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, extractHsTyRdrTyVars,
47 extractHsCtxtRdrTyVars, extractGenericPatTyVars,
49 mkHsOpApp, mkClassDecl, mkClassOpSigDM, mkConDecl,
50 mkHsNegApp, mkNPlusKPat, mkHsIntegral, mkHsFractional,
56 cvValSig, cvClassOpSig, cvInstDeclSig,
60 #include "HsVersions.h"
62 import HsSyn -- Lots of it
63 import OccName ( mkClassTyConOcc, mkClassDataConOcc, mkWorkerOcc,
64 mkSuperDictSelOcc, mkDefaultMethodOcc, mkGenOcc1,
67 import RdrName ( RdrName, isRdrTyVar, mkRdrUnqual, rdrNameOcc, isRdrTyVar )
69 import BasicTypes ( RecFlag(..) )
70 import Class ( DefMeth (..) )
74 %************************************************************************
76 \subsection{Type synonyms}
78 %************************************************************************
81 type RdrNameArithSeqInfo = ArithSeqInfo RdrName RdrNamePat
82 type RdrNameBangType = BangType RdrName
83 type RdrNameClassOpSig = Sig RdrName
84 type RdrNameConDecl = ConDecl RdrName
85 type RdrNameConDetails = ConDetails RdrName
86 type RdrNameContext = HsContext RdrName
87 type RdrNameHsDecl = HsDecl RdrName RdrNamePat
88 type RdrNameDefaultDecl = DefaultDecl RdrName
89 type RdrNameForeignDecl = ForeignDecl RdrName
90 type RdrNameGRHS = GRHS RdrName RdrNamePat
91 type RdrNameGRHSs = GRHSs RdrName RdrNamePat
92 type RdrNameHsBinds = HsBinds RdrName RdrNamePat
93 type RdrNameHsExpr = HsExpr RdrName RdrNamePat
94 type RdrNameHsModule = HsModule RdrName RdrNamePat
95 type RdrNameIE = IE RdrName
96 type RdrNameImportDecl = ImportDecl RdrName
97 type RdrNameInstDecl = InstDecl RdrName RdrNamePat
98 type RdrNameMatch = Match RdrName RdrNamePat
99 type RdrNameMonoBinds = MonoBinds RdrName RdrNamePat
100 type RdrNamePat = InPat RdrName
101 type RdrNameHsType = HsType RdrName
102 type RdrNameHsTyVar = HsTyVarBndr RdrName
103 type RdrNameSig = Sig RdrName
104 type RdrNameStmt = Stmt RdrName RdrNamePat
105 type RdrNameTyClDecl = TyClDecl RdrName RdrNamePat
107 type RdrNameRuleBndr = RuleBndr RdrName
108 type RdrNameRuleDecl = RuleDecl RdrName RdrNamePat
109 type RdrNameDeprecation = DeprecDecl RdrName
110 type RdrNameFixitySig = FixitySig RdrName
112 type RdrNameHsRecordBinds = HsRecordBinds RdrName RdrNamePat
116 %************************************************************************
118 \subsection{A few functions over HsSyn at RdrName}
120 %************************************************************************
122 @extractHsTyRdrNames@ finds the free variables of a HsType
123 It's used when making the for-alls explicit.
126 extractHsTyRdrNames :: RdrNameHsType -> [RdrName]
127 extractHsTyRdrNames ty = nub (extract_ty ty [])
129 extractHsTyRdrTyVars :: RdrNameHsType -> [RdrName]
130 extractHsTyRdrTyVars ty = nub (filter isRdrTyVar (extract_ty ty []))
132 extractHsCtxtRdrNames :: HsContext RdrName -> [RdrName]
133 extractHsCtxtRdrNames ty = nub (extract_ctxt ty [])
134 extractHsCtxtRdrTyVars :: HsContext RdrName -> [RdrName]
135 extractHsCtxtRdrTyVars ty = filter isRdrTyVar (extractHsCtxtRdrNames ty)
137 extract_ctxt ctxt acc = foldr extract_pred acc ctxt
139 extract_pred (HsClassP cls tys) acc = foldr extract_ty (cls : acc) tys
140 extract_pred (HsIParam n ty) acc = extract_ty ty acc
142 extract_tys tys = foldr extract_ty [] tys
144 extract_ty (HsAppTy ty1 ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
145 extract_ty (HsListTy ty) acc = extract_ty ty acc
146 extract_ty (HsPArrTy ty) acc = extract_ty ty acc
147 extract_ty (HsTupleTy _ tys) acc = foldr extract_ty acc tys
148 extract_ty (HsFunTy ty1 ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
