-
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TyCon]{The @TyCon@ datatype}
\begin{code}
module TyCon(
- TyCon,
+ TyCon, KindCon, Boxity(..),
- Arity, NewOrData(..),
+ isFunTyCon, isUnLiftedTyCon, isBoxedTyCon, isProductTyCon,
+ isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
+ isEnumerationTyCon, isTupleTyCon, isUnboxedTupleTyCon,
- isFunTyCon, isPrimTyCon, isBoxedTyCon, isProductTyCon,
- isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon,
- isEnumerationTyCon, isTupleTyCon,
-
- mkDataTyCon,
+ mkAlgTyCon,
mkFunTyCon,
mkPrimTyCon,
- mkSpecTyCon,
mkTupleTyCon,
-
mkSynTyCon,
+ mkKindCon,
+ superKindCon,
tyConKind,
tyConUnique,
tyConClass_maybe,
getSynTyConDefn,
- maybeTyConSingleCon
+ maybeTyConSingleCon,
+
+ matchesTyCon
) where
#include "HsVersions.h"
-import {-# SOURCE #-} Type ( Type )
-import {-# SOURCE #-} Class ( Class )
-import {-# SOURCE #-} Id ( Id, isNullaryDataCon )
-import {-# SOURCE #-} TysWiredIn ( tupleCon )
-
+import {-# SOURCE #-} Type ( Type, Kind )
+import {-# SOURCE #-} DataCon ( DataCon )
+import Class ( Class )
+import Var ( TyVar )
import BasicTypes ( Arity, NewOrData(..), RecFlag(..) )
-import TyVar ( GenTyVar, alphaTyVars, alphaTyVar, betaTyVar, TyVar )
-import Kind ( Kind, mkBoxedTypeKind, mkTypeKind, mkUnboxedTypeKind,
- mkArrowKind, resultKind, argKind
- )
import Maybes
-import Name ( Name, nameUnique, mkWiredInTyConName, NamedThing(getName) )
-import Unique ( Unique, funTyConKey, Uniquable(..) )
+import Name ( Name, nameUnique, NamedThing(getName) )
+import Unique ( Unique, Uniquable(..), superKindConKey )
import PrimRep ( PrimRep(..), isFollowableRep )
-import PrelMods ( pREL_GHC )
-import Util ( panic )
+import Outputable
\end{code}
+%************************************************************************
+%* *
+\subsection{The data type}
+%* *
+%************************************************************************
+
\begin{code}
+type KindCon = TyCon
+
data TyCon
- = FunTyCon -- Kind = Type -> Type -> Type
-
- | DataTyCon Unique
- Name
- Kind
- [TyVar]
- [(Class,[Type])] -- Its context
- [Id{-DataCon-}] -- Its data constructors, with fully polymorphic types
- -- This list can be empty, when we import a data type abstractly,
- -- either (a) the interface is hand-written and doesn't give
- -- the constructors, or
- -- (b) in a quest for fast compilation we don't import
- -- the constructors
- [Class] -- Classes which have derived instances
- (Maybe Class) -- Nothing for ordinary types; Just c for the type constructor
- -- for dictionaries of class c.
- NewOrData
- RecFlag -- Tells whether the data type is part of
- -- a mutually-recursive group or not
-
- | TupleTyCon Unique -- cached
- Name -- again, we could do without this, but
- -- it makes life somewhat easier
- Arity -- just a special case of DataTyCon
- -- Kind = BoxedTypeKind
- -- -> ... (n times) ...
- -- -> BoxedTypeKind
- -- -> BoxedTypeKind
-
- | PrimTyCon -- Primitive types; cannot be defined in Haskell
- Unique -- Always unpointed; hence never represented by a closure
- Name -- Often represented by a bit-pattern for the thing
- Kind -- itself (eg Int#), but sometimes by a pointer to
- Arity -- the thing.
