2 % (c) The GRASP Project, Glasgow University, 1994-1998
4 \section[TysWiredIn]{Wired-in knowledge about {\em non-primitive} types}
7 -- | This module is about types that can be defined in Haskell, but which
8 -- must be wired into the compiler nonetheless. C.f module TysPrim
10 -- * All wired in things
14 boolTy, boolTyCon, boolTyCon_RDR, boolTyConName,
15 trueDataCon, trueDataConId, true_RDR,
16 falseDataCon, falseDataConId, false_RDR,
19 charTyCon, charDataCon, charTyCon_RDR,
20 charTy, stringTy, charTyConName,
23 doubleTyCon, doubleDataCon, doubleTy, doubleTyConName,
26 floatTyCon, floatDataCon, floatTy, floatTyConName,
29 intTyCon, intDataCon, intTyCon_RDR, intDataCon_RDR, intTyConName,
33 wordTyCon, wordDataCon, wordTyConName, wordTy,
36 listTyCon, nilDataCon, consDataCon,
37 listTyCon_RDR, consDataCon_RDR, listTyConName,
41 mkTupleTy, mkBoxedTupleTy,
43 unitTyCon, unitDataCon, unitDataConId, pairTyCon,
44 unboxedSingletonTyCon, unboxedSingletonDataCon,
45 unboxedPairTyCon, unboxedPairDataCon,
50 -- * Heterogeneous Metaprogramming
52 hetMetCodeTypeTyConName,
53 hetMetCodeTypeTyCon, isHetMetCodeTypeTyCon,
54 hetMetCodeTypeTyCon_RDR,
58 parrTyCon, parrFakeCon, isPArrTyCon, isPArrFakeCon,
59 parrTyCon_RDR, parrTyConName
62 #include "HsVersions.h"
64 import {-# SOURCE #-} MkId( mkDataConIds )
71 import Constants ( mAX_TUPLE_SIZE )
72 import Module ( Module )
75 import DataCon ( DataCon, mkDataCon, dataConWorkId, dataConSourceArity )
77 import TyCon ( TyCon, AlgTyConRhs(DataTyCon), tyConDataCons,
78 mkTupleTyCon, mkAlgTyCon, tyConName,
79 TyConParent(NoParentTyCon) )
81 import BasicTypes ( Arity, RecFlag(..), Boxity(..), isBoxed, HsBang(..) )
83 import Type ( Type, mkTyConTy, mkTyConApp, mkTyVarTy, mkTyVarTys,
85 import Coercion ( unsafeCoercionTyCon, symCoercionTyCon,
86 transCoercionTyCon, leftCoercionTyCon,
87 rightCoercionTyCon, instCoercionTyCon )
88 import TypeRep ( mkArrowKinds, liftedTypeKind, ubxTupleKind )
89 import Unique ( incrUnique, mkTupleTyConUnique,
90 mkTupleDataConUnique, mkPArrDataConUnique )
95 alpha_tyvar :: [TyVar]
96 alpha_tyvar = [alphaTyVar]
103 %************************************************************************
105 \subsection{Wired in type constructors}
107 %************************************************************************
109 If you change which things are wired in, make sure you change their
110 names in PrelNames, so they use wTcQual, wDataQual, etc
113 wiredInTyCons :: [TyCon] -- Excludes tuples
114 -- This list is used only to define PrelInfo.wiredInThings
116 -- It does not need to include kind constructors, because
117 -- all that wiredInThings does is to initialise the Name table,
118 -- and kind constructors don't appear in source code.
