-%
+
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
%
\section[TyCon]{The @TyCon@ datatype}
\begin{code}
-#include "HsVersions.h"
-
module TyCon(
- TyCon(..), -- NB: some pals need to see representation
+ TyCon,
- Arity(..), NewOrData(..),
+ Arity, NewOrData(..),
- isFunTyCon, isPrimTyCon, isBoxedTyCon,
- isDataTyCon, isSynTyCon,
+ isFunTyCon, isPrimTyCon, isBoxedTyCon, isProductTyCon,
+ isAlgTyCon, isDataTyCon, isSynTyCon, isNewTyCon,
+ isEnumerationTyCon, isTupleTyCon,
mkDataTyCon,
mkFunTyCon,
tyConDataCons,
tyConFamilySize,
tyConDerivings,
- tyConArity, synTyConArity,
+ tyConTheta,
+ tyConPrimRep,
+ tyConArity,
+ tyConClass_maybe,
getSynTyConDefn,
- maybeTyConSingleCon,
- isEnumerationTyCon,
- derivedFor
+ maybeTyConSingleCon
) where
-CHK_Ubiq() -- debugging consistency check
+#include "HsVersions.h"
-import TyLoop ( Type(..), GenType,
- Class(..), GenClass,
- Id(..), GenId,
- mkTupleCon, dataConSig,
- specMaybeTysSuffix
- )
+import {-# SOURCE #-} Type ( Type )
+import {-# SOURCE #-} Class ( Class )
+import {-# SOURCE #-} Id ( Id, isNullaryDataCon, idType )
+import {-# SOURCE #-} TysWiredIn ( tupleCon )
-import TyVar ( GenTyVar, alphaTyVars, alphaTyVar, betaTyVar )
-import Usage ( GenUsage, Usage(..) )
-import Kind ( Kind, mkBoxedTypeKind, mkArrowKind, resultKind, argKind )
-import Maybes
-import Name ( Name, RdrName(..), appendRdr, nameUnique,
- mkTupleTyConName, mkFunTyConName
+import BasicTypes ( Arity, NewOrData(..), RecFlag(..) )
+import TyVar ( GenTyVar, alphaTyVars, alphaTyVar, betaTyVar, TyVar )
+import Kind ( Kind, mkBoxedTypeKind, mkTypeKind, mkUnboxedTypeKind,
+ mkArrowKind, resultKind, argKind
)
-import Unique ( Unique, funTyConKey, mkTupleTyConUnique )
-import Pretty ( Pretty(..), PrettyRep )
-import PprStyle ( PprStyle )
+import Maybes
+import Name ( Name, nameUnique, mkWiredInTyConName, NamedThing(getName) )
+import Unique ( Unique, funTyConKey, Uniquable(..) )
+import PrimRep ( PrimRep(..), isFollowableRep )
+import PrelMods ( pREL_GHC, pREL_TUP, pREL_BASE )
+import Lex ( mkTupNameStr )
import SrcLoc ( SrcLoc, mkBuiltinSrcLoc )
-import Util ( panic, panic#, nOfThem, isIn, Ord3(..) )
+import Util ( nOfThem, isIn )
+import Outputable
\end{code}
\begin{code}
-type Arity = Int
-
data TyCon
= FunTyCon -- Kind = Type -> Type -> Type
- | DataTyCon Unique{-TyConKey-}
+ | DataTyCon Unique
Name
Kind
[TyVar]
- [(Class,Type)] -- Its context
- [Id] -- Its data constructors, with fully polymorphic types
+ [(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
-- -> BoxedTypeKind
| PrimTyCon -- Primitive types; cannot be defined in Haskell
- Unique -- Always unboxed; hence never represented by a closure
+ 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
Type -- Right-hand side, mentioning these type vars.
-- Acts as a template for the expansion when
-- the tycon is applied to some types.
-
-data NewOrData
- = NewType -- "newtype Blah ..."
- | DataType -- "data Blah ..."
\end{code}
\begin{code}
-mkFunTyCon = FunTyCon
+mkFunTyCon = FunTyCon
+mkFunTyConName = mkWiredInTyConName funTyConKey pREL_GHC SLIT("->") FunTyCon
+
mkSpecTyCon = SpecTyCon
+mkTupleTyCon = TupleTyCon
+
+mkDataTyCon name = DataTyCon (nameUnique name) name
-mkTupleTyCon arity
- = TupleTyCon u n arity
+mkPrimTyCon name arity rep
+ = PrimTyCon (nameUnique name) name (mk_kind arity) arity rep
where
- n = mkTupleTyConName arity
- u = uniqueOf n
+ 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)
-mkDataTyCon name
- = DataTyCon (nameUnique name) name
-mkPrimTyCon name
- = PrimTyCon (nameUnique name) name
-mkSynTyCon name
- = SynTyCon (nameUnique name) name
+mkSynTyCon name = SynTyCon (nameUnique name) name
isFunTyCon FunTyCon = True
isFunTyCon _ = False
-isPrimTyCon (PrimTyCon _ _ _) = True
+isPrimTyCon (PrimTyCon _ _ _ _ _) = True
isPrimTyCon _ = False
-- At present there are no unboxed non-primitive types, so
-- isBoxedTyCon is just the negation of isPrimTyCon.
