2 % (c) The University of Glasgow, 1996-2003
4 Functions over HsSyn specialised to RdrName.
9 extractHsRhoRdrTyVars, extractGenericPatTyVars,
11 mkHsOpApp, mkClassDecl,
12 mkHsNegApp, mkHsIntegral, mkHsFractional,
14 mkTyData, mkPrefixCon, mkRecCon,
15 mkRecConstrOrUpdate, -- HsExp -> [HsFieldUpdate] -> P HsExp
22 -- Stuff to do with Foreign declarations
24 mkImport, -- CallConv -> Safety
25 -- -> (FastString, RdrName, RdrNameHsType)
28 -- -> (FastString, RdrName, RdrNameHsType)
30 mkExtName, -- RdrName -> CLabelString
32 -- Bunch of functions in the parser monad for
33 -- checking and constructing values
34 checkPrecP, -- Int -> P Int
35 checkContext, -- HsType -> P HsContext
36 checkPred, -- HsType -> P HsPred
39 checkInstType, -- HsType -> P HsType
40 checkPattern, -- HsExp -> P HsPat
41 checkPatterns, -- SrcLoc -> [HsExp] -> P [HsPat]
42 checkDo, -- [Stmt] -> P [Stmt]
43 checkMDo, -- [Stmt] -> P [Stmt]
44 checkValDef, -- (SrcLoc, HsExp, HsRhs, [HsDecl]) -> P HsDecl
45 checkValSig, -- (SrcLoc, HsExp, HsRhs, [HsDecl]) -> P HsDecl
46 parseError, -- String -> Pa
49 #include "HsVersions.h"
51 import HsSyn -- Lots of it
52 import RdrName ( RdrName, isRdrTyVar, mkUnqual, rdrNameOcc,
53 isRdrDataCon, isUnqual, getRdrName, isQual,
55 import BasicTypes ( maxPrecedence )
56 import Lexer ( P, failSpanMsgP )
57 import TysWiredIn ( unitTyCon )
58 import ForeignCall ( CCallConv, Safety, CCallTarget(..), CExportSpec(..),
59 DNCallSpec(..), DNKind(..), CLabelString )
60 import OccName ( srcDataName, varName, isDataOcc, isTcOcc,
63 import OrdList ( OrdList, fromOL )
64 import Bag ( Bag, emptyBag, snocBag, consBag, foldrBag )
69 import List ( isSuffixOf, nubBy )
73 %************************************************************************
75 \subsection{A few functions over HsSyn at RdrName}
77 %************************************************************************
79 extractHsTyRdrNames finds the free variables of a HsType
80 It's used when making the for-alls explicit.
83 extractHsTyRdrTyVars :: LHsType RdrName -> [Located RdrName]
84 extractHsTyRdrTyVars ty = nubBy eqLocated (extract_lty ty [])
86 extractHsRhoRdrTyVars :: LHsContext RdrName -> LHsType RdrName -> [Located RdrName]
87 -- This one takes the context and tau-part of a
88 -- sigma type and returns their free type variables
89 extractHsRhoRdrTyVars ctxt ty
90 = nubBy eqLocated $ extract_lctxt ctxt (extract_lty ty [])
92 extract_lctxt ctxt acc = foldr (extract_pred . unLoc) acc (unLoc ctxt)
94 extract_pred (HsClassP cls tys) acc = foldr extract_lty acc tys
95 extract_pred (HsIParam n ty) acc = extract_lty ty acc
97 extract_lty (L loc ty) acc
99 HsTyVar tv -> extract_tv loc tv acc
100 HsBangTy _ ty -> extract_lty ty acc
101 HsAppTy ty1 ty2 -> extract_lty ty1 (extract_lty ty2 acc)
102 HsListTy ty -> extract_lty ty acc
103 HsPArrTy ty -> extract_lty ty acc
104 HsTupleTy _ tys -> foldr extract_lty acc tys
105 HsFunTy ty1 ty2 -> extract_lty ty1 (extract_lty ty2 acc)
106 HsPredTy p -> extract_pred p acc
107 HsOpTy ty1 (L loc tv) ty2 -> extract_tv loc tv (extract_lty ty1 (extract_lty ty2 acc))
108 HsParTy ty -> extract_lty ty acc
110 HsSpliceTy _ -> acc -- Type splices mention no type variables
111 HsKindSig ty k -> extract_lty ty acc
112 HsForAllTy exp [] cx ty -> extract_lctxt cx (extract_lty ty acc)
113 HsForAllTy exp tvs cx ty -> acc ++ (filter ((`notElem` locals) . unLoc) $
114 extract_lctxt cx (extract_lty ty []))
116 locals = hsLTyVarNames tvs
118 extract_tv :: SrcSpan -> RdrName -> [Located RdrName] -> [Located RdrName]
119 extract_tv loc tv acc | isRdrTyVar tv = L loc tv : acc
122 extractGenericPatTyVars :: LHsBinds RdrName -> [Located RdrName]
123 -- Get the type variables out of the type patterns in a bunch of
