2 % (c) The AQUA Project, Glasgow University, 1994-1998
4 \section[TysPrim]{Wired-in knowledge about primitive types}
8 alphaTyVars, betaTyVars, alphaTyVar, betaTyVar, gammaTyVar, deltaTyVar,
9 alphaTy, betaTy, gammaTy, deltaTy,
10 openAlphaTy, openAlphaTyVar, openAlphaTyVars,
14 charPrimTyCon, charPrimTy,
15 intPrimTyCon, intPrimTy,
16 wordPrimTyCon, wordPrimTy,
17 addrPrimTyCon, addrPrimTy,
18 floatPrimTyCon, floatPrimTy,
19 doublePrimTyCon, doublePrimTy,
21 statePrimTyCon, mkStatePrimTy,
22 realWorldTyCon, realWorldTy, realWorldStatePrimTy,
24 arrayPrimTyCon, mkArrayPrimTy,
25 byteArrayPrimTyCon, byteArrayPrimTy,
26 mutableArrayPrimTyCon, mkMutableArrayPrimTy,
27 mutableByteArrayPrimTyCon, mkMutableByteArrayPrimTy,
28 mutVarPrimTyCon, mkMutVarPrimTy,
30 mVarPrimTyCon, mkMVarPrimTy,
31 stablePtrPrimTyCon, mkStablePtrPrimTy,
32 stableNamePrimTyCon, mkStableNamePrimTy,
33 bcoPrimTyCon, bcoPrimTy,
34 weakPrimTyCon, mkWeakPrimTy,
35 foreignObjPrimTyCon, foreignObjPrimTy,
36 threadIdPrimTyCon, threadIdPrimTy,
38 int32PrimTyCon, int32PrimTy,
39 word32PrimTyCon, word32PrimTy,
41 int64PrimTyCon, int64PrimTy,
42 word64PrimTyCon, word64PrimTy
45 #include "HsVersions.h"
47 import Var ( TyVar, mkTyVar )
48 import Name ( Name, mkInternalName, mkWiredInName )
49 import OccName ( mkVarOcc, mkOccFS, tcName )
50 import PrimRep ( PrimRep(..) )
51 import TyCon ( TyCon, ArgVrcs, mkPrimTyCon, mkLiftedPrimTyCon )
52 import Type ( mkTyConApp, mkTyConTy, mkTyVarTys, mkTyVarTy,
53 unliftedTypeKind, liftedTypeKind, openTypeKind,
57 import SrcLoc ( noSrcLoc )
58 import Unique ( mkAlphaTyVarUnique )
60 import FastString ( FastString, mkFastString )
63 import Char ( ord, chr )
66 %************************************************************************
68 \subsection{Primitive type constructors}
70 %************************************************************************
87 , mutableArrayPrimTyCon
88 , mutableByteArrayPrimTyCon
101 mkPrimTc :: FastString -> Unique -> TyCon -> Name
102 mkPrimTc fs uniq tycon
103 = mkWiredInName gHC_PRIM (mkOccFS tcName fs)
105 Nothing -- No parent object
106 (ATyCon tycon) -- Relevant TyCon
108 charPrimTyConName = mkPrimTc FSLIT("Char#") charPrimTyConKey charPrimTyCon
109 intPrimTyConName = mkPrimTc FSLIT("Int#") intPrimTyConKey intPrimTyCon
110 int32PrimTyConName = mkPrimTc FSLIT("Int32#") int32PrimTyConKey int32PrimTyCon
111 int64PrimTyConName = mkPrimTc FSLIT("Int64#") int64PrimTyConKey int64PrimTyCon
112 wordPrimTyConName = mkPrimTc FSLIT("Word#") wordPrimTyConKey wordPrimTyCon
113 word32PrimTyConName = mkPrimTc FSLIT("Word32#") word32PrimTyConKey word32PrimTyCon
114 word64PrimTyConName = mkPrimTc FSLIT("Word64#") word64PrimTyConKey word64PrimTyCon
115 addrPrimTyConName = mkPrimTc FSLIT("Addr#") addrPrimTyConKey addrPrimTyCon
