%
% (c) The AQUA Project, Glasgow University, 1994-1998
%
+
+
\section[TysPrim]{Wired-in knowledge about primitive types}
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
+-- | This module defines TyCons that can't be expressed in Haskell.
+-- They are all, therefore, wired-in TyCons. C.f module TysWiredIn
module TysPrim(
alphaTyVars, betaTyVars, alphaTyVar, betaTyVar, gammaTyVar, deltaTyVar,
- alphaTy, betaTy, gammaTy, deltaTy,
+ alphaTy, betaTy, gammaTy, deltaTy, ecTyVars,
openAlphaTy, openBetaTy, openAlphaTyVar, openBetaTyVar, openAlphaTyVars,
+ argAlphaTy, argAlphaTyVar, argBetaTy, argBetaTyVar,
+
+ -- Kind constructors...
+ tySuperKindTyCon, tySuperKind,
+ liftedTypeKindTyCon, openTypeKindTyCon, unliftedTypeKindTyCon,
+ argTypeKindTyCon, ubxTupleKindTyCon,
- primTyCons,
+ tySuperKindTyConName, liftedTypeKindTyConName,
+ openTypeKindTyConName, unliftedTypeKindTyConName,
+ ubxTupleKindTyConName, argTypeKindTyConName,
+
+ -- Kinds
+ liftedTypeKind, unliftedTypeKind, openTypeKind,
+ argTypeKind, ubxTupleKind,
+ mkArrowKind, mkArrowKinds, isCoercionKind,
+
+ funTyCon, funTyConName,
+ primTyCons,
charPrimTyCon, charPrimTy,
intPrimTyCon, intPrimTy,
word32PrimTyCon, word32PrimTy,
int64PrimTyCon, int64PrimTy,
- word64PrimTyCon, word64PrimTy,
+ word64PrimTyCon, word64PrimTy,
+
+ eqPredPrimTyCon, -- ty1 ~ ty2
- anyPrimTyCon, anyPrimTy, anyPrimTyCon1, mkAnyPrimTyCon
+ -- * Any
+ anyTyCon, anyTyConOfKind, anyTypeOfKind
) where
#include "HsVersions.h"
import Var ( TyVar, mkTyVar )
import Name ( Name, BuiltInSyntax(..), mkInternalName, mkWiredInName )
-import OccName ( mkOccNameFS, tcName, mkTyVarOcc )
-import TyCon ( TyCon, mkPrimTyCon, mkLiftedPrimTyCon,
- PrimRep(..) )
-import Type ( mkTyConApp, mkTyConTy, mkTyVarTys, mkTyVarTy,
- unliftedTypeKind,
- liftedTypeKind, openTypeKind,
- Kind, mkArrowKinds, mkArrowKind,
- TyThing(..)
- )
+import OccName ( mkTcOcc,mkTyVarOccFS, mkTcOccFS )
+import TyCon
+import TypeRep
+import Type
+import Coercion
import SrcLoc
-import Unique ( mkAlphaTyVarUnique, pprUnique )
+import Unique ( mkAlphaTyVarUnique )
import PrelNames
-import FastString ( FastString, mkFastString )
+import FastString
import Outputable
-import Char ( ord, chr )
+import Data.Char
\end{code}
%************************************************************************
, wordPrimTyCon
, word32PrimTyCon
, word64PrimTyCon
- , anyPrimTyCon, anyPrimTyCon1
+ , anyTyCon
+ , eqPredPrimTyCon
]
mkPrimTc :: FastString -> Unique -> TyCon -> Name
-mkPrimTc fs uniq tycon
- = mkWiredInName gHC_PRIM (mkOccNameFS tcName fs)
- uniq
+mkPrimTc fs unique tycon
+ = mkWiredInName gHC_PRIM (mkTcOccFS fs)
+ unique
(ATyCon tycon) -- Relevant TyCon
UserSyntax -- None are built-in syntax
-charPrimTyConName = mkPrimTc FSLIT("Char#") charPrimTyConKey charPrimTyCon
-intPrimTyConName = mkPrimTc FSLIT("Int#") intPrimTyConKey intPrimTyCon
-int32PrimTyConName = mkPrimTc FSLIT("Int32#") int32PrimTyConKey int32PrimTyCon
-int64PrimTyConName = mkPrimTc FSLIT("Int64#") int64PrimTyConKey int64PrimTyCon