124 -- possibly-generic bindings in a class declaration
125 extractGenericPatTyVars binds
126 = nubBy eqLocated (foldrBag get [] binds)
128 get (L _ (FunBind _ _ (MatchGroup ms _) _)) acc = foldr (get_m.unLoc) acc ms
131 get_m (Match (L _ (TypePat ty) : _) _ _) acc = extract_lty ty acc
132 get_m other acc = acc
136 %************************************************************************
138 \subsection{Construction functions for Rdr stuff}
140 %************************************************************************
142 mkClassDecl builds a RdrClassDecl, filling in the names for tycon and datacon
143 by deriving them from the name of the class. We fill in the names for the
144 tycon and datacon corresponding to the class, by deriving them from the
145 name of the class itself. This saves recording the names in the interface
146 file (which would be equally good).
148 Similarly for mkConDecl, mkClassOpSig and default-method names.
150 *** See "THE NAMING STORY" in HsDecls ****
153 mkClassDecl (cxt, cname, tyvars) fds sigs mbinds
154 = ClassDecl { tcdCtxt = cxt, tcdLName = cname, tcdTyVars = tyvars,
160 mkTyData new_or_data (L _ (context, tname, tyvars)) ksig data_cons maybe_deriv
161 = TyData { tcdND = new_or_data, tcdCtxt = context, tcdLName = tname,
162 tcdTyVars = tyvars, tcdCons = data_cons,
163 tcdKindSig = ksig, tcdDerivs = maybe_deriv }
167 mkHsNegApp :: LHsExpr RdrName -> HsExpr RdrName
168 -- RdrName If the type checker sees (negate 3#) it will barf, because negate
169 -- can't take an unboxed arg. But that is exactly what it will see when
170 -- we write "-3#". So we have to do the negation right now!
171 mkHsNegApp (L loc e) = f e
172 where f (HsLit (HsIntPrim i)) = HsLit (HsIntPrim (-i))
173 f (HsLit (HsFloatPrim i)) = HsLit (HsFloatPrim (-i))
174 f (HsLit (HsDoublePrim i)) = HsLit (HsDoublePrim (-i))
175 f expr = NegApp (L loc e) noSyntaxExpr
178 %************************************************************************
180 \subsection[cvBinds-etc]{Converting to @HsBinds@, etc.}
182 %************************************************************************
184 Function definitions are restructured here. Each is assumed to be recursive
185 initially, and non recursive definitions are discovered by the dependency
190 -- | Groups together bindings for a single function
191 cvTopDecls :: OrdList (LHsDecl RdrName) -> [LHsDecl RdrName]
192 cvTopDecls decls = go (fromOL decls)
194 go :: [LHsDecl RdrName] -> [LHsDecl RdrName]
196 go (L l (ValD b) : ds) = L l' (ValD b') : go ds'
197 where (L l' b', ds') = getMonoBind (L l b) ds
198 go (d : ds) = d : go ds
200 cvBindGroup :: OrdList (LHsDecl RdrName) -> HsValBinds RdrName
202 = case (cvBindsAndSigs binding) of { (mbs, sigs) ->
206 cvBindsAndSigs :: OrdList (LHsDecl RdrName)
207 -> (Bag (LHsBind RdrName), [LSig RdrName])
208 -- Input decls contain just value bindings and signatures
209 cvBindsAndSigs fb = go (fromOL fb)
211 go [] = (emptyBag, [])
212 go (L l (SigD s) : ds) = (bs, L l s : ss)
213 where (bs,ss) = go ds
214 go (L l (ValD b) : ds) = (b' `consBag` bs, ss)
215 where (b',ds') = getMonoBind (L l b) ds
218 -----------------------------------------------------------------------------
219 -- Group function bindings into equation groups
221 getMonoBind :: LHsBind RdrName -> [LHsDecl RdrName]
222 -> (LHsBind RdrName, [LHsDecl RdrName])
223 -- Suppose (b',ds') = getMonoBind b ds
224 -- ds is a *reversed* list of parsed bindings
225 -- b is a MonoBinds that has just been read off the front
227 -- Then b' is the result of grouping more equations from ds that
228 -- belong with b into a single MonoBinds, and ds' is the depleted
229 -- list of parsed bindings.
