2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 This module converts Template Haskell syntax into HsSyn
9 module Convert( convertToHsExpr, convertToHsDecls, convertToHsType ) where
11 #include "HsVersions.h"
13 import Language.Haskell.TH as TH hiding (sigP)
14 import Language.Haskell.TH.Syntax as TH
17 import RdrName ( RdrName, mkRdrUnqual, mkRdrQual, mkOrig, nameRdrName, getRdrName )
18 import Module ( ModuleName, mkModuleName )
19 import RdrHsSyn ( mkHsIntegral, mkHsFractional, mkClassDecl, mkTyData )
20 import Name ( mkInternalName )
21 import qualified OccName
22 import SrcLoc ( SrcLoc, generatedSrcLoc, noLoc, unLoc, Located(..),
23 noSrcSpan, SrcSpan, srcLocSpan, noSrcLoc )
25 import TysWiredIn ( unitTyCon, tupleTyCon, trueDataCon, falseDataCon )
26 import BasicTypes( Boxity(..), RecFlag(Recursive) )
27 import ForeignCall ( Safety(..), CCallConv(..), CCallTarget(..),
29 import HsDecls ( CImportSpec(..), ForeignImport(..), ForeignExport(..),
31 import FastString( FastString, mkFastString, nilFS )
32 import Char ( ord, isAscii, isAlphaNum, isAlpha )
33 import List ( partition )
34 import Unique ( Unique, mkUniqueGrimily )
35 import ErrUtils (Message)
36 import GLAEXTS ( Int#, Int(..) )
37 import Bag ( emptyBag, consBag )
41 -------------------------------------------------------------------
42 convertToHsDecls :: [TH.Dec] -> [Either (LHsDecl RdrName) Message]
43 convertToHsDecls ds = map cvt_ltop ds
45 mk_con con = L loc0 $ mk_nlcon con
47 mk_nlcon con = case con of
49 -> ConDecl (noLoc (cName c)) noExistentials noContext
50 (PrefixCon (map mk_arg strtys))
52 -> ConDecl (noLoc (cName c)) noExistentials noContext
53 (RecCon (map mk_id_arg varstrtys))
55 -> ConDecl (noLoc (cName c)) noExistentials noContext
56 (InfixCon (mk_arg st1) (mk_arg st2))
57 ForallC tvs ctxt (ForallC tvs' ctxt' con')
58 -> mk_nlcon (ForallC (tvs ++ tvs') (ctxt ++ ctxt') con')
59 ForallC tvs ctxt con' -> case mk_nlcon con' of
60 ConDecl l [] (L _ []) x ->
61 ConDecl l (cvt_tvs tvs) (cvt_context ctxt) x
62 c -> panic "ForallC: Can't happen"
63 mk_arg (IsStrict, ty) = noLoc $ HsBangTy HsStrict (cvtType ty)
64 mk_arg (NotStrict, ty) = cvtType ty
66 mk_id_arg (i, IsStrict, ty)
67 = (noLoc (vName i), noLoc $ HsBangTy HsStrict (cvtType ty))
68 mk_id_arg (i, NotStrict, ty)
69 = (noLoc (vName i), cvtType ty)
71 mk_derivs [] = Nothing
72 mk_derivs cs = Just [noLoc $ HsPredTy $ HsClassP (tconName c) [] | c <- cs]
74 cvt_ltop :: TH.Dec -> Either (LHsDecl RdrName) Message
75 cvt_ltop d = case cvt_top d of
76 Left d -> Left (L loc0 d)
79 cvt_top :: TH.Dec -> Either (HsDecl RdrName) Message
80 cvt_top d@(TH.ValD _ _ _) = Left $ Hs.ValD (unLoc (cvtd d))
81 cvt_top d@(TH.FunD _ _) = Left $ Hs.ValD (unLoc (cvtd d))
83 cvt_top (TySynD tc tvs rhs)
84 = Left $ TyClD (TySynonym (noLoc (tconName tc)) (cvt_tvs tvs) (cvtType rhs))
86 cvt_top (DataD ctxt tc tvs constrs derivs)
87 = Left $ TyClD (mkTyData DataType
88 (noLoc (cvt_context ctxt, noLoc (tconName tc), cvt_tvs tvs))
89 Nothing (map mk_con constrs)
92 cvt_top (NewtypeD ctxt tc tvs constr derivs)
93 = Left $ TyClD (mkTyData NewType