-wordPrimTyConName = mkPrimTc FSLIT("Word#") wordPrimTyConKey wordPrimTyCon
-word32PrimTyConName = mkPrimTc FSLIT("Word32#") word32PrimTyConKey word32PrimTyCon
-word64PrimTyConName = mkPrimTc FSLIT("Word64#") word64PrimTyConKey word64PrimTyCon
-addrPrimTyConName = mkPrimTc FSLIT("Addr#") addrPrimTyConKey addrPrimTyCon
-floatPrimTyConName = mkPrimTc FSLIT("Float#") floatPrimTyConKey floatPrimTyCon
-doublePrimTyConName = mkPrimTc FSLIT("Double#") doublePrimTyConKey doublePrimTyCon
-statePrimTyConName = mkPrimTc FSLIT("State#") statePrimTyConKey statePrimTyCon
-realWorldTyConName = mkPrimTc FSLIT("RealWorld") realWorldTyConKey realWorldTyCon
-arrayPrimTyConName = mkPrimTc FSLIT("Array#") arrayPrimTyConKey arrayPrimTyCon
-byteArrayPrimTyConName = mkPrimTc FSLIT("ByteArray#") byteArrayPrimTyConKey byteArrayPrimTyCon
-mutableArrayPrimTyConName = mkPrimTc FSLIT("MutableArray#") mutableArrayPrimTyConKey mutableArrayPrimTyCon
-mutableByteArrayPrimTyConName = mkPrimTc FSLIT("MutableByteArray#") mutableByteArrayPrimTyConKey mutableByteArrayPrimTyCon
-mutVarPrimTyConName = mkPrimTc FSLIT("MutVar#") mutVarPrimTyConKey mutVarPrimTyCon
-mVarPrimTyConName = mkPrimTc FSLIT("MVar#") mVarPrimTyConKey mVarPrimTyCon
-tVarPrimTyConName = mkPrimTc FSLIT("TVar#") tVarPrimTyConKey tVarPrimTyCon
-stablePtrPrimTyConName = mkPrimTc FSLIT("StablePtr#") stablePtrPrimTyConKey stablePtrPrimTyCon
-stableNamePrimTyConName = mkPrimTc FSLIT("StableName#") stableNamePrimTyConKey stableNamePrimTyCon
-bcoPrimTyConName = mkPrimTc FSLIT("BCO#") bcoPrimTyConKey bcoPrimTyCon
-weakPrimTyConName = mkPrimTc FSLIT("Weak#") weakPrimTyConKey weakPrimTyCon
-threadIdPrimTyConName = mkPrimTc FSLIT("ThreadId#") threadIdPrimTyConKey threadIdPrimTyCon
-anyPrimTyConName = mkPrimTc FSLIT("Any") anyPrimTyConKey anyPrimTyCon
-anyPrimTyCon1Name = mkPrimTc FSLIT("Any1") anyPrimTyCon1Key anyPrimTyCon
+charPrimTyConName, intPrimTyConName, int32PrimTyConName, int64PrimTyConName, wordPrimTyConName, word32PrimTyConName, word64PrimTyConName, addrPrimTyConName, floatPrimTyConName, doublePrimTyConName, statePrimTyConName, realWorldTyConName, arrayPrimTyConName, byteArrayPrimTyConName, mutableArrayPrimTyConName, mutableByteArrayPrimTyConName, mutVarPrimTyConName, mVarPrimTyConName, tVarPrimTyConName, stablePtrPrimTyConName, stableNamePrimTyConName, bcoPrimTyConName, weakPrimTyConName, threadIdPrimTyConName, eqPredPrimTyConName :: Name
+charPrimTyConName = mkPrimTc (fsLit "Char#") charPrimTyConKey charPrimTyCon
+intPrimTyConName = mkPrimTc (fsLit "Int#") intPrimTyConKey intPrimTyCon
+int32PrimTyConName = mkPrimTc (fsLit "Int32#") int32PrimTyConKey int32PrimTyCon
+int64PrimTyConName = mkPrimTc (fsLit "Int64#") int64PrimTyConKey int64PrimTyCon
+wordPrimTyConName = mkPrimTc (fsLit "Word#") wordPrimTyConKey wordPrimTyCon
+word32PrimTyConName = mkPrimTc (fsLit "Word32#") word32PrimTyConKey word32PrimTyCon
+word64PrimTyConName = mkPrimTc (fsLit "Word64#") word64PrimTyConKey word64PrimTyCon
+addrPrimTyConName = mkPrimTc (fsLit "Addr#") addrPrimTyConKey addrPrimTyCon
