+
+%************************************************************************
+%* *
+\subsection{Free variables of declarations}
+%* *
+%************************************************************************
+
+Return the Names that must be in scope if we are to use this declaration.
+In all cases this is set up for interface-file declarations:
+ - for class decls we ignore the bindings
+ - for instance decls likewise, plus the pragmas
+ - for rule decls, we ignore HsRules
+ - for data decls, we ignore derivings
+
+ *** See "THE NAMING STORY" in HsDecls ****
+
+\begin{code}
+tyClDeclFVs :: RenamedTyClDecl -> NameSet
+tyClDeclFVs (ForeignType {})
+ = emptyFVs
+
+tyClDeclFVs (IfaceSig {tcdType = ty, tcdIdInfo = id_infos})
+ = extractHsTyNames ty `plusFV`
+ plusFVs (map hsIdInfoFVs id_infos)
+
+tyClDeclFVs (TyData {tcdCtxt = context, tcdTyVars = tyvars, tcdCons = condecls})
+ = delFVs (map hsTyVarName tyvars) $
+ extractHsCtxtTyNames context `plusFV`
+ plusFVs (map conDeclFVs condecls)
+
+tyClDeclFVs (TySynonym {tcdTyVars = tyvars, tcdSynRhs = ty})
+ = delFVs (map hsTyVarName tyvars) (extractHsTyNames ty)
+
+tyClDeclFVs (ClassDecl {tcdCtxt = context, tcdTyVars = tyvars, tcdFDs = fds,
+ tcdSigs = sigs, tcdMeths = maybe_meths})
+ = delFVs (map hsTyVarName tyvars) $
+ extractHsCtxtTyNames context `plusFV`
+ plusFVs (map extractFunDepNames fds) `plusFV`
+ hsSigsFVs sigs `plusFV`
+ dm_fvs
+ where
+ dm_fvs = case maybe_meths of
+ Nothing -> mkFVs [v | ClassOpSig _ (DefMeth v) _ _ <- sigs]
+ -- No method bindings, so this class decl comes from an interface file,
+ -- So we want to treat the default-method names as free (they should
+ -- be defined somewhere else). [In source code this is not so; the class
+ -- decl will bind whatever default-methods are necessary.]
+ Just _ -> emptyFVs -- Source code, so the default methods
+ -- are *bound* not *free*
+
+----------------
+hsSigsFVs sigs = plusFVs (map hsSigFVs sigs)
+
+hsSigFVs (Sig v ty _) = extractHsTyNames ty
+hsSigFVs (SpecInstSig ty _) = extractHsTyNames ty
+hsSigFVs (SpecSig v ty _) = extractHsTyNames ty
+hsSigFVs (ClassOpSig _ _ ty _) = extractHsTyNames ty
+hsSigFVs other = emptyFVs
+
+----------------
+instDeclFVs (InstDecl inst_ty _ _ maybe_dfun _)
+ = extractHsTyNames inst_ty `plusFV`
+ (case maybe_dfun of { Just n -> unitFV n; Nothing -> emptyFVs })
+
+----------------
+ruleDeclFVs (HsRule _ _ _ _ _ _) = emptyFVs
+ruleDeclFVs (IfaceRuleOut _ _) = emptyFVs
+ruleDeclFVs (IfaceRule _ _ vars _ args rhs _)
+ = delFVs (map ufBinderName vars) $
+ ufExprFVs rhs `plusFV` plusFVs (map ufExprFVs args)
+
+----------------
+conDeclFVs (ConDecl _ _ tyvars context details _)
+ = delFVs (map hsTyVarName tyvars) $
+ extractHsCtxtTyNames context `plusFV`
+ conDetailsFVs details
+
+conDetailsFVs (VanillaCon btys) = plusFVs (map bangTyFVs btys)
+conDetailsFVs (InfixCon bty1 bty2) = bangTyFVs bty1 `plusFV` bangTyFVs bty2
+conDetailsFVs (RecCon flds) = plusFVs [bangTyFVs bty | (_, bty) <- flds]
+
+bangTyFVs bty = extractHsTyNames (getBangType bty)
+
+----------------
+hsIdInfoFVs (HsUnfold _ unf) = ufExprFVs unf
+hsIdInfoFVs (HsWorker n a) = unitFV n
+hsIdInfoFVs other = emptyFVs
+
+----------------
+ufExprFVs (UfVar n) = unitFV n
+ufExprFVs (UfLit l) = emptyFVs
+ufExprFVs (UfLitLit l ty) = extractHsTyNames ty
+ufExprFVs (UfFCall cc ty) = extractHsTyNames ty
+ufExprFVs (UfType ty) = extractHsTyNames ty
+ufExprFVs (UfTuple tc es) = hsTupConFVs tc `plusFV` plusFVs (map ufExprFVs es)
+ufExprFVs (UfLam v e) = ufBndrFVs v (ufExprFVs e)
+ufExprFVs (UfApp e1 e2) = ufExprFVs e1 `plusFV` ufExprFVs e2
+ufExprFVs (UfCase e n as) = ufExprFVs e `plusFV` delFV n (plusFVs (map ufAltFVs as))
+ufExprFVs (UfNote n e) = ufNoteFVs n `plusFV` ufExprFVs e
+ufExprFVs (UfLet (UfNonRec b r) e) = ufExprFVs r `plusFV` ufBndrFVs b (ufExprFVs e)
+ufExprFVs (UfLet (UfRec prs) e) = foldr ufBndrFVs
+ (foldr (plusFV . ufExprFVs . snd) (ufExprFVs e) prs)
+ (map fst prs)
+
+ufBndrFVs (UfValBinder n ty) fvs = extractHsTyNames ty `plusFV` delFV n fvs
+ufBndrFVs (UfTyBinder n k) fvs = delFV n fvs
+
+ufAltFVs (con, vs, e) = ufConFVs con `plusFV` delFVs vs (ufExprFVs e)
+
+ufConFVs (UfDataAlt n) = unitFV n
+ufConFVs (UfTupleAlt t) = hsTupConFVs t
+ufConFVs (UfLitLitAlt _ ty) = extractHsTyNames ty
+ufConFVs other = emptyFVs
+
+ufNoteFVs (UfCoerce ty) = extractHsTyNames ty
+ufNoteFVs note = emptyFVs
+
+hsTupConFVs (HsTupCon n _ _) = unitFV n
+\end{code}
+
+%************************************************************************
+%* *
+\subsection{A few functions on generic defintions
+%* *
+%************************************************************************
+
+These functions on generics are defined over RenamedMatches, which is
+why they are here and not in HsMatches.
+
+\begin{code}
+maybeGenericMatch :: RenamedMatch -> Maybe (RenamedHsType, RenamedMatch)
+ -- Tells whether a Match is for a generic definition
+ -- and extract the type from a generic match and put it at the front
+
+maybeGenericMatch (Match (TypePatIn ty : pats) sig_ty grhss)
+ = Just (ty, Match pats sig_ty grhss)
+
+maybeGenericMatch other_match = Nothing
+\end{code}