X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTyCon.lhs;h=f03fb8952ef8a7626f51695871e0b28cab11a53a;hb=683ccf1854b2ffd2e703b120e39da8234d555075;hp=fab15fc6821126e025e51a0db6b7e4d99a0fd8ae;hpb=3e0b6b2542d8464bfba365b97a6e4b95c3885f10;p=ghc-hetmet.git diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs index fab15fc..f03fb89 100644 --- a/compiler/types/TyCon.lhs +++ b/compiler/types/TyCon.lhs @@ -10,17 +10,20 @@ module TyCon( PrimRep(..), tyConPrimRep, - AlgTyConRhs(..), visibleDataCons, + AlgTyConRhs(..), visibleDataCons, AlgTyConParent(..), + SynTyConRhs(..), isFunTyCon, isUnLiftedTyCon, isProductTyCon, - isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isPrimTyCon, - isEnumerationTyCon, isGadtSyntaxTyCon, + isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isClosedNewTyCon, + isPrimTyCon, + isEnumerationTyCon, isGadtSyntaxTyCon, isOpenTyCon, + assocTyConArgPoss_maybe, isTyConAssoc, setTyConArgPoss, isTupleTyCon, isUnboxedTupleTyCon, isBoxedTupleTyCon, tupleTyConBoxity, - isRecursiveTyCon, newTyConRep, newTyConRhs, newTyConCo, + isRecursiveTyCon, newTyConRep, newTyConRhs, newTyConCo_maybe, isHiBootTyCon, isSuperKindTyCon, isCoercionTyCon_maybe, isCoercionTyCon, - tcExpandTyCon_maybe, coreExpandTyCon_maybe, stgExpandTyCon_maybe, + tcExpandTyCon_maybe, coreExpandTyCon_maybe, makeTyConAbstract, isAbstractTyCon, @@ -46,7 +49,8 @@ module TyCon( tyConStupidTheta, tyConArity, isClassTyCon, tyConClass_maybe, - synTyConDefn, synTyConRhs, + isFamInstTyCon, tyConFamInst_maybe, tyConFamilyCoercion_maybe, + synTyConDefn, synTyConRhs, synTyConType, synTyConResKind, tyConExtName, -- External name for foreign types maybeTyConSingleCon, @@ -57,7 +61,7 @@ module TyCon( #include "HsVersions.h" -import {-# SOURCE #-} TypeRep ( Kind, Type, Coercion, PredType ) +import {-# SOURCE #-} TypeRep ( Kind, Type, PredType ) import {-# SOURCE #-} DataCon ( DataCon, isVanillaDataCon ) import Var ( TyVar, Id ) @@ -65,6 +69,7 @@ import Class ( Class ) import BasicTypes ( Arity, RecFlag(..), Boxity(..), isBoxed ) import Name ( Name, nameUnique, NamedThing(getName) ) import PrelNames ( Unique, Uniquable(..) ) +import Maybe ( isJust ) import Maybes ( orElse ) import Outputable import FastString @@ -92,11 +97,22 @@ data TyCon tyConName :: Name, tyConKind :: Kind, tyConArity :: Arity, - - tyConTyVars :: [TyVar], -- Scopes over (a) the [PredType] in AlgTyConRhs.DataTyCon - -- (b) the cached types in AlgTyConRhs.NewTyCon + + tyConTyVars :: [TyVar], -- Scopes over (a) the algTcStupidTheta + -- (b) the cached types in + -- algTyConRhs.NewTyCon + -- (c) the family instance + -- types if present -- But not over the data constructors - algTcSelIds :: [Id], -- Its record selectors (empty if none): + + 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. + + algTcSelIds :: [Id], -- Its record selectors (empty if none) algTcGadtSyntax :: Bool, -- True <=> the data type was declared using GADT syntax -- That doesn't mean it's a true GADT; only that the "where" @@ -107,14 +123,15 @@ data TyCon algTcRhs :: AlgTyConRhs, -- Data constructors in here - algTcRec :: RecFlag, -- Tells whether the data type is part of - -- a mutually-recursive group or not + algTcRec :: RecFlag, -- Tells whether the data type is part + -- of a mutually-recursive group or not hasGenerics :: Bool, -- True <=> generic to/from functions are available -- (in the exports of the data type's source module) - algTcClass :: Maybe Class - -- Just cl if this tycon came from a class declaration + algTcParent :: AlgTyConParent -- Gives the class or family tycon for + -- derived tycons representing classes + -- or family instances, respectively. } | TupleTyCon { @@ -129,15 +146,21 @@ data TyCon } | SynTyCon { - tyConUnique :: Unique, - tyConName :: Name, - tyConKind :: Kind, - tyConArity :: Arity, - - tyConTyVars :: [TyVar], -- Bound tyvars - synTcRhs :: Type -- Right-hand side, mentioning these type vars. - -- Acts as a template for the expansion when - -- the tycon is applied to some types. + tyConUnique :: Unique, + tyConName :: Name, + tyConKind :: Kind, + tyConArity :: Arity, + + 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 } | PrimTyCon { -- Primitive types; cannot be defined in Haskell @@ -162,8 +185,10 @@ data TyCon tyConUnique :: Unique, tyConName :: Name, tyConArity :: Arity, - coKindFun :: [Type] -> Kind - } + coKindFun :: [Type] -> (Type,Type) + } -- INVARAINT: coKindFun is always applied to exactly 'arity' args + -- E.g. for trans (c1 :: ta=tb) (c2 :: tb=tc), the coKindFun returns + -- the kind as a pair of types: (ta,tc) | SuperKindTyCon { -- Super Kinds, TY (box) and CO (diamond). -- They have no kind; and arity zero @@ -171,10 +196,6 @@ data TyCon tyConName :: Name } -type KindCon = TyCon - -type SuperKindCon = TyCon - type FieldLabel = Name data AlgTyConRhs @@ -183,6 +204,9 @@ data AlgTyConRhs -- 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) + | DataTyCon { data_cons :: [DataCon], -- The constructors; can be empty if the user declares @@ -199,8 +223,9 @@ data AlgTyConRhs -- = the representation type of the tycon -- The free tyvars of this type are the tyConTyVars - nt_co :: TyCon, -- The coercion used to create the newtype + nt_co :: Maybe TyCon, -- The coercion used to create the newtype -- from the representation + -- optional for non-recursive newtypes -- See Note [Newtype coercions] nt_etad_rhs :: ([TyVar], Type) , @@ -226,8 +251,35 @@ data AlgTyConRhs visibleDataCons :: AlgTyConRhs -> [DataCon] visibleDataCons AbstractTyCon = [] +visibleDataCons OpenDataTyCon = [] +visibleDataCons OpenNewTyCon = [] 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 +-- structure (ie, the class or family from which they derive) using a type of +-- the following form. +-- +data AlgTyConParent = -- An ordinary type constructor has no parent. + NoParentTyCon + + -- Type constructors representing a class dictionary. + | ClassTyCon Class + + -- Type constructors representing an instances of a type + -- family. + | FamilyTyCon TyCon -- the type family + [Type] -- instance types + TyCon -- a *coercion* identifying + -- the representation type + -- with the type instance + +data SynTyConRhs + = OpenSynTyCon Kind -- Type family: *result* kind given + | SynonymTyCon Type -- Mentioning head type vars. Acts as a template for + -- the expansion when the tycon is applied to some + -- types. \end{code} Note [Newtype coercions] @@ -237,15 +289,23 @@ The NewTyCon field nt_co is a a TyCon (a coercion constructor in fact) which is used for coercing from the representation type of the newtype, to the newtype itself. For example, - newtype T a = MkT [a] + newtype T a = MkT (a -> a) -the NewTyCon for T will contain nt_co = CoT where CoT t : [t] :=: T t. -This TyCon is a CoercionTyCon, so it does not have a kind on its own; -it basically has its own typing rule for the fully-applied version. -If the newtype T has k type variables then CoT has arity k. +the NewTyCon for T will contain nt_co = CoT where CoT t : T t :=: t -> +t. This TyCon is a CoercionTyCon, so it does not have a kind on its +own; it basically has its own typing rule for the fully-applied +version. If the newtype T has k type variables then CoT has arity at +most k. In the case that the right hand side is a type application +ending with the same type variables as the left hand side, we +"eta-contract" the coercion. So if we had + + newtype S a = MkT [a] + +then we would generate the arity 0 coercion CoS : S :=: []. The +primary reason we do this is to make newtype deriving cleaner. In the paper we'd write - axiom CoT : (forall t. [t]) :=: (forall t. T t) + axiom CoT : (forall t. T t) :=: (forall t. [t]) and then when we used CoT at a particular type, s, we'd say CoT @ s which encodes as (TyConApp instCoercionTyCon [TyConApp CoT [], s]) @@ -253,10 +313,10 @@ which encodes as (TyConApp instCoercionTyCon [TyConApp CoT [], s]) But in GHC we instead make CoT into a new piece of type syntax (like instCoercionTyCon, symCoercionTyCon etc), which must always be saturated, but which encodes as - TyConAp CoT [s] + TyConApp CoT [s] In the vocabulary of the paper it's as if we had axiom declarations like - axiom CoT t : ([t] :=: T t) + axiom CoT t : T t :=: [t] Note [Newtype eta] ~~~~~~~~~~~~~~~~~~ @@ -351,38 +411,25 @@ mkFunTyCon name kind -- This is the making of a TyCon. Just the same as the old mkAlgTyCon, -- but now you also have to pass in the generic information about the type -- constructor - you can get hold of it easily (see Generics module) -mkAlgTyCon name kind tyvars stupid rhs sel_ids is_rec gen_info gadt_syn +mkAlgTyCon name kind tyvars stupid rhs sel_ids parent is_rec gen_info gadt_syn = AlgTyCon { tyConName = name, tyConUnique = nameUnique name, tyConKind = kind, tyConArity = length tyvars, tyConTyVars = tyvars, + tyConArgPoss = Nothing, algTcStupidTheta = stupid, algTcRhs = rhs, algTcSelIds = sel_ids, - algTcClass = Nothing, + algTcParent = parent, algTcRec = is_rec, algTcGadtSyntax = gadt_syn, hasGenerics = gen_info } -mkClassTyCon name kind tyvars rhs clas is_rec - = AlgTyCon { - tyConName = name, - tyConUnique = nameUnique name, - tyConKind = kind, - tyConArity = length tyvars, - tyConTyVars = tyvars, - algTcStupidTheta = [], - algTcRhs = rhs, - algTcSelIds = [], - algTcClass = Just clas, - algTcRec = is_rec, - algTcGadtSyntax = False, -- Doesn't really matter - hasGenerics = False - } - +mkClassTyCon name kind tyvars rhs clas is_rec = + mkAlgTyCon name kind tyvars [] rhs [] (ClassTyCon clas) is_rec False False mkTupleTyCon name kind arity tyvars con boxed gen_info = TupleTyCon { @@ -441,6 +488,7 @@ mkSynTyCon name kind tyvars rhs tyConKind = kind, tyConArity = length tyvars, tyConTyVars = tyvars, + tyConArgPoss = Nothing, synTcRhs = rhs } @@ -498,25 +546,38 @@ isDataTyCon :: TyCon -> Bool -- unboxed tuples isDataTyCon tc@(AlgTyCon {algTcRhs = rhs}) = case rhs of + OpenDataTyCon -> True DataTyCon {} -> True + OpenNewTyCon -> False NewTyCon {} -> False AbstractTyCon -> pprPanic "isDataTyCon" (ppr tc) - isDataTyCon (TupleTyCon {tyConBoxed = boxity}) = isBoxed boxity isDataTyCon other = False isNewTyCon :: TyCon -> Bool -isNewTyCon (AlgTyCon {algTcRhs = NewTyCon {}}) = True -isNewTyCon other = False +isNewTyCon (AlgTyCon {algTcRhs = rhs}) = case rhs of + OpenNewTyCon -> True + 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 +-- family, there is no unique right hand side by which `T a' can be replaced +-- by a cast. +-- +isClosedNewTyCon :: TyCon -> Bool +isClosedNewTyCon tycon = isNewTyCon tycon && not (isOpenTyCon tycon) isProductTyCon :: TyCon -> Bool -- A "product" tycon -- has *one* constructor, -- is *not* existential -- but --- may be DataType or NewType, +-- may be DataType, NewType -- may be unboxed or not, -- may be recursive or not +-- isProductTyCon tc@(AlgTyCon {}) = case algTcRhs tc of DataTyCon{ data_cons = [data_con] } -> isVanillaDataCon data_con @@ -537,6 +598,25 @@ isEnumerationTyCon :: TyCon -> Bool 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 + +assocTyConArgPoss_maybe :: TyCon -> Maybe [Int] +assocTyConArgPoss_maybe (AlgTyCon { tyConArgPoss = poss }) = poss +assocTyConArgPoss_maybe (SynTyCon { tyConArgPoss = 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 _ = pprPanic "setTyConArgPoss" (ppr tc) + isTupleTyCon :: TyCon -> Bool -- The unit tycon didn't used to be classed as a tuple tycon -- but I thought that was silly so I've undone it @@ -577,7 +657,7 @@ isSuperKindTyCon :: TyCon -> Bool isSuperKindTyCon (SuperKindTyCon {}) = True isSuperKindTyCon other = False -isCoercionTyCon_maybe :: TyCon -> Maybe (Arity, [Type] -> Kind) +isCoercionTyCon_maybe :: TyCon -> Maybe (Arity, [Type] -> (Type,Type)) isCoercionTyCon_maybe (CoercionTyCon {tyConArity = ar, coKindFun = rule}) = Just (ar, rule) isCoercionTyCon_maybe other = Nothing @@ -600,30 +680,22 @@ tcExpandTyCon_maybe, coreExpandTyCon_maybe [Type]) -- Leftover args -- For the *typechecker* view, we expand synonyms only -tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs, synTcRhs = rhs }) tys +tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs, + synTcRhs = SynonymTyCon rhs }) tys = expand tvs rhs tys tcExpandTyCon_maybe other_tycon tys = Nothing --------------- -- For the *Core* view, we expand synonyms only as well -{- + coreExpandTyCon_maybe (AlgTyCon {algTcRec = NonRecursive, -- Not recursive - algTcRhs = NewTyCon { nt_etad_rhs = etad_rhs }}) tys + algTcRhs = NewTyCon { nt_etad_rhs = etad_rhs, nt_co = Nothing }}) tys = case etad_rhs of -- Don't do this in the pattern match, lest we accidentally -- match the etad_rhs of a *recursive* newtype (tvs,rhs) -> expand tvs rhs tys --} -coreExpandTyCon_maybe tycon tys = tcExpandTyCon_maybe tycon tys ---------------- --- For the *STG* view, we expand synonyms *and* non-recursive newtypes -stgExpandTyCon_maybe (AlgTyCon {algTcRec = NonRecursive, -- Not recursive - algTcRhs = NewTyCon { nt_etad_rhs = etad_rhs }}) tys - = case etad_rhs of -- Don't do this in the pattern match, lest we accidentally - -- match the etad_rhs of a *recursive* newtype - (tvs,rhs) -> expand tvs rhs tys +coreExpandTyCon_maybe tycon tys = tcExpandTyCon_maybe tycon tys -stgExpandTyCon_maybe tycon tys = coreExpandTyCon_maybe tycon tys ---------------- expand :: [TyVar] -> Type -- Template @@ -656,9 +728,11 @@ tyConDataCons_maybe (TupleTyCon {dataCon = con}) = Just [con] tyConDataCons_maybe other = Nothing tyConFamilySize :: TyCon -> Int -tyConFamilySize (AlgTyCon {algTcRhs = DataTyCon { data_cons = cons }}) = length cons -tyConFamilySize (AlgTyCon {algTcRhs = NewTyCon {}}) = 1 -tyConFamilySize (TupleTyCon {}) = 1 +tyConFamilySize (AlgTyCon {algTcRhs = DataTyCon {data_cons = cons}}) = + length cons +tyConFamilySize (AlgTyCon {algTcRhs = NewTyCon {}}) = 1 +tyConFamilySize (AlgTyCon {algTcRhs = OpenDataTyCon}) = 0 +tyConFamilySize (TupleTyCon {}) = 1 #ifdef DEBUG tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other) #endif @@ -682,9 +756,9 @@ newTyConRep :: TyCon -> ([TyVar], Type) newTyConRep (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_rep = rep }}) = (tvs, rep) newTyConRep tycon = pprPanic "newTyConRep" (ppr tycon) -newTyConCo :: TyCon -> TyCon -newTyConCo (AlgTyCon {tyConTyVars = tvs, algTcRhs = NewTyCon { nt_co = co }}) = co -newTyConCo tycon = pprPanic "newTyConCo" (ppr tycon) +newTyConCo_maybe :: TyCon -> Maybe TyCon +newTyConCo_maybe (AlgTyCon {algTcRhs = NewTyCon { nt_co = co }}) = co +newTyConCo_maybe _ = Nothing tyConPrimRep :: TyCon -> PrimRep tyConPrimRep (PrimTyCon {primTyConRep = rep}) = rep @@ -700,11 +774,22 @@ tyConStupidTheta tycon = pprPanic "tyConStupidTheta" (ppr tycon) \begin{code} synTyConDefn :: TyCon -> ([TyVar], Type) -synTyConDefn (SynTyCon {tyConTyVars = tyvars, synTcRhs = ty}) = (tyvars,ty) +synTyConDefn (SynTyCon {tyConTyVars = tyvars, synTcRhs = SynonymTyCon ty}) + = (tyvars, ty) synTyConDefn tycon = pprPanic "getSynTyConDefn" (ppr tycon) -synTyConRhs :: TyCon -> Type -synTyConRhs tc = synTcRhs tc +synTyConRhs :: TyCon -> SynTyConRhs +synTyConRhs (SynTyCon {synTcRhs = rhs}) = rhs +synTyConRhs tc = pprPanic "synTyConRhs" (ppr tc) + +synTyConType :: TyCon -> Type +synTyConType tc = case synTcRhs tc of + SynonymTyCon t -> t + _ -> pprPanic "synTyConType" (ppr tc) + +synTyConResKind :: TyCon -> Kind +synTyConResKind (SynTyCon {synTcRhs = OpenSynTyCon kind}) = kind +synTyConResKind tycon = pprPanic "synTyConResKind" (ppr tycon) \end{code} \begin{code} @@ -720,12 +805,28 @@ maybeTyConSingleCon tc = pprPanic "maybeTyConSingleCon: unexpected tycon " $ ppr \begin{code} isClassTyCon :: TyCon -> Bool -isClassTyCon (AlgTyCon {algTcClass = Just _}) = True -isClassTyCon other_tycon = False +isClassTyCon (AlgTyCon {algTcParent = ClassTyCon _}) = True +isClassTyCon other_tycon = False tyConClass_maybe :: TyCon -> Maybe Class -tyConClass_maybe (AlgTyCon {algTcClass = maybe_clas}) = maybe_clas -tyConClass_maybe ther_tycon = Nothing +tyConClass_maybe (AlgTyCon {algTcParent = ClassTyCon clas}) = Just clas +tyConClass_maybe ther_tycon = Nothing + +isFamInstTyCon :: TyCon -> Bool +isFamInstTyCon (AlgTyCon {algTcParent = FamilyTyCon _ _ _ }) = True +isFamInstTyCon other_tycon = False + +tyConFamInst_maybe :: TyCon -> Maybe (TyCon, [Type]) +tyConFamInst_maybe (AlgTyCon {algTcParent = FamilyTyCon fam instTys _}) = + Just (fam, instTys) +tyConFamInst_maybe ther_tycon = + Nothing + +tyConFamilyCoercion_maybe :: TyCon -> Maybe TyCon +tyConFamilyCoercion_maybe (AlgTyCon {algTcParent = FamilyTyCon _ _ coe}) = + Just coe +tyConFamilyCoercion_maybe ther_tycon = + Nothing \end{code}