+floatPrimTyConName = mkPrimTc (fsLit "Float#") floatPrimTyConKey floatPrimTyCon
+doublePrimTyConName = mkPrimTc (fsLit "Double#") doublePrimTyConKey doublePrimTyCon
+statePrimTyConName = mkPrimTc (fsLit "State#") statePrimTyConKey statePrimTyCon
+eqPredPrimTyConName = mkPrimTc (fsLit "~") eqPredPrimTyConKey eqPredPrimTyCon
+realWorldTyConName = mkPrimTc (fsLit "RealWorld") realWorldTyConKey realWorldTyCon
+arrayPrimTyConName = mkPrimTc (fsLit "Array#") arrayPrimTyConKey arrayPrimTyCon
+byteArrayPrimTyConName = mkPrimTc (fsLit "ByteArray#") byteArrayPrimTyConKey byteArrayPrimTyCon
+mutableArrayPrimTyConName = mkPrimTc (fsLit "MutableArray#") mutableArrayPrimTyConKey mutableArrayPrimTyCon
+mutableByteArrayPrimTyConName = mkPrimTc (fsLit "MutableByteArray#") mutableByteArrayPrimTyConKey mutableByteArrayPrimTyCon
+mutVarPrimTyConName = mkPrimTc (fsLit "MutVar#") mutVarPrimTyConKey mutVarPrimTyCon
+mVarPrimTyConName = mkPrimTc (fsLit "MVar#") mVarPrimTyConKey mVarPrimTyCon
+tVarPrimTyConName = mkPrimTc (fsLit "TVar#") tVarPrimTyConKey tVarPrimTyCon
+stablePtrPrimTyConName = mkPrimTc (fsLit "StablePtr#") stablePtrPrimTyConKey stablePtrPrimTyCon
+stableNamePrimTyConName = mkPrimTc (fsLit "StableName#") stableNamePrimTyConKey stableNamePrimTyCon
+bcoPrimTyConName = mkPrimTc (fsLit "BCO#") bcoPrimTyConKey bcoPrimTyCon
+weakPrimTyConName = mkPrimTc (fsLit "Weak#") weakPrimTyConKey weakPrimTyCon
+threadIdPrimTyConName = mkPrimTc (fsLit "ThreadId#") threadIdPrimTyConKey threadIdPrimTyCon
\end{code}
%************************************************************************
\begin{code}
tyVarList :: Kind -> [TyVar]
tyVarList kind = [ mkTyVar (mkInternalName (mkAlphaTyVarUnique u)
- (mkTyVarOcc (mkFastString name))
+ (mkTyVarOccFS (mkFastString name))
noSrcSpan) kind
| u <- [2..],
let name | c <= 'z' = [c]
where c = chr (u-2 + ord 'a')
]
+ecTyVars :: [TyVar]
+ecTyVars = tyVarList ecKind
+
alphaTyVars :: [TyVar]
alphaTyVars = tyVarList liftedTypeKind
+betaTyVars :: [TyVar]
betaTyVars = tail alphaTyVars
-alphaTyVar, betaTyVar, gammaTyVar :: TyVar
+alphaTyVar, betaTyVar, gammaTyVar, deltaTyVar :: TyVar
(alphaTyVar:betaTyVar:gammaTyVar:deltaTyVar:_) = alphaTyVars
+alphaTys :: [Type]
alphaTys = mkTyVarTys alphaTyVars
+alphaTy, betaTy, gammaTy, deltaTy :: Type
(alphaTy:betaTy:gammaTy:deltaTy:_) = alphaTys
-- openAlphaTyVar is prepared to be instantiated
-- to a lifted or unlifted type variable. It's used for the
-- result type for "error", so that we can have (error Int# "Help")
openAlphaTyVars :: [TyVar]
+openAlphaTyVar, openBetaTyVar :: TyVar
openAlphaTyVars@(openAlphaTyVar:openBetaTyVar:_) = tyVarList openTypeKind
+openAlphaTy, openBetaTy :: Type
openAlphaTy = mkTyVarTy openAlphaTyVar
-openBetaTy = mkTyVarTy openBetaTyVar
+openBetaTy = mkTyVarTy openBetaTyVar
+
+argAlphaTyVar, argBetaTyVar :: TyVar
+(argAlphaTyVar : argBetaTyVar : _) = tyVarList argTypeKind
+argAlphaTy, argBetaTy :: Type
+argAlphaTy = mkTyVarTy argAlphaTyVar
+argBetaTy = mkTyVarTy argBetaTyVar
