prelude/TysPrim.lhs

% % (c) The AQUA Project, Glasgow University, 1994-1998 % \section[TysPrim]{Wired-in knowledge about primitive types} \begin{code}

    {-# OPTIONS -fno-warn-tabs #-}
    -- The above warning supression flag is a temporary kludge.
    -- While working on this module you are encouraged to remove it and
    -- detab the module (please do the detabbing in a separate patch). See
    --     http://ghc.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
    -- 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(
    	mkPrimTyConName, -- For implicit parameters in TysWiredIn only

            tyVarList, alphaTyVars, betaTyVars, alphaTyVar, betaTyVar, gammaTyVar, deltaTyVar,
    	alphaTy, betaTy, gammaTy, deltaTy,
    	openAlphaTy, openBetaTy, openAlphaTyVar, openBetaTyVar, openAlphaTyVars,
            kKiVar,

            -- Kind constructors...
            superKindTyCon, superKind, anyKindTyCon, liftedTypeKindTyCon,
            openTypeKindTyCon, unliftedTypeKindTyCon, constraintKindTyCon,

            superKindTyConName, anyKindTyConName, liftedTypeKindTyConName,
            openTypeKindTyConName, unliftedTypeKindTyConName,
            constraintKindTyConName,

            -- Kinds
    	anyKind, liftedTypeKind, unliftedTypeKind, openTypeKind, constraintKind,
            mkArrowKind, mkArrowKinds,

            funTyCon, funTyConName,
            primTyCons,

    	charPrimTyCon, 		charPrimTy,
    	intPrimTyCon,		intPrimTy,
    	wordPrimTyCon,		wordPrimTy,
    	addrPrimTyCon,		addrPrimTy,
    	floatPrimTyCon,		floatPrimTy,
    	doublePrimTyCon,	doublePrimTy,

    	voidPrimTyCon,		voidPrimTy,
    	statePrimTyCon,		mkStatePrimTy,
    	realWorldTyCon,		realWorldTy, realWorldStatePrimTy,

    	proxyPrimTyCon,		mkProxyPrimTy,

    	arrayPrimTyCon,	mkArrayPrimTy,
    	byteArrayPrimTyCon,	byteArrayPrimTy,
    	arrayArrayPrimTyCon, mkArrayArrayPrimTy,
    	mutableArrayPrimTyCon, mkMutableArrayPrimTy,
    	mutableByteArrayPrimTyCon, mkMutableByteArrayPrimTy,
    	mutableArrayArrayPrimTyCon, mkMutableArrayArrayPrimTy,
    	mutVarPrimTyCon, mkMutVarPrimTy,

    	mVarPrimTyCon,			mkMVarPrimTy,
            tVarPrimTyCon,                  mkTVarPrimTy,
    	stablePtrPrimTyCon,		mkStablePtrPrimTy,
    	stableNamePrimTyCon,		mkStableNamePrimTy,
    	bcoPrimTyCon,			bcoPrimTy,
    	weakPrimTyCon,  		mkWeakPrimTy,
    	threadIdPrimTyCon,		threadIdPrimTy,

    	int32PrimTyCon,		int32PrimTy,
    	word32PrimTyCon,	word32PrimTy,

    	int64PrimTyCon,		int64PrimTy,
            word64PrimTyCon,        word64PrimTy,

            eqPrimTyCon,            -- ty1 ~# ty2
            eqReprPrimTyCon,        -- ty1 ~R# ty2  (at role Representational)

    	-- * Any
    	anyTy, anyTyCon, anyTypeOfKind,

    	-- * SIMD
    #include "primop-vector-tys-exports.hs-incl"
      ) where

    #include "HsVersions.h"

    import Var		( TyVar, KindVar, mkTyVar )
    import Name		( Name, BuiltInSyntax(..), mkInternalName, mkWiredInName )
    import OccName          ( mkTyVarOccFS, mkTcOccFS )
    import TyCon
    import TypeRep
    import SrcLoc
    import Unique		( mkAlphaTyVarUnique )
    import PrelNames
    import FastString

    import Data.Char

\end{code} %************************************************************************ %* * \subsection{Primitive type constructors} %* * %************************************************************************ \begin{code}