231 -- No AndMonoBinds or EmptyMonoBinds here; just single equations
233 getMonoBind (L loc (FunBind lf@(L _ f) inf (MatchGroup mtchs _) _)) binds
237 go mtchs1 loc1 (L loc2 (ValD (FunBind f2 inf2 (MatchGroup mtchs2 _) _)) : binds)
238 | f == unLoc f2 = go (mtchs2++mtchs1) loc binds
239 where loc = combineSrcSpans loc1 loc2
241 = (L loc (FunBind lf inf (mkMatchGroup (reverse mtchs1)) placeHolderNames), binds)
242 -- Reverse the final matches, to get it back in the right order
244 getMonoBind bind binds = (bind, binds)
246 has_args ((L _ (Match args _ _)) : _) = not (null args)
247 -- Don't group together FunBinds if they have
248 -- no arguments. This is necessary now that variable bindings
249 -- with no arguments are now treated as FunBinds rather
250 -- than pattern bindings (tests/rename/should_fail/rnfail002).
254 findSplice :: [LHsDecl a] -> (HsGroup a, Maybe (SpliceDecl a, [LHsDecl a]))
255 findSplice ds = addl emptyRdrGroup ds
257 mkGroup :: [LHsDecl a] -> HsGroup a
258 mkGroup ds = addImpDecls emptyRdrGroup ds
260 addImpDecls :: HsGroup a -> [LHsDecl a] -> HsGroup a
261 -- The decls are imported, and should not have a splice
262 addImpDecls group decls = case addl group decls of
263 (group', Nothing) -> group'
264 other -> panic "addImpDecls"
266 addl :: HsGroup a -> [LHsDecl a] -> (HsGroup a, Maybe (SpliceDecl a, [LHsDecl a]))
267 -- This stuff reverses the declarations (again) but it doesn't matter
270 addl gp [] = (gp, Nothing)
271 addl gp (L l d : ds) = add gp l d ds
274 add :: HsGroup a -> SrcSpan -> HsDecl a -> [LHsDecl a]
275 -> (HsGroup a, Maybe (SpliceDecl a, [LHsDecl a]))
277 add gp l (SpliceD e) ds = (gp, Just (e, ds))
279 -- Class declarations: pull out the fixity signatures to the top
280 add gp@(HsGroup {hs_tyclds = ts, hs_fixds = fs}) l (TyClD d) ds
282 let fsigs = [ L l f | L l (FixSig f) <- tcdSigs d ] in
283 addl (gp { hs_tyclds = L l d : ts, hs_fixds = fsigs ++ fs }) ds
285 addl (gp { hs_tyclds = L l d : ts }) ds
287 -- Signatures: fixity sigs go a different place than all others
288 add gp@(HsGroup {hs_fixds = ts}) l (SigD (FixSig f)) ds
289 = addl (gp {hs_fixds = L l f : ts}) ds
290 add gp@(HsGroup {hs_valds = ts}) l (SigD d) ds
291 = addl (gp {hs_valds = add_sig (L l d) ts}) ds
293 -- Value declarations: use add_bind
294 add gp@(HsGroup {hs_valds = ts}) l (ValD d) ds
295 = addl (gp { hs_valds = add_bind (L l d) ts }) ds
297 -- The rest are routine
298 add gp@(HsGroup {hs_instds = ts}) l (InstD d) ds
299 = addl (gp { hs_instds = L l d : ts }) ds
300 add gp@(HsGroup {hs_defds = ts}) l (DefD d) ds