+\end{code}
+
+
+%************************************************************************
+%* *
+ FunTyCon
+%* *
+%************************************************************************
+
+\begin{code}
+funTyConName :: Name
+funTyConName = mkPrimTyConName (fsLit "(->)") funTyConKey funTyCon
+
+funTyCon :: TyCon
+funTyCon = mkFunTyCon funTyConName (mkArrowKinds [argTypeKind, openTypeKind] liftedTypeKind)
+ -- You might think that (->) should have type (?? -> ? -> *), and you'd be right
+ -- But if we do that we get kind errors when saying
+ -- instance Control.Arrow (->)
+ -- becuase the expected kind is (*->*->*). The trouble is that the
+ -- expected/actual stuff in the unifier does not go contra-variant, whereas
+ -- the kind sub-typing does. Sigh. It really only matters if you use (->) in
+ -- a prefix way, thus: (->) Int# Int#. And this is unusual.
+ -- because they are never in scope in the source
+\end{code}
+
+
+%************************************************************************
+%* *
+ Kinds
+%* *
+%************************************************************************
+
+\begin{code}
+-- | See "Type#kind_subtyping" for details of the distinction between the 'Kind' 'TyCon's
+tySuperKindTyCon, liftedTypeKindTyCon,
+ openTypeKindTyCon, unliftedTypeKindTyCon,
+ ubxTupleKindTyCon, argTypeKindTyCon
+ :: TyCon
+tySuperKindTyConName, liftedTypeKindTyConName,
+ openTypeKindTyConName, unliftedTypeKindTyConName,
+ ubxTupleKindTyConName, argTypeKindTyConName
+ :: Name
+
+tySuperKindTyCon = mkSuperKindTyCon tySuperKindTyConName
+liftedTypeKindTyCon = mkKindTyCon liftedTypeKindTyConName tySuperKind
+openTypeKindTyCon = mkKindTyCon openTypeKindTyConName tySuperKind
+unliftedTypeKindTyCon = mkKindTyCon unliftedTypeKindTyConName tySuperKind
+ubxTupleKindTyCon = mkKindTyCon ubxTupleKindTyConName tySuperKind
+argTypeKindTyCon = mkKindTyCon argTypeKindTyConName tySuperKind
+
+--------------------------
+-- ... and now their names
+
+tySuperKindTyConName = mkPrimTyConName (fsLit "BOX") tySuperKindTyConKey tySuperKindTyCon
+liftedTypeKindTyConName = mkPrimTyConName (fsLit "*") liftedTypeKindTyConKey liftedTypeKindTyCon
+openTypeKindTyConName = mkPrimTyConName (fsLit "?") openTypeKindTyConKey openTypeKindTyCon
+unliftedTypeKindTyConName = mkPrimTyConName (fsLit "#") unliftedTypeKindTyConKey unliftedTypeKindTyCon
+ubxTupleKindTyConName = mkPrimTyConName (fsLit "(#)") ubxTupleKindTyConKey ubxTupleKindTyCon
+argTypeKindTyConName = mkPrimTyConName (fsLit "??") argTypeKindTyConKey argTypeKindTyCon
+
+mkPrimTyConName :: FastString -> Unique -> TyCon -> Name
+mkPrimTyConName occ key tycon = mkWiredInName gHC_PRIM (mkTcOccFS occ)
+ key
+ (ATyCon tycon)
+ BuiltInSyntax
+ -- All of the super kinds and kinds are defined in Prim and use BuiltInSyntax,
+ -- because they are never in scope in the source
\end{code}
+\begin{code}
+kindTyConType :: TyCon -> Type
+kindTyConType kind = TyConApp kind []
+
+-- | See "Type#kind_subtyping" for details of the distinction between these 'Kind's
