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, BuiltInSyntax(..), mkInternalName, mkWiredInName )
49 import OccName ( mkVarOcc, mkOccFS, tcName )
50 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
107 UserSyntax -- None are built-in syntax
109 charPrimTyConName = mkPrimTc FSLIT("Char#") charPrimTyConKey charPrimTyCon
110 intPrimTyConName = mkPrimTc FSLIT("Int#") intPrimTyConKey intPrimTyCon
111 int32PrimTyConName = mkPrimTc FSLIT("Int32#") int32PrimTyConKey int32PrimTyCon
112 int64PrimTyConName = mkPrimTc FSLIT("Int64#") int64PrimTyConKey int64PrimTyCon
113 wordPrimTyConName = mkPrimTc FSLIT("Word#") wordPrimTyConKey wordPrimTyCon
114 word32PrimTyConName = mkPrimTc FSLIT("Word32#") word32PrimTyConKey word32PrimTyCon
115 word64PrimTyConName = mkPrimTc FSLIT("Word64#") word64PrimTyConKey word64PrimTyCon
116 addrPrimTyConName = mkPrimTc FSLIT("Addr#") addrPrimTyConKey addrPrimTyCon
117 floatPrimTyConName = mkPrimTc FSLIT("Float#") floatPrimTyConKey floatPrimTyCon
118 doublePrimTyConName = mkPrimTc FSLIT("Double#") doublePrimTyConKey doublePrimTyCon
119 statePrimTyConName = mkPrimTc FSLIT("State#") statePrimTyConKey statePrimTyCon
120 realWorldTyConName = mkPrimTc FSLIT("RealWorld") realWorldTyConKey realWorldTyCon
121 arrayPrimTyConName = mkPrimTc FSLIT("Array#") arrayPrimTyConKey arrayPrimTyCon
122 byteArrayPrimTyConName = mkPrimTc FSLIT("ByteArray#") byteArrayPrimTyConKey byteArrayPrimTyCon
123 mutableArrayPrimTyConName = mkPrimTc FSLIT("MutableArray#") mutableArrayPrimTyConKey mutableArrayPrimTyCon
124 mutableByteArrayPrimTyConName = mkPrimTc FSLIT("MutableByteArray#") mutableByteArrayPrimTyConKey mutableByteArrayPrimTyCon
125 mutVarPrimTyConName = mkPrimTc FSLIT("MutVar#") mutVarPrimTyConKey mutVarPrimTyCon
126 mVarPrimTyConName = mkPrimTc FSLIT("MVar#") mVarPrimTyConKey mVarPrimTyCon
127 stablePtrPrimTyConName = mkPrimTc FSLIT("StablePtr#") stablePtrPrimTyConKey stablePtrPrimTyCon
128 stableNamePrimTyConName = mkPrimTc FSLIT("StableName#") stableNamePrimTyConKey stableNamePrimTyCon
129 foreignObjPrimTyConName = mkPrimTc FSLIT("ForeignObj#") foreignObjPrimTyConKey foreignObjPrimTyCon
130 bcoPrimTyConName = mkPrimTc FSLIT("BCO#") bcoPrimTyConKey bcoPrimTyCon
131 weakPrimTyConName = mkPrimTc FSLIT("Weak#") weakPrimTyConKey weakPrimTyCon
132 threadIdPrimTyConName = mkPrimTc FSLIT("ThreadId#") threadIdPrimTyConKey threadIdPrimTyCon
135 %************************************************************************
137 \subsection{Support code}
139 %************************************************************************
141 alphaTyVars is a list of type variables for use in templates:
142 ["a", "b", ..., "z", "t1", "t2", ... ]
145 tyVarList :: Kind -> [TyVar]
146 tyVarList kind = [ mkTyVar (mkInternalName (mkAlphaTyVarUnique u)
147 (mkVarOcc (mkFastString name))
150 let name | c <= 'z' = [c]
151 | otherwise = 't':show u
152 where c = chr (u-2 + ord 'a')
155 alphaTyVars :: [TyVar]
156 alphaTyVars = tyVarList liftedTypeKind
158 betaTyVars = tail alphaTyVars
160 alphaTyVar, betaTyVar, gammaTyVar :: TyVar
161 (alphaTyVar:betaTyVar:gammaTyVar:deltaTyVar:_) = alphaTyVars
163 alphaTys = mkTyVarTys alphaTyVars
164 (alphaTy:betaTy:gammaTy:deltaTy:_) = alphaTys
166 -- openAlphaTyVar is prepared to be instantiated
