3 % (c) The University of Glasgow, 1992-2006
6 Here we collect a variety of helper functions that construct or
7 analyse HsSyn. All these functions deal with generic HsSyn; functions
8 which deal with the intantiated versions are located elsewhere:
10 Parameterised by Module
11 ---------------- -------------
12 RdrName parser/RdrHsSyn
19 mkHsPar, mkHsApp, mkHsConApp, mkSimpleHsAlt,
20 mkSimpleMatch, unguardedGRHSs, unguardedRHS,
21 mkMatchGroup, mkMatch, mkHsLam,
22 mkHsWrap, mkLHsWrap, mkHsWrapCoI, coiToHsWrapper, mkHsDictLet,
25 nlHsTyApp, nlHsVar, nlHsLit, nlHsApp, nlHsApps, nlHsIntLit, nlHsVarApps,
26 nlHsDo, nlHsOpApp, nlHsLam, nlHsPar, nlHsIf, nlHsCase, nlList,
27 mkLHsTupleExpr, mkLHsVarTuple, missingTupArg,
30 mkFunBind, mkVarBind, mkHsVarBind, mk_easy_FunBind, mk_FunBind,
33 mkHsIntegral, mkHsFractional, mkHsIsString, mkHsString,
36 mkNPat, mkNPlusKPat, nlVarPat, nlLitPat, nlConVarPat, nlConPat, nlInfixConPat,
37 nlNullaryConPat, nlWildConPat, nlWildPat, nlTuplePat,
40 mkHsAppTy, userHsTyVarBndrs,
41 nlHsAppTy, nlHsTyVar, nlHsFunTy, nlHsTyConApp,
44 mkTransformStmt, mkTransformByStmt, mkExprStmt, mkBindStmt,
45 mkGroupUsingStmt, mkGroupByStmt, mkGroupByUsingStmt,
46 emptyRecStmt, mkRecStmt,
49 unqualSplice, mkHsSpliceTy, mkHsSplice, mkHsQuasiQuote, unqualQuasiQuote,
55 collectLocalBinders, collectHsValBinders,
56 collectHsBindsBinders, collectHsBindBinders, collectMethodBinders,
57 collectPatBinders, collectPatsBinders,
58 collectLStmtsBinders, collectStmtsBinders,
59 collectLStmtBinders, collectStmtBinders,
60 collectSigTysFromPats, collectSigTysFromPat,
62 hsTyClDeclBinders, hsTyClDeclsBinders, hsConDeclsBinders,
63 hsForeignDeclsBinders, hsGroupBinders
89 %************************************************************************
91 Some useful helpers for constructing syntax
93 %************************************************************************
95 These functions attempt to construct a not-completely-useless SrcSpan
96 from their components, compared with the nl* functions below which
97 just attach noSrcSpan to everything.
100 mkHsPar :: LHsExpr id -> LHsExpr id
101 mkHsPar e = L (getLoc e) (HsPar e)
103 mkSimpleMatch :: [LPat id] -> LHsExpr id -> LMatch id
104 mkSimpleMatch pats rhs
106 Match pats Nothing (unguardedGRHSs rhs)
110 (pat:_) -> combineSrcSpans (getLoc pat) (getLoc rhs)
112 unguardedGRHSs :: LHsExpr id -> GRHSs id
113 unguardedGRHSs rhs = GRHSs (unguardedRHS rhs) emptyLocalBinds
115 unguardedRHS :: LHsExpr id -> [LGRHS id]
116 unguardedRHS rhs@(L loc _) = [L loc (GRHS [] rhs)]
118 mkHsAppTy :: LHsType name -> LHsType name -> LHsType name
119 mkHsAppTy t1 t2 = addCLoc t1 t2 (HsAppTy t1 t2)
121 mkHsApp :: LHsExpr name -> LHsExpr name -> LHsExpr name
122 mkHsApp e1 e2 = addCLoc e1 e2 (HsApp e1 e2)
124 nlHsTyApp :: name -> [Type] -> LHsExpr name
125 nlHsTyApp fun_id tys = noLoc (HsWrap (mkWpTyApps tys) (HsVar fun_id))
127 mkLHsWrap :: HsWrapper -> LHsExpr id -> LHsExpr id
128 mkLHsWrap co_fn (L loc e) = L loc (mkHsWrap co_fn e)
130 mkHsWrap :: HsWrapper -> HsExpr id -> HsExpr id
131 mkHsWrap co_fn e | isIdHsWrapper co_fn = e
132 | otherwise = HsWrap co_fn e
134 mkHsWrapCoI :: CoercionI -> HsExpr id -> HsExpr id