+liftedTypeKind, unliftedTypeKind, openTypeKind, argTypeKind, ubxTupleKind :: Kind
+
+liftedTypeKind = kindTyConType liftedTypeKindTyCon
+unliftedTypeKind = kindTyConType unliftedTypeKindTyCon
+openTypeKind = kindTyConType openTypeKindTyCon
+argTypeKind = kindTyConType argTypeKindTyCon
+ubxTupleKind = kindTyConType ubxTupleKindTyCon
+
+-- | Given two kinds @k1@ and @k2@, creates the 'Kind' @k1 -> k2@
+mkArrowKind :: Kind -> Kind -> Kind
+mkArrowKind k1 k2 = FunTy k1 k2
+
+-- | Iterated application of 'mkArrowKind'
+mkArrowKinds :: [Kind] -> Kind -> Kind
+mkArrowKinds arg_kinds result_kind = foldr mkArrowKind result_kind arg_kinds
+
+tySuperKind :: SuperKind
+tySuperKind = kindTyConType tySuperKindTyCon
+\end{code}
+
%************************************************************************
%* *
\subsection[TysPrim-basic]{Basic primitive types (@Char#@, @Int#@, etc.)}
where
result_kind = unliftedTypeKind
+charPrimTy :: Type
charPrimTy = mkTyConTy charPrimTyCon
+charPrimTyCon :: TyCon
charPrimTyCon = pcPrimTyCon0 charPrimTyConName WordRep
+intPrimTy :: Type
intPrimTy = mkTyConTy intPrimTyCon
+intPrimTyCon :: TyCon
intPrimTyCon = pcPrimTyCon0 intPrimTyConName IntRep
+int32PrimTy :: Type
int32PrimTy = mkTyConTy int32PrimTyCon
+int32PrimTyCon :: TyCon
int32PrimTyCon = pcPrimTyCon0 int32PrimTyConName IntRep
+int64PrimTy :: Type
int64PrimTy = mkTyConTy int64PrimTyCon
+int64PrimTyCon :: TyCon
int64PrimTyCon = pcPrimTyCon0 int64PrimTyConName Int64Rep
+wordPrimTy :: Type
wordPrimTy = mkTyConTy wordPrimTyCon
+wordPrimTyCon :: TyCon
wordPrimTyCon = pcPrimTyCon0 wordPrimTyConName WordRep
+word32PrimTy :: Type
word32PrimTy = mkTyConTy word32PrimTyCon
+word32PrimTyCon :: TyCon
word32PrimTyCon = pcPrimTyCon0 word32PrimTyConName WordRep
+word64PrimTy :: Type
word64PrimTy = mkTyConTy word64PrimTyCon
+word64PrimTyCon :: TyCon
word64PrimTyCon = pcPrimTyCon0 word64PrimTyConName Word64Rep
+addrPrimTy :: Type
addrPrimTy = mkTyConTy addrPrimTyCon
+addrPrimTyCon :: TyCon
addrPrimTyCon = pcPrimTyCon0 addrPrimTyConName AddrRep
+floatPrimTy :: Type
floatPrimTy = mkTyConTy floatPrimTyCon
+floatPrimTyCon :: TyCon
floatPrimTyCon = pcPrimTyCon0 floatPrimTyConName FloatRep
+doublePrimTy :: Type
doublePrimTy = mkTyConTy doublePrimTyCon
+doublePrimTyCon :: TyCon
doublePrimTyCon = pcPrimTyCon0 doublePrimTyConName DoubleRep
\end{code}
%* *
%************************************************************************
+Note [The (~) TyCon)
+~~~~~~~~~~~~~~~~~~~~
+There is a perfectly ordinary type constructor (~) that represents the type
+of coercions (which, remember, are values). For example
+ Refl Int :: Int ~ Int
+
+Atcually it is not quite "perfectly ordinary" because it is kind-polymorphic:
+ Refl Maybe :: Maybe ~ Maybe
+
+So the true kind of (~) :: forall k. k -> k -> #. But we don't have
+polymorphic kinds (yet). However, (~) really only appears saturated in
+which case there is no problem in finding the kind of (ty1 ~ ty2). So
+we check that in CoreLint (and, in an assertion, in Kind.typeKind).
