANT: length matches arity of the dcRepTyCon + dcExTyVars :: [TyVar], -- Existentially-quantified type vars -- In general, the dcUnivTyVars are NOT NECESSARILY THE SAME AS THE TYVARS -- FOR THE PARENT TyCon. With GADTs the data con might not even have @@ -262,6 +260,9 @@ data DataCon -- [This is a change (Oct05): previously, vanilla datacons guaranteed to -- have the same type variables as their parent TyCon, but that seems ugly.] + -- INVARIANT: the UnivTyVars and ExTyVars all have distinct OccNames + -- Reason: less confusing, and easier to generate IfaceSyn + dcEqSpec :: [(TyVar,Type)], -- Equalities derived from the result type, -- *as written by the programmer* -- This field allows us to move conveniently between the two ways @@ -294,9 +295,11 @@ data DataCon dcOrigArgTys :: [Type], -- Original argument types -- (before unboxing and flattening of strict fields) - - -- Result type of constructor is T t1..tn - dcTyCon :: TyCon, -- Result tycon, T + dcOrigResTy :: Type, -- Original result type + -- NB: for a data instance, the original user result type may + -- differ from the DataCon's representation TyCon. Example + -- data instance T [a] where MkT :: a -> T [a] + -- The OrigResTy is T [a], but the dcRepTyCon might be :T123 -- Now the strictness annotations and field labels of the constructor dcStrictMarks :: [StrictnessMark], @@ -306,7 +309,7 @@ data DataCon dcFields :: [FieldLabel], -- Field labels for this constructor, in the - -- same order as the argument types; + -- same order as the dcOrigArgTys; -- length = 0 (if not a record) or dataConSourceArity. -- Constructor representation @@ -315,6 +318,10 @@ data DataCon -- and *including* existential dictionaries dcRepStrictness :: [StrictnessMark], -- One for each *representation* argument + -- See also Note [Data-con worker strictness] in MkId.lhs + + -- Result type of constructor is T t1..tn + dcRepTyCon :: TyCon, -- Result tycon, T dcRepType :: Type, -- Type of the constructor -- forall a x y. (a:=:(x,y), Ord x) => x -> y -> MkT a @@ -336,13 +343,9 @@ data DataCon -- An entirely separate wrapper function is built in TcTyDecls dcIds :: DataConIds, - dcInfix :: Bool, -- True <=> declared infix + dcInfix :: Bool -- True <=> declared infix -- Used for Template Haskell and 'deriving' only -- The actual fixity is stored elsewhere - - dcInstTys :: Maybe [Type] -- If this data constructor is part of a - -- data instance, then these are the type - -- patterns of the instance. } data DataConIds @@ -359,7 +362,7 @@ data DataConIds -- The 'Nothing' case of DCIds is important -- Not only is this efficient, -- but it also ensures that the wrapper is replaced - -- by the worker (becuase it *is* the wroker) + -- by the worker (becuase it *is* the worker) -- even when there are no args. E.g. in -- f (:) x -- the (:) *is* the worker. @@ -438,7 +441,6 @@ mkDataCon :: Name -> [TyVar] -> [TyVar] -> [(TyVar,Type)] -> ThetaType -> [Type] -> TyCon - -> Maybe [Type] -> ThetaType -> DataConIds -> DataCon -- Can get the tag from the TyCon @@ -449,28 +451,33 @@ mkDataCon name declared_infix univ_tvs ex_tvs eq_spec theta orig_arg_tys tycon - mb_typats stupid_theta ids +-- Warning: mkDataCon is not a good place to