- PrimRep
-
- | SpecTyCon -- A specialised TyCon; eg (Arr# Int#), or (List Int#)
- TyCon
- [Maybe Type] -- Specialising types
-
- -- OLD STUFF ABOUT Array types. Use SpecTyCon instead
- -- ([PrimRep] -> PrimRep) -- a heap-allocated object (eg ArrInt#).
- -- The primitive types Arr# and StablePtr# have
- -- parameters (hence arity /= 0); but the rest don't.
- -- Only arrays use the list in a non-trivial way.
- -- Length of that list must == arity.
-
- | SynTyCon
- Unique
- Name
- Kind
- Arity
- [TyVar] -- Argument type variables
- Type -- Right-hand side, mentioning these type vars.
- -- Acts as a template for the expansion when
- -- the tycon is applied to some types.
+ = FunTyCon {
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity
+ }
+
+
+ | AlgTyCon { -- Tuples, data type, and newtype decls.
+ -- All lifted, all boxed
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ tyConTyVars :: [TyVar],
+ dataTyConTheta :: [(Class,[Type])],
+
+ dataCons :: [DataCon],
+ -- Its data constructors, with fully polymorphic types
+ -- This list can be empty, when we import a data type abstractly,
+ -- either (a) the interface is hand-written and doesn't give
+ -- the constructors, or
+ -- (b) in a quest for fast compilation we don't import
+ -- the constructors
+
+ dataTyConDerivings :: [Class], -- Classes which have derived instances
+
+ dataTyConClass_maybe :: (Maybe Class), -- Nothing for ordinary types;
+ -- Just c for the type constructor
+ -- for dictionaries of class c.
+ algTyConFlavour :: NewOrData,
+ algTyConRec :: RecFlag -- Tells whether the data type is part of
+ -- a mutually-recursive group or not
+ }
+
+ | PrimTyCon { -- Primitive types; cannot be defined in Haskell
+ -- NB: All of these guys are *unlifted*, but not all are *unboxed*
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+ primTyConRep :: PrimRep
+ }
+
+ | TupleTyCon {
+
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+ tyConBoxed :: Bool,
+ tyConTyVars :: [TyVar],
+ dataCon :: DataCon
+ }
+
+ | SynTyCon {
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ tyConTyVars :: [TyVar], -- Bound tyvars
+ synTyConDefn :: Type -- Right-hand side, mentioning these type vars.
+ -- Acts as a template for the expansion when
+ -- the tycon is applied to some types.
+ }
+
+ | KindCon { -- Type constructor at the kind level
+ tyConUnique :: Unique,
+ tyConName :: Name,
+ tyConKind :: Kind,
+ tyConArity :: Arity,
+
+ kindConBoxity :: Boxity
+ }
+
+ | SuperKindCon { -- The type of kind variables,
+ tyConUnique :: Unique -- sometimes written as a box
+ }
+
+data Boxity = Boxed | Unboxed | Open
\end{code}
-\begin{code}
-mkFunTyCon = FunTyCon
-mkFunTyConName = mkWiredInTyConName funTyConKey pREL_GHC SLIT("->") FunTyCon
-
-mkSpecTyCon = SpecTyCon
-mkTupleTyCon = TupleTyCon
+%************************************************************************
+%* *
+\subsection{TyCon Construction}
+%* *
+%************************************************************************
-mkDataTyCon name = DataTyCon (nameUnique name) name
+Note: the TyCon constructors all take a Kind as one argument, even though
+they could, in principle, work out their Kind from their other arguments.
+But to do so they need functions from Types, and that makes a nasty
+module mutual-recursion. And they aren't called from many places.
+So we compromise, and move their Kind calculation to the call site.