+
+Note [The State# TyCon]
+~~~~~~~~~~~~~~~~~~~~~~~
State# is the primitive, unlifted type of states. It has one type parameter,
thus
State# RealWorld
keep different state threads separate. It is represented by nothing at all.
\begin{code}
+mkStatePrimTy :: Type -> Type
mkStatePrimTy ty = mkTyConApp statePrimTyCon [ty]
+
+statePrimTyCon :: TyCon -- See Note [The State# TyCon]
statePrimTyCon = pcPrimTyCon statePrimTyConName 1 VoidRep
+
+eqPredPrimTyCon :: TyCon -- The representation type for equality predicates
+ -- See Note [The (~) TyCon]
+eqPredPrimTyCon = pcPrimTyCon eqPredPrimTyConName 2 VoidRep
\end{code}
RealWorld is deeply magical. It is *primitive*, but it is not
RealWorld; it's only used in the type system, to parameterise State#.
\begin{code}
+realWorldTyCon :: TyCon
realWorldTyCon = mkLiftedPrimTyCon realWorldTyConName liftedTypeKind 0 PtrRep
+realWorldTy :: Type
realWorldTy = mkTyConTy realWorldTyCon
+realWorldStatePrimTy :: Type
realWorldStatePrimTy = mkStatePrimTy realWorldTy -- State# RealWorld
\end{code}
Note: the ``state-pairing'' types are not truly primitive, so they are
defined in \tr{TysWiredIn.lhs}, not here.
-
-%************************************************************************
-%* *
- Any
-%* *
-%************************************************************************
-
-The type constructor Any is type to which you can unsafely coerce any
-lifted type, and back.
-
- * It is lifted, and hence represented by a pointer
-
- * It does not claim to be a *data* type, and that's important for
- the code generator, because the code gen may *enter* a data value
- but never enters a function value.
-
-It's also used to instantiate un-constrained type variables after type
-checking. For example
- lenth Any []
-Annoyingly, we sometimes need Anys of other kinds, such as (*->*) etc.
-This is a bit like tuples. We define a couple of useful ones here,
-and make others up on the fly. If any of these others end up being exported
-into interface files, we'll get a crash; at least until we add interface-file
-syntax to support them.