301 = addl (gp { hs_defds = L l d : ts }) ds
302 add gp@(HsGroup {hs_fords = ts}) l (ForD d) ds
303 = addl (gp { hs_fords = L l d : ts }) ds
304 add gp@(HsGroup {hs_depds = ts}) l (DeprecD d) ds
305 = addl (gp { hs_depds = L l d : ts }) ds
306 add gp@(HsGroup {hs_ruleds = ts}) l (RuleD d) ds
307 = addl (gp { hs_ruleds = L l d : ts }) ds
309 add_bind b (ValBindsIn bs sigs) = ValBindsIn (bs `snocBag` b) sigs
310 add_sig s (ValBindsIn bs sigs) = ValBindsIn bs (s:sigs)
313 %************************************************************************
315 \subsection[PrefixToHS-utils]{Utilities for conversion}
317 %************************************************************************
321 -----------------------------------------------------------------------------
324 -- When parsing data declarations, we sometimes inadvertently parse
325 -- a constructor application as a type (eg. in data T a b = C a b `D` E a b)
326 -- This function splits up the type application, adds any pending
327 -- arguments, and converts the type constructor back into a data constructor.
329 mkPrefixCon :: LHsType RdrName -> [LBangType RdrName]
330 -> P (Located RdrName, HsConDetails RdrName (LBangType RdrName))
334 split (L _ (HsAppTy t u)) ts = split t (u : ts)
335 split (L l (HsTyVar tc)) ts = do data_con <- tyConToDataCon l tc
336 return (data_con, PrefixCon ts)
337 split (L l _) _ = parseError l "parse error in data/newtype declaration"
339 mkRecCon :: Located RdrName -> [([Located RdrName], LBangType RdrName)]
340 -> P (Located RdrName, HsConDetails RdrName (LBangType RdrName))
341 mkRecCon (L loc con) fields
342 = do data_con <- tyConToDataCon loc con
343 return (data_con, RecCon [ (l,t) | (ls,t) <- fields, l <- ls ])
345 tyConToDataCon :: SrcSpan -> RdrName -> P (Located RdrName)
346 tyConToDataCon loc tc
347 | isTcOcc (rdrNameOcc tc)
348 = return (L loc (setRdrNameSpace tc srcDataName))
350 = parseError loc (showSDoc (text "Not a constructor:" <+> quotes (ppr tc)))
352 ----------------------------------------------------------------------------
353 -- Various Syntactic Checks
355 checkInstType :: LHsType RdrName -> P (LHsType RdrName)
356 checkInstType (L l t)
358 HsForAllTy exp tvs ctxt ty -> do
359 dict_ty <- checkDictTy ty
360 return (L l (HsForAllTy exp tvs ctxt dict_ty))
362 HsParTy ty -> checkInstType ty
364 ty -> do dict_ty <- checkDictTy (L l ty)
365 return (L l (HsForAllTy Implicit [] (noLoc []) dict_ty))
367 checkTyVars :: [LHsType RdrName] -> P [LHsTyVarBndr RdrName]
371 -- Check that the name space is correct!
