-%************************************************************************
-%* *
-\subsection{Provenance and export info}
-%* *
-%************************************************************************
-
-A LocalRdrEnv is used for local bindings (let, where, lambda, case)
-Also used in
-
-\begin{code}
-type LocalRdrEnv = RdrNameEnv Name
-
-extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
-extendLocalRdrEnv env names
- = addListToRdrEnv env [(mkRdrUnqual (nameOccName n), n) | n <- names]
-\end{code}
-
-The GlobalRdrEnv gives maps RdrNames to Names. There is a separate
-one for each module, corresponding to that module's top-level scope.
-
-\begin{code}
-type GlobalRdrEnv = RdrNameEnv [GlobalRdrElt]
- -- The list is because there may be name clashes
- -- These only get reported on lookup, not on construction
-
-emptyGlobalRdrEnv = emptyRdrEnv
-
-data GlobalRdrElt
- = GRE { gre_name :: Name,
- gre_parent :: Name, -- Name of the "parent" structure
- -- * the tycon of a data con
- -- * the class of a class op
- -- For others it's just the same as gre_name
- gre_prov :: Provenance, -- Why it's in scope
- gre_deprec :: Maybe DeprecTxt -- Whether this name is deprecated
- }
-
-instance Outputable GlobalRdrElt where
- ppr gre = ppr (gre_name gre) <+>
- parens (hsep [text "parent:" <+> ppr (gre_parent gre) <> comma,
- pprNameProvenance gre])
-pprGlobalRdrEnv env
- = vcat (map pp (rdrEnvToList env))
- where
- pp (rn, gres) = ppr rn <> colon <+>
- vcat [ ppr (gre_name gre) <+> pprNameProvenance gre
- | gre <- gres]
-
-isLocalGRE :: GlobalRdrElt -> Bool
-isLocalGRE (GRE {gre_prov = LocalDef}) = True
-isLocalGRE other = False
-\end{code}
-
-@unQualInScope@ returns a function that takes a @Name@ and tells whether
-its unqualified name is in scope. This is put as a boolean flag in
-the @Name@'s provenance to guide whether or not to print the name qualified
-in error messages.
-
-\begin{code}
-unQualInScope :: GlobalRdrEnv -> Name -> Bool
--- True if 'f' is in scope, and has only one binding,
--- and the thing it is bound to is the name we are looking for
--- (i.e. false if A.f and B.f are both in scope as unqualified 'f')
---
--- Also checks for built-in syntax, which is always 'in scope'
---
--- This fn is only efficient if the shared
--- partial application is used a lot.
-unQualInScope env
- = \n -> n `elemNameSet` unqual_names || isBuiltInSyntaxName n
- where
- unqual_names :: NameSet
- unqual_names = foldRdrEnv add emptyNameSet env
- add rdr_name [gre] unquals | isUnqual rdr_name = addOneToNameSet unquals (gre_name gre)
- add _ _ unquals = unquals
-\end{code}
-
-The "provenance" of something says how it came to be in scope.
-
-\begin{code}
-data Provenance
- = LocalDef -- Defined locally
-
- | NonLocalDef -- Defined non-locally
- ImportReason
-
--- Just used for grouping error messages (in RnEnv.warnUnusedBinds)
-instance Eq Provenance where
- p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
-
-instance Eq ImportReason where
- p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
-
-instance Ord Provenance where
- compare LocalDef LocalDef = EQ
- compare LocalDef (NonLocalDef _) = LT
- compare (NonLocalDef _) LocalDef = GT
-
- compare (NonLocalDef reason1) (NonLocalDef reason2)
- = compare reason1 reason2
-
-instance Ord ImportReason where
- compare ImplicitImport ImplicitImport = EQ
- compare ImplicitImport (UserImport _ _ _) = LT
- compare (UserImport _ _ _) ImplicitImport = GT
- compare (UserImport m1 loc1 _) (UserImport m2 loc2 _)
- = (m1 `compare` m2) `thenCmp` (loc1 `compare` loc2)
-
-
-data ImportReason
- = UserImport Module SrcLoc Bool -- Imported from module M on line L
- -- Note the M may well not be the defining module
- -- for this thing!
- -- The Bool is true iff the thing was named *explicitly* in the import spec,
- -- rather than being imported as part of a group; e.g.
- -- import B
- -- import C( T(..) )
- -- Here, everything imported by B, and the constructors of T
- -- are not named explicitly; only T is named explicitly.
- -- This info is used when warning of unused names.
-
- | ImplicitImport -- Imported implicitly for some other reason
-\end{code}