116 floatPrimTyConName = mkPrimTc FSLIT("Float#") floatPrimTyConKey floatPrimTyCon
117 doublePrimTyConName = mkPrimTc FSLIT("Double#") doublePrimTyConKey doublePrimTyCon
118 statePrimTyConName = mkPrimTc FSLIT("State#") statePrimTyConKey statePrimTyCon
119 realWorldTyConName = mkPrimTc FSLIT("RealWorld") realWorldTyConKey realWorldTyCon
120 arrayPrimTyConName = mkPrimTc FSLIT("Array#") arrayPrimTyConKey arrayPrimTyCon
121 byteArrayPrimTyConName = mkPrimTc FSLIT("ByteArray#") byteArrayPrimTyConKey byteArrayPrimTyCon
122 mutableArrayPrimTyConName = mkPrimTc FSLIT("MutableArray#") mutableArrayPrimTyConKey mutableArrayPrimTyCon
123 mutableByteArrayPrimTyConName = mkPrimTc FSLIT("MutableByteArray#") mutableByteArrayPrimTyConKey mutableByteArrayPrimTyCon
124 mutVarPrimTyConName = mkPrimTc FSLIT("MutVar#") mutVarPrimTyConKey mutVarPrimTyCon
125 mVarPrimTyConName = mkPrimTc FSLIT("MVar#") mVarPrimTyConKey mVarPrimTyCon
126 stablePtrPrimTyConName = mkPrimTc FSLIT("StablePtr#") stablePtrPrimTyConKey stablePtrPrimTyCon
127 stableNamePrimTyConName = mkPrimTc FSLIT("StableName#") stableNamePrimTyConKey stableNamePrimTyCon
128 foreignObjPrimTyConName = mkPrimTc FSLIT("ForeignObj#") foreignObjPrimTyConKey foreignObjPrimTyCon
129 bcoPrimTyConName = mkPrimTc FSLIT("BCO#") bcoPrimTyConKey bcoPrimTyCon
130 weakPrimTyConName = mkPrimTc FSLIT("Weak#") weakPrimTyConKey weakPrimTyCon
131 threadIdPrimTyConName = mkPrimTc FSLIT("ThreadId#") threadIdPrimTyConKey threadIdPrimTyCon
134 %************************************************************************
136 \subsection{Support code}
138 %************************************************************************
140 alphaTyVars is a list of type variables for use in templates:
141 ["a", "b", ..., "z", "t1", "t2", ... ]
144 tyVarList :: Kind -> [TyVar]
145 tyVarList kind = [ mkTyVar (mkInternalName (mkAlphaTyVarUnique u)
146 (mkVarOcc (mkFastString name))
149 let name | c <= 'z' = [c]
150 | otherwise = 't':show u
151 where c = chr (u-2 + ord 'a')
154 alphaTyVars :: [TyVar]
155 alphaTyVars = tyVarList liftedTypeKind
157 betaTyVars = tail alphaTyVars
159 alphaTyVar, betaTyVar, gammaTyVar :: TyVar
160 (alphaTyVar:betaTyVar:gammaTyVar:deltaTyVar:_) = alphaTyVars
162 alphaTys = mkTyVarTys alphaTyVars
163 (alphaTy:betaTy:gammaTy:deltaTy:_) = alphaTys
165 -- openAlphaTyVar is prepared to be instantiated
166 -- to a lifted or unlifted type variable. It's used for the
167 -- result type for "error", so that we can have (error Int# "Help")
168 openAlphaTyVars :: [TyVar]
169 openAlphaTyVars@(openAlphaTyVar:_) = tyVarList openTypeKind
171 openAlphaTy = mkTyVarTy openAlphaTyVar
173 vrcPos,vrcZero :: (Bool,Bool)
174 vrcPos = (True,False)
175 vrcZero = (False,False)
177 vrcsP,vrcsZ,vrcsZP :: ArgVrcs
180 vrcsZP = [vrcZero,vrcPos]
184 %************************************************************************