94 (noLoc (cvt_context ctxt, noLoc (tconName tc), cvt_tvs tvs))
95 Nothing [mk_con constr]
98 cvt_top (ClassD ctxt cl tvs decs)
99 = Left $ TyClD (mkClassDecl (cvt_context ctxt, noLoc (tconName cl), cvt_tvs tvs)
103 (binds,sigs) = cvtBindsAndSigs decs
105 cvt_top (InstanceD tys ty decs)
106 = Left $ InstD (InstDecl (noLoc inst_ty) binds sigs)
108 (binds, sigs) = cvtBindsAndSigs decs
109 inst_ty = mkImplicitHsForAllTy (cvt_context tys) (noLoc (HsPredTy (cvt_pred ty)))
111 cvt_top (TH.SigD nm typ) = Left $ Hs.SigD (Sig (noLoc (vName nm)) (cvtType typ))
113 cvt_top (ForeignD (ImportF callconv safety from nm typ))
115 Just (c_header, cis) ->
116 let i = CImport callconv' safety' c_header nilFS cis
117 in Left $ ForD (ForeignImport (noLoc (vName nm)) (cvtType typ) i False)
118 Nothing -> Right $ text (show from)
119 <+> ptext SLIT("is not a valid ccall impent")
120 where callconv' = case callconv of
122 StdCall -> StdCallConv
123 safety' = case safety of
125 Safe -> PlaySafe False
126 Threadsafe -> PlaySafe True
127 parsed = parse_ccall_impent (TH.nameBase nm) from
129 cvt_top (ForeignD (ExportF callconv as nm typ))
130 = let e = CExport (CExportStatic (mkFastString as) callconv')
131 in Left $ ForD (ForeignExport (noLoc (vName nm)) (cvtType typ) e False)
132 where callconv' = case callconv of
134 StdCall -> StdCallConv
136 parse_ccall_impent :: String -> String -> Maybe (FastString, CImportSpec)
137 parse_ccall_impent nm s
138 = case lex_ccall_impent s of
139 Just ["dynamic"] -> Just (nilFS, CFunction DynamicTarget)
140 Just ["wrapper"] -> Just (nilFS, CWrapper)
141 Just ("static":ts) -> parse_ccall_impent_static nm ts
142 Just ts -> parse_ccall_impent_static nm ts
145 parse_ccall_impent_static :: String
147 -> Maybe (FastString, CImportSpec)
148 parse_ccall_impent_static nm ts
149 = let ts' = case ts of
150 [ "&", cid] -> [ cid]
151 [fname, "&" ] -> [fname ]
152 [fname, "&", cid] -> [fname, cid]
155 [ cid] | is_cid cid -> Just (nilFS, mk_cid cid)
156 [fname, cid] | is_cid cid -> Just (mkFastString fname, mk_cid cid)
157 [ ] -> Just (nilFS, mk_cid nm)
158 [fname ] -> Just (mkFastString fname, mk_cid nm)
160 where is_cid :: String -> Bool
161 is_cid x = all (/= '.') x && (isAlpha (head x) || head x == '_')
162 mk_cid :: String -> CImportSpec
163 mk_cid = CFunction . StaticTarget . mkFastString
165 lex_ccall_impent :: String -> Maybe [String]
166 lex_ccall_impent "" = Just []
167 lex_ccall_impent ('&':xs) = fmap ("&":) $ lex_ccall_impent xs
168 lex_ccall_impent (' ':xs) = lex_ccall_impent xs
169 lex_ccall_impent ('\t':xs) = lex_ccall_impent xs
170 lex_ccall_impent xs = case span is_valid xs of
172 (t, xs') -> fmap (t:) $ lex_ccall_impent xs'
173 where is_valid :: Char -> Bool
174 is_valid c = isAscii c && (isAlphaNum c || c `elem` "._")
180 -------------------------------------------------------------------
181 convertToHsExpr :: TH.Exp -> LHsExpr RdrName
182 convertToHsExpr = cvtl
184 cvtl e = noLoc (cvt e)
186 cvt (VarE s) = HsVar (vName s)
187 cvt (ConE s) = HsVar (cName s)
189 | overloadedLit l = HsOverLit (cvtOverLit l)
190 | otherwise = HsLit (cvtLit l)