167 -- to a lifted or unlifted type variable. It's used for the
168 -- result type for "error", so that we can have (error Int# "Help")
169 openAlphaTyVars :: [TyVar]
170 openAlphaTyVars@(openAlphaTyVar:_) = tyVarList openTypeKind
172 openAlphaTy = mkTyVarTy openAlphaTyVar
174 vrcPos,vrcZero :: (Bool,Bool)
175 vrcPos = (True,False)
176 vrcZero = (False,False)
178 vrcsP,vrcsZ,vrcsZP :: ArgVrcs
181 vrcsZP = [vrcZero,vrcPos]
185 %************************************************************************
187 \subsection[TysPrim-basic]{Basic primitive types (@Char#@, @Int#@, etc.)}
189 %************************************************************************
193 pcPrimTyCon :: Name -> ArgVrcs -> PrimRep -> TyCon
194 pcPrimTyCon name arg_vrcs rep
195 = mkPrimTyCon name kind arity arg_vrcs rep
197 arity = length arg_vrcs
198 kind = mkArrowKinds (replicate arity liftedTypeKind) result_kind
199 result_kind = unliftedTypeKind -- all primitive types are unlifted
201 pcPrimTyCon0 :: Name -> PrimRep -> TyCon
202 pcPrimTyCon0 name rep
203 = mkPrimTyCon name result_kind 0 [] rep
205 result_kind = unliftedTypeKind -- all primitive types are unlifted
207 charPrimTy = mkTyConTy charPrimTyCon
208 charPrimTyCon = pcPrimTyCon0 charPrimTyConName WordRep
210 intPrimTy = mkTyConTy intPrimTyCon
211 intPrimTyCon = pcPrimTyCon0 intPrimTyConName IntRep
213 int32PrimTy = mkTyConTy int32PrimTyCon
214 int32PrimTyCon = pcPrimTyCon0 int32PrimTyConName IntRep
216 int64PrimTy = mkTyConTy int64PrimTyCon
217 int64PrimTyCon = pcPrimTyCon0 int64PrimTyConName Int64Rep
219 wordPrimTy = mkTyConTy wordPrimTyCon
220 wordPrimTyCon = pcPrimTyCon0 wordPrimTyConName WordRep
222 word32PrimTy = mkTyConTy word32PrimTyCon
223 word32PrimTyCon = pcPrimTyCon0 word32PrimTyConName WordRep
225 word64PrimTy = mkTyConTy word64PrimTyCon
226 word64PrimTyCon = pcPrimTyCon0 word64PrimTyConName Word64Rep
228 addrPrimTy = mkTyConTy addrPrimTyCon
229 addrPrimTyCon = pcPrimTyCon0 addrPrimTyConName AddrRep
231 floatPrimTy = mkTyConTy floatPrimTyCon
232 floatPrimTyCon = pcPrimTyCon0 floatPrimTyConName FloatRep
234 doublePrimTy = mkTyConTy doublePrimTyCon
235 doublePrimTyCon = pcPrimTyCon0 doublePrimTyConName DoubleRep
239 %************************************************************************
241 \subsection[TysPrim-state]{The @State#@ type (and @_RealWorld@ types)}
243 %************************************************************************
245 State# is the primitive, unlifted type of states. It has one type parameter,
251 where s is a type variable. The only purpose of the type parameter is to
252 keep different state threads separate. It is represented by nothing at all.
255 mkStatePrimTy ty = mkTyConApp statePrimTyCon [ty]
256 statePrimTyCon = pcPrimTyCon statePrimTyConName vrcsZ VoidRep
259 RealWorld is deeply magical. It is *primitive*, but it is not
260 *unlifted* (hence ptrArg). We never manipulate values of type
261 RealWorld; it's only used in the type system, to parameterise State#.
264 realWorldTyCon = mkLiftedPrimTyCon realWorldTyConName liftedTypeKind 0 [] PtrRep
265 realWorldTy = mkTyConTy realWorldTyCon
266 realWorldStatePrimTy = mkStatePrimTy realWorldTy -- State# RealWorld
269 Note: the ``state-pairing'' types are not truly primitive, so they are
270 defined in \tr{TysWiredIn.lhs}, not here.