check invariants. +-- If the programmer writes the wrong result type in the decl, thus: +-- data T a where { MkT :: S } +-- then it's possible that the univ_tvs may hit an assertion failure +-- if you pull on univ_tvs. This case is checked by checkValidDataCon, +-- so the error is detected properly... it's just that asaertions here +-- are a little dodgy. + = ASSERT( not (any isEqPred theta) ) -- We don't currently allow any equality predicates on -- a data constructor (apart from the GADT ones in eq_spec) con where is_vanilla = null ex_tvs && null eq_spec && null theta - con = ASSERT( is_vanilla || not (isNewTyCon tycon) ) - -- Invariant: newtypes have a vanilla data-con - MkData {dcName = name, dcUnique = nameUnique name, + con = MkData {dcName = name, dcUnique = nameUnique name, dcVanilla = is_vanilla, dcInfix = declared_infix, dcUnivTyVars = univ_tvs, dcExTyVars = ex_tvs, dcEqSpec = eq_spec, dcStupidTheta = stupid_theta, dcTheta = theta, - dcOrigArgTys = orig_arg_tys, dcTyCon = tycon, + dcOrigArgTys = orig_arg_tys, dcOrigResTy = orig_res_ty, + dcRepTyCon = tycon, dcRepArgTys = rep_arg_tys, dcStrictMarks = arg_stricts, dcRepStrictness = rep_arg_stricts, dcFields = fields, dcTag = tag, dcRepType = ty, - dcIds = ids, - dcInstTys = mb_typats } + dcIds = ids } -- Strictness marks for source-args -- *after unboxing choices*, @@ -483,6 +490,15 @@ mkDataCon name declared_infix real_arg_tys = dict_tys ++ orig_arg_tys real_stricts = map mk_dict_strict_mark theta ++ arg_stricts + -- Example + -- data instance T (b,c) where + -- TI :: forall e. e -> T (e,e) + -- + -- The representation tycon looks like this: + -- data :R7T b c where + -- TI :: forall b1 c1. (b1 ~ c1) => b1 -> :R7T b1 c1 + orig_res_ty = mkFamilyTyConApp tycon (substTyVars (mkTopTvSubst eq_spec) univ_tvs) + -- Representation arguments and demands -- To do: eliminate duplication with MkId (rep_arg_stricts, rep_arg_tys) = computeRep real_stricts real_arg_tys @@ -511,7 +527,7 @@ dataConTag :: DataCon -> ConTag dataConTag = dcTag dataConTyCon :: DataCon -> TyCon -dataConTyCon = dcTyCon +dataConTyCon = dcRepTyCon dataConRepType :: DataCon -> Type dataConRepType = dcRepType @@ -590,79 +606,71 @@ dataConRepStrictness :: DataCon -> [StrictnessMark] -- Core constructor application (Con dc args) dataConRepStrictness dc = dcRepStrictness dc -dataConSig :: DataCon -> ([TyVar], ThetaType, [Type]) +dataConSig :: DataCon -> ([TyVar], ThetaType, [Type], Type) dataConSig (MkData {dcUnivTyVars = univ_tvs, dcExTyVars = ex_tvs, dcEqSpec = eq_spec, - dcTheta = theta, dcOrigArgTys = arg_tys, dcTyCon = tycon}) - = (univ_tvs ++ ex_tvs, eqSpecPreds eq_spec ++ theta, arg_tys) + dcTheta = theta, dcOrigArgTys = arg_tys, dcOrigResTy = res_ty}) + = (univ_tvs ++ ex_tvs, eqSpecPreds eq_spec ++ theta, arg_tys, res_ty) dataConFullSig :: DataCon - -> ([TyVar], [TyVar], [(TyVar,Type)], ThetaType, [Type]) + -> ([TyVar], [TyVar], [(TyVar,Type)], ThetaType, [Type], Type) dataConFullSig (MkData {dcUnivTyVars = univ_tvs, dcExTyVars = ex_tvs, dcEqSpec = eq_spec, - dcTheta = theta, dcOrigArgTys = arg_tys, dcTyCon = tycon}) - = (univ_tvs, ex_tvs, eq_spec, theta, arg_tys) + dcTheta = theta, dcOrigArgTys = arg_tys, dcOrigResTy = res_ty}) + = (univ_tvs, ex_tvs, eq_spec, theta, arg_tys, res_ty) + +dataConOrigResTy :: DataCon -> Type +dataConOrigResTy dc = dcOrigResTy dc dataConStupidTheta :: DataCon -> ThetaType dataConStupidTheta dc = dcStupidTheta dc -dataConResTys :: DataCon -> [Type] -dataConResTys dc = [substTyVar env tv | tv <- dcUnivTyVars dc] - where - env = mkTopTvSubst (dcEqSpec dc) - -dataConInstTys :: DataCon -> Maybe [Type] -dataConInstTys = dcInstTys - dataConUserType :: DataCon -> Type -- The user-declared type of the data constructor -- in the nice-to-read form --- T :: forall a. a -> T [a] +-- T :: forall a b. a -> b -> T [a] -- rather than --- T :: forall b. forall a. (a=[b]) => a -> T b +-- T :: forall a c. forall b. (c=[a]) => a -> b -> T c -- NB: If the constructor is part of a data instance, the result type -- mentions the family tycon, not the internal one. dataConUserType (MkData { dcUnivTyVars = univ_tvs, dcExTyVars = ex_tvs, dcEqSpec = eq_spec, dcTheta = theta, dcOrigArgTys = arg_tys, - dcTyCon = tycon, dcInstTys = mb_insttys }) + dcOrigResTy = res_ty }) = mkForAllTys ((univ_tvs `minusList` map fst eq_spec) ++ ex_tvs) $ mkFunTys (mkPredTys theta) $ mkFunTys arg_tys $ - case mb_insttys of - Nothing -> mkTyConApp tycon (map (substTyVar subst) univ_tvs) - Just insttys -> mkTyConApp ftycon insttys -- data instance - where - ftycon = case tyConFamily_maybe tycon of - Just ftycon -> ftycon - Nothing -> panic err - err = "dataConUserType: type patterns without family tycon" - where - subst = mkTopTvSubst eq_spec + res_ty -dataConInstArgTys :: DataCon +dataConInstArgTys :: DataCon -- A datacon with no existentials or equality constraints + -- However, it can have a dcTheta (notably it can be a + -- class dictionary, with superclasses) -> [Type] -- Instantiated at these types - -- NB: these INCLUDE the existentially quantified arg types -> [Type] -- Needs arguments of these types - -- NB: these INCLUDE the existentially quantified dict args + -- NB: these INCLUDE any dict args -- but EXCLUDE the data-decl context which is discarded -- It's all post-flattening etc; this is a representation type -dataConInstArgTys (MkData {dcRepArgTys = arg_tys, - dcUnivTyVars = univ_tvs, - dcExTyVars = ex_tvs}) inst_tys - = ASSERT( length tyvars == length inst_tys ) - map (substTyWith tyvars inst_tys) arg_tys - where - tyvars = univ_tvs ++ ex_tvs - - --- And the same deal for the original arg tys -dataConInstOrigArgTys :: DataCon -> [Type] -> [Type] +dataConInstArgTys dc@(MkData {dcRepArgTys = rep_arg_tys, + dcUnivTyVars = univ_tvs, dcEqSpec = eq_spec, + dcExTyVars = ex_tvs}) inst_tys + = ASSERT2 ( length univ_tvs == length inst_tys + , ptext SLIT("dataConInstArgTys") <+> ppr dc $$ ppr univ_tvs $$ ppr inst_tys) + ASSERT2 ( null ex_tvs && null eq_spec, ppr dc ) + map (substTyWith univ_tvs inst_tys) rep_arg_tys + +dataConInstOrigArgTys + :: DataCon -- Works for any DataCon + -> [Type] -- Includes existential tyvar args, but NOT + -- equality constraints or dicts + -> [Type] -- Returns just the instsantiated *value* arguments +-- For vanilla datacons, it's all quite straightforward +-- But for the call in MatchCon, we really do want just the value args dataConInstOrigArgTys