135 mkHsWrapCoI IdCo e = e
136 mkHsWrapCoI (ACo co) e = mkHsWrap (WpCast co) e
138 coiToHsWrapper :: CoercionI -> HsWrapper
139 coiToHsWrapper IdCo = idHsWrapper
140 coiToHsWrapper (ACo co) = WpCast co
142 mkHsLam :: [LPat id] -> LHsExpr id -> LHsExpr id
143 mkHsLam pats body = mkHsPar (L (getLoc body) (HsLam matches))
145 matches = mkMatchGroup [mkSimpleMatch pats body]
147 mkMatchGroup :: [LMatch id] -> MatchGroup id
148 mkMatchGroup matches = MatchGroup matches placeHolderType
150 mkHsDictLet :: LHsBinds Id -> LHsExpr Id -> LHsExpr Id
151 -- Used for the dictionary bindings gotten from TcSimplify
152 -- We make them recursive to be on the safe side
153 mkHsDictLet binds expr
154 | isEmptyLHsBinds binds = expr
155 | otherwise = L (getLoc expr) (HsLet (HsValBinds val_binds) expr)
157 val_binds = ValBindsOut [(Recursive, binds)] []
159 mkHsConApp :: DataCon -> [Type] -> [HsExpr Id] -> LHsExpr Id
160 -- Used for constructing dictionary terms etc, so no locations
161 mkHsConApp data_con tys args
162 = foldl mk_app (nlHsTyApp (dataConWrapId data_con) tys) args
164 mk_app f a = noLoc (HsApp f (noLoc a))
166 mkSimpleHsAlt :: LPat id -> LHsExpr id -> LMatch id
167 -- A simple lambda with a single pattern, no binds, no guards; pre-typechecking
168 mkSimpleHsAlt pat expr
169 = mkSimpleMatch [pat] expr
171 -------------------------------
172 -- These are the bits of syntax that contain rebindable names
173 -- See RnEnv.lookupSyntaxName
175 mkHsIntegral :: Integer -> PostTcType -> HsOverLit id
176 mkHsFractional :: Rational -> PostTcType -> HsOverLit id
177 mkHsIsString :: FastString -> PostTcType -> HsOverLit id
178 mkHsDo :: HsStmtContext Name -> [LStmt id] -> LHsExpr id -> HsExpr id
180 mkNPat :: HsOverLit id -> Maybe (SyntaxExpr id) -> Pat id
181 mkNPlusKPat :: Located id -> HsOverLit id -> Pat id
183 mkTransformStmt :: [LStmt idL] -> LHsExpr idR -> StmtLR idL idR
184 mkTransformByStmt :: [LStmt idL] -> LHsExpr idR -> LHsExpr idR -> StmtLR idL idR
186 mkExprStmt :: LHsExpr idR -> StmtLR idL idR
187 mkBindStmt :: LPat idL -> LHsExpr idR -> StmtLR idL idR
189 emptyRecStmt :: StmtLR idL idR
190 mkRecStmt :: [LStmtLR idL idR] -> StmtLR idL idR
193 mkHsIntegral i = OverLit (HsIntegral i) noRebindableInfo noSyntaxExpr
194 mkHsFractional f = OverLit (HsFractional f) noRebindableInfo noSyntaxExpr
195 mkHsIsString s = OverLit (HsIsString s) noRebindableInfo noSyntaxExpr
197 noRebindableInfo :: Bool
198 noRebindableInfo = error "noRebindableInfo" -- Just another placeholder;
200 mkHsDo ctxt stmts body = HsDo ctxt stmts body placeHolderType
202 mkNPat lit neg = NPat lit neg noSyntaxExpr
203 mkNPlusKPat id lit = NPlusKPat id lit noSyntaxExpr noSyntaxExpr
205 mkTransformStmt stmts usingExpr = TransformStmt stmts [] usingExpr Nothing
206 mkTransformByStmt stmts usingExpr byExpr = TransformStmt stmts [] usingExpr (Just byExpr)
208 mkGroupUsingStmt :: [LStmt idL] -> LHsExpr idR -> StmtLR idL idR
209 mkGroupByStmt :: [LStmt idL] -> LHsExpr idR -> StmtLR idL idR
210 mkGroupByUsingStmt :: [LStmt idL] -> LHsExpr idR -> LHsExpr idR -> StmtLR idL idR
212 mkGroupUsingStmt stmts usingExpr = GroupStmt stmts [] Nothing (Left usingExpr)