186 \subsection[TysPrim-basic]{Basic primitive types (@Char#@, @Int#@, etc.)}
188 %************************************************************************
192 pcPrimTyCon :: Name -> ArgVrcs -> PrimRep -> TyCon
193 pcPrimTyCon name arg_vrcs rep
194 = mkPrimTyCon name kind arity arg_vrcs rep
196 arity = length arg_vrcs
197 kind = mkArrowKinds (replicate arity liftedTypeKind) result_kind
198 result_kind = unliftedTypeKind -- all primitive types are unlifted
200 pcPrimTyCon0 :: Name -> PrimRep -> TyCon
201 pcPrimTyCon0 name rep
202 = mkPrimTyCon name result_kind 0 [] rep
204 result_kind = unliftedTypeKind -- all primitive types are unlifted
206 charPrimTy = mkTyConTy charPrimTyCon
207 charPrimTyCon = pcPrimTyCon0 charPrimTyConName CharRep
209 intPrimTy = mkTyConTy intPrimTyCon
210 intPrimTyCon = pcPrimTyCon0 intPrimTyConName IntRep
212 int32PrimTy = mkTyConTy int32PrimTyCon
213 int32PrimTyCon = pcPrimTyCon0 int32PrimTyConName Int32Rep
215 int64PrimTy = mkTyConTy int64PrimTyCon
216 int64PrimTyCon = pcPrimTyCon0 int64PrimTyConName Int64Rep
218 wordPrimTy = mkTyConTy wordPrimTyCon
219 wordPrimTyCon = pcPrimTyCon0 wordPrimTyConName WordRep
221 word32PrimTy = mkTyConTy word32PrimTyCon
222 word32PrimTyCon = pcPrimTyCon0 word32PrimTyConName Word32Rep
224 word64PrimTy = mkTyConTy word64PrimTyCon
225 word64PrimTyCon = pcPrimTyCon0 word64PrimTyConName Word64Rep
227 addrPrimTy = mkTyConTy addrPrimTyCon
228 addrPrimTyCon = pcPrimTyCon0 addrPrimTyConName AddrRep
230 floatPrimTy = mkTyConTy floatPrimTyCon
231 floatPrimTyCon = pcPrimTyCon0 floatPrimTyConName FloatRep
233 doublePrimTy = mkTyConTy doublePrimTyCon
234 doublePrimTyCon = pcPrimTyCon0 doublePrimTyConName DoubleRep
238 %************************************************************************
240 \subsection[TysPrim-state]{The @State#@ type (and @_RealWorld@ types)}
242 %************************************************************************
244 State# is the primitive, unlifted type of states. It has one type parameter,
250 where s is a type variable. The only purpose of the type parameter is to
251 keep different state threads separate. It is represented by nothing at all.
254 mkStatePrimTy ty = mkTyConApp statePrimTyCon [ty]
255 statePrimTyCon = pcPrimTyCon statePrimTyConName vrcsZ VoidRep
258 RealWorld is deeply magical. It is *primitive*, but it is not
259 *unlifted* (hence PtrRep). We never manipulate values of type
260 RealWorld; it's only used in the type system, to parameterise State#.
263 realWorldTyCon = mkLiftedPrimTyCon realWorldTyConName liftedTypeKind 0 [] PtrRep
264 realWorldTy = mkTyConTy realWorldTyCon
265 realWorldStatePrimTy = mkStatePrimTy realWorldTy -- State# RealWorld
268 Note: the ``state-pairing'' types are not truly primitive, so they are
269 defined in \tr{TysWiredIn.lhs}, not here.