372 chk (L l (HsKindSig (L _ (HsTyVar tv)) k))
373 | isRdrTyVar tv = return (L l (KindedTyVar tv k))
374 chk (L l (HsTyVar tv))
375 | isRdrTyVar tv = return (L l (UserTyVar tv))
377 = parseError l "Type found where type variable expected"
379 checkSynHdr :: LHsType RdrName -> P (Located RdrName, [LHsTyVarBndr RdrName])
380 checkSynHdr ty = do { (_, tc, tvs) <- checkTyClHdr (noLoc []) ty
383 checkTyClHdr :: LHsContext RdrName -> LHsType RdrName
384 -> P (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName])
385 -- The header of a type or class decl should look like
386 -- (C a, D b) => T a b
390 checkTyClHdr (L l cxt) ty
391 = do (tc, tvs) <- gol ty []
393 return (L l cxt, tc, tvs)
395 gol (L l ty) acc = go l ty acc
397 go l (HsTyVar tc) acc
398 | not (isRdrTyVar tc) = checkTyVars acc >>= \ tvs ->
400 go l (HsOpTy t1 tc t2) acc = checkTyVars (t1:t2:acc) >>= \ tvs ->
402 go l (HsParTy ty) acc = gol ty acc
403 go l (HsAppTy t1 t2) acc = gol t1 (t2:acc)
404 go l other acc = parseError l "Malformed LHS to type of class declaration"
406 -- The predicates in a type or class decl must all
407 -- be HsClassPs. They need not all be type variables,
408 -- even in Haskell 98. E.g. class (Monad m, Monad (t m)) => MonadT t m
409 chk_pred (L l (HsClassP _ args)) = return ()
411 = parseError l "Malformed context in type or class declaration"
414 checkContext :: LHsType RdrName -> P (LHsContext RdrName)
418 check (HsTupleTy _ ts) -- (Eq a, Ord b) shows up as a tuple type
419 = do ctx <- mapM checkPred ts
422 check (HsParTy ty) -- to be sure HsParTy doesn't get into the way
425 check (HsTyVar t) -- Empty context shows up as a unit type ()
426 | t == getRdrName unitTyCon = return (L l [])
429 = do p <- checkPred (L l t)
433 checkPred :: LHsType RdrName -> P (LHsPred RdrName)
434 -- Watch out.. in ...deriving( Show )... we use checkPred on
435 -- the list of partially applied predicates in the deriving,
436 -- so there can be zero args.
437 checkPred (L spn (HsPredTy (HsIParam n ty)))
438 = return (L spn (HsIParam n ty))
442 checkl (L l ty) args = check l ty args
444 check _loc (HsTyVar t) args | not (isRdrTyVar t)
445 = return (L spn (HsClassP t args))
446 check _loc (HsAppTy l r) args = checkl l (r:args)
447 check _loc (HsOpTy l (L loc tc) r) args = check loc (HsTyVar tc) (l:r:args)
448 check _loc (HsParTy t) args = checkl t args
449 check loc _ _ = parseError loc "malformed class assertion"
451 checkDictTy :: LHsType RdrName -> P (LHsType RdrName)
452 checkDictTy (L spn ty) = check ty []
454 check (HsTyVar t) args | not (isRdrTyVar t)
455 = return (L spn (HsPredTy (HsClassP t args)))
456 check (HsAppTy l r) args = check (unLoc l) (r:args)
457 check (HsParTy t) args = check (unLoc t) args
458 check _ _ = parseError spn "Malformed context in instance header"
460 ---------------------------------------------------------------------------
461 -- Checking statements in a do-expression
462 -- We parse do { e1 ; e2 ; }
463 -- as [ExprStmt e1, ExprStmt e2]
464 -- checkDo (a) checks that the last thing is an ExprStmt
465 -- (b) returns it separately
466 -- same comments apply for mdo as well
468 checkDo = checkDoMDo "a " "'do'"
469 checkMDo = checkDoMDo "an " "'mdo'"
471 checkDoMDo :: String -> String -> SrcSpan -> [LStmt RdrName] -> P ([LStmt RdrName], LHsExpr RdrName)
472 checkDoMDo pre nm loc [] = parseError loc ("Empty " ++ nm ++ " construct")
473 checkDoMDo pre nm loc ss = do
476 check [L l (ExprStmt e _ _)] = return ([], e)
477 check [L l _] = parseError l ("The last statement in " ++ pre ++ nm ++
478 " construct must be an expression")
483 -- -------------------------------------------------------------------------
484 -- Checking Patterns.
486 -- We parse patterns as expressions and check for valid patterns below,
487 -- converting the expression into a pattern at the same time.