213 mkGroupByStmt stmts byExpr = GroupStmt stmts [] (Just byExpr) (Right noSyntaxExpr)
214 mkGroupByUsingStmt stmts byExpr usingExpr = GroupStmt stmts [] (Just byExpr) (Left usingExpr)
216 mkExprStmt expr = ExprStmt expr noSyntaxExpr placeHolderType
217 mkBindStmt pat expr = BindStmt pat expr noSyntaxExpr noSyntaxExpr
219 emptyRecStmt = RecStmt { recS_stmts = [], recS_later_ids = [], recS_rec_ids = []
220 , recS_ret_fn = noSyntaxExpr, recS_mfix_fn = noSyntaxExpr
221 , recS_bind_fn = noSyntaxExpr
222 , recS_rec_rets = [], recS_dicts = emptyLHsBinds }
224 mkRecStmt stmts = emptyRecStmt { recS_stmts = stmts }
226 -------------------------------
227 --- A useful function for building @OpApps@. The operator is always a
228 -- variable, and we don't know the fixity yet.
229 mkHsOpApp :: LHsExpr id -> id -> LHsExpr id -> HsExpr id
230 mkHsOpApp e1 op e2 = OpApp e1 (noLoc (HsVar op)) (error "mkOpApp:fixity") e2
232 mkHsSplice :: LHsExpr RdrName -> HsSplice RdrName
233 mkHsSplice e = HsSplice unqualSplice e
235 mkHsSpliceTy :: LHsExpr RdrName -> HsType RdrName
236 mkHsSpliceTy e = HsSpliceTy (mkHsSplice e) emptyFVs placeHolderKind
238 unqualSplice :: RdrName
239 unqualSplice = mkRdrUnqual (mkVarOccFS (fsLit "splice"))
240 -- A name (uniquified later) to
241 -- identify the splice
243 mkHsQuasiQuote :: RdrName -> SrcSpan -> FastString -> HsQuasiQuote RdrName
244 mkHsQuasiQuote quoter span quote = HsQuasiQuote quoter span quote
246 unqualQuasiQuote :: RdrName
247 unqualQuasiQuote = mkRdrUnqual (mkVarOccFS (fsLit "quasiquote"))
248 -- A name (uniquified later) to
249 -- identify the quasi-quote
251 mkHsString :: String -> HsLit
252 mkHsString s = HsString (mkFastString s)
255 userHsTyVarBndrs :: [Located name] -> [Located (HsTyVarBndr name)]
256 userHsTyVarBndrs bndrs = [ L loc (UserTyVar v placeHolderKind) | L loc v <- bndrs ]
260 %************************************************************************
262 Constructing syntax with no location info
264 %************************************************************************
267 nlHsVar :: id -> LHsExpr id
268 nlHsVar n = noLoc (HsVar n)
270 nlHsLit :: HsLit -> LHsExpr id
271 nlHsLit n = noLoc (HsLit n)
273 nlVarPat :: id -> LPat id
274 nlVarPat n = noLoc (VarPat n)
276 nlLitPat :: HsLit -> LPat id
277 nlLitPat l = noLoc (LitPat l)
279 nlHsApp :: LHsExpr id -> LHsExpr id -> LHsExpr id
280 nlHsApp f x = noLoc (HsApp f x)
282 nlHsIntLit :: Integer -> LHsExpr id
283 nlHsIntLit n = noLoc (HsLit (HsInt n))
285 nlHsApps :: id -> [LHsExpr id] -> LHsExpr id
286 nlHsApps f xs = foldl nlHsApp (nlHsVar f) xs
288 nlHsVarApps :: id -> [id] -> LHsExpr id
289 nlHsVarApps f xs = noLoc (foldl mk (HsVar f) (map HsVar xs))
291 mk f a = HsApp (noLoc f) (noLoc a)
293 nlConVarPat :: id -> [id] -> LPat id
294 nlConVarPat con vars = nlConPat con (map nlVarPat vars)
296 nlInfixConPat :: id -> LPat id -> LPat id -> LPat id
297 nlInfixConPat con l r = noLoc (ConPatIn (noLoc con) (InfixCon l r))
299 nlConPat :: id -> [LPat id] -> LPat id
300 nlConPat con pats = noLoc (ConPatIn (noLoc con) (PrefixCon pats))
302 nlNullaryConPat :: id -> LPat id
303 nlNullaryConPat con = noLoc (ConPatIn (noLoc con) (PrefixCon []))