-
-\begin{code}
-anyPrimTy = mkTyConApp anyPrimTyCon []
-
-anyPrimTyCon :: TyCon -- Kind *
-anyPrimTyCon = mkLiftedPrimTyCon anyPrimTyConName liftedTypeKind 0 PtrRep
-
-anyPrimTyCon1 :: TyCon -- Kind *->*
-anyPrimTyCon1 = mkLiftedPrimTyCon anyPrimTyCon1Name kind 0 PtrRep
- where
- kind = mkArrowKind liftedTypeKind liftedTypeKind
-
-mkAnyPrimTyCon :: Unique -> Kind -> TyCon
--- Grotesque hack alert: the client gives the unique; so equality won't work
-mkAnyPrimTyCon uniq kind
- = pprTrace "Urk! Inventing strangely-kinded Any TyCon:" (ppr uniq <+> ppr kind)
- tycon
- where
- name = mkPrimTc (mkFastString ("Any" ++ showSDoc (pprUnique uniq))) uniq tycon
- tycon = mkLiftedPrimTyCon name kind 0 PtrRep
-\end{code}
-
-
%************************************************************************
%* *
\subsection[TysPrim-arrays]{The primitive array types}
%************************************************************************
\begin{code}
+arrayPrimTyCon, mutableArrayPrimTyCon, mutableByteArrayPrimTyCon,
+ byteArrayPrimTyCon :: TyCon
arrayPrimTyCon = pcPrimTyCon arrayPrimTyConName 1 PtrRep
mutableArrayPrimTyCon = pcPrimTyCon mutableArrayPrimTyConName 2 PtrRep
mutableByteArrayPrimTyCon = pcPrimTyCon mutableByteArrayPrimTyConName 1 PtrRep
byteArrayPrimTyCon = pcPrimTyCon0 byteArrayPrimTyConName PtrRep
+mkArrayPrimTy :: Type -> Type
mkArrayPrimTy elt = mkTyConApp arrayPrimTyCon [elt]
+byteArrayPrimTy :: Type
byteArrayPrimTy = mkTyConTy byteArrayPrimTyCon
+mkMutableArrayPrimTy :: Type -> Type -> Type
mkMutableArrayPrimTy s elt = mkTyConApp mutableArrayPrimTyCon [s, elt]
+mkMutableByteArrayPrimTy :: Type -> Type
mkMutableByteArrayPrimTy s = mkTyConApp mutableByteArrayPrimTyCon [s]
\end{code}
%************************************************************************
\begin{code}
+mutVarPrimTyCon :: TyCon
mutVarPrimTyCon = pcPrimTyCon mutVarPrimTyConName 2 PtrRep
+mkMutVarPrimTy :: Type -> Type -> Type
mkMutVarPrimTy s elt = mkTyConApp mutVarPrimTyCon [s, elt]
\end{code}
%************************************************************************
\begin{code}
+mVarPrimTyCon :: TyCon
mVarPrimTyCon = pcPrimTyCon mVarPrimTyConName 2 PtrRep
+mkMVarPrimTy :: Type -> Type -> Type
mkMVarPrimTy s elt = mkTyConApp mVarPrimTyCon [s, elt]
\end{code}
%************************************************************************
\begin{code}
+tVarPrimTyCon :: TyCon
tVarPrimTyCon = pcPrimTyCon tVarPrimTyConName 2 PtrRep
-mkTVarPrimTy s elt = mkTyConApp tVarPrimTyCon [s, elt]
+mkTVarPrimTy :: Type -> Type -> Type
+mkTVarPrimTy s elt = mkTyConApp tVarPrimTyCon [s, elt]
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
+stablePtrPrimTyCon :: TyCon
stablePtrPrimTyCon = pcPrimTyCon stablePtrPrimTyConName 1 AddrRep
+mkStablePtrPrimTy :: Type -> Type
mkStablePtrPrimTy ty = mkTyConApp stablePtrPrimTyCon [ty]
\end{code}
%************************************************************************
\begin{code}
+stableNamePrimTyCon :: TyCon
stableNamePrimTyCon = pcPrimTyCon stableNamePrimTyConName 1 PtrRep
+mkStableNamePrimTy :: Type -> Type
mkStableNamePrimTy ty = mkTyConApp stableNamePrimTyCon [ty]
\end{code}
%************************************************************************
\begin{code}
+bcoPrimTy :: Type
bcoPrimTy = mkTyConTy bcoPrimTyCon
+bcoPrimTyCon :: TyCon
bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName PtrRep
\end{code}
%************************************************************************
\begin{code}
+weakPrimTyCon :: TyCon
weakPrimTyCon = pcPrimTyCon weakPrimTyConName 1 PtrRep
+mkWeakPrimTy :: Type -> Type
mkWeakPrimTy v = mkTyConApp weakPrimTyCon [v]
\end{code}
to the thread id internally.
