2 % (c) The AQUA Project, Glasgow University, 1996-1998
4 \section[RdrHsSyn]{Specialisations of the @HsSyn@ syntax for the reader}
6 (Well, really, for specialisations involving @RdrName@s, even if
7 they are used somewhat later on in the compiler...)
46 extractHsTyRdrNames, extractSomeHsTyRdrNames,
47 extractHsTysRdrNames, extractSomeHsTysRdrNames,
48 extractRuleBndrsTyVars,
49 extractHsCtxtRdrTyVars, extractGenericPatTyVars,
51 mkHsOpApp, mkClassDecl, mkClassOpSigDM, mkConDecl,
52 mkHsNegApp, mkNPlusKPat, mkHsIntegral, mkHsFractional,
57 cvValSig, cvClassOpSig, cvInstDeclSig,
61 #include "HsVersions.h"
63 import HsSyn -- Lots of it
64 import OccName ( mkClassTyConOcc, mkClassDataConOcc, mkWorkerOcc,
65 mkSuperDictSelOcc, mkDefaultMethodOcc, mkGenOcc1,
68 import PrelNames ( minusName, negateName, fromIntegerName, fromRationalName )
69 import RdrName ( RdrName, isRdrTyVar, mkRdrUnqual, rdrNameOcc,
72 import BasicTypes ( RecFlag(..) )
73 import Class ( DefMeth (..) )