isBoxedTyCon = not . isPrimTyCon
+-- isAlgTyCon returns True for both @data@ and @newtype@
+isAlgTyCon (DataTyCon _ _ _ _ _ _ _ _ _ _) = True
+isAlgTyCon (TupleTyCon _ _ _) = True
+isAlgTyCon other = False
+
-- isDataTyCon returns False for @newtype@.
--- Not sure about this decision yet.
-isDataTyCon (DataTyCon _ _ _ _ _ _ _ DataType) = True
-isDataTyCon (TupleTyCon _ _ _) = True
-isDataTyCon other = False
+isDataTyCon (DataTyCon _ _ _ _ _ _ _ _ DataType _) = True
+isDataTyCon (TupleTyCon _ _ _) = True
+isDataTyCon other = False
+
+isNewTyCon (DataTyCon _ _ _ _ _ _ _ _ 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}
\begin{code}
kind2 = mkBoxedTypeKind `mkArrowKind` kind1
tyConKind :: TyCon -> Kind
-tyConKind FunTyCon = kind2
-tyConKind (DataTyCon _ _ kind _ _ _ _ _) = kind
-tyConKind (PrimTyCon _ _ kind) = kind
-tyConKind (SynTyCon _ _ k _ _ _) = k
+tyConKind FunTyCon = kind2
+tyConKind (DataTyCon _ _ kind _ _ _ _ _ _ _) = kind
+tyConKind (PrimTyCon _ _ kind _ _) = kind
+tyConKind (SynTyCon _ _ k _ _ _) = k
tyConKind (TupleTyCon _ _ n)
= mkArrow n
\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 _ _ _ tvs _ _ _ _) = length tvs
-tyConArity (TupleTyCon _ _ arity) = arity
-tyConArity (PrimTyCon _ _ _) = 0 -- ??
-tyConArity (SpecTyCon _ _) = 0
-tyConArity (SynTyCon _ _ _ arity _ _) = arity
-
-synTyConArity :: TyCon -> Maybe Arity -- Nothing <=> not a syn tycon
-synTyConArity (SynTyCon _ _ _ arity _ _) = Just arity
-synTyConArity _ = Nothing
+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}
\begin{code}
tyConTyVars :: TyCon -> [TyVar]
-tyConTyVars FunTyCon = [alphaTyVar,betaTyVar]
-tyConTyVars (DataTyCon _ _ _ tvs _ _ _ _) = tvs
-tyConTyVars (TupleTyCon _ _ arity) = take arity alphaTyVars
-tyConTyVars (SynTyCon _ _ _ _ tvs _) = tvs
-tyConTyVars (PrimTyCon _ _ _) = panic "tyConTyVars:PrimTyCon"
+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
\end{code}
\begin{code}
tyConDataCons :: TyCon -> [Id]
tyConFamilySize :: TyCon -> Int
-tyConDataCons (DataTyCon _ _ _ _ _ data_cons _ _) = data_cons
-tyConDataCons (TupleTyCon _ _ a) = [mkTupleCon a]
-tyConDataCons other = []
+tyConDataCons (DataTyCon _ _ _ _ _ data_cons _ _ _ _) = data_cons
+tyConDataCons (TupleTyCon _ _ a) = [tupleCon a]
+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 (DataTyCon _ _ _ _ _ data_cons _ _ _ _) = length data_cons
+tyConFamilySize (TupleTyCon _ _ _) = 1
+#ifdef DEBUG
+--tyConFamilySize other = pprPanic "tyConFamilySize:" (pprTyCon other)
+#endif
+
+tyConPrimRep :: TyCon -> PrimRep
+tyConPrimRep (PrimTyCon _ __ _ rep) = rep
+tyConPrimRep _ = PtrRep
\end{code}
\begin{code}
tyConDerivings :: TyCon -> [Class]
-tyConDerivings (DataTyCon _ _ _ _ _ _ derivs _) = derivs
-tyConDerivings other = []
+tyConDerivings (DataTyCon _ _ _ _ _ _ derivs _ _ _) = derivs
+tyConDerivings other = []
+\end{code}
+
+\begin{code}
+tyConTheta :: TyCon -> [(Class, [Type])]
+tyConTheta (DataTyCon _ _ _ _ theta _ _ _ _ _) = theta
+tyConTheta (TupleTyCon _ _ _) = []
+-- should ask about anything else
\end{code}
\begin{code}
\begin{code}
maybeTyConSingleCon :: TyCon -> Maybe Id
-maybeTyConSingleCon (TupleTyCon _ _ arity) = Just (mkTupleCon arity)
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ [c] _ _) = Just c
-maybeTyConSingleCon (DataTyCon _ _ _ _ _ _ _ _) = Nothing
-maybeTyConSingleCon (PrimTyCon _ _ _) = Nothing
-maybeTyConSingleCon (SpecTyCon tc tys) = panic "maybeTyConSingleCon:SpecTyCon"
+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
+\end{code}
-isEnumerationTyCon (TupleTyCon _ _ arity)
- = arity == 0
-isEnumerationTyCon (DataTyCon _ _ _ _ _ data_cons _ _)
- = not (null data_cons) && all is_nullary data_cons
- where
- is_nullary con = case (dataConSig con) of { (_,_, arg_tys, _) ->
- null arg_tys }
+\begin{code}
+tyConClass_maybe :: TyCon -> Maybe Class
+tyConClass_maybe (DataTyCon _ _ _ _ _ _ _ maybe_cls _ _) = maybe_cls
+tyConClass_maybe other_tycon = Nothing
\end{code}
@derivedFor@ reports if we have an {\em obviously}-derived instance
ToDo: what about derivings for specialised tycons !!!