305 nlWildConPat :: DataCon -> LPat RdrName
306 nlWildConPat con = noLoc (ConPatIn (noLoc (getRdrName con))
307 (PrefixCon (nOfThem (dataConSourceArity con) nlWildPat)))
310 nlWildPat = noLoc (WildPat placeHolderType) -- Pre-typechecking
312 nlHsDo :: HsStmtContext Name -> [LStmt id] -> LHsExpr id -> LHsExpr id
313 nlHsDo ctxt stmts body = noLoc (mkHsDo ctxt stmts body)
315 nlHsOpApp :: LHsExpr id -> id -> LHsExpr id -> LHsExpr id
316 nlHsOpApp e1 op e2 = noLoc (mkHsOpApp e1 op e2)
318 nlHsLam :: LMatch id -> LHsExpr id
319 nlHsPar :: LHsExpr id -> LHsExpr id
320 nlHsIf :: LHsExpr id -> LHsExpr id -> LHsExpr id -> LHsExpr id
321 nlHsCase :: LHsExpr id -> [LMatch id] -> LHsExpr id
322 nlList :: [LHsExpr id] -> LHsExpr id
324 nlHsLam match = noLoc (HsLam (mkMatchGroup [match]))
325 nlHsPar e = noLoc (HsPar e)
326 nlHsIf cond true false = noLoc (HsIf cond true false)
327 nlHsCase expr matches = noLoc (HsCase expr (mkMatchGroup matches))
328 nlList exprs = noLoc (ExplicitList placeHolderType exprs)
330 nlHsAppTy :: LHsType name -> LHsType name -> LHsType name
331 nlHsTyVar :: name -> LHsType name
332 nlHsFunTy :: LHsType name -> LHsType name -> LHsType name
334 nlHsAppTy f t = noLoc (HsAppTy f t)
335 nlHsTyVar x = noLoc (HsTyVar x)
336 nlHsFunTy a b = noLoc (HsFunTy a b)
338 nlHsTyConApp :: name -> [LHsType name] -> LHsType name
339 nlHsTyConApp tycon tys = foldl nlHsAppTy (nlHsTyVar tycon) tys
342 Tuples. All these functions are *pre-typechecker* because they lack
346 mkLHsTupleExpr :: [LHsExpr a] -> LHsExpr a
347 -- Makes a pre-typechecker boxed tuple, deals with 1 case
348 mkLHsTupleExpr [e] = e
349 mkLHsTupleExpr es = noLoc $ ExplicitTuple (map Present es) Boxed
351 mkLHsVarTuple :: [a] -> LHsExpr a
352 mkLHsVarTuple ids = mkLHsTupleExpr (map nlHsVar ids)
354 nlTuplePat :: [LPat id] -> Boxity -> LPat id
355 nlTuplePat pats box = noLoc (TuplePat pats box placeHolderType)
357 missingTupArg :: HsTupArg a
358 missingTupArg = Missing placeHolderType
361 %************************************************************************
363 Bindings; with a location at the top
365 %************************************************************************
368 mkFunBind :: Located id -> [LMatch id] -> HsBind id
369 -- Not infix, with place holders for coercion and free vars
370 mkFunBind fn ms = FunBind { fun_id = fn, fun_infix = False, fun_matches = mkMatchGroup ms,
371 fun_co_fn = idHsWrapper, bind_fvs = placeHolderNames,
375 mkHsVarBind :: SrcSpan -> id -> LHsExpr id -> LHsBind id
376 mkHsVarBind loc var rhs = mk_easy_FunBind loc var [] rhs
378 mkVarBind :: id -> LHsExpr id -> LHsBind id
379 mkVarBind var rhs = L (getLoc rhs) $
380 VarBind { var_id = var, var_rhs = rhs, var_inline = False }
383 mk_easy_FunBind :: SrcSpan -> id -> [LPat id]
384 -> LHsExpr id -> LHsBind id
386 mk_easy_FunBind loc fun pats expr
387 = L loc $ mkFunBind (L loc fun) [mkMatch pats expr emptyLocalBinds]
390 mk_FunBind :: SrcSpan -> id
391 -> [([LPat id], LHsExpr id)]
394 mk_FunBind _ _ [] = panic "TcGenDeriv:mk_FunBind"
395 mk_FunBind loc fun pats_and_exprs
396 = L loc $ mkFunBind (L loc fun) matches
398 matches = [mkMatch p e emptyLocalBinds | (p,e) <-pats_and_exprs]