192 cvt (AppE x y) = HsApp (cvtl x) (cvtl y)
193 cvt (LamE ps e) = HsLam (mkMatchGroup [mkSimpleMatch (map cvtlp ps) (cvtl e)])
194 cvt (TupE [e]) = cvt e
195 cvt (TupE es) = ExplicitTuple(map cvtl es) Boxed
196 cvt (CondE x y z) = HsIf (cvtl x) (cvtl y) (cvtl z)
197 cvt (LetE ds e) = HsLet (cvtdecs ds) (cvtl e)
198 cvt (CaseE e ms) = HsCase (cvtl e) (mkMatchGroup (map cvtm ms))
199 cvt (DoE ss) = HsDo DoExpr (cvtstmts ss) [] void
200 cvt (CompE ss) = HsDo ListComp (cvtstmts ss) [] void
201 cvt (ArithSeqE dd) = ArithSeqIn (cvtdd dd)
202 cvt (ListE xs) = ExplicitList void (map cvtl xs)
203 cvt (InfixE (Just x) s (Just y))
204 = HsPar (noLoc $ OpApp (cvtl x) (cvtl s) undefined (cvtl y))
205 cvt (InfixE Nothing s (Just y)) = SectionR (cvtl s) (cvtl y)
206 cvt (InfixE (Just x) s Nothing ) = SectionL (cvtl x) (cvtl s)
207 cvt (InfixE Nothing s Nothing ) = cvt s -- Can I indicate this is an infix thing?
208 cvt (SigE e t) = ExprWithTySig (cvtl e) (cvtType t)
209 cvt (RecConE c flds) = RecordCon (noLoc (cName c)) (map (\(x,y) -> (noLoc (vName x), cvtl y)) flds)
210 cvt (RecUpdE e flds) = RecordUpd (cvtl e) (map (\(x,y) -> (noLoc (vName x), cvtl y)) flds)
212 cvtdecs :: [TH.Dec] -> [HsBindGroup RdrName]
214 cvtdecs ds = [HsBindGroup binds sigs Recursive]
216 (binds, sigs) = cvtBindsAndSigs ds
219 = (cvtds non_sigs, map cvtSig sigs)
221 (sigs, non_sigs) = partition sigP ds
223 cvtSig (TH.SigD nm typ) = noLoc (Hs.Sig (noLoc (vName nm)) (cvtType typ))
225 cvtds :: [TH.Dec] -> LHsBinds RdrName
227 cvtds (d:ds) = cvtd d `consBag` cvtds ds
229 cvtd :: TH.Dec -> LHsBind RdrName
230 -- Used only for declarations in a 'let/where' clause,
231 -- not for top level decls
232 cvtd (TH.ValD (TH.VarP s) body ds)
233 = noLoc $ FunBind (noLoc (vName s)) False (mkMatchGroup [cvtclause (Clause [] body ds)])
235 = noLoc $ FunBind (noLoc (vName nm)) False (mkMatchGroup (map cvtclause cls))
236 cvtd (TH.ValD p body ds)
237 = noLoc $ PatBind (cvtlp p) (GRHSs (cvtguard body) (cvtdecs ds)) void
239 cvtd d = cvtPanic "Illegal kind of declaration in where clause"
243 cvtclause :: TH.Clause -> Hs.LMatch RdrName
244 cvtclause (Clause ps body wheres)
245 = noLoc $ Hs.Match (map cvtlp ps) Nothing (GRHSs (cvtguard body) (cvtdecs wheres))
249 cvtdd :: Range -> ArithSeqInfo RdrName
250 cvtdd (FromR x) = (From (cvtl x))
251 cvtdd (FromThenR x y) = (FromThen (cvtl x) (cvtl y))
252 cvtdd (FromToR x y) = (FromTo (cvtl x) (cvtl y))
253 cvtdd (FromThenToR x y z) = (FromThenTo (cvtl x) (cvtl y) (cvtl z))
256 cvtstmts :: [TH.Stmt] -> [Hs.LStmt RdrName]
257 cvtstmts [] = [] -- this is probably an error as every [stmt] should end with ResultStmt
258 cvtstmts [NoBindS e] = [nlResultStmt (cvtl e)] -- when its the last element use ResultStmt
259 cvtstmts (NoBindS e : ss) = nlExprStmt (cvtl e) : cvtstmts ss
260 cvtstmts (TH.BindS p e : ss) = nlBindStmt (cvtlp p) (cvtl e) : cvtstmts ss
261 cvtstmts (TH.LetS ds : ss) = nlLetStmt (cvtdecs ds) : cvtstmts ss
262 cvtstmts (TH.ParS dss : ss) = nlParStmt [(cvtstmts ds, undefined) | ds <- dss] : cvtstmts ss
264 cvtm :: TH.Match -> Hs.LMatch RdrName