-mkPrimTyCon name arity rep
- = PrimTyCon (nameUnique name) name (mk_kind arity) arity rep
- where
- mk_kind 0 | isFollowableRep rep = mkBoxedTypeKind -- Represented by a GC-ish ptr
- | otherwise = mkUnboxedTypeKind -- Represented by a non-ptr
- mk_kind n = mkTypeKind `mkArrowKind` mk_kind (n-1)
+\begin{code}
+superKindCon = SuperKindCon superKindConKey
+
+mkKindCon name kind boxity
+ = KindCon {
+ tyConUnique = nameUnique name,
+ tyConName = name,
+ tyConArity = 0,
+ tyConKind = kind,
+ kindConBoxity = boxity
+ }
+
+mkFunTyCon name kind
+ = FunTyCon {
+ tyConUnique = nameUnique name,
+ tyConName = name,
+ tyConKind = kind,
+ tyConArity = 2
+ }
+
+mkAlgTyCon name kind tyvars theta cons derivs maybe_clas flavour rec
+ = AlgTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = length tyvars,
+ tyConTyVars = tyvars,
+ dataTyConTheta = theta,
+ dataCons = cons,
+ dataTyConDerivings = derivs,
+ dataTyConClass_maybe = maybe_clas,
+ algTyConFlavour = flavour,
+ algTyConRec = rec
+ }
+
+mkTupleTyCon name kind arity tyvars con boxed
+ = TupleTyCon {
+ tyConUnique = nameUnique name,
+ tyConName = name,
+ tyConKind = kind,
+ tyConArity = arity,
+ tyConBoxed = boxed,
+ tyConTyVars = tyvars,
+ dataCon = con
+ }
+
+mkPrimTyCon name kind arity rep
+ = PrimTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = arity,
+ primTyConRep = rep
+ }
+
+mkSynTyCon name kind arity tyvars rhs
+ = SynTyCon {
+ tyConName = name,
+ tyConUnique = nameUnique name,
+ tyConKind = kind,
+ tyConArity = arity,
+ tyConTyVars = tyvars,
+ synTyConDefn = rhs
+ }
+\end{code}
-mkSynTyCon name = SynTyCon (nameUnique name) name
+\begin{code}
+isFunTyCon (FunTyCon {}) = True
+isFunTyCon _ = False
-isFunTyCon FunTyCon = True
-isFunTyCon _ = False
+isPrimTyCon (PrimTyCon {}) = True
+isPrimTyCon _ = False
-isPrimTyCon (PrimTyCon _ _ _ _ _) = True
-isPrimTyCon _ = False
+isUnLiftedTyCon (PrimTyCon {}) = True
+isUnLiftedTyCon (TupleTyCon { tyConBoxed = False }) = True
+isUnLiftedTyCon _ = False
--- At present there are no unboxed non-primitive types, so
--- isBoxedTyCon is just the negation of isPrimTyCon.
-isBoxedTyCon = not . isPrimTyCon
+-- isBoxedTyCon should not be applied to SynTyCon, nor KindCon
+isBoxedTyCon (AlgTyCon {}) = True
+isBoxedTyCon (FunTyCon {}) = True
+isBoxedTyCon (TupleTyCon {tyConBoxed = boxed}) = boxed
+isBoxedTyCon (PrimTyCon {primTyConRep = rep}) = isFollowableRep rep
-- isAlgTyCon returns True for both @data@ and @newtype@
-isAlgTyCon (DataTyCon _ _ _ _ _ _ _ _ _ _) = True
-isAlgTyCon (TupleTyCon _ _ _) = True
-isAlgTyCon other = False
+isAlgTyCon (AlgTyCon {}) = True
+isAlgTyCon (TupleTyCon {}) = True
+isAlgTyCon other = False
-- isDataTyCon returns False for @newtype@.
-isDataTyCon (DataTyCon _ _ _ _ _ _ _ _ DataType _) = True
-isDataTyCon (TupleTyCon _ _ _) = True
-isDataTyCon other = False
+isDataTyCon (AlgTyCon {algTyConFlavour = new_or_data}) = case new_or_data of
+ NewType -> False
+ other -> True
+isDataTyCon (TupleTyCon {}) = True -- is an unboxed tuple a datatype?