401 mkMatch :: [LPat id] -> LHsExpr id -> HsLocalBinds id -> LMatch id
402 mkMatch pats expr binds
403 = noLoc (Match (map paren pats) Nothing
404 (GRHSs (unguardedRHS expr) binds))
406 paren lp@(L l p) | hsPatNeedsParens p = L l (ParPat lp)
411 %************************************************************************
415 %************************************************************************
417 Get all the binders in some HsBindGroups, IN THE ORDER OF APPEARANCE. eg.
425 it should return [x, y, f, a, b] (remember, order important).
427 Note [Collect binders only after renaming]
428 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
429 These functions should only be used on HsSyn *after* the renamer,
430 to return a [Name] or [Id]. Before renaming the record punning
431 and wild-card mechanism makes it hard to know what is bound.
432 So these functions should not be applied to (HsSyn RdrName)
435 ----------------- Bindings --------------------------
436 collectLocalBinders :: HsLocalBindsLR idL idR -> [idL]
437 collectLocalBinders (HsValBinds val_binds) = collectHsValBinders val_binds
438 collectLocalBinders (HsIPBinds _) = []
439 collectLocalBinders EmptyLocalBinds = []
441 collectHsValBinders :: HsValBindsLR idL idR -> [idL]
442 collectHsValBinders (ValBindsIn binds _) = collectHsBindsBinders binds
443 collectHsValBinders (ValBindsOut binds _) = foldr collect_one [] binds
445 collect_one (_,binds) acc = collect_binds binds acc
447 collectHsBindBinders :: HsBindLR idL idR -> [idL]
448 collectHsBindBinders b = collect_bind b []
450 collect_bind :: HsBindLR idL idR -> [idL] -> [idL]
451 collect_bind (PatBind { pat_lhs = p }) acc = collect_lpat p acc
452 collect_bind (FunBind { fun_id = L _ f }) acc = f : acc
453 collect_bind (VarBind { var_id = f }) acc = f : acc
454 collect_bind (AbsBinds { abs_exports = dbinds, abs_binds = _binds }) acc
455 = [dp | (_,dp,_,_) <- dbinds] ++ acc
456 -- ++ foldr collect_bind acc binds
457 -- I don't think we want the binders from the nested binds
458 -- The only time we collect binders from a typechecked
459 -- binding (hence see AbsBinds) is in zonking in TcHsSyn
461 collectHsBindsBinders :: LHsBindsLR idL idR -> [idL]
462 collectHsBindsBinders binds = collect_binds binds []
464 collect_binds :: LHsBindsLR idL idR -> [idL] -> [idL]
465 collect_binds binds acc = foldrBag (collect_bind . unLoc) acc binds
467 collectMethodBinders :: LHsBindsLR RdrName idR -> [Located RdrName]
468 -- Used exclusively for the bindings of an instance decl which are all FunBinds
469 collectMethodBinders binds = foldrBag get [] binds
471 get (L _ (FunBind { fun_id = f })) fs = f : fs
473 -- Someone else complains about non-FunBinds
475 ----------------- Statements --------------------------
476 collectLStmtsBinders :: [LStmtLR idL idR] -> [idL]
477 collectLStmtsBinders = concatMap collectLStmtBinders
479 collectStmtsBinders :: [StmtLR idL idR] -> [idL]
480 collectStmtsBinders = concatMap collectStmtBinders
482 collectLStmtBinders :: LStmtLR idL idR -> [idL]
483 collectLStmtBinders = collectStmtBinders . unLoc
485 collectStmtBinders :: StmtLR idL idR -> [idL]
486 -- Id Binders for a Stmt... [but what about pattern-sig type vars]?