dc@(MkData {dcOrigArgTys = arg_tys, - dcUnivTyVars = univ_tvs, - dcExTyVars = ex_tvs}) inst_tys - = ASSERT2( length tyvars == length inst_tys, ptext SLIT("dataConInstOrigArgTys") <+> ppr dc <+> ppr inst_tys ) - map (substTyWith tyvars inst_tys) arg_tys - where - tyvars = univ_tvs ++ ex_tvs + dcUnivTyVars = univ_tvs, + dcExTyVars = ex_tvs}) inst_tys + = ASSERT2( length tyvars == length inst_tys + , ptext SLIT("dataConInstOrigArgTys") <+> ppr dc $$ ppr tyvars $$ ppr inst_tys ) + map (substTyWith tyvars inst_tys) arg_tys + where + tyvars = univ_tvs ++ ex_tvs \end{code} These two functions get the real argument types of the constructor, @@ -681,13 +689,26 @@ dataConRepArgTys :: DataCon -> [Type] dataConRepArgTys dc = dcRepArgTys dc \end{code} +The string :. identifying a constructor, which is attached +to its info table and used by the GHCi debugger and the heap profiler. We want +this string to be UTF-8, so we get the bytes directly from the FastStrings. + +\begin{code} +dataConIdentity :: DataCon -> [Word8] +dataConIdentity dc = bytesFS (packageIdFS (modulePackageId mod)) ++ + fromIntegral (ord ':') : bytesFS (moduleNameFS (moduleName mod)) ++ + fromIntegral (ord '.') : bytesFS (occNameFS (nameOccName name)) + where name = dataConName dc + mod = nameModule name +\end{code} + \begin{code} isTupleCon :: DataCon -> Bool -isTupleCon (MkData {dcTyCon = tc}) = isTupleTyCon tc +isTupleCon (MkData {dcRepTyCon = tc}) = isTupleTyCon tc isUnboxedTupleCon :: DataCon -> Bool -isUnboxedTupleCon (MkData {dcTyCon = tc}) = isUnboxedTupleTyCon tc +isUnboxedTupleCon (MkData {dcRepTyCon = tc}) = isUnboxedTupleTyCon tc isVanillaDataCon :: DataCon -> Bool isVanillaDataCon dc = dcVanilla dc @@ -698,6 +719,7 @@ isVanillaDataCon dc = dcVanilla dc classDataCon :: Class -> DataCon classDataCon clas = case tyConDataCons (classTyCon clas) of (dict_constr:no_more) -> ASSERT( null no_more ) dict_constr + [] -> panic "classDataCon" \end{code} %************************************************************************ @@ -731,7 +753,8 @@ splitProductType_maybe ty -- and for constructors visible -> Just (tycon, ty_args, data_con, dataConInstArgTys data_con ty_args) where - data_con = head (tyConDataCons tycon) + data_con = ASSERT( not (null (tyConDataCons tycon)) ) + head (tyConDataCons tycon) other -> Nothing splitProductType str ty @@ -743,9 +766,10 @@ splitProductType str ty deepSplitProductType_maybe ty = do { (res@(tycon, tycon_args, _, _)) <- splitProductType_maybe ty ; let {result - | isNewTyCon tycon && not (isRecursiveTyCon tycon) + | isClosedNewTyCon tycon && not (isRecursiveTyCon tycon) = deepSplitProductType_maybe (newTyConInstRhs tycon tycon_args) - | isNewTyCon tycon = Nothing -- cannot unbox through recursive newtypes + | isNewTyCon tycon = Nothing -- cannot unbox through recursive + -- newtypes nor through families | otherwise = Just res} ; result } @@ -767,6 +791,6 @@ computeRep stricts tys unbox MarkedStrict ty = [(MarkedStrict, ty)] unbox MarkedUnboxed ty = zipEqual "computeRep" (dataConRepStrictness arg_dc) arg_tys where - (tycon, tycon_args, arg_dc, arg_tys) + (_tycon, _tycon_args, arg_dc, arg_tys) = deepSplitProductType "unbox_strict_arg_ty" ty \end{code}