489 checkPattern :: LHsExpr RdrName -> P (LPat RdrName)
490 checkPattern e = checkLPat e
492 checkPatterns :: [LHsExpr RdrName] -> P [LPat RdrName]
493 checkPatterns es = mapM checkPattern es
495 checkLPat :: LHsExpr RdrName -> P (LPat RdrName)
496 checkLPat e@(L l _) = checkPat l e []
498 checkPat :: SrcSpan -> LHsExpr RdrName -> [LPat RdrName] -> P (LPat RdrName)
499 checkPat loc (L l (HsVar c)) args
500 | isRdrDataCon c = return (L loc (ConPatIn (L l c) (PrefixCon args)))
501 checkPat loc (L _ (HsApp f x)) args = do
503 checkPat loc f (x:args)
504 checkPat loc (L _ e) [] = do
507 checkPat loc pat _some_args
510 checkAPat loc e = case e of
511 EWildPat -> return (WildPat placeHolderType)
512 HsVar x | isQual x -> parseError loc ("Qualified variable in pattern: "
514 | otherwise -> return (VarPat x)
515 HsLit l -> return (LitPat l)
517 -- Overloaded numeric patterns (e.g. f 0 x = x)
518 -- Negation is recorded separately, so that the literal is zero or +ve
519 -- NB. Negative *primitive* literals are already handled by
520 -- RdrHsSyn.mkHsNegApp
521 HsOverLit pos_lit -> return (mkNPat pos_lit Nothing)
522 NegApp (L _ (HsOverLit pos_lit)) _
523 -> return (mkNPat pos_lit (Just noSyntaxExpr))
525 ELazyPat e -> checkLPat e >>= (return . LazyPat)
526 EAsPat n e -> checkLPat e >>= (return . AsPat n)
527 ExprWithTySig e t -> checkLPat e >>= \e ->
528 -- Pattern signatures are parsed as sigtypes,
529 -- but they aren't explicit forall points. Hence
530 -- we have to remove the implicit forall here.
532 L _ (HsForAllTy Implicit _ (L _ []) ty) -> ty
535 return (SigPatIn e t')
538 OpApp (L nloc (HsVar n)) (L _ (HsVar plus)) _
539 (L _ (HsOverLit lit@(HsIntegral _ _)))
541 -> return (mkNPlusKPat (L nloc n) lit)
543 plus_RDR = mkUnqual varName FSLIT("+") -- Hack
545 OpApp l op fix r -> checkLPat l >>= \l ->
546 checkLPat r >>= \r ->
548 L cl (HsVar c) | isDataOcc (rdrNameOcc c)
549 -> return (ConPatIn (L cl c) (InfixCon l r))
552 HsPar e -> checkLPat e >>= (return . ParPat)
553 ExplicitList _ es -> mapM (\e -> checkLPat e) es >>= \ps ->
554 return (ListPat ps placeHolderType)
555 ExplicitPArr _ es -> mapM (\e -> checkLPat e) es >>= \ps ->
556 return (PArrPat ps placeHolderType)
558 ExplicitTuple es b -> mapM (\e -> checkLPat e) es >>= \ps ->
559 return (TuplePat ps b)
561 RecordCon c _ fs -> mapM checkPatField fs >>= \fs ->
562 return (ConPatIn c (RecCon fs))
564 HsType ty -> return (TypePat ty)
567 checkPatField :: (Located RdrName, LHsExpr RdrName) -> P (Located RdrName, LPat RdrName)
568 checkPatField (n,e) = do
572 patFail loc = parseError loc "Parse error in pattern"
575 ---------------------------------------------------------------------------
576 -- Check Equation Syntax
580 -> Maybe (LHsType RdrName)
581 -> Located (GRHSs RdrName)
582 -> P (HsBind RdrName)
584 checkValDef lhs opt_sig (L rhs_span grhss)
585 | Just (f,inf,es) <- isFunLhs lhs []
586 = if isQual (unLoc f)
587 then parseError (getLoc f) ("Qualified name in function definition: " ++
588 showRdrName (unLoc f))
589 else do ps <- checkPatterns es
590 let match_span = combineSrcSpans (getLoc lhs) rhs_span
591 matches = mkMatchGroup [L match_span (Match ps opt_sig grhss)]
592 return (FunBind f inf matches placeHolderNames)
593 -- The span of the match covers the entire equation.