487 collectStmtBinders (BindStmt pat _ _ _) = collectPatBinders pat
488 collectStmtBinders (LetStmt binds) = collectLocalBinders binds
489 collectStmtBinders (ExprStmt _ _ _) = []
490 collectStmtBinders (ParStmt xs) = collectLStmtsBinders
492 collectStmtBinders (TransformStmt stmts _ _ _) = collectLStmtsBinders stmts
493 collectStmtBinders (GroupStmt stmts _ _ _) = collectLStmtsBinders stmts
494 collectStmtBinders (RecStmt { recS_stmts = ss }) = collectLStmtsBinders ss
497 ----------------- Patterns --------------------------
498 collectPatBinders :: LPat a -> [a]
499 collectPatBinders pat = collect_lpat pat []
501 collectPatsBinders :: [LPat a] -> [a]
502 collectPatsBinders pats = foldr collect_lpat [] pats
505 collect_lpat :: LPat name -> [name] -> [name]
506 collect_lpat (L _ pat) bndrs
509 go (VarPat var) = var : bndrs
510 go (VarPatOut var bs) = var : collect_binds bs bndrs
511 go (WildPat _) = bndrs
512 go (LazyPat pat) = collect_lpat pat bndrs
513 go (BangPat pat) = collect_lpat pat bndrs
514 go (AsPat (L _ a) pat) = a : collect_lpat pat bndrs
515 go (ViewPat _ pat _) = collect_lpat pat bndrs
516 go (ParPat pat) = collect_lpat pat bndrs
518 go (ListPat pats _) = foldr collect_lpat bndrs pats
519 go (PArrPat pats _) = foldr collect_lpat bndrs pats
520 go (TuplePat pats _ _) = foldr collect_lpat bndrs pats
522 go (ConPatIn _ ps) = foldr collect_lpat bndrs (hsConPatArgs ps)
523 go (ConPatOut {pat_args=ps}) = foldr collect_lpat bndrs (hsConPatArgs ps)
524 -- See Note [Dictionary binders in ConPatOut]
525 go (LitPat _) = bndrs
526 go (NPat _ _ _) = bndrs
527 go (NPlusKPat (L _ n) _ _ _) = n : bndrs
529 go (SigPatIn pat _) = collect_lpat pat bndrs
530 go (SigPatOut pat _) = collect_lpat pat bndrs
531 go (QuasiQuotePat _) = bndrs
532 go (TypePat _) = bndrs
533 go (CoPat _ pat _) = go pat
536 Note [Dictionary binders in ConPatOut] See also same Note in DsArrows
537 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
538 Do *not* gather (a) dictionary and (b) dictionary bindings as binders
539 of a ConPatOut pattern. For most calls it doesn't matter, because
540 it's pre-typechecker and there are no ConPatOuts. But it does matter
541 more in the desugarer; for example, DsUtils.mkSelectorBinds uses
542 collectPatBinders. In a lazy pattern, for example f ~(C x y) = ...,
543 we want to generate bindings for x,y but not for dictionaries bound by
544 C. (The type checker ensures they would not be used.)
546 Desugaring of arrow case expressions needs these bindings (see DsArrows
547 and arrowcase1), but SPJ (Jan 2007) says it's safer for it to use its
548 own pat-binder-collector:
550 Here's the problem. Consider
553 C :: Num a => a -> Int -> T a
555 f ~(C (n+1) m) = (n,m)
557 Here, the pattern (C (n+1)) binds a hidden dictionary (d::Num a),
558 and *also* uses that dictionary to match the (n+1) pattern. Yet, the
559 variables bound by the lazy pattern are n,m, *not* the dictionary d.