77 %************************************************************************
79 \subsection{Type synonyms}
81 %************************************************************************
84 type RdrNameArithSeqInfo = ArithSeqInfo RdrName RdrNamePat
85 type RdrNameBangType = BangType RdrName
86 type RdrNameClassOpSig = Sig RdrName
87 type RdrNameConDecl = ConDecl RdrName
88 type RdrNameConDetails = ConDetails RdrName
89 type RdrNameContext = HsContext RdrName
90 type RdrNameHsDecl = HsDecl RdrName RdrNamePat
91 type RdrNameDefaultDecl = DefaultDecl RdrName
92 type RdrNameForeignDecl = ForeignDecl RdrName
93 type RdrNameGRHS = GRHS RdrName RdrNamePat
94 type RdrNameGRHSs = GRHSs RdrName RdrNamePat
95 type RdrNameHsBinds = HsBinds RdrName RdrNamePat
96 type RdrNameHsExpr = HsExpr RdrName RdrNamePat
97 type RdrNameHsModule = HsModule RdrName RdrNamePat
98 type RdrNameIE = IE RdrName
99 type RdrNameImportDecl = ImportDecl RdrName
100 type RdrNameInstDecl = InstDecl RdrName RdrNamePat
101 type RdrNameMatch = Match RdrName RdrNamePat
102 type RdrNameMonoBinds = MonoBinds RdrName RdrNamePat
103 type RdrNamePat = InPat RdrName
104 type RdrNameHsType = HsType RdrName
105 type RdrNameHsTyVar = HsTyVarBndr RdrName
106 type RdrNameSig = Sig RdrName
107 type RdrNameStmt = Stmt RdrName RdrNamePat
108 type RdrNameTyClDecl = TyClDecl RdrName RdrNamePat
110 type RdrNameRuleBndr = RuleBndr RdrName
111 type RdrNameRuleDecl = RuleDecl RdrName RdrNamePat
112 type RdrNameDeprecation = DeprecDecl RdrName
113 type RdrNameFixitySig = FixitySig RdrName
115 type RdrNameHsRecordBinds = HsRecordBinds RdrName RdrNamePat
119 %************************************************************************
121 \subsection{A few functions over HsSyn at RdrName}
123 %************************************************************************
125 @extractHsTyRdrNames@ finds the free variables of a HsType
126 It's used when making the for-alls explicit.
129 extractHsTyRdrNames :: RdrNameHsType -> [RdrName]
130 extractHsTyRdrNames ty = nub (extract_ty ty [])
132 extractHsTysRdrNames :: [RdrNameHsType] -> [RdrName]
133 extractHsTysRdrNames tys = nub (extract_tys tys)
135 extractSomeHsTyRdrNames :: (RdrName -> Bool) -> RdrNameHsType -> [RdrName]
136 extractSomeHsTyRdrNames ok ty = nub (filter ok (extract_ty ty []))
138 extractSomeHsTysRdrNames :: (RdrName -> Bool) -> [RdrNameHsType] -> [RdrName]
139 extractSomeHsTysRdrNames ok tys = nub (filter ok (extract_tys tys))
141 extractRuleBndrsTyVars :: [RuleBndr RdrName] -> [RdrName]
142 extractRuleBndrsTyVars bndrs = filter isRdrTyVar (nub (foldr go [] bndrs))
144 go (RuleBndr _) acc = acc
145 go (RuleBndrSig _ ty) acc = extract_ty ty acc
147 extractHsCtxtRdrNames :: HsContext RdrName -> [RdrName]
148 extractHsCtxtRdrNames ty = nub (extract_ctxt ty [])
149 extractHsCtxtRdrTyVars :: HsContext RdrName -> [RdrName]
150 extractHsCtxtRdrTyVars ty = filter isRdrTyVar (extractHsCtxtRdrNames ty)
152 extract_ctxt ctxt acc = foldr extract_pred acc ctxt
154 extract_pred (HsClassP cls tys) acc = foldr extract_ty (cls : acc) tys
155 extract_pred (HsIParam n ty) acc = extract_ty ty acc
157 extract_tys tys = foldr extract_ty [] tys
159 extract_ty (HsAppTy ty1 ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
160 extract_ty (HsListTy ty) acc = extract_ty ty acc
161 extract_ty (HsTupleTy _ tys) acc = foldr extract_ty acc tys
162 extract_ty (HsFunTy ty1 ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
163 extract_ty (HsPredTy p) acc = extract_pred p acc
164 extract_ty (HsTyVar tv) acc = tv : acc
165 extract_ty (HsForAllTy Nothing ctxt ty) acc = extract_ctxt ctxt (extract_ty ty acc)
167 extract_ty (HsOpTy ty1 nam ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
168 extract_ty (HsNumTy num) acc = acc
170 extract_ty (HsForAllTy (Just tvs) ctxt ty)
172 (filter (`notElem` locals) $
173 extract_ctxt ctxt (extract_ty ty []))
175 locals = hsTyVarNames tvs
177 extractGenericPatTyVars :: RdrNameMonoBinds -> [RdrName]
178 -- Get the type variables out of the type patterns in a bunch of
179 -- possibly-generic bindings in a class declaration
180 extractGenericPatTyVars binds
181 = filter isRdrTyVar (nub (get binds []))
183 get (AndMonoBinds b1 b2) acc = get b1 (get b2 acc)
184 get (FunMonoBind _ _ ms _) acc = foldr get_m acc ms
187 get_m (Match _ (TypePatIn ty : _) _ _) acc = extract_ty ty acc
188 get_m other acc = acc
192 %************************************************************************
194 \subsection{Construction functions for Rdr stuff}
196 %************************************************************************
198 mkClassDecl builds a RdrClassDecl, filling in the names for tycon and datacon
199 by deriving them from the name of the class. We fill in the names for the
200 tycon and datacon corresponding to the class, by deriving them from the
201 name of the class itself. This saves recording the names in the interface
202 file (which would be equally good).
204 Similarly for mkConDecl, mkClassOpSig and default-method names.
206 *** See "THE NAMING STORY" in HsDecls ****
209 mkClassDecl cxt cname tyvars fds sigs mbinds loc
210 = ClassDecl { tcdCtxt = cxt, tcdName = cname, tcdTyVars = tyvars,
211 tcdFDs = fds, tcdSigs = sigs, tcdMeths = mbinds,
212 tcdSysNames = new_names, tcdLoc = loc }
214 cls_occ = rdrNameOcc cname
215 data_occ = mkClassDataConOcc cls_occ
216 dname = mkRdrUnqual data_occ
217 dwname = mkRdrUnqual (mkWorkerOcc data_occ)
218 tname = mkRdrUnqual (mkClassTyConOcc cls_occ)
219 sc_sel_names = [ mkRdrUnqual (mkSuperDictSelOcc n cls_occ)
220 | n <- [1..length cxt]]
221 -- We number off the superclass selectors, 1, 2, 3 etc so that we
222 -- can construct names for the selectors. Thus
223 -- class (C a, C b) => D a b where ...
224 -- gives superclass selectors
226 -- (We used to call them D_C, but now we can have two different
227 -- superclasses both called C!)
228 new_names = mkClassDeclSysNames (tname, dname, dwname, sc_sel_names)
231 mkTyData new_or_data context tname list_var list_con i maybe src
232 = let t_occ = rdrNameOcc tname
233 name1 = mkRdrUnqual (mkGenOcc1 t_occ)
234 name2 = mkRdrUnqual (mkGenOcc2 t_occ)
235 in TyData { tcdND = new_or_data, tcdCtxt = context, tcdName = tname,
236 tcdTyVars = list_var, tcdCons = list_con, tcdNCons = i,
237 tcdDerivs = maybe, tcdLoc = src, tcdSysNames = [name1, name2] }
239 mkClassOpSigDM op ty loc
240 = ClassOpSig op (DefMeth dm_rn) ty loc
242 dm_rn = mkRdrUnqual (mkDefaultMethodOcc (rdrNameOcc op))
244 mkConDecl cname ex_vars cxt details loc
245 = ConDecl cname wkr_name ex_vars cxt details loc
247 wkr_name = mkRdrUnqual (mkWorkerOcc (rdrNameOcc cname))
251 mkHsNegApp :: RdrNameHsExpr -> RdrNameHsExpr
252 -- If the type checker sees (negate 3#) it will barf, because negate
253 -- can't take an unboxed arg. But that is exactly what it will see when
254 -- we write "-3#". So we have to do the negation right now!