    primTyCons :: [TyCon]
    primTyCons
      = [ addrPrimTyCon
        , arrayPrimTyCon
        , byteArrayPrimTyCon
        , arrayArrayPrimTyCon
        , charPrimTyCon
        , doublePrimTyCon
        , floatPrimTyCon
        , intPrimTyCon
        , int32PrimTyCon
        , int64PrimTyCon
        , bcoPrimTyCon
        , weakPrimTyCon
        , mutableArrayPrimTyCon
        , mutableByteArrayPrimTyCon
        , mutableArrayArrayPrimTyCon
        , mVarPrimTyCon
        , tVarPrimTyCon
        , mutVarPrimTyCon
        , realWorldTyCon
        , stablePtrPrimTyCon
        , stableNamePrimTyCon
        , statePrimTyCon
        , voidPrimTyCon
        , proxyPrimTyCon
        , threadIdPrimTyCon
        , wordPrimTyCon
        , word32PrimTyCon
        , word64PrimTyCon
        , anyTyCon
        , eqPrimTyCon
        , eqReprPrimTyCon

        , liftedTypeKindTyCon
        , unliftedTypeKindTyCon
        , openTypeKindTyCon
        , constraintKindTyCon
        , superKindTyCon
        , anyKindTyCon

    #include "primop-vector-tycons.hs-incl"
        ]

    mkPrimTc :: FastString -> Unique -> TyCon -> Name
    mkPrimTc fs unique tycon
      = mkWiredInName gHC_PRIM (mkTcOccFS fs)
    		  unique
    		  (ATyCon tycon)	-- Relevant TyCon
    		  UserSyntax		-- None are built-in syntax

    charPrimTyConName, intPrimTyConName, int32PrimTyConName, int64PrimTyConName, wordPrimTyConName, word32PrimTyConName, word64PrimTyConName, addrPrimTyConName, floatPrimTyConName, doublePrimTyConName, statePrimTyConName, proxyPrimTyConName, realWorldTyConName, arrayPrimTyConName, arrayArrayPrimTyConName, byteArrayPrimTyConName, mutableArrayPrimTyConName, mutableByteArrayPrimTyConName, mutableArrayArrayPrimTyConName, mutVarPrimTyConName, mVarPrimTyConName, tVarPrimTyConName, stablePtrPrimTyConName, stableNamePrimTyConName, bcoPrimTyConName, weakPrimTyConName, threadIdPrimTyConName, eqPrimTyConName, eqReprPrimTyConName, voidPrimTyConName :: 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
    voidPrimTyConName             = mkPrimTc (fsLit "Void#") voidPrimTyConKey voidPrimTyCon
    proxyPrimTyConName            = mkPrimTc (fsLit "Proxy#") proxyPrimTyConKey proxyPrimTyCon
    eqPrimTyConName               = mkPrimTc (fsLit "~#") eqPrimTyConKey eqPrimTyCon
    eqReprPrimTyConName           = mkPrimTc (fsLit "~R#") eqReprPrimTyConKey eqReprPrimTyCon
    realWorldTyConName            = mkPrimTc (fsLit "RealWorld") realWorldTyConKey realWorldTyCon
    arrayPrimTyConName   	      = mkPrimTc (fsLit "Array#") arrayPrimTyConKey arrayPrimTyCon
    byteArrayPrimTyConName	      = mkPrimTc (fsLit "ByteArray#") byteArrayPrimTyConKey byteArrayPrimTyCon
    arrayArrayPrimTyConName   	  = mkPrimTc (fsLit "ArrayArray#") arrayArrayPrimTyConKey arrayArrayPrimTyCon
    mutableArrayPrimTyConName     = mkPrimTc (fsLit "MutableArray#") mutableArrayPrimTyConKey mutableArrayPrimTyCon
    mutableByteArrayPrimTyConName = mkPrimTc (fsLit "MutableByteArray#") mutableByteArrayPrimTyConKey mutableByteArrayPrimTyCon
    mutableArrayArrayPrimTyConName= mkPrimTc (fsLit "MutableArrayArray#") mutableArrayArrayPrimTyConKey mutableArrayArrayPrimTyCon
    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} %************************************************************************ %* * \subsection{Support code} %* * %************************************************************************ alphaTyVars is a list of type variables for use in templates: ["a", "b", ..., "z", "t1", "t2", ... ] \begin{code}