265 cvtm (TH.Match p body wheres)
266 = noLoc (Hs.Match [cvtlp p] Nothing (GRHSs (cvtguard body) (cvtdecs wheres)))
268 cvtguard :: TH.Body -> [LGRHS RdrName]
269 cvtguard (GuardedB pairs) = map cvtpair pairs
270 cvtguard (NormalB e) = [noLoc (GRHS [ nlResultStmt (cvtl e) ])]
272 cvtpair :: (TH.Guard,TH.Exp) -> LGRHS RdrName
273 cvtpair (NormalG x,y) = noLoc (GRHS [nlBindStmt truePat (cvtl x),
274 nlResultStmt (cvtl y)])
275 cvtpair (PatG x,y) = noLoc (GRHS (cvtstmts x ++ [nlResultStmt (cvtl y)]))
277 cvtOverLit :: Lit -> HsOverLit
278 cvtOverLit (IntegerL i) = mkHsIntegral i
279 cvtOverLit (RationalL r) = mkHsFractional r
280 -- An Integer is like an an (overloaded) '3' in a Haskell source program
281 -- Similarly 3.5 for fractionals
283 cvtLit :: Lit -> HsLit
284 cvtLit (IntPrimL i) = HsIntPrim i
285 cvtLit (FloatPrimL f) = HsFloatPrim f
286 cvtLit (DoublePrimL f) = HsDoublePrim f
287 cvtLit (CharL c) = HsChar c
288 cvtLit (StringL s) = HsString (mkFastString s)
290 cvtlp :: TH.Pat -> Hs.LPat RdrName
291 cvtlp pat = noLoc (cvtp pat)
293 cvtp :: TH.Pat -> Hs.Pat RdrName
295 | overloadedLit l = NPatIn (cvtOverLit l) Nothing -- Not right for negative
296 -- patterns; need to think
298 | otherwise = Hs.LitPat (cvtLit l)
299 cvtp (TH.VarP s) = Hs.VarPat(vName s)
300 cvtp (TupP [p]) = cvtp p
301 cvtp (TupP ps) = TuplePat (map cvtlp ps) Boxed
302 cvtp (ConP s ps) = ConPatIn (noLoc (cName s)) (PrefixCon (map cvtlp ps))
303 cvtp (InfixP p1 s p2)
304 = ConPatIn (noLoc (cName s)) (InfixCon (cvtlp p1) (cvtlp p2))
305 cvtp (TildeP p) = LazyPat (cvtlp p)
306 cvtp (TH.AsP s p) = AsPat (noLoc (vName s)) (cvtlp p)
307 cvtp TH.WildP = WildPat void
308 cvtp (RecP c fs) = ConPatIn (noLoc (cName c)) $ Hs.RecCon (map (\(s,p) -> (noLoc (vName s),cvtlp p)) fs)
309 cvtp (ListP ps) = ListPat (map cvtlp ps) void
310 cvtp (SigP p t) = SigPatIn (cvtlp p) (cvtType t)
312 -----------------------------------------------------------
313 -- Types and type variables
315 cvt_tvs :: [TH.Name] -> [LHsTyVarBndr RdrName]
316 cvt_tvs tvs = map (noLoc . UserTyVar . tName) tvs
318 cvt_context :: Cxt -> LHsContext RdrName
319 cvt_context tys = noLoc (map (noLoc . cvt_pred) tys)
321 cvt_pred :: TH.Type -> HsPred RdrName
322 cvt_pred ty = case split_ty_app ty of
323 (ConT tc, tys) -> HsClassP (tconName tc) (map cvtType tys)
324 (VarT tv, tys) -> HsClassP (tName tv) (map cvtType tys)
325 other -> cvtPanic "Malformed predicate" (text (TH.pprint ty))
327 convertToHsType = cvtType
329 cvtType :: TH.Type -> LHsType RdrName
330 cvtType ty = trans (root ty [])
331 where root (AppT a b) zs = root a (cvtType b : zs)
334 trans (TupleT n,args)
335 | length args == n = noLoc (HsTupleTy Boxed args)
336 | n == 0 = foldl nlHsAppTy (nlHsTyVar (getRdrName unitTyCon)) args
337 | otherwise = foldl nlHsAppTy (nlHsTyVar (getRdrName (tupleTyCon Boxed n))) args
338 trans (ArrowT, [x,y]) = nlHsFunTy x y
339 trans (ListT, [x]) = noLoc (HsListTy x)
341 trans (VarT nm, args) = foldl nlHsAppTy (nlHsTyVar (tName nm)) args
342 trans (ConT tc, args) = foldl nlHsAppTy (nlHsTyVar (tconName tc)) args
344 trans (ForallT tvs cxt ty, []) = noLoc $ mkExplicitHsForAllTy