273 %************************************************************************
275 \subsection[TysPrim-arrays]{The primitive array types}
277 %************************************************************************
280 arrayPrimTyCon = pcPrimTyCon arrayPrimTyConName vrcsP PtrRep
281 mutableArrayPrimTyCon = pcPrimTyCon mutableArrayPrimTyConName vrcsZP PtrRep
282 mutableByteArrayPrimTyCon = pcPrimTyCon mutableByteArrayPrimTyConName vrcsZ PtrRep
283 byteArrayPrimTyCon = pcPrimTyCon0 byteArrayPrimTyConName PtrRep
285 mkArrayPrimTy elt = mkTyConApp arrayPrimTyCon [elt]
286 byteArrayPrimTy = mkTyConTy byteArrayPrimTyCon
287 mkMutableArrayPrimTy s elt = mkTyConApp mutableArrayPrimTyCon [s, elt]
288 mkMutableByteArrayPrimTy s = mkTyConApp mutableByteArrayPrimTyCon [s]
291 %************************************************************************
293 \subsection[TysPrim-mut-var]{The mutable variable type}
295 %************************************************************************
298 mutVarPrimTyCon = pcPrimTyCon mutVarPrimTyConName vrcsZP PtrRep
300 mkMutVarPrimTy s elt = mkTyConApp mutVarPrimTyCon [s, elt]
303 %************************************************************************
305 \subsection[TysPrim-synch-var]{The synchronizing variable type}
307 %************************************************************************
310 mVarPrimTyCon = pcPrimTyCon mVarPrimTyConName vrcsZP PtrRep
312 mkMVarPrimTy s elt = mkTyConApp mVarPrimTyCon [s, elt]
315 %************************************************************************
317 \subsection[TysPrim-stable-ptrs]{The stable-pointer type}
319 %************************************************************************
322 stablePtrPrimTyCon = pcPrimTyCon stablePtrPrimTyConName vrcsP AddrRep
324 mkStablePtrPrimTy ty = mkTyConApp stablePtrPrimTyCon [ty]
327 %************************************************************************
329 \subsection[TysPrim-stable-names]{The stable-name type}
331 %************************************************************************
334 stableNamePrimTyCon = pcPrimTyCon stableNamePrimTyConName vrcsP PtrRep
336 mkStableNamePrimTy ty = mkTyConApp stableNamePrimTyCon [ty]
339 %************************************************************************
341 \subsection[TysPrim-foreign-objs]{The ``foreign object'' type}
343 %************************************************************************
345 A Foreign Object is just a boxed, unlifted, Addr#. They're needed
346 because finalisers (weak pointers) can't watch Addr#s, they can only
347 watch heap-resident objects.
349 We can't use a lifted Addr# (such as Addr) because race conditions
350 could bite us. For example, if the program deconstructed the Addr
351 before passing its contents to a ccall, and a weak pointer was
352 watching the Addr, the weak pointer might deduce that the Addr was
353 dead before it really was.
356 foreignObjPrimTy = mkTyConTy foreignObjPrimTyCon
357 foreignObjPrimTyCon = pcPrimTyCon0 foreignObjPrimTyConName PtrRep
360 %************************************************************************
362 \subsection[TysPrim-BCOs]{The ``bytecode object'' type}
364 %************************************************************************
367 bcoPrimTy = mkTyConTy bcoPrimTyCon
368 bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName PtrRep
371 %************************************************************************
373 \subsection[TysPrim-Weak]{The ``weak pointer'' type}
375 %************************************************************************
378 weakPrimTyCon = pcPrimTyCon weakPrimTyConName vrcsP PtrRep
380 mkWeakPrimTy v = mkTyConApp weakPrimTyCon [v]
383 %************************************************************************
385 \subsection[TysPrim-thread-ids]{The ``thread id'' type}
387 %************************************************************************
389 A thread id is represented by a pointer to the TSO itself, to ensure
390 that they are always unique and we can always find the TSO for a given
391 thread id. However, this has the unfortunate consequence that a
392 ThreadId# for a given thread is treated as a root by the garbage
393 collector and can keep TSOs around for too long.
395 Hence the programmer API for thread manipulation uses a weak pointer
396 to the thread id internally.
399 threadIdPrimTy = mkTyConTy threadIdPrimTyCon
400 threadIdPrimTyCon = pcPrimTyCon0 threadIdPrimTyConName PtrRep