+isDataTyCon other = False
-isNewTyCon (DataTyCon _ _ _ _ _ _ _ _ NewType _) = True
-isNewTyCon other = False
+isNewTyCon (AlgTyCon {algTyConFlavour = NewType}) = True
+isNewTyCon other = False
-- A "product" tycon is non-recursive and has one constructor,
-- whether DataType or NewType
-isProductTyCon (TupleTyCon _ _ _) = True
-isProductTyCon (DataTyCon _ _ _ _ _ [c] _ _ _ NonRecursive) = True
-isProductTyCon other = False
-
-isSynTyCon (SynTyCon _ _ _ _ _ _) = True
-isSynTyCon _ = False
-
-isEnumerationTyCon (TupleTyCon _ _ arity)
- = arity == 0
-isEnumerationTyCon (DataTyCon _ _ _ _ _ data_cons _ _ DataType _)
- = not (null data_cons) && all isNullaryDataCon data_cons
-isEnumerationTyCon other = False
-
-isTupleTyCon (TupleTyCon _ _ arity) = arity >= 2 -- treat "0-tuple" specially
-isTupleTyCon (SpecTyCon tc tys) = isTupleTyCon tc
-isTupleTyCon other = False
-\end{code}
+isProductTyCon (AlgTyCon {dataCons = [c], algTyConRec = NonRecursive}) = True
+isProductTyCon (TupleTyCon {}) = True
+isProductTyCon other = False
-\begin{code}
--- Special cases to avoid reconstructing lots of kinds
-kind1 = mkBoxedTypeKind `mkArrowKind` mkBoxedTypeKind
-kind2 = mkBoxedTypeKind `mkArrowKind` kind1
-
-tyConKind :: TyCon -> Kind
-tyConKind FunTyCon = kind2
-tyConKind (DataTyCon _ _ kind _ _ _ _ _ _ _) = kind
-tyConKind (PrimTyCon _ _ kind _ _) = kind
-tyConKind (SynTyCon _ _ k _ _ _) = k
-
-tyConKind (TupleTyCon _ _ n)
- = mkArrow n
- where
- mkArrow 0 = mkBoxedTypeKind
- mkArrow 1 = kind1
- mkArrow 2 = kind2
- mkArrow n = mkBoxedTypeKind `mkArrowKind` mkArrow (n-1)
-
-tyConKind (SpecTyCon tc tys)
- = spec (tyConKind tc) tys
- where
- spec kind [] = kind
- spec kind (Just _ : tys) = spec (resultKind kind) tys
- spec kind (Nothing : tys) =
- argKind kind `mkArrowKind` spec (resultKind kind) tys
-\end{code}
+isSynTyCon (SynTyCon {}) = True
+isSynTyCon _ = False
-\begin{code}
-tyConUnique :: TyCon -> Unique
-tyConUnique FunTyCon = funTyConKey
-tyConUnique (DataTyCon uniq _ _ _ _ _ _ _ _ _) = uniq
-tyConUnique (TupleTyCon uniq _ _) = uniq
-tyConUnique (PrimTyCon uniq _ _ _ _) = uniq
-tyConUnique (SynTyCon uniq _ _ _ _ _) = uniq
-tyConUnique (SpecTyCon _ _ ) = panic "tyConUnique:SpecTyCon"
-
-tyConArity :: TyCon -> Arity
-tyConArity FunTyCon = 2
-tyConArity (DataTyCon _ _ _ tyvars _ _ _ _ _ _) = length tyvars
-tyConArity (TupleTyCon _ _ arity) = arity
-tyConArity (PrimTyCon _ _ _ arity _) = arity
-tyConArity (SynTyCon _ _ _ arity _ _) = arity
-tyConArity (SpecTyCon _ _ ) = panic "tyConArity:SpecTyCon"
-\end{code}
+isEnumerationTyCon (AlgTyCon {algTyConFlavour = EnumType}) = True
+isEnumerationTyCon other = False
-\begin{code}
-tyConTyVars :: TyCon -> [TyVar]
-tyConTyVars FunTyCon = [alphaTyVar,betaTyVar]
-tyConTyVars (DataTyCon _ _ _ tvs _ _ _ _ _ _) = tvs
-tyConTyVars (TupleTyCon _ _ arity) = take arity alphaTyVars