120 wiredInTyCons = [ unitTyCon -- Not treated like other tuples, because
121 -- it's defined in GHC.Base, and there's only
122 -- one of it. We put it in wiredInTyCons so
123 -- that it'll pre-populate the name cache, so
124 -- the special case in lookupOrigNameCache
125 -- doesn't need to look out for it
133 , hetMetCodeTypeTyCon
134 , unsafeCoercionTyCon
144 mkWiredInTyConName :: BuiltInSyntax -> Module -> FastString -> Unique -> TyCon -> Name
145 mkWiredInTyConName built_in modu fs unique tycon
146 = mkWiredInName modu (mkTcOccFS fs) unique
147 (ATyCon tycon) -- Relevant TyCon
150 mkWiredInDataConName :: BuiltInSyntax -> Module -> FastString -> Unique -> DataCon -> Name
151 mkWiredInDataConName built_in modu fs unique datacon
152 = mkWiredInName modu (mkDataOccFS fs) unique
153 (ADataCon datacon) -- Relevant DataCon
156 charTyConName, charDataConName, intTyConName, intDataConName :: Name
157 charTyConName = mkWiredInTyConName UserSyntax gHC_TYPES (fsLit "Char") charTyConKey charTyCon
158 charDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "C#") charDataConKey charDataCon
159 intTyConName = mkWiredInTyConName UserSyntax gHC_TYPES (fsLit "Int") intTyConKey intTyCon
160 intDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "I#") intDataConKey intDataCon
162 boolTyConName, falseDataConName, trueDataConName :: Name
163 boolTyConName = mkWiredInTyConName UserSyntax gHC_TYPES (fsLit "Bool") boolTyConKey boolTyCon
164 falseDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "False") falseDataConKey falseDataCon
165 trueDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "True") trueDataConKey trueDataCon
167 listTyConName, nilDataConName, consDataConName :: Name
168 listTyConName = mkWiredInTyConName BuiltInSyntax gHC_TYPES (fsLit "[]") listTyConKey listTyCon
169 nilDataConName = mkWiredInDataConName BuiltInSyntax gHC_TYPES (fsLit "[]") nilDataConKey nilDataCon
170 consDataConName = mkWiredInDataConName BuiltInSyntax gHC_TYPES (fsLit ":") consDataConKey consDataCon
172 floatTyConName, floatDataConName, doubleTyConName, doubleDataConName :: Name
173 floatTyConName = mkWiredInTyConName UserSyntax gHC_TYPES (fsLit "Float") floatTyConKey floatTyCon
174 floatDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "F#") floatDataConKey floatDataCon
175 doubleTyConName = mkWiredInTyConName UserSyntax gHC_TYPES (fsLit "Double") doubleTyConKey doubleTyCon
176 doubleDataConName = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "D#") doubleDataConKey doubleDataCon
178 parrTyConName, parrDataConName :: Name
179 parrTyConName = mkWiredInTyConName BuiltInSyntax gHC_PARR (fsLit "[::]") parrTyConKey parrTyCon
180 parrDataConName = mkWiredInDataConName UserSyntax gHC_PARR (fsLit "PArr") parrDataConKey parrDataCon
182 hetMetCodeTypeTyConName :: Name
183 hetMetCodeTypeTyConName = mkWiredInTyConName BuiltInSyntax gHC_HETMET_CODETYPES (fsLit "<[]>@") hetMetCodeTypeTyConKey hetMetCodeTypeTyCon
184 hetMetCodeTypeDataConName :: Name
185 hetMetCodeTypeDataConName =
186 mkWiredInDataConName BuiltInSyntax gHC_HETMET_CODETYPES (fsLit "<[]>") hetMetCodeTypeDataConKey hetMetCodeTypeDataCon
188 boolTyCon_RDR, false_RDR, true_RDR, intTyCon_RDR, charTyCon_RDR,
189 intDataCon_RDR, listTyCon_RDR, consDataCon_RDR, parrTyCon_RDR, hetMetCodeTypeTyCon_RDR :: RdrName
190 boolTyCon_RDR = nameRdrName boolTyConName
191 false_RDR = nameRdrName falseDataConName
192 true_RDR = nameRdrName trueDataConName
193 intTyCon_RDR = nameRdrName intTyConName
194 charTyCon_RDR = nameRdrName charTyConName
195 intDataCon_RDR = nameRdrName intDataConName
196 listTyCon_RDR = nameRdrName listTyConName
197 consDataCon_RDR = nameRdrName consDataConName
198 parrTyCon_RDR = nameRdrName parrTyConName
199 hetMetCodeTypeTyCon_RDR = nameRdrName hetMetCodeTypeTyConName