149 extract_ty (HsPredTy p) acc = extract_pred p acc
150 extract_ty (HsTyVar tv) acc = tv : acc
151 extract_ty (HsForAllTy Nothing cx ty) acc = extract_ctxt cx (extract_ty ty acc)
152 extract_ty (HsOpTy ty1 nam ty2) acc = extract_ty ty1 (extract_ty ty2 acc)
153 extract_ty (HsParTy ty) acc = extract_ty ty acc
155 extract_ty (HsNumTy num) acc = acc
156 extract_ty (HsKindSig ty k) acc = extract_ty ty acc
157 extract_ty (HsForAllTy (Just tvs) ctxt ty)
159 (filter (`notElem` locals) $
160 extract_ctxt ctxt (extract_ty ty []))
162 locals = hsTyVarNames tvs
164 extractGenericPatTyVars :: RdrNameMonoBinds -> [RdrName]
165 -- Get the type variables out of the type patterns in a bunch of
166 -- possibly-generic bindings in a class declaration
167 extractGenericPatTyVars binds
168 = filter isRdrTyVar (nub (get binds []))
170 get (AndMonoBinds b1 b2) acc = get b1 (get b2 acc)
171 get (FunMonoBind _ _ ms _) acc = foldr get_m acc ms
174 get_m (Match (TypePatIn ty : _) _ _) acc = extract_ty ty acc
175 get_m other acc = acc
179 %************************************************************************
181 \subsection{Construction functions for Rdr stuff}
183 %************************************************************************
185 mkClassDecl builds a RdrClassDecl, filling in the names for tycon and datacon
186 by deriving them from the name of the class. We fill in the names for the
187 tycon and datacon corresponding to the class, by deriving them from the
188 name of the class itself. This saves recording the names in the interface
189 file (which would be equally good).
191 Similarly for mkConDecl, mkClassOpSig and default-method names.
193 *** See "THE NAMING STORY" in HsDecls ****
196 mkClassDecl (cxt, cname, tyvars) fds sigs mbinds loc
197 = ClassDecl { tcdCtxt = cxt, tcdName = cname, tcdTyVars = tyvars,
198 tcdFDs = fds, tcdSigs = sigs, tcdMeths = mbinds,
199 tcdSysNames = new_names, tcdLoc = loc }
201 cls_occ = rdrNameOcc cname
202 data_occ = mkClassDataConOcc cls_occ
203 dname = mkRdrUnqual data_occ
204 dwname = mkRdrUnqual (mkWorkerOcc data_occ)
205 tname = mkRdrUnqual (mkClassTyConOcc cls_occ)
206 sc_sel_names = [ mkRdrUnqual (mkSuperDictSelOcc n cls_occ)
207 | n <- [1..length cxt]]
208 -- We number off the superclass selectors, 1, 2, 3 etc so that we
209 -- can construct names for the selectors. Thus
210 -- class (C a, C b) => D a b where ...
211 -- gives superclass selectors
213 -- (We used to call them D_C, but now we can have two different
214 -- superclasses both called C!)
215 new_names = mkClassDeclSysNames (tname, dname, dwname, sc_sel_names)
217 mkTyData new_or_data (context, tname, tyvars) data_cons maybe src
218 = let t_occ = rdrNameOcc tname
219 name1 = mkRdrUnqual (mkGenOcc1 t_occ)
220 name2 = mkRdrUnqual (mkGenOcc2 t_occ)
221 in TyData { tcdND = new_or_data, tcdCtxt = context, tcdName = tname,
222 tcdTyVars = tyvars, tcdCons = data_cons,
223 tcdDerivs = maybe, tcdLoc = src, tcdSysNames = [name1, name2] }
225 mkClassOpSigDM op ty loc
226 = ClassOpSig op (DefMeth dm_rn) ty loc
228 dm_rn = mkRdrUnqual (mkDefaultMethodOcc (rdrNameOcc op))
230 mkConDecl cname ex_vars cxt details loc
231 = ConDecl cname wkr_name ex_vars cxt details loc
233 wkr_name = mkRdrUnqual (mkWorkerOcc (rdrNameOcc cname))
237 mkHsNegApp :: RdrNameHsExpr -> RdrNameHsExpr
238 -- If the type checker sees (negate 3#) it will barf, because negate
239 -- can't take an unboxed arg. But that is exactly what it will see when
240 -- we write "-3#". So we have to do the negation right now!