    tyVarList :: Kind -> [TyVar]
    tyVarList kind = [ mkTyVar (mkInternalName (mkAlphaTyVarUnique u)
    				(mkTyVarOccFS (mkFastString name))
    			 	noSrcSpan) kind
    	         | u <- [2..],
    		   let name | c <= 'z'  = [c]
    		            | otherwise = 't':show u
    			    where c = chr (u-2 + ord 'a')
    	         ]

    alphaTyVars :: [TyVar]
    alphaTyVars = tyVarList liftedTypeKind

    betaTyVars :: [TyVar]
    betaTyVars = tail alphaTyVars

    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

    kKiVar :: KindVar
    kKiVar = (tyVarList superKind) !! 10

\end{code} %************************************************************************ %* * FunTyCon %* * %************************************************************************ \begin{code}

    funTyConName :: Name
    funTyConName = mkPrimTyConName (fsLit "(->)") funTyConKey funTyCon

    funTyCon :: TyCon
    funTyCon = mkFunTyCon funTyConName $
               mkArrowKinds [liftedTypeKind, liftedTypeKind] 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 (->)
    	-- because 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

    -- One step to remove subkinding.
    -- (->) :: * -> * -> *
    -- but we should have (and want) the following typing rule for fully applied arrows
    --      Gamma |- tau   :: k1    k1 in {*, #}
    --      Gamma |- sigma :: k2    k2 in {*, #, (#)}
    --      -----------------------------------------
    --      Gamma |- tau -> sigma :: *
    -- Currently we have the following rule which achieves more or less the same effect
    --      Gamma |- tau   :: ??
    --      Gamma |- sigma :: ?
    --      --------------------------
    --      Gamma |- tau -> sigma :: *
    -- In the end we don't want subkinding at all.

\end{code} %************************************************************************ %* * Kinds %* * %************************************************************************ Note [SuperKind (BOX)] ~~~~~~~~~~~~~~~~~~~~~~ Kinds are classified by "super-kinds". There is only one super-kind, namely BOX. Perhaps surprisingly we give BOX the kind BOX, thus BOX :: BOX Reason: we want to have kind equalities, thus (without the kind applications) keq :: * ~ * = Eq# Remember that (~) :: forall (k:BOX). k -> k -> Constraint (~#) :: forall (k:BOX). k -> k -> # Eq# :: forall (k:BOX). forall (a:k) (b:k). (~#) k a b -> (~) k a b So the full defn of keq is keq :: (~) BOX * * = Eq# BOX * * So you can see it's convenient to have BOX:BOX \begin{code}

    -- | See "Type#kind_subtyping" for details of the distinction between the 'Kind' 'TyCon's
    superKindTyCon, anyKindTyCon, liftedTypeKindTyCon,
          openTypeKindTyCon, unliftedTypeKindTyCon,
          constraintKindTyCon
       :: TyCon
    superKindTyConName, anyKindTyConName, liftedTypeKindTyConName,
          openTypeKindTyConName, unliftedTypeKindTyConName,
          constraintKindTyConName
       :: Name

    superKindTyCon        = mkKindTyCon superKindTyConName        superKind
       -- See Note [SuperKind (BOX)]

    anyKindTyCon          = mkKindTyCon anyKindTyConName          superKind
    liftedTypeKindTyCon   = mkKindTyCon liftedTypeKindTyConName   superKind
    openTypeKindTyCon     = mkKindTyCon openTypeKindTyConName     superKind
    unliftedTypeKindTyCon = mkKindTyCon unliftedTypeKindTyConName superKind
    constraintKindTyCon   = mkKindTyCon constraintKindTyConName   superKind