203 %************************************************************************
205 \subsection{mkWiredInTyCon}
207 %************************************************************************
210 pcNonRecDataTyCon :: Name -> [TyVar] -> [DataCon] -> TyCon
211 pcNonRecDataTyCon = pcTyCon False NonRecursive
212 pcRecDataTyCon :: Name -> [TyVar] -> [DataCon] -> TyCon
213 pcRecDataTyCon = pcTyCon False Recursive
215 pcTyCon :: Bool -> RecFlag -> Name -> [TyVar] -> [DataCon] -> TyCon
216 pcTyCon is_enum is_rec name tyvars cons
219 tycon = mkAlgTyCon name
220 (mkArrowKinds (map tyVarKind tyvars) liftedTypeKind)
222 [] -- No stupid theta
223 (DataTyCon cons is_enum)
226 True -- All the wired-in tycons have generics
227 False -- Not in GADT syntax
229 pcDataCon :: Name -> [TyVar] -> [Type] -> TyCon -> DataCon
230 pcDataCon = pcDataConWithFixity False
232 pcDataConWithFixity :: Bool -> Name -> [TyVar] -> [Type] -> TyCon -> DataCon
233 -- The Name should be in the DataName name space; it's the name
234 -- of the DataCon itself.
236 -- The unique is the first of two free uniques;
237 -- the first is used for the datacon itself,
238 -- the second is used for the "worker name"
240 pcDataConWithFixity declared_infix dc_name tyvars arg_tys tycon
243 data_con = mkDataCon dc_name declared_infix
244 (map (const HsNoBang) arg_tys)
245 [] -- No labelled fields
247 [] -- No existential type variables
248 [] -- No equality spec
250 arg_tys (mkTyConApp tycon (mkTyVarTys tyvars))
252 [] -- No stupid theta
253 (mkDataConIds bogus_wrap_name wrk_name data_con)
256 modu = ASSERT( isExternalName dc_name )
258 wrk_occ = mkDataConWorkerOcc (nameOccName dc_name)
259 wrk_key = incrUnique (nameUnique dc_name)
260 wrk_name = mkWiredInName modu wrk_occ wrk_key
261 (AnId (dataConWorkId data_con)) UserSyntax
262 bogus_wrap_name = pprPanic "Wired-in data wrapper id" (ppr dc_name)
263 -- Wired-in types are too simple to need wrappers
267 %************************************************************************
269 \subsection[TysWiredIn-tuples]{The tuple types}
271 %************************************************************************
274 tupleTyCon :: Boxity -> Arity -> TyCon
275 tupleTyCon boxity i | i > mAX_TUPLE_SIZE = fst (mk_tuple boxity i) -- Build one specially
276 tupleTyCon Boxed i = fst (boxedTupleArr ! i)
277 tupleTyCon Unboxed i = fst (unboxedTupleArr ! i)
279 tupleCon :: Boxity -> Arity -> DataCon
280 tupleCon boxity i | i > mAX_TUPLE_SIZE = snd (mk_tuple boxity i) -- Build one specially
281 tupleCon Boxed i = snd (boxedTupleArr ! i)
282 tupleCon Unboxed i = snd (unboxedTupleArr ! i)
284 boxedTupleArr, unboxedTupleArr :: Array Int (TyCon,DataCon)
285 boxedTupleArr = listArray (0,mAX_TUPLE_SIZE) [mk_tuple Boxed i | i <- [0..mAX_TUPLE_SIZE]]
286 unboxedTupleArr = listArray (0,mAX_TUPLE_SIZE) [mk_tuple Unboxed i | i <- [0..mAX_TUPLE_SIZE]]
288 mk_tuple :: Boxity -> Int -> (TyCon,DataCon)
289 mk_tuple boxity arity = (tycon, tuple_con)
291 tycon = mkTupleTyCon tc_name tc_kind arity tyvars tuple_con boxity gen_info
292 modu = mkTupleModule boxity arity
293 tc_name = mkWiredInName modu (mkTupleOcc tcName boxity arity) tc_uniq
294 (ATyCon tycon) BuiltInSyntax
295 tc_kind = mkArrowKinds (map tyVarKind tyvars) res_kind
296 res_kind | isBoxed boxity = liftedTypeKind
297 | otherwise = ubxTupleKind
299 tyvars | isBoxed boxity = take arity alphaTyVars
300 | otherwise = take arity openAlphaTyVars
302 tuple_con = pcDataCon dc_name tyvars tyvar_tys tycon
303 tyvar_tys = mkTyVarTys tyvars
304 dc_name = mkWiredInName modu (mkTupleOcc dataName boxity arity) dc_uniq
305 (ADataCon tuple_con) BuiltInSyntax
306 tc_uniq = mkTupleTyConUnique boxity arity
307 dc_uniq = mkTupleDataConUnique boxity arity
308 gen_info = True -- Tuples all have generics..