560 So in mkSelectorBinds in DsUtils, we want just m,n as the variables bound.
563 hsGroupBinders :: HsGroup Name -> [Name]
564 hsGroupBinders (HsGroup { hs_valds = val_decls, hs_tyclds = tycl_decls,
565 hs_instds = inst_decls, hs_fords = foreign_decls })
566 -- Collect the binders of a Group
567 = collectHsValBinders val_decls
568 ++ hsTyClDeclsBinders tycl_decls inst_decls
569 ++ hsForeignDeclsBinders foreign_decls
571 hsForeignDeclsBinders :: [LForeignDecl Name] -> [Name]
572 hsForeignDeclsBinders foreign_decls
573 = [n | L _ (ForeignImport (L _ n) _ _) <- foreign_decls]
575 hsTyClDeclsBinders :: [Located (TyClDecl Name)] -> [Located (InstDecl Name)] -> [Name]
576 hsTyClDeclsBinders tycl_decls inst_decls
577 = [n | d <- instDeclATs inst_decls ++ tycl_decls, L _ n <- hsTyClDeclBinders d]
579 hsTyClDeclBinders :: Eq name => Located (TyClDecl name) -> [Located name]
580 -- ^ Returns all the /binding/ names of the decl, along with their SrcLocs.
581 -- The first one is guaranteed to be the name of the decl. For record fields
582 -- mentioned in multiple constructors, the SrcLoc will be from the first
583 -- occurence. We use the equality to filter out duplicate field names
585 hsTyClDeclBinders (L _ (TyFamily {tcdLName = name})) = [name]
586 hsTyClDeclBinders (L _ (TySynonym {tcdLName = name})) = [name]
587 hsTyClDeclBinders (L _ (ForeignType {tcdLName = name})) = [name]
589 hsTyClDeclBinders (L _ (ClassDecl {tcdLName = cls_name, tcdSigs = sigs, tcdATs = ats}))
591 concatMap hsTyClDeclBinders ats ++ [n | L _ (TypeSig n _) <- sigs]
593 hsTyClDeclBinders (L _ (TyData {tcdLName = tc_name, tcdCons = cons}))
594 = tc_name : hsConDeclsBinders cons
596 hsConDeclsBinders :: (Eq name) => [LConDecl name] -> [Located name]
597 -- See hsTyClDeclBinders for what this does
598 -- The function is boringly complicated because of the records
599 -- And since we only have equality, we have to be a little careful
600 hsConDeclsBinders cons
601 = snd (foldl do_one ([], []) cons)
603 do_one (flds_seen, acc) (L _ (ConDecl { con_name = lname, con_details = RecCon flds }))
604 = (map unLoc new_flds ++ flds_seen, lname : new_flds ++ acc)
606 new_flds = filterOut (\f -> unLoc f `elem` flds_seen)
607 (map cd_fld_name flds)
609 do_one (flds_seen, acc) (L _ (ConDecl { con_name = lname }))
610 = (flds_seen, lname:acc)
614 %************************************************************************
616 Collecting type signatures from patterns
618 %************************************************************************
621 collectSigTysFromPats :: [InPat name] -> [LHsType name]
622 collectSigTysFromPats pats = foldr collect_sig_lpat [] pats
624 collectSigTysFromPat :: InPat name -> [LHsType name]
625 collectSigTysFromPat pat = collect_sig_lpat pat []
627 collect_sig_lpat :: InPat name -> [LHsType name] -> [LHsType name]
628 collect_sig_lpat pat acc = collect_sig_pat (unLoc pat) acc
630 collect_sig_pat :: Pat name -> [LHsType name] -> [LHsType name]
631 collect_sig_pat (SigPatIn pat ty) acc = collect_sig_lpat pat (ty:acc)
632 collect_sig_pat (TypePat ty) acc = ty:acc
634 collect_sig_pat (LazyPat pat) acc = collect_sig_lpat pat acc
635 collect_sig_pat (BangPat pat) acc = collect_sig_lpat pat acc
636 collect_sig_pat (AsPat _ pat) acc = collect_sig_lpat pat acc
637 collect_sig_pat (ParPat pat) acc = collect_sig_lpat pat acc
638 collect_sig_pat (ListPat pats _) acc = foldr collect_sig_lpat acc pats
639 collect_sig_pat (PArrPat pats _) acc = foldr collect_sig_lpat acc pats
640 collect_sig_pat (TuplePat pats _ _) acc = foldr collect_sig_lpat acc pats
641 collect_sig_pat (ConPatIn _ ps) acc = foldr collect_sig_lpat acc (hsConPatArgs ps)
642 collect_sig_pat _ acc = acc -- Literals, vars, wildcard