594 -- That isn't quite right, but it'll do for now.
596 lhs <- checkPattern lhs
597 return (PatBind lhs grhss placeHolderType placeHolderNames)
603 checkValSig (L l (HsVar v)) ty | isUnqual v = return (Sig (L l v) ty)
604 checkValSig (L l other) ty
605 = parseError l "Type signature given for an expression"
607 -- A variable binding is parsed as a FunBind.
609 isFunLhs :: LHsExpr RdrName -> [LHsExpr RdrName]
610 -> Maybe (Located RdrName, Bool, [LHsExpr RdrName])
611 isFunLhs (L loc e) = isFunLhs' loc e
613 isFunLhs' loc (HsVar f) es
614 | not (isRdrDataCon f) = Just (L loc f, False, es)
615 isFunLhs' loc (HsApp f e) es = isFunLhs f (e:es)
616 isFunLhs' loc (HsPar e) es@(_:_) = isFunLhs e es
617 isFunLhs' loc (OpApp l (L loc' (HsVar op)) fix r) es
618 | not (isRdrDataCon op) = Just (L loc' op, True, (l:r:es))
620 case isFunLhs l es of
621 Just (op', True, j : k : es') ->
623 j : L loc (OpApp k (L loc' (HsVar op)) fix r) : es')
625 isFunLhs' _ _ _ = Nothing
627 ---------------------------------------------------------------------------
628 -- Miscellaneous utilities
630 checkPrecP :: Located Int -> P Int
632 | 0 <= i && i <= maxPrecedence = return i
633 | otherwise = parseError l "Precedence out of range"
638 -> HsRecordBinds RdrName
639 -> P (HsExpr RdrName)
641 mkRecConstrOrUpdate (L l (HsVar c)) loc fs | isRdrDataCon c
642 = return (RecordCon (L l c) noPostTcExpr fs)
643 mkRecConstrOrUpdate exp loc fs@(_:_)
644 = return (RecordUpd exp fs placeHolderType placeHolderType)
645 mkRecConstrOrUpdate _ loc []
646 = parseError loc "Empty record update"
648 -----------------------------------------------------------------------------
649 -- utilities for foreign declarations
651 -- supported calling conventions
653 data CallConv = CCall CCallConv -- ccall or stdcall
656 -- construct a foreign import declaration
660 -> (Located FastString, Located RdrName, LHsType RdrName)
661 -> P (HsDecl RdrName)
662 mkImport (CCall cconv) safety (entity, v, ty) = do
663 importSpec <- parseCImport entity cconv safety v
664 return (ForD (ForeignImport v ty importSpec False))
665 mkImport (DNCall ) _ (entity, v, ty) = do
666 spec <- parseDImport entity
667 return $ ForD (ForeignImport v ty (DNImport spec) False)
669 -- parse the entity string of a foreign import declaration for the `ccall' or
670 -- `stdcall' calling convention'
672 parseCImport :: Located FastString
677 parseCImport (L loc entity) cconv safety v
678 -- FIXME: we should allow white space around `dynamic' and `wrapper' -=chak
679 | entity == FSLIT ("dynamic") =
680 return $ CImport cconv safety nilFS nilFS (CFunction DynamicTarget)
681 | entity == FSLIT ("wrapper") =
682 return $ CImport cconv safety nilFS nilFS CWrapper
683 | otherwise = parse0 (unpackFS entity)
685 -- using the static keyword?