242 mkHsNegApp (HsLit (HsIntPrim i)) = HsLit (HsIntPrim (-i))
243 mkHsNegApp (HsLit (HsFloatPrim i)) = HsLit (HsFloatPrim (-i))
244 mkHsNegApp (HsLit (HsDoublePrim i)) = HsLit (HsDoublePrim (-i))
245 mkHsNegApp expr = NegApp expr placeHolderName
248 A useful function for building @OpApps@. The operator is always a
249 variable, and we don't know the fixity yet.
252 mkHsOpApp e1 op e2 = OpApp e1 (HsVar op) (error "mkOpApp:fixity") e2
255 These are the bits of syntax that contain rebindable names
256 See RnEnv.lookupSyntaxName
259 mkHsIntegral i = HsIntegral i placeHolderName
260 mkHsFractional f = HsFractional f placeHolderName
261 mkNPlusKPat n k = NPlusKPatIn n k placeHolderName
262 mkHsDo ctxt stmts loc = HsDo ctxt stmts [] placeHolderType loc
266 %************************************************************************
268 \subsection[rdrBinding]{Bindings straight out of the parser}
270 %************************************************************************
274 = -- On input we use the Empty/And form rather than a list
276 | RdrAndBindings RdrBinding RdrBinding
278 -- Value bindings havn't been united with their
280 | RdrValBinding RdrNameMonoBinds
282 -- Signatures are mysterious; we can't
283 -- tell if its a Sig or a ClassOpSig,
284 -- so we just save the pieces:
287 -- The remainder all fit into the main HsDecl form
288 | RdrHsDecl RdrNameHsDecl
290 type SigConverter = RdrNameSig -> RdrNameSig
297 (Maybe RdrNameHsType)
301 %************************************************************************
303 \subsection[cvDecls]{Convert various top-level declarations}
305 %************************************************************************
307 We make a point not to throw any user-pragma ``sigs'' at
308 these conversion functions:
311 cvValSig, cvClassOpSig, cvInstDeclSig :: SigConverter
315 cvInstDeclSig sig = sig
317 cvClassOpSig (Sig var poly_ty src_loc) = mkClassOpSigDM var poly_ty src_loc
318 cvClassOpSig sig = sig
322 %************************************************************************
324 \subsection[cvBinds-etc]{Converting to @HsBinds@, @MonoBinds@, etc.}
326 %************************************************************************
328 Function definitions are restructured here. Each is assumed to be recursive
329 initially, and non recursive definitions are discovered by the dependency
333 cvBinds :: SigConverter -> RdrBinding -> RdrNameHsBinds
334 -- The mysterious SigConverter converts Sigs to ClassOpSigs
335 -- in class declarations. Mostly it's just an identity function
337 cvBinds sig_cvtr binding
338 = case (cvMonoBindsAndSigs sig_cvtr binding) of { (mbs, sigs) ->
339 MonoBind mbs sigs Recursive
344 cvMonoBindsAndSigs :: SigConverter
346 -> (RdrNameMonoBinds, [RdrNameSig])
348 cvMonoBindsAndSigs sig_cvtr fb
349 = mangle_bind (EmptyMonoBinds, []) fb
351 mangle_bind acc RdrNullBind
354 mangle_bind acc (RdrAndBindings fb1 fb2)
355 = mangle_bind (mangle_bind acc fb1) fb2
357 mangle_bind (b_acc, s_acc) (RdrSig sig)
358 = (b_acc, sig_cvtr sig : s_acc)
360 mangle_bind (b_acc, s_acc) (RdrValBinding binding)
361 = (b_acc `AndMonoBinds` binding, s_acc)
365 %************************************************************************
367 \subsection[PrefixToHS-utils]{Utilities for conversion}
369 %************************************************************************
371 Separate declarations into all the various kinds:
374 cvTopDecls :: RdrBinding -> [RdrNameHsDecl]
377 (top_decls, mono_binds, sigs) = go ([], EmptyMonoBinds, []) bind
379 (ValD (MonoBind mono_binds sigs Recursive) : top_decls)
381 go acc RdrNullBind = acc
382 go acc (RdrAndBindings b1 b2) = go (go acc b1) b2
383 go (topds, mbs, sigs) (RdrHsDecl d) = (d : topds, mbs, sigs)
384 go (topds, mbs, sigs) (RdrSig (FixSig d)) = (FixD d : topds, mbs, sigs)
385 go (topds, mbs, sigs) (RdrSig sig) = (topds, mbs, sig:sigs)
386 go (topds, mbs, sigs) (RdrValBinding bind) = (topds, mbs `AndMonoBinds` bind, sigs)