X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTyCon.lhs;h=cf2de8986ab85dd2a4687487d6f973f6b93b5eff;hb=fa56e2107bd1b097580fbd2cf2c5760a772cc402;hp=6dba52b50081cd275a548d6141a2698a93fa21bb;hpb=272fb49ecfeffe7aaa66b9b61bab12d8a858458d;p=ghc-hetmet.git diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs index 6dba52b..cf2de89 100644 --- a/compiler/types/TyCon.lhs +++ b/compiler/types/TyCon.lhs @@ -13,7 +13,7 @@ module TyCon( tyConPrimRep, AlgTyConRhs(..), visibleDataCons, - AlgTyConParent(..), + TyConParent(..), SynTyConRhs(..), isFunTyCon, isUnLiftedTyCon, isProductTyCon, @@ -108,15 +108,6 @@ data TyCon -- types if present -- But not over the data constructors - tyConArgPoss :: Maybe [Int], -- for associated families: for each - -- tyvar in the AT decl, gives the - -- position of that tyvar in the class - -- argument list (starting from 0). - -- NB: Length is less than tyConArity - -- if higher kind signature. - -- NB: Just _ <=> associated (not - -- toplevel) family - algTcSelIds :: [Id], -- Its record selectors (empty if none) algTcGadtSyntax :: Bool, -- True <=> the data type was declared using GADT syntax @@ -134,7 +125,7 @@ data TyCon hasGenerics :: Bool, -- True <=> generic to/from functions are available -- (in the exports of the data type's source module) - algTcParent :: AlgTyConParent -- Gives the class or family tycon for + algTcParent :: TyConParent -- Gives the class or family tycon for -- derived tycons representing classes -- or family instances, respectively. } @@ -158,14 +149,12 @@ data TyCon tyConTyVars :: [TyVar], -- Bound tyvars - tyConArgPoss :: Maybe [Int], -- for associated families: for each - -- tyvar in the AT decl, gives the - -- position of that tyvar in the class - -- argument list (starting from 0). - -- NB: Length is less than tyConArity - -- if higher kind signature. - - synTcRhs :: SynTyConRhs -- Expanded type in here + synTcRhs :: SynTyConRhs, -- Expanded type in here + + synTcParent :: TyConParent -- Gives the family tycon of + -- representation tycons of family + -- instances + } | PrimTyCon { -- Primitive types; cannot be defined in Haskell @@ -204,21 +193,38 @@ data TyCon type FieldLabel = Name +-- Right hand sides of type constructors for algebraic types +-- data AlgTyConRhs - = AbstractTyCon -- We know nothing about this data type, except - -- that it's represented by a pointer - -- Used when we export a data type abstractly into - -- an hi file - | OpenDataTyCon -- data family (further instances can appear - | OpenNewTyCon -- newtype family at any time) + -- We know nothing about this data type, except that it's represented by a + -- pointer. Used when we export a data type abstractly into an hi file. + -- + = AbstractTyCon + + -- The constructor represents an open family without a fixed right hand + -- side. Additional instances can appear at any time. + -- + | OpenTyCon { + + otArgPoss :: Maybe [Int], + -- Nothing <=> top-level indexed type family + -- Just ns <=> associated (not toplevel) family + -- In the latter case, for each tyvar in the AT decl, 'ns' gives the + -- position of that tyvar in the class argument list (starting from 0). + -- NB: Length is less than tyConArity iff higher kind signature. + + otIsNewtype :: Bool + -- is a newtype (rather than data type)? + + } | DataTyCon { data_cons :: [DataCon], -- The constructors; can be empty if the user declares -- the type to have no constructors -- INVARIANT: Kept in order of increasing tag - -- (see the tag assignment in DataCon.mkDataCon) + -- (see the tag assignment