-tyConTyVars (SynTyCon _ _ _ _ tvs _) = tvs
-#ifdef DEBUG
-tyConTyVars (PrimTyCon _ _ _ _ _) = panic "tyConTyVars:PrimTyCon"
-tyConTyVars (SpecTyCon _ _ ) = panic "tyConTyVars:SpecTyCon"
-#endif
+-- The unit tycon isn't classed as a tuple tycon
+isTupleTyCon (TupleTyCon {tyConArity = arity, tyConBoxed = True}) = arity >= 2
+isTupleTyCon other = False
+
+isUnboxedTupleTyCon (TupleTyCon {tyConBoxed = False}) = True
+isUnboxedTupleTyCon other = False
\end{code}
\begin{code}
-tyConDataCons :: TyCon -> [Id]
-tyConFamilySize :: TyCon -> Int
-
-tyConDataCons (DataTyCon _ _ _ _ _ data_cons _ _ _ _) = data_cons
-tyConDataCons (TupleTyCon _ _ a) = [tupleCon a]
-tyConDataCons other = []
+tyConDataCons :: TyCon -> [DataCon]
+tyConDataCons (AlgTyCon {dataCons = cons}) = cons
+tyConDataCons (TupleTyCon {dataCon = con}) = [con]
+tyConDataCons other = []
-- You may think this last equation should fail,
-- but it's quite convenient to return no constructors for
-- a synonym; see for example the call in TcTyClsDecls.
-tyConFamilySize (DataTyCon _ _ _ _ _ data_cons _ _ _ _) = length data_cons
-tyConFamilySize (TupleTyCon _ _ _) = 1
+tyConFamilySize :: TyCon -> Int
+tyConFamilySize (AlgTyCon {dataCons = cons}) = length cons
+tyConFamilySize (TupleTyCon {}) = 1
#ifdef DEBUG
---tyConFamilySize other = pprPanic "tyConFamilySize:" (pprTyCon other)
+tyConFamilySize other = pprPanic "tyConFamilySize:" (ppr other)
#endif
tyConPrimRep :: TyCon -> PrimRep
-tyConPrimRep (PrimTyCon _ __ _ rep) = rep
-tyConPrimRep _ = PtrRep
+tyConPrimRep (PrimTyCon {primTyConRep = rep}) = rep
+tyConPrimRep _ = PtrRep
\end{code}
\begin{code}
tyConDerivings :: TyCon -> [Class]
-tyConDerivings (DataTyCon _ _ _ _ _ _ derivs _ _ _) = derivs
-tyConDerivings other = []
+tyConDerivings (AlgTyCon {dataTyConDerivings = derivs}) = derivs
+tyConDerivings other = []
\end{code}
\begin{code}
tyConTheta :: TyCon -> [(Class, [Type])]
-tyConTheta (DataTyCon _ _ _ _ theta _ _ _ _ _) = theta
-tyConTheta (TupleTyCon _ _ _) = []
+tyConTheta (AlgTyCon {dataTyConTheta = theta}) = theta
-- should ask about anything else
\end{code}
\begin{code}
getSynTyConDefn :: TyCon -> ([TyVar], Type)
-getSynTyConDefn (SynTyCon _ _ _ _ tyvars ty) = (tyvars,ty)
+getSynTyConDefn (SynTyCon {tyConTyVars = tyvars, synTyConDefn = ty}) = (tyvars,ty)
\end{code}
\begin{code}
-maybeTyConSingleCon :: TyCon -> Maybe Id
-
-maybeTyConSingleCon (TupleTyCon _ _ arity) = Just (tupleCon arity)
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ [c] _ _ _ _) = Just c
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ _ _ _ _ _) = Nothing
-maybeTyConSingleCon (PrimTyCon _ _ _ _ _) = Nothing
-maybeTyConSingleCon (SpecTyCon tc tys) = panic "maybeTyConSingleCon:SpecTyCon"
- -- requires DataCons of TyCon
+maybeTyConSingleCon :: TyCon -> Maybe DataCon
+maybeTyConSingleCon (AlgTyCon {dataCons = [c]}) = Just c
+maybeTyConSingleCon (AlgTyCon {}) = Nothing