345 (cvt_tvs tvs) (cvt_context cxt) (cvtType ty)
347 split_ty_app :: TH.Type -> (TH.Type, [TH.Type])
348 split_ty_app ty = go ty []
350 go (AppT f a) as = go f (a:as)
353 -----------------------------------------------------------
355 sigP (TH.SigD _ _) = True
359 -----------------------------------------------------------
360 cvtPanic :: String -> SDoc -> b
361 cvtPanic herald thing
362 = pprPanic herald (thing $$ ptext SLIT("When splicing generated code into the program"))
364 -----------------------------------------------------------
365 -- some useful things
367 truePat = nlConPat (getRdrName trueDataCon) []
368 falsePat = nlConPat (getRdrName falseDataCon) []
370 overloadedLit :: Lit -> Bool
371 -- True for literals that Haskell treats as overloaded
372 overloadedLit (IntegerL l) = True
373 overloadedLit (RationalL l) = True
374 overloadedLit l = False
377 void = placeHolderType
380 loc0 = srcLocSpan generatedSrcLoc
382 --------------------------------------------------------------------
383 -- Turning Name back into RdrName
384 --------------------------------------------------------------------
387 vName :: TH.Name -> RdrName
388 vName = thRdrName OccName.varName
390 -- Constructor function names; this is Haskell source, hence srcDataName
391 cName :: TH.Name -> RdrName
392 cName = thRdrName OccName.srcDataName
394 -- Type variable names
395 tName :: TH.Name -> RdrName
396 tName = thRdrName OccName.tvName
398 -- Type Constructor names
399 tconName = thRdrName OccName.tcName
401 thRdrName :: OccName.NameSpace -> TH.Name -> RdrName
402 -- This turns a Name into a RdrName
403 -- The last case is slightly interesting. It constructs a
404 -- unique name from the unique in the TH thingy, so that the renamer
405 -- won't mess about. I hope. (Another possiblity would be to generate
406 -- "x_77" etc, but that could conceivably clash.)
408 thRdrName ns (TH.Name occ (TH.NameG ns' mod)) = mkOrig (mk_mod mod) (mk_occ ns occ)
409 thRdrName ns (TH.Name occ TH.NameS) = mkDynName ns occ
410 thRdrName ns (TH.Name occ (TH.NameU uniq)) = nameRdrName (mkInternalName (mk_uniq uniq) (mk_occ ns occ) noSrcLoc)
412 mk_uniq :: Int# -> Unique
413 mk_uniq u = mkUniqueGrimily (I# u)
415 -- The packing and unpacking is rather turgid :-(
416 mk_occ :: OccName.NameSpace -> TH.OccName -> OccName.OccName
417 mk_occ ns occ = OccName.mkOccFS ns (mkFastString (TH.occString occ))
419 mk_mod :: TH.ModName -> ModuleName
420 mk_mod mod = mkModuleName (TH.modString mod)
422 mkDynName :: OccName.NameSpace -> TH.OccName -> RdrName
423 -- Parse the string to see if it has a "." in it
424 -- so we know whether to generate a qualified or unqualified name
425 -- It's a bit tricky because we need to parse
426 -- Foo.Baz.x as Qual Foo.Baz x
427 -- So we parse it from back to front
430 = split [] (reverse (TH.occString th_occ))
432 split occ [] = mkRdrUnqual (mk_occ occ)
433 split occ ('.':rev) = mkRdrQual (mk_mod (reverse rev)) (mk_occ occ)
434 split occ (c:rev) = split (c:occ) rev
436 mk_occ occ = OccName.mkOccFS ns (mkFastString occ)
437 mk_mod mod = mkModuleName mod