    --------------------------
    -- ... and now their names

    -- If you edit these, you may need to update the GHC formalism
    -- See Note [GHC Formalism] in coreSyn/CoreLint.lhs
    superKindTyConName      = mkPrimTyConName (fsLit "BOX") superKindTyConKey superKindTyCon
    anyKindTyConName          = mkPrimTyConName (fsLit "AnyK") anyKindTyConKey anyKindTyCon
    liftedTypeKindTyConName   = mkPrimTyConName (fsLit "*") liftedTypeKindTyConKey liftedTypeKindTyCon
    openTypeKindTyConName     = mkPrimTyConName (fsLit "OpenKind") openTypeKindTyConKey openTypeKindTyCon
    unliftedTypeKindTyConName = mkPrimTyConName (fsLit "#") unliftedTypeKindTyConKey unliftedTypeKindTyCon
    constraintKindTyConName   = mkPrimTyConName (fsLit "Constraint") constraintKindTyConKey constraintKindTyCon

    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 []   -- mkTyConApp isn't defined yet

    -- | See "Type#kind_subtyping" for details of the distinction between these 'Kind's
    anyKind, liftedTypeKind, unliftedTypeKind, openTypeKind, constraintKind, superKind :: Kind

    superKind        = kindTyConType superKindTyCon
    anyKind          = kindTyConType anyKindTyCon  -- See Note [Any kinds]
    liftedTypeKind   = kindTyConType liftedTypeKindTyCon
    unliftedTypeKind = kindTyConType unliftedTypeKindTyCon
    openTypeKind     = kindTyConType openTypeKindTyCon
    constraintKind   = kindTyConType constraintKindTyCon

    -- | 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

\end{code} %************************************************************************ %* * \subsection[TysPrim-basic]{Basic primitive types (@Char#@, @Int#@, etc.)} %* * %************************************************************************ \begin{code}

    -- only used herein
    pcPrimTyCon :: Name -> [Role] -> PrimRep -> TyCon
    pcPrimTyCon name roles rep
      = mkPrimTyCon name kind roles rep
      where
        kind        = mkArrowKinds (map (const liftedTypeKind) roles) result_kind
        result_kind = unliftedTypeKind

    pcPrimTyCon0 :: Name -> PrimRep -> TyCon
    pcPrimTyCon0 name rep
      = mkPrimTyCon name result_kind [] rep
      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} %************************************************************************ %* * \subsection[TysPrim-state]{The @State#@ type (and @_RealWorld@ types)} %* * %************************************************************************ 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 It is a kind-polymorphic type constructor like Any: Refl Maybe :: ~# (* -> *) Maybe Maybe (~) only appears saturated. 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 or State# s where s is a type variable. The only purpose of the type parameter is to keep different state threads separate. It is represented by nothing at all. The type parameter to State# is intended to keep separate threads separate. Even though this parameter is not used in the definition of State#, it is given role Nominal to enforce its intended use. \begin{code}

    mkStatePrimTy :: Type -> Type
    mkStatePrimTy ty = TyConApp statePrimTyCon [ty]

    statePrimTyCon :: TyCon   -- See Note [The State# TyCon]
    statePrimTyCon	 = pcPrimTyCon statePrimTyConName [Nominal] VoidRep

    voidPrimTy :: Type
    voidPrimTy = TyConApp voidPrimTyCon []

    voidPrimTyCon :: TyCon
    voidPrimTyCon	 = pcPrimTyCon voidPrimTyConName [] VoidRep

    mkProxyPrimTy :: Type -> Type -> Type
    mkProxyPrimTy k ty = TyConApp proxyPrimTyCon [k, ty]

    proxyPrimTyCon :: TyCon
    proxyPrimTyCon = mkPrimTyCon proxyPrimTyConName kind [Nominal,Nominal] VoidRep
      where kind = ForAllTy kv $ mkArrowKind k unliftedTypeKind
            kv   = kKiVar
            k    = mkTyVarTy kv

    eqPrimTyCon :: TyCon  -- The representation type for equality predicates
    		      -- See Note [The ~# TyCon]
    eqPrimTyCon  = mkPrimTyCon eqPrimTyConName kind [Nominal, Nominal, Nominal] VoidRep
      where kind = ForAllTy kv $ mkArrowKinds [k, k] unliftedTypeKind
            kv = kKiVar
            k = mkTyVarTy kv