+maybeTyConSingleCon (TupleTyCon {dataCon = con}) = Just con
+maybeTyConSingleCon (PrimTyCon {}) = Nothing
\end{code}
\begin{code}
tyConClass_maybe :: TyCon -> Maybe Class
-tyConClass_maybe (DataTyCon _ _ _ _ _ _ _ maybe_cls _ _) = maybe_cls
-tyConClass_maybe other_tycon = Nothing
+tyConClass_maybe (AlgTyCon {dataTyConClass_maybe = maybe_cls}) = maybe_cls
+tyConClass_maybe other_tycon = Nothing
\end{code}
-@derivedFor@ reports if we have an {\em obviously}-derived instance
-for the given class/tycon. Of course, you might be deriving something
-because it a superclass of some other obviously-derived class --- this
-function doesn't deal with that.
-
-ToDo: what about derivings for specialised tycons !!!
%************************************************************************
%* *
a < b = case (a `compare` b) of { LT -> True; EQ -> False; GT -> False }
a >= b = case (a `compare` b) of { LT -> False; EQ -> True; GT -> True }
a > b = case (a `compare` b) of { LT -> False; EQ -> False; GT -> True }
- compare a b = uniqueOf a `compare` uniqueOf b
+ compare a b = getUnique a `compare` getUnique b
instance Uniquable TyCon where
- uniqueOf tc = tyConUnique tc
+ getUnique tc = tyConUnique tc
+
+instance Outputable TyCon where
+ ppr tc = ppr (getName tc)
+
+instance NamedThing TyCon where
+ getName = tyConName
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Kind constructors}
+%* *
+%************************************************************************
+
+@matchesTyCon tc1 tc2@ checks whether an appliation
+(tc1 t1..tn) matches (tc2 t1..tn). By "matches" we basically mean "equals",
+except that at the kind level tc2 might have more boxity info that tc1.
+
+E.g. It's ok to bind a type variable
+ tv :: k2
+to a type
+ t :: k1
+
\begin{code}
-instance NamedThing TyCon where
- getName (DataTyCon _ n _ _ _ _ _ _ _ _) = n
- getName (PrimTyCon _ n _ _ _) = n
- getName (SpecTyCon tc _) = getName tc
- getName (SynTyCon _ n _ _ _ _) = n
- getName FunTyCon = mkFunTyConName
- getName (TupleTyCon _ n _) = n
-
-{- LATER:
- getName (SpecTyCon tc tys) = let (OrigName m n) = origName "????" tc in
- (m, n _APPEND_ specMaybeTysSuffix tys)
- getName other_tc = moduleNamePair (expectJust "tycon1" (getName other_tc))
- getName other = Nothing
--}
+matchesTyCon :: TyCon -- Expected (e.g. arg type of function)
+ -> TyCon -- Inferred (e.g. type of actual arg to function)
+ -> Bool
+
+matchesTyCon (KindCon {kindConBoxity = k1}) (KindCon {kindConBoxity = k2})
+ = k2 `has_more` k1
+ where
+ -- "has_more" means has more boxity info
+ Boxed `has_more` Open = True
+ Boxed `has_more` Boxed = True
+ Unboxed `has_more` Open = True
+ Unboxed `has_more` Unboxed = True
+ Open `has_more` Open = True
+ k1 `has_more` k2 = False
+
+matchesTyCon tc1 tc2 = tyConUnique tc1 == tyConUnique tc2
\end{code}
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