686 parse0 (' ': rest) = parse0 rest
687 parse0 ('s':'t':'a':'t':'i':'c':rest) = parse1 rest
688 parse0 rest = parse1 rest
689 -- check for header file name
690 parse1 "" = parse4 "" nilFS False nilFS
691 parse1 (' ':rest) = parse1 rest
692 parse1 str@('&':_ ) = parse2 str nilFS
693 parse1 str@('[':_ ) = parse3 str nilFS False
695 | ".h" `isSuffixOf` first = parse2 rest (mkFastString first)
696 | otherwise = parse4 str nilFS False nilFS
698 (first, rest) = break (\c -> c == ' ' || c == '&' || c == '[') str
699 -- check for address operator (indicating a label import)
700 parse2 "" header = parse4 "" header False nilFS
701 parse2 (' ':rest) header = parse2 rest header
702 parse2 ('&':rest) header = parse3 rest header True
703 parse2 str@('[':_ ) header = parse3 str header False
704 parse2 str header = parse4 str header False nilFS
705 -- check for library object name
706 parse3 (' ':rest) header isLbl = parse3 rest header isLbl
707 parse3 ('[':rest) header isLbl =
708 case break (== ']') rest of
709 (lib, ']':rest) -> parse4 rest header isLbl (mkFastString lib)
710 _ -> parseError loc "Missing ']' in entity"
711 parse3 str header isLbl = parse4 str header isLbl nilFS
712 -- check for name of C function
713 parse4 "" header isLbl lib = build (mkExtName (unLoc v)) header isLbl lib
714 parse4 (' ':rest) header isLbl lib = parse4 rest header isLbl lib
715 parse4 str header isLbl lib
716 | all (== ' ') rest = build (mkFastString first) header isLbl lib
717 | otherwise = parseError loc "Malformed entity string"
719 (first, rest) = break (== ' ') str
721 build cid header False lib = return $
722 CImport cconv safety header lib (CFunction (StaticTarget cid))
723 build cid header True lib = return $
724 CImport cconv safety header lib (CLabel cid )
727 -- Unravel a dotnet spec string.
729 parseDImport :: Located FastString -> P DNCallSpec
730 parseDImport (L loc entity) = parse0 comps
732 comps = words (unpackFS entity)
736 | x == "static" = parse1 True xs
737 | otherwise = parse1 False (x:xs)
740 parse1 isStatic (x:xs)
741 | x == "method" = parse2 isStatic DNMethod xs
742 | x == "field" = parse2 isStatic DNField xs
743 | x == "ctor" = parse2 isStatic DNConstructor xs
744 parse1 isStatic xs = parse2 isStatic DNMethod xs
747 parse2 isStatic kind (('[':x):xs) =
750 vs | last vs == ']' -> parse3 isStatic kind (init vs) xs
751 parse2 isStatic kind xs = parse3 isStatic kind "" xs
753 parse3 isStatic kind assem [x] =
754 return (DNCallSpec isStatic kind assem x
755 -- these will be filled in once known.
756 (error "FFI-dotnet-args")
757 (error "FFI-dotnet-result"))
758 parse3 _ _ _ _ = d'oh
760 d'oh = parseError loc "Malformed entity string"
762 -- construct a foreign export declaration
765 -> (Located FastString, Located RdrName, LHsType RdrName)
766 -> P (HsDecl RdrName)
767 mkExport (CCall cconv) (L loc entity, v, ty) = return $
768 ForD (ForeignExport v ty (CExport (CExportStatic entity' cconv)) False)
770 entity' | nullFastString entity = mkExtName (unLoc v)
772 mkExport DNCall (L loc entity, v, ty) =
773 parseError (getLoc v){-TODO: not quite right-}
774 "Foreign export is not yet supported for .NET"
776 -- Supplying the ext_name in a foreign decl is optional; if it
777 -- isn't there, the Haskell name is assumed. Note that no transformation
778 -- of the Haskell name is then performed, so if you foreign export (++),
779 -- it's external name will be "++". Too bad; it's important because we don't
780 -- want z-encoding (e.g. names with z's in them shouldn't be doubled)
781 -- (This is why we use occNameUserString.)
783 mkExtName :: RdrName -> CLabelString
784 mkExtName rdrNm = mkFastString (occNameUserString (rdrNameOcc rdrNm))
788 -----------------------------------------------------------------------------
792 showRdrName :: RdrName -> String
793 showRdrName r = showSDoc (ppr r)
795 parseError :: SrcSpan -> String -> P a
796 parseError span s = failSpanMsgP span s