    -- like eqPrimTyCon, but the type for *Representational* coercions
    -- this should only ever appear as the type of a covar. Its role is
    -- interpreted in coercionRole
    eqReprPrimTyCon :: TyCon
    eqReprPrimTyCon = mkPrimTyCon eqReprPrimTyConName kind
                                      -- the roles really should be irrelevant!
                                  [Nominal, Representational, Representational] VoidRep
      where kind = ForAllTy kv $ mkArrowKinds [k, k] unliftedTypeKind
            kv = kKiVar
            k  = mkTyVarTy kv

\end{code} RealWorld is deeply magical. It is *primitive*, but it is not *unlifted* (hence ptrArg). We never manipulate values of type RealWorld; it's only used in the type system, to parameterise State#. \begin{code}

    realWorldTyCon :: TyCon
    realWorldTyCon = mkLiftedPrimTyCon realWorldTyConName liftedTypeKind [] 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. %************************************************************************ %* * \subsection[TysPrim-arrays]{The primitive array types} %* * %************************************************************************ \begin{code}

    arrayPrimTyCon, mutableArrayPrimTyCon, mutableByteArrayPrimTyCon,
        byteArrayPrimTyCon, arrayArrayPrimTyCon, mutableArrayArrayPrimTyCon :: TyCon
    arrayPrimTyCon             = pcPrimTyCon arrayPrimTyConName             [Representational] PtrRep
    mutableArrayPrimTyCon      = pcPrimTyCon  mutableArrayPrimTyConName     [Nominal, Representational] PtrRep
    mutableByteArrayPrimTyCon  = pcPrimTyCon mutableByteArrayPrimTyConName  [Nominal] PtrRep
    byteArrayPrimTyCon         = pcPrimTyCon0 byteArrayPrimTyConName        PtrRep
    arrayArrayPrimTyCon        = pcPrimTyCon0 arrayArrayPrimTyConName       PtrRep
    mutableArrayArrayPrimTyCon = pcPrimTyCon mutableArrayArrayPrimTyConName [Nominal] PtrRep

    mkArrayPrimTy :: Type -> Type
    mkArrayPrimTy elt    	    = TyConApp arrayPrimTyCon [elt]
    byteArrayPrimTy :: Type
    byteArrayPrimTy	    	    = mkTyConTy byteArrayPrimTyCon
    mkArrayArrayPrimTy :: Type
    mkArrayArrayPrimTy = mkTyConTy arrayArrayPrimTyCon
    mkMutableArrayPrimTy :: Type -> Type -> Type
    mkMutableArrayPrimTy s elt  = TyConApp mutableArrayPrimTyCon [s, elt]
    mkMutableByteArrayPrimTy :: Type -> Type
    mkMutableByteArrayPrimTy s  = TyConApp mutableByteArrayPrimTyCon [s]
    mkMutableArrayArrayPrimTy :: Type -> Type
    mkMutableArrayArrayPrimTy s = TyConApp mutableArrayArrayPrimTyCon [s]

\end{code} %************************************************************************ %* * \subsection[TysPrim-mut-var]{The mutable variable type} %* * %************************************************************************ \begin{code}

    mutVarPrimTyCon :: TyCon
    mutVarPrimTyCon = pcPrimTyCon mutVarPrimTyConName [Nominal, Representational] PtrRep

    mkMutVarPrimTy :: Type -> Type -> Type
    mkMutVarPrimTy s elt 	    = TyConApp mutVarPrimTyCon [s, elt]

\end{code} %************************************************************************ %* * \subsection[TysPrim-synch-var]{The synchronizing variable type} %* * %************************************************************************ \begin{code}

    mVarPrimTyCon :: TyCon
    mVarPrimTyCon = pcPrimTyCon mVarPrimTyConName [Nominal, Representational] PtrRep

    mkMVarPrimTy :: Type -> Type -> Type
    mkMVarPrimTy s elt 	    = TyConApp mVarPrimTyCon [s, elt]

\end{code} %************************************************************************ %* * \subsection[TysPrim-stm-var]{The transactional variable type} %* * %************************************************************************ \begin{code}

    tVarPrimTyCon :: TyCon
    tVarPrimTyCon = pcPrimTyCon tVarPrimTyConName [Nominal, Representational] PtrRep

    mkTVarPrimTy :: Type -> Type -> Type
    mkTVarPrimTy s elt = TyConApp tVarPrimTyCon [s, elt]