272 %************************************************************************
274 \subsection[TysPrim-arrays]{The primitive array types}
276 %************************************************************************
279 arrayPrimTyCon = pcPrimTyCon arrayPrimTyConName vrcsP PtrRep
280 mutableArrayPrimTyCon = pcPrimTyCon mutableArrayPrimTyConName vrcsZP PtrRep
281 mutableByteArrayPrimTyCon = pcPrimTyCon mutableByteArrayPrimTyConName vrcsZ PtrRep
282 byteArrayPrimTyCon = pcPrimTyCon0 byteArrayPrimTyConName PtrRep
284 mkArrayPrimTy elt = mkTyConApp arrayPrimTyCon [elt]
285 byteArrayPrimTy = mkTyConTy byteArrayPrimTyCon
286 mkMutableArrayPrimTy s elt = mkTyConApp mutableArrayPrimTyCon [s, elt]
287 mkMutableByteArrayPrimTy s = mkTyConApp mutableByteArrayPrimTyCon [s]
290 %************************************************************************
292 \subsection[TysPrim-mut-var]{The mutable variable type}
294 %************************************************************************
297 mutVarPrimTyCon = pcPrimTyCon mutVarPrimTyConName vrcsZP PtrRep
299 mkMutVarPrimTy s elt = mkTyConApp mutVarPrimTyCon [s, elt]
302 %************************************************************************
304 \subsection[TysPrim-synch-var]{The synchronizing variable type}
306 %************************************************************************
309 mVarPrimTyCon = pcPrimTyCon mVarPrimTyConName vrcsZP PtrRep
311 mkMVarPrimTy s elt = mkTyConApp mVarPrimTyCon [s, elt]
314 %************************************************************************
316 \subsection[TysPrim-stable-ptrs]{The stable-pointer type}
318 %************************************************************************
321 stablePtrPrimTyCon = pcPrimTyCon stablePtrPrimTyConName vrcsP StablePtrRep
323 mkStablePtrPrimTy ty = mkTyConApp stablePtrPrimTyCon [ty]
326 %************************************************************************
328 \subsection[TysPrim-stable-names]{The stable-name type}
330 %************************************************************************
333 stableNamePrimTyCon = pcPrimTyCon stableNamePrimTyConName vrcsP PtrRep
335 mkStableNamePrimTy ty = mkTyConApp stableNamePrimTyCon [ty]
338 %************************************************************************
340 \subsection[TysPrim-foreign-objs]{The ``foreign object'' type}
342 %************************************************************************
344 A Foreign Object is just a boxed, unlifted, Addr#. They're needed
345 because finalisers (weak pointers) can't watch Addr#s, they can only
346 watch heap-resident objects.
348 We can't use a lifted Addr# (such as Addr) because race conditions
349 could bite us. For example, if the program deconstructed the Addr
350 before passing its contents to a ccall, and a weak pointer was
351 watching the Addr, the weak pointer might deduce that the Addr was
352 dead before it really was.
355 foreignObjPrimTy = mkTyConTy foreignObjPrimTyCon
356 foreignObjPrimTyCon = pcPrimTyCon0 foreignObjPrimTyConName PtrRep
359 %************************************************************************
361 \subsection[TysPrim-BCOs]{The ``bytecode object'' type}
363 %************************************************************************
366 bcoPrimTy = mkTyConTy bcoPrimTyCon
367 bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName PtrRep
370 %************************************************************************
372 \subsection[TysPrim-Weak]{The ``weak pointer'' type}
374 %************************************************************************
377 weakPrimTyCon = pcPrimTyCon weakPrimTyConName vrcsP PtrRep
379 mkWeakPrimTy v = mkTyConApp weakPrimTyCon [v]
382 %************************************************************************
384 \subsection[TysPrim-thread-ids]{The ``thread id'' type}
386 %************************************************************************
388 A thread id is represented by a pointer to the TSO itself, to ensure
389 that they are always unique and we can always find the TSO for a given
390 thread id. However, this has the unfortunate consequence that a
391 ThreadId# for a given thread is treated as a root by the garbage
392 collector and can keep TSOs around for too long.
394 Hence the programmer API for thread manipulation uses a weak pointer
395 to the thread id internally.
398 threadIdPrimTy = mkTyConTy threadIdPrimTyCon
399 threadIdPrimTyCon = pcPrimTyCon0 threadIdPrimTyConName PtrRep