in DataCon.mkDataCon) is_enum :: Bool -- Cached: True <=> an enumeration type } -- Includes data types with no constructors. @@ -257,17 +263,17 @@ data AlgTyConRhs visibleDataCons :: AlgTyConRhs -> [DataCon] visibleDataCons AbstractTyCon = [] -visibleDataCons OpenDataTyCon = [] -visibleDataCons OpenNewTyCon = [] +visibleDataCons OpenTyCon {} = [] visibleDataCons (DataTyCon{ data_cons = cs }) = cs visibleDataCons (NewTyCon{ data_con = c }) = [c] --- Both type classes as well as data/newtype family instances imply implicit --- type constructors. These implicit type constructors refer to their parent +-- Both type classes as well as family instances imply implicit type +-- constructors. These implicit type constructors refer to their parent -- structure (ie, the class or family from which they derive) using a type of --- the following form. +-- the following form. We use `TyConParent' for both algebraic and synonym +-- types, but the variant `ClassTyCon' will only be used by algebraic tycons. -- -data AlgTyConParent +data TyConParent = NoParentTyCon -- An ordinary type constructor has no parent. | ClassTyCon -- Type constructors representing a class dictionary. @@ -275,21 +281,29 @@ data AlgTyConParent | FamilyTyCon -- Type constructors representing an instance of a type TyCon -- The type family - [Type] -- Instance types + [Type] -- Instance types; free variables are the tyConTyVars + -- of this TyCon TyCon -- A CoercionTyCon identifying the representation -- type with the type instance family. -- c.f. Note [Newtype coercions] -- E.g. data intance T [a] = ... -- gives a representation tycon: - -- data T77 a = ... - -- axiom co a :: T [a] ~ T77 a - -- with T77's algTcParent = FamilyTyCon T [a] co + -- data :R7T a = ... + -- axiom co a :: T [a] ~ :R7T a + -- with :R7T's algTcParent = FamilyTyCon T [a] co data SynTyConRhs - = OpenSynTyCon Kind -- Type family: *result* kind given + = OpenSynTyCon Kind -- Type family: *result* kind given + (Maybe [Int]) -- for associated families: for each tyvars in + -- the AT decl, gives the position of that + -- tyvar in the class argument list (starting + -- from 0). + -- NB: Length is less than tyConArity + -- if higher kind signature. + | SynonymTyCon Type -- Mentioning head type vars. Acts as a template for -- the expansion when the tycon is applied to some - -- types. + -- types. \end{code} Note [Newtype coercions] @@ -428,7 +442,6 @@ mkAlgTyCon name kind tyvars stupid rhs sel_ids parent is_rec gen_info gadt_syn tyConKind = kind, tyConArity = length tyvars, tyConTyVars = tyvars, - tyConArgPoss = Nothing, algTcStupidTheta = stupid, algTcRhs = rhs, algTcSelIds = sel_ids, @@ -491,15 +504,15 @@ mkPrimTyCon' name kind arity rep is_unlifted tyConExtName = Nothing } -mkSynTyCon name kind tyvars rhs +mkSynTyCon name kind tyvars rhs parent = SynTyCon { tyConName = name, tyConUnique = nameUnique name, tyConKind = kind, tyConArity = length tyvars, tyConTyVars = tyvars, - tyConArgPoss = Nothing, - synTcRhs = rhs + synTcRhs = rhs, + synTcParent = parent } mkCoercionTyCon name arity kindRule @@ -556,20 +569,20 @@ isDataTyCon :: TyCon -> Bool -- unboxed tuples isDataTyCon tc@(AlgTyCon {algTcRhs = rhs}) = case rhs of - OpenDataTyCon -> True + OpenTyCon {} -> not (otIsNewtype rhs) DataTyCon {} -> True - OpenNewTyCon -> False NewTyCon {} -> False - AbstractTyCon -> False -- We don't know, so return False + AbstractTyCon -> False -- We don't know, so return False isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity isDataTyCon other = False isNewTyCon :: TyCon -> Bool -isNewTyCon (AlgTyCon {algTcRhs = rhs}) = case rhs of - OpenNewTyCon -> True - NewTyCon {} -> True - _ -> False -isNewTyCon other = False +isNewTyCon (AlgTyCon {algTcRhs = rhs}) = + case rhs of + OpenTyCon {} -> otIsNewtype rhs + NewTyCon {} -> True + _ -> False +isNewTyCon other = False -- This is an important refinement as typical newtype optimisations do *not* -- hold for newtype families. Why? Given a type `T a', if T is a newtype @@ -616,22 +629,24 @@ isEnumerationTyCon (AlgTyCon {algTcRhs = DataTyCon { is_enum = res }}) = res isEnumerationTyCon other = False isOpenTyCon :: TyCon -> Bool -isOpenTyCon (SynTyCon {synTcRhs = OpenSynTyCon _}) = True -isOpenTyCon (AlgTyCon {algTcRhs = OpenDataTyCon }) = True -isOpenTyCon (AlgTyCon {algTcRhs = OpenNewTyCon }) = True -isOpenTyCon _ = False +isOpenTyCon (SynTyCon {synTcRhs = OpenSynTyCon _ _}) = True +isOpenTyCon (AlgTyCon {algTcRhs = OpenTyCon {} }) = True +isOpenTyCon _ = False assocTyConArgPoss_maybe :: TyCon -> Maybe [Int] -assocTyConArgPoss_maybe (AlgTyCon { tyConArgPoss = poss }) = poss -assocTyConArgPoss_maybe (SynTyCon { tyConArgPoss = poss }) = poss -assocTyConArgPoss_maybe _ = Nothing +assocTyConArgPoss_maybe (AlgTyCon { + algTcRhs = OpenTyCon {otArgPoss = poss}}) = poss +assocTyConArgPoss_maybe (SynTyCon { synTcRhs = OpenSynTyCon _ poss }) = poss +assocTyConArgPoss_maybe _ = Nothing isTyConAssoc :: TyCon -> Bool isTyConAssoc = isJust . assocTyConArgPoss_maybe setTyConArgPoss :: TyCon -> [Int] -> TyCon -setTyConArgPoss tc@(AlgTyCon {}) poss = tc { tyConArgPoss = Just poss } -setTyConArgPoss tc@(SynTyCon {}) poss = tc { tyConArgPoss = Just poss } +setTyConArgPoss tc@(AlgTyCon { algTcRhs = rhs }) poss = + tc { algTcRhs = rhs {otArgPoss = Just poss} } +setTyConArgPoss tc@(SynTyCon { synTcRhs = OpenSynTyCon ki _ }) poss = + tc { synTcRhs = OpenSynTyCon ki (Just poss) } setTyConArgPoss tc _ = pprPanic "setTyConArgPoss" (ppr tc) isTupleTyCon :: TyCon -> Bool @@ -769,7 +784,7 @@ tyConFamilySize :: TyCon -> Int tyConFamilySize (AlgTyCon {algTcRhs = DataTyCon {data_cons = cons}}) = length cons tyConFamilySize (AlgTyCon {algTcRhs = NewTyCon {}}) = 1 -tyConFamilySize (AlgTyCon {algTcRhs = OpenDataTyCon}) = 0 +tyConFamilySize (AlgTyCon {algTcRhs = OpenTyCon {}}) = 0 tyConFamilySize (TupleTyCon {}) = 1 #ifdef DEBUG tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other) @@ -826,7 +841,7 @@ synTyConType tc = case synTcRhs tc of _ -> pprPanic "synTyConType" (ppr tc) synTyConResKind :: TyCon -> Kind -synTyConResKind (SynTyCon {synTcRhs = OpenSynTyCon kind}) = kind +synTyConResKind (SynTyCon {synTcRhs = OpenSynTyCon kind _}) = kind synTyConResKind tycon = pprPanic "synTyConResKind" (ppr tycon) \end{code} @@ -852,17 +867,22 @@ tyConClass_maybe other_tycon = Nothing isFamInstTyCon :: TyCon -> Bool isFamInstTyCon (AlgTyCon {algTcParent = FamilyTyCon _ _ _ }) = True +isFamInstTyCon (SynTyCon {synTcParent = FamilyTyCon _ _ _ }) = True isFamInstTyCon other_tycon = False tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type]) tyConFamInst_maybe (AlgTyCon {algTcParent = FamilyTyCon fam instTys _}) = Just (fam, instTys) +tyConFamInst_maybe (SynTyCon {synTcParent = FamilyTyCon fam instTys _}) = + Just (fam, instTys) tyConFamInst_maybe other_tycon = Nothing tyConFamilyCoercion_maybe :: TyCon -> Maybe TyCon tyConFamilyCoercion_maybe (AlgTyCon {algTcParent = FamilyTyCon _ _ coe}) = Just coe +tyConFamilyCoercion_maybe (SynTyCon {synTcParent = FamilyTyCon _ _ coe}) = + Just coe tyConFamilyCoercion_maybe other_tycon = Nothing \end{code}