-%*********************************************************
-%* *
-\subsection{Looking up names}
-%* *
-%*********************************************************
-
-Looking up a name in the RnEnv.
-
-\begin{code}
-lookupBndrRn rdr_name
- = traceRn (text "lookupBndrRn" <+> ppr rdr_name) `thenRn_`
- getNameEnvs `thenRn` \ (global_env, local_env) ->
-
- -- Try local env
- case lookupRdrEnv local_env rdr_name of {
- Just name -> returnRn name ;
- Nothing ->
-
- getModeRn `thenRn` \ mode ->
- case mode of
- InterfaceMode -> -- Look in the global name cache
- mkImportedGlobalFromRdrName rdr_name `thenRn` \ n ->
- traceRn (text "lookupBndrRn result:" <+> ppr n) `thenRn_`
- returnRn n
-
- SourceMode -> -- Source mode, so look up a *qualified* version
- -- of the name, so that we get the right one even
- -- if there are many with the same occ name
- -- There must *be* a binding
- getModuleRn `thenRn` \ mod ->
- case lookupRdrEnv global_env (qualifyRdrName mod rdr_name) of
- Just (name:rest) -> ASSERT( null rest )
- returnRn name
- Nothing -> -- Almost always this case is a compiler bug.
- -- But consider a type signature that doesn't have
- -- a corresponding binder:
- -- module M where { f :: Int->Int }
- -- We use lookupSigOccRn, which uses lookupBndrRn (for good reasons)
- -- and we don't want to panic. So we report an out-of-scope error
- failWithRn (mkUnboundName rdr_name)
- (unknownNameErr rdr_name)
- }
-
--- lookupOccRn looks up an occurrence of a RdrName
-lookupOccRn :: RdrName -> RnMS Name
-lookupOccRn rdr_name
- = getNameEnvs `thenRn` \ (global_env, local_env) ->
- lookup_occ global_env local_env rdr_name
-
--- lookupGlobalOccRn is like lookupOccRn, except that it looks in the global
--- environment. It's used only for
--- record field names
--- class op names in class and instance decls
-lookupGlobalOccRn :: RdrName -> RnMS Name
-lookupGlobalOccRn rdr_name
- = getNameEnvs `thenRn` \ (global_env, local_env) ->
- lookup_global_occ global_env rdr_name
-
--- lookupSigOccRn is used for type signatures and pragmas
--- Is this valid?
--- module A
--- import M( f )
--- f :: Int -> Int
--- f x = x
--- It's clear that the 'f' in the signature must refer to A.f
--- The Haskell98 report does not stipulate this, but it will!
--- So we must treat the 'f' in the signature in the same way
--- as the binding occurrence of 'f', using lookupBndrRn
-lookupSigOccRn :: RdrName -> RnMS Name
-lookupSigOccRn = lookupBndrRn
-
-
--- Look in both local and global env
-lookup_occ global_env local_env rdr_name
- = case lookupRdrEnv local_env rdr_name of
- Just name -> returnRn name
- Nothing -> lookup_global_occ global_env rdr_name
-
--- Look in global env only
-lookup_global_occ global_env rdr_name
- = case lookupRdrEnv global_env rdr_name of
- Just [name] -> returnRn name
- Just stuff@(name:_) -> addNameClashErrRn rdr_name stuff `thenRn_`
- returnRn name
- Nothing -> getModeRn `thenRn` \ mode ->
- case mode of
- -- Not found when processing source code; so fail
- SourceMode -> failWithRn (mkUnboundName rdr_name)
- (unknownNameErr rdr_name)
-
- -- Not found when processing an imported declaration,
- -- so we create a new name for the purpose
- InterfaceMode -> mkImportedGlobalFromRdrName rdr_name
-\end{code}
-%
-@lookupImplicitOccRn@ takes an RdrName representing an {\em original} name,
-and adds it to the occurrence pool so that it'll be loaded later.
-This is used when language constructs
-(such as monad comprehensions, overloaded literals, or deriving clauses)
-require some stuff to be loaded that isn't explicitly mentioned in the code.
-
-This doesn't apply in interface mode, where everything is explicit,
-but we don't check for this case:
-it does no harm to record an ``extra'' occurrence
-and @lookupImplicitOccRn@ isn't used much in interface mode
-(it's only the @Nothing@ clause of @rnDerivs@ that calls it at all I think).
-
- \fbox{{\em Jan 98: this comment is wrong: @rnHsType@ uses it quite a bit.}}
-
-For List and Tuple types it's important to get the correct
-@isLocallyDefined@ flag, which is used in turn when deciding
-whether there are any instance decls in this module are ``special''.
-The name cache should have the correct provenance, though.
-
-\begin{code}
-lookupImplicitOccRn :: RdrName -> RnM d Name
-lookupImplicitOccRn rdr_name = mkImportedGlobalFromRdrName rdr_name
-
-lookupImplicitOccsRn :: [RdrName] -> RnM d NameSet
-lookupImplicitOccsRn rdr_names
- = mapRn lookupImplicitOccRn rdr_names `thenRn` \ names ->
- returnRn (mkNameSet names)
-\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
-unQualInScope env
- = lookup
- where
- lookup name = case lookupRdrEnv env (mkRdrUnqual (nameOccName name)) of
- Just [name'] -> name == name'
- other -> False
-\end{code}
-