\end{code} %************************************************************************ %* * \subsection[TysPrim-stable-ptrs]{The stable-pointer type} %* * %************************************************************************ \begin{code}

    stablePtrPrimTyCon :: TyCon
    stablePtrPrimTyCon = pcPrimTyCon stablePtrPrimTyConName [Representational] AddrRep

    mkStablePtrPrimTy :: Type -> Type
    mkStablePtrPrimTy ty = TyConApp stablePtrPrimTyCon [ty]

\end{code} %************************************************************************ %* * \subsection[TysPrim-stable-names]{The stable-name type} %* * %************************************************************************ \begin{code}

    stableNamePrimTyCon :: TyCon
    stableNamePrimTyCon = pcPrimTyCon stableNamePrimTyConName [Representational] PtrRep

    mkStableNamePrimTy :: Type -> Type
    mkStableNamePrimTy ty = TyConApp stableNamePrimTyCon [ty]

\end{code} %************************************************************************ %* * \subsection[TysPrim-BCOs]{The ``bytecode object'' type} %* * %************************************************************************ \begin{code}

    bcoPrimTy    :: Type
    bcoPrimTy    = mkTyConTy bcoPrimTyCon
    bcoPrimTyCon :: TyCon
    bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName PtrRep

\end{code} %************************************************************************ %* * \subsection[TysPrim-Weak]{The ``weak pointer'' type} %* * %************************************************************************ \begin{code}

    weakPrimTyCon :: TyCon
    weakPrimTyCon = pcPrimTyCon weakPrimTyConName [Representational] PtrRep

    mkWeakPrimTy :: Type -> Type
    mkWeakPrimTy v = TyConApp weakPrimTyCon [v]

\end{code} %************************************************************************ %* * \subsection[TysPrim-thread-ids]{The ``thread id'' type} %* * %************************************************************************ A thread id is represented by a pointer to the TSO itself, to ensure that they are always unique and we can always find the TSO for a given thread id. However, this has the unfortunate consequence that a ThreadId# for a given thread is treated as a root by the garbage collector and can keep TSOs around for too long. Hence the programmer API for thread manipulation uses a weak pointer 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 of kind forall k. k -> k 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 * It is a *closed* type family, with no instances. This means that if ty :: '(k1, k2) we add a given coercion g :: ty ~ (Fst ty, Snd ty) If Any was a *data* type, then we'd get inconsistency because 'ty' could be (Any '(k1,k2)) and then we'd have an equality with Any on one side and '(,) on the other * 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 Any, 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 For example length Any [] See Note [Strangely-kinded void TyCons] Note [Any kinds] ~~~~~~~~~~~~~~~~ The type constructor AnyK (of sort BOX) is used internally only to zonk kind variables with no constraints on them. It appears in similar circumstances to Any, but at the kind level. For example: type family Length (l :: [k]) :: Nat type instance Length [] = Zero Length is kind-polymorphic, and when applied to the empty (promoted) list it will have the kind Length AnyK []. 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

    anyTy :: Type
    anyTy = mkTyConTy anyTyCon

    anyTyCon :: TyCon
    anyTyCon = mkLiftedPrimTyCon anyTyConName kind [Nominal] PtrRep
      where kind = ForAllTy kKiVar (mkTyVarTy kKiVar)

    {-   Can't do this yet without messing up kind proxies
    -- RAE: I think you can now.
    anyTyCon :: TyCon
    anyTyCon = mkSynTyCon anyTyConName kind [kKiVar]
                          syn_rhs
                          NoParentTyCon
      where
        kind = ForAllTy kKiVar (mkTyVarTy kKiVar)
        syn_rhs = SynFamilyTyCon { synf_open = False, synf_injective = True }
                      -- NB Closed, injective
    -}

    anyTypeOfKind :: Kind -> Type
    anyTypeOfKind kind = TyConApp anyTyCon [kind]

\end{code} %************************************************************************ %* * \subsection{SIMD vector types} %* * %************************************************************************ \begin{code}

    #include "primop-vector-tys.hs-incl"

\end{code}