-\begin{code}
-derivedFor :: Class -> TyCon -> Bool
-derivedFor clas (DataTyCon _ _ _ _ _ _ derivs _) = isIn "derivedFor" clas derivs
-derivedFor clas something_weird = False
-\end{code}
-
%************************************************************************
%* *
\subsection[TyCon-instances]{Instance declarations for @TyCon@}
the property @(a<=b) || (b<=a)@.
\begin{code}
-instance Ord3 TyCon where
- cmp FunTyCon FunTyCon = EQ_
- cmp (DataTyCon a _ _ _ _ _ _ _) (DataTyCon b _ _ _ _ _ _ _) = a `cmp` b
- cmp (SynTyCon a _ _ _ _ _) (SynTyCon b _ _ _ _ _) = a `cmp` b
- cmp (TupleTyCon _ _ a) (TupleTyCon _ _ b) = a `cmp` b
- cmp (PrimTyCon a _ _) (PrimTyCon b _ _) = a `cmp` b
- cmp (SpecTyCon tc1 mtys1) (SpecTyCon tc2 mtys2)
- = panic# "cmp on SpecTyCons" -- case (tc1 `cmp` tc2) of { EQ_ -> mtys1 `cmp` mtys2; xxx -> xxx }
-
- -- now we *know* the tags are different, so...
- cmp other_1 other_2
- | tag1 _LT_ tag2 = LT_
- | otherwise = GT_
- where
- tag1 = tag_TyCon other_1
- tag2 = tag_TyCon other_2
-
- tag_TyCon FunTyCon = ILIT(1)
- tag_TyCon (DataTyCon _ _ _ _ _ _ _ _) = ILIT(2)
- tag_TyCon (TupleTyCon _ _ _) = ILIT(3)
- tag_TyCon (PrimTyCon _ _ _) = ILIT(4)
- tag_TyCon (SpecTyCon _ _) = ILIT(5)
- tag_TyCon (SynTyCon _ _ _ _ _ _) = ILIT(6)
-
instance Eq TyCon where
- a == b = case (a `cmp` b) of { EQ_ -> True; _ -> False }
- a /= b = case (a `cmp` b) of { EQ_ -> False; _ -> True }
+ a == b = case (a `compare` b) of { EQ -> True; _ -> False }
+ a /= b = case (a `compare` b) of { EQ -> False; _ -> True }
instance Ord TyCon where
- a <= b = case (a `cmp` b) of { LT_ -> True; EQ_ -> True; GT__ -> False }
- a < b = case (a `cmp` b) of { LT_ -> True; EQ_ -> False; GT__ -> False }
- a >= b = case (a `cmp` b) of { LT_ -> False; EQ_ -> True; GT__ -> True }
- a > b = case (a `cmp` b) of { LT_ -> False; EQ_ -> False; GT__ -> True }
- _tagCmp a b = case (a `cmp` b) of { LT_ -> _LT; EQ_ -> _EQ; GT__ -> _GT }
+ a <= b = case (a `compare` b) of { LT -> True; EQ -> True; GT -> False }
+ 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
instance Uniquable TyCon where
- uniqueOf (DataTyCon u _ _ _ _ _ _ _) = u
- uniqueOf (TupleTyCon u _ _) = u
- uniqueOf (PrimTyCon u _ _) = u
- uniqueOf (SynTyCon u _ _ _ _ _) = u
- uniqueOf tc@(SpecTyCon _ _) = panic "uniqueOf:SpecTyCon"
- uniqueOf tc = uniqueOf (getName tc)
+ uniqueOf tc = tyConUnique tc
\end{code}
\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
- getName tc = panic "TyCon.getName"
+ 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 (m,n) = moduleNamePair tc in
+ 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