309 -- hmm: that's a *lot* of code
312 unitTyCon = tupleTyCon Boxed 0
313 unitDataCon :: DataCon
314 unitDataCon = head (tyConDataCons unitTyCon)
316 unitDataConId = dataConWorkId unitDataCon
319 pairTyCon = tupleTyCon Boxed 2
321 unboxedSingletonTyCon :: TyCon
322 unboxedSingletonTyCon = tupleTyCon Unboxed 1
323 unboxedSingletonDataCon :: DataCon
324 unboxedSingletonDataCon = tupleCon Unboxed 1
326 unboxedPairTyCon :: TyCon
327 unboxedPairTyCon = tupleTyCon Unboxed 2
328 unboxedPairDataCon :: DataCon
329 unboxedPairDataCon = tupleCon Unboxed 2
333 %************************************************************************
335 \subsection[TysWiredIn-boxed-prim]{The ``boxed primitive'' types (@Char@, @Int@, etc)}
337 %************************************************************************
341 charTy = mkTyConTy charTyCon
344 charTyCon = pcNonRecDataTyCon charTyConName [] [charDataCon]
345 charDataCon :: DataCon
346 charDataCon = pcDataCon charDataConName [] [charPrimTy] charTyCon
349 stringTy = mkListTy charTy -- convenience only
354 intTy = mkTyConTy intTyCon
357 intTyCon = pcNonRecDataTyCon intTyConName [] [intDataCon]
358 intDataCon :: DataCon
359 intDataCon = pcDataCon intDataConName [] [intPrimTy] intTyCon
364 wordTy = mkTyConTy wordTyCon
367 wordTyCon = pcNonRecDataTyCon wordTyConName [] [wordDataCon]
368 wordDataCon :: DataCon
369 wordDataCon = pcDataCon wordDataConName [] [wordPrimTy] wordTyCon
374 floatTy = mkTyConTy floatTyCon
377 floatTyCon = pcNonRecDataTyCon floatTyConName [] [floatDataCon]
378 floatDataCon :: DataCon
379 floatDataCon = pcDataCon floatDataConName [] [floatPrimTy] floatTyCon
384 doubleTy = mkTyConTy doubleTyCon
387 doubleTyCon = pcNonRecDataTyCon doubleTyConName [] [doubleDataCon]
389 doubleDataCon :: DataCon
390 doubleDataCon = pcDataCon doubleDataConName [] [doublePrimTy] doubleTyCon
394 %************************************************************************
396 \subsection[TysWiredIn-Bool]{The @Bool@ type}
398 %************************************************************************
400 An ordinary enumeration type, but deeply wired in. There are no
401 magical operations on @Bool@ (just the regular Prelude code).
403 {\em BEGIN IDLE SPECULATION BY SIMON}
405 This is not the only way to encode @Bool@. A more obvious coding makes
406 @Bool@ just a boxed up version of @Bool#@, like this:
409 data Bool = MkBool Bool#
412 Unfortunately, this doesn't correspond to what the Report says @Bool@
413 looks like! Furthermore, we get slightly less efficient code (I
414 think) with this coding. @gtInt@ would look like this:
417 gtInt :: Int -> Int -> Bool
418 gtInt x y = case x of I# x# ->
420 case (gtIntPrim x# y#) of
424 Notice that the result of the @gtIntPrim@ comparison has to be turned
425 into an integer (here called @b#@), and returned in a @MkBool@ box.