\begin{code}
+threadIdPrimTy :: Type
threadIdPrimTy = mkTyConTy threadIdPrimTyCon
+threadIdPrimTyCon :: TyCon
threadIdPrimTyCon = pcPrimTyCon0 threadIdPrimTyConName PtrRep
\end{code}
+
+
+
+%************************************************************************
+%* *
+ Any
+%* *
+%************************************************************************
+
+Note [Any types]
+~~~~~~~~~~~~~~~~
+The type constructor Any::* has these properties
+
+ * It is defined in module GHC.Prim, and exported so that it is
+ available to users. For this reason it's treated like any other
+ primitive type:
+ - has a fixed unique, anyTyConKey,
+ - lives in the global name cache
+ - built with TyCon.PrimTyCon
+
+ * It is lifted, and hence represented by a pointer
+
+ * It is inhabited by at least one value, namely bottom
+
+ * You can unsafely coerce any lifted type to Ayny, and back.
+
+ * It does not claim to be a *data* type, and that's important for
+ the code generator, because the code gen may *enter* a data value
+ but never enters a function value.
+
+ * It is used to instantiate otherwise un-constrained type variables of kind *
+ For example length Any []
+ See Note [Strangely-kinded void TyCons]
+
+In addition, we have a potentially-infinite family of types, one for
+each kind /other than/ *, needed to instantiate otherwise
+un-constrained type variables of kinds other than *. This is a bit
+like tuples; there is a potentially-infinite family. They have slightly
+different characteristics to Any::*:
+
+ * They are built with TyCon.AnyTyCon
+ * They have non-user-writable names like "Any(*->*)"
+ * They are not exported by GHC.Prim
+ * They are uninhabited (of course; not kind *)
+ * They have a unique derived from their OccName (see Note [Uniques of Any])
+ * Their Names do not live in the global name cache
+
+Note [Uniques of Any]
+~~~~~~~~~~~~~~~~~~~~~
+Although Any(*->*), say, doesn't have a binding site, it still needs
+to have a Unique. Unlike tuples (which are also an infinite family)
+there is no convenient way to index them, so we use the Unique from
+their OccName instead. That should be unique,
+ - both wrt each other, because their strings differ
+
+ - and wrt any other Name, because Names get uniques with
+ various 'char' tags, but the OccName of Any will
+ get a Unique built with mkTcOccUnique, which has a particular 'char'
+ tag; see Unique.mkTcOccUnique!
+
+Note [Strangely-kinded void TyCons]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+See Trac #959 for more examples
+
+When the type checker finds a type variable with no binding, which
+means it can be instantiated with an arbitrary type, it usually
+instantiates it to Void. Eg.
+
+ length []
+===>
+ length Any (Nil Any)
+
+But in really obscure programs, the type variable might have a kind
+other than *, so we need to invent a suitably-kinded type.
+
+This commit uses
+ Any for kind *
+ Any(*->*) for kind *->*
+ etc
+
+\begin{code}
+anyTyConName :: Name
+anyTyConName = mkPrimTc (fsLit "Any") anyTyConKey anyTyCon
+
+anyTyCon :: TyCon
+anyTyCon = mkLiftedPrimTyCon anyTyConName liftedTypeKind 0 PtrRep
+
+anyTypeOfKind :: Kind -> Type
+anyTypeOfKind kind = mkTyConApp (anyTyConOfKind kind) []
+
+anyTyConOfKind :: Kind -> TyCon
+-- Map all superkinds of liftedTypeKind to liftedTypeKind
+anyTyConOfKind kind
+ | isLiftedTypeKind kind = anyTyCon
+ | otherwise = tycon
+ where
+ -- Derive the name from the kind, thus:
+ -- Any(*->*), Any(*->*->*)
+ -- These are names that can't be written by the user,
+ -- and are not allocated in the global name cache
+ str = "Any" ++ showSDoc (pprParendKind kind)
+
+ occ = mkTcOcc str
+ uniq = getUnique occ -- See Note [Uniques of Any]
+ name = mkWiredInName gHC_PRIM occ uniq (ATyCon tycon) UserSyntax
+ tycon = mkAnyTyCon name kind
+\end{code}
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