256 -- We also do the same service for boxed literals, because this function
257 -- is also used for patterns (which, remember, are parsed as expressions)
258 -- and pattern don't have negation in them.
260 -- Finally, it's important to represent minBound as minBound, and not
261 -- as (negate (-minBound)), becuase the latter is out of range.
263 mkHsNegApp (HsLit (HsIntPrim i)) = HsLit (HsIntPrim (-i))
264 mkHsNegApp (HsLit (HsFloatPrim i)) = HsLit (HsFloatPrim (-i))
265 mkHsNegApp (HsLit (HsDoublePrim i)) = HsLit (HsDoublePrim (-i))
267 mkHsNegApp (HsOverLit (HsIntegral i n)) = HsOverLit (HsIntegral (-i) n)
268 mkHsNegApp (HsOverLit (HsFractional f n)) = HsOverLit (HsFractional (-f) n)
269 mkHsNegApp expr = NegApp expr negateName
272 A useful function for building @OpApps@. The operator is always a
273 variable, and we don't know the fixity yet.
276 mkHsOpApp e1 op e2 = OpApp e1 (HsVar op) (error "mkOpApp:fixity") e2
279 These are the bits of syntax that contain rebindable names
280 See RnEnv.lookupSyntaxName
283 mkHsIntegral i = HsIntegral i fromIntegerName
284 mkHsFractional f = HsFractional f fromRationalName
285 mkNPlusKPat n k = NPlusKPatIn n k minusName
289 %************************************************************************
291 \subsection[rdrBinding]{Bindings straight out of the parser}
293 %************************************************************************
297 = -- On input we use the Empty/And form rather than a list
299 | RdrAndBindings RdrBinding RdrBinding
301 -- Value bindings havn't been united with their
303 | RdrValBinding RdrNameMonoBinds
305 -- Signatures are mysterious; we can't
306 -- tell if its a Sig or a ClassOpSig,
307 -- so we just save the pieces:
310 -- The remainder all fit into the main HsDecl form
311 | RdrHsDecl RdrNameHsDecl
313 type SigConverter = RdrNameSig -> RdrNameSig
320 (Maybe RdrNameHsType)
324 %************************************************************************
326 \subsection[cvDecls]{Convert various top-level declarations}
328 %************************************************************************
330 We make a point not to throw any user-pragma ``sigs'' at
331 these conversion functions:
334 cvValSig, cvClassOpSig, cvInstDeclSig :: SigConverter
338 cvInstDeclSig sig = sig
340 cvClassOpSig (Sig var poly_ty src_loc) = mkClassOpSigDM var poly_ty src_loc
341 cvClassOpSig sig = sig
345 %************************************************************************
347 \subsection[cvBinds-etc]{Converting to @HsBinds@, @MonoBinds@, etc.}
349 %************************************************************************
351 Function definitions are restructured here. Each is assumed to be recursive
352 initially, and non recursive definitions are discovered by the dependency
356 cvBinds :: SigConverter -> RdrBinding -> RdrNameHsBinds
357 -- The mysterious SigConverter converts Sigs to ClassOpSigs
358 -- in class declarations. Mostly it's just an identity function
360 cvBinds sig_cvtr binding
361 = case (cvMonoBindsAndSigs sig_cvtr binding) of { (mbs, sigs) ->
362 MonoBind mbs sigs Recursive
367 cvMonoBindsAndSigs :: SigConverter
369 -> (RdrNameMonoBinds, [RdrNameSig])
371 cvMonoBindsAndSigs sig_cvtr fb
372 = mangle_bind (EmptyMonoBinds, []) fb
374 mangle_bind acc RdrNullBind
377 mangle_bind acc (RdrAndBindings fb1 fb2)
378 = mangle_bind (mangle_bind acc fb1) fb2
380 mangle_bind (b_acc, s_acc) (RdrSig sig)
381 = (b_acc, sig_cvtr sig : s_acc)
383 mangle_bind (b_acc, s_acc) (RdrValBinding binding)
384 = (b_acc `AndMonoBinds` binding, s_acc)
388 %************************************************************************
390 \subsection[PrefixToHS-utils]{Utilities for conversion}
392 %************************************************************************
394 Separate declarations into all the various kinds:
397 cvTopDecls :: RdrBinding -> [RdrNameHsDecl]
400 (top_decls, mono_binds, sigs) = go ([], EmptyMonoBinds, []) bind
402 (ValD (MonoBind mono_binds sigs Recursive) : top_decls)
404 go acc RdrNullBind = acc
405 go acc (RdrAndBindings b1 b2) = go (go acc b1) b2
406 go (topds, mbs, sigs) (RdrHsDecl d) = (d : topds, mbs, sigs)
407 go (topds, mbs, sigs) (RdrSig (FixSig d)) = (FixD d : topds, mbs, sigs)
408 go (topds, mbs, sigs) (RdrSig sig) = (topds, mbs, sig:sigs)
409 go (topds, mbs, sigs) (RdrValBinding bind) = (topds, mbs `AndMonoBinds` bind, sigs)