427 The @if@ expression would compile to this:
430 MkBool b# -> case b# of { 1# -> e1; 0# -> e2 }
433 I think this code is a little less efficient than the previous code,
434 but I'm not certain. At all events, corresponding with the Report is
435 important. The interesting thing is that the language is expressive
436 enough to describe more than one alternative; and that a type doesn't
437 necessarily need to be a straightforwardly boxed version of its
438 primitive counterpart.
440 {\em END IDLE SPECULATION BY SIMON}
444 boolTy = mkTyConTy boolTyCon
447 boolTyCon = pcTyCon True NonRecursive boolTyConName
448 [] [falseDataCon, trueDataCon]
450 falseDataCon, trueDataCon :: DataCon
451 falseDataCon = pcDataCon falseDataConName [] [] boolTyCon
452 trueDataCon = pcDataCon trueDataConName [] [] boolTyCon
454 falseDataConId, trueDataConId :: Id
455 falseDataConId = dataConWorkId falseDataCon
456 trueDataConId = dataConWorkId trueDataCon
459 %************************************************************************
461 \subsection[TysWiredIn-List]{The @List@ type (incl ``build'' magic)}
463 %************************************************************************
465 Special syntax, deeply wired in, but otherwise an ordinary algebraic
468 data [] a = [] | a : (List a)
470 data (,) a b = (,,) a b
475 mkListTy :: Type -> Type
476 mkListTy ty = mkTyConApp listTyCon [ty]
479 listTyCon = pcRecDataTyCon listTyConName alpha_tyvar [nilDataCon, consDataCon]
481 nilDataCon :: DataCon
482 nilDataCon = pcDataCon nilDataConName alpha_tyvar [] listTyCon
484 consDataCon :: DataCon
485 consDataCon = pcDataConWithFixity True {- Declared infix -}
487 alpha_tyvar [alphaTy, mkTyConApp listTyCon alpha_ty] listTyCon
488 -- Interesting: polymorphic recursion would help here.
489 -- We can't use (mkListTy alphaTy) in the defn of consDataCon, else mkListTy
490 -- gets the over-specific type (Type -> Type)
493 %************************************************************************
495 \subsection[TysWiredIn-Tuples]{The @Tuple@ types}
497 %************************************************************************
499 The tuple types are definitely magic, because they form an infinite
504 They have a special family of type constructors, of type @TyCon@
505 These contain the tycon arity, but don't require a Unique.
508 They have a special family of constructors, of type
509 @Id@. Again these contain their arity but don't need a Unique.
512 There should be a magic way of generating the info tables and
513 entry code for all tuples.
515 But at the moment we just compile a Haskell source
516 file\srcloc{lib/prelude/...} containing declarations like:
519 data Tuple2 a b = Tup2 a b
520 data Tuple3 a b c = Tup3 a b c
521 data Tuple4 a b c d = Tup4 a b c d
524 The print-names associated with the magic @Id@s for tuple constructors
525 ``just happen'' to be the same as those generated by these
529 The instance environment should have a magic way to know
530 that each tuple type is an instances of classes @Eq@, @Ix@, @Ord@ and
531 so on. \ToDo{Not implemented yet.}
534 There should also be a way to generate the appropriate code for each
535 of these instances, but (like the info tables and entry code) it is
536 done by enumeration\srcloc{lib/prelude/InTup?.hs}.
540 mkTupleTy :: Boxity -> [Type] -> Type
541 -- Special case for *boxed* 1-tuples, which are represented by the type itself
542 mkTupleTy boxity [ty] | Boxed <- boxity = ty
543 mkTupleTy boxity tys = mkTyConApp (tupleTyCon boxity (length tys)) tys
545 -- | Build the type of a small tuple that holds the specified type of thing
546 mkBoxedTupleTy :: [Type] -> Type
547 mkBoxedTupleTy tys = mkTupleTy Boxed tys
550 unitTy = mkTupleTy Boxed []
553 %************************************************************************
555 \subsection[TysWiredIn-PArr]{The @[::]@ type}
557 %************************************************************************
559 Special syntax for parallel arrays needs some wired in definitions.
562 -- | Construct a type representing the application of the parallel array constructor
563 mkPArrTy :: Type -> Type
564 mkPArrTy ty = mkTyConApp parrTyCon [ty]
566 -- | Represents the type constructor of parallel arrays
568 -- * This must match the definition in @PrelPArr@
570 -- NB: Although the constructor is given here, it will not be accessible in
571 -- user code as it is not in the environment of any compiled module except
575 parrTyCon = pcNonRecDataTyCon parrTyConName alpha_tyvar [parrDataCon]
577 parrDataCon :: DataCon
578 parrDataCon = pcDataCon
580 alpha_tyvar -- forall'ed type variables
581 [intPrimTy, -- 1st argument: Int#
582 mkTyConApp -- 2nd argument: Array# a
587 -- | Check whether a type constructor is the constructor for parallel arrays
588 isPArrTyCon :: TyCon -> Bool
589 isPArrTyCon tc = tyConName tc == parrTyConName
591 -- | Fake array constructors
593 -- * These constructors are never really used to represent array values;
594 -- however, they are very convenient during desugaring (and, in particular,
595 -- in the pattern matching compiler) to treat array pattern just like
596 -- yet another constructor pattern
598 parrFakeCon :: Arity -> DataCon
599 parrFakeCon i | i > mAX_TUPLE_SIZE = mkPArrFakeCon i -- build one specially
600 parrFakeCon i = parrFakeConArr!i
602 -- pre-defined set of constructors
604 parrFakeConArr :: Array Int DataCon
605 parrFakeConArr = array (0, mAX_TUPLE_SIZE) [(i, mkPArrFakeCon i)
606 | i <- [0..mAX_TUPLE_SIZE]]
608 -- build a fake parallel array constructor for the given arity
610 mkPArrFakeCon :: Int -> DataCon
611 mkPArrFakeCon arity = data_con
613 data_con = pcDataCon name [tyvar] tyvarTys parrTyCon
614 tyvar = head alphaTyVars
615 tyvarTys = replicate arity $ mkTyVarTy tyvar
616 nameStr = mkFastString ("MkPArr" ++ show arity)
617 name = mkWiredInName gHC_PARR (mkDataOccFS nameStr) unique
618 (ADataCon data_con) UserSyntax
619 unique = mkPArrDataConUnique arity
621 -- | Checks whether a data constructor is a fake constructor for parallel arrays
622 isPArrFakeCon :: DataCon -> Bool
623 isPArrFakeCon dcon = dcon == parrFakeCon (dataConSourceArity dcon)
627 Heterogeneous Metaprogramming
630 -- | Construct a type representing the application of the box type
631 mkHetMetCodeTypeTy :: TyVar -> Type -> Type
632 mkHetMetCodeTypeTy ecn ty = mkTyConApp hetMetCodeTypeTyCon [(mkTyVarTy ecn), ty]
634 -- | Represents the type constructor of box types
635 hetMetCodeTypeTyCon :: TyCon
636 hetMetCodeTypeTyCon = pcNonRecDataTyCon hetMetCodeTypeTyConName [alphaTyVar, betaTyVar] [hetMetCodeTypeDataCon]
638 -- | Check whether a type constructor is the constructor for box types
639 isHetMetCodeTypeTyCon :: TyCon -> Bool
640 isHetMetCodeTypeTyCon tc = tyConName tc == hetMetCodeTypeTyConName
642 hetMetCodeTypeDataCon :: DataCon
643 hetMetCodeTypeDataCon = pcDataCon
644 hetMetCodeTypeDataConName
645 [betaTyVar] -- forall'ed type variables