import RnMonad
import Name ( Name,
getSrcLoc, nameIsLocalOrFrom,
- mkLocalName, mkGlobalName,
+ mkLocalName, mkGlobalName, nameModule,
mkIPName, nameOccName, nameModule_maybe,
setNameModuleAndLoc
)
import BasicTypes ( mapIPName )
import List ( nub )
import UniqFM ( lookupWithDefaultUFM )
+import Maybe ( mapMaybe )
import CmdLineOpts
import FastString ( FastString )
\end{code}
lookupSigOccRn :: RdrName -> RnMS Name
lookupSigOccRn = lookupBndrRn
+-- lookupInstDeclBndr is used for the binders in an
+-- instance declaration. Here we use the class name to
+-- disambiguate.
+
+lookupInstDeclBndr :: Name -> RdrName -> RnMS Name
+ -- We use the selector name as the binder
+lookupInstDeclBndr cls_name rdr_name
+ | isOrig rdr_name -- Occurs in derived instances, where we just
+ -- refer diectly to the right method
+ = lookupOrigName rdr_name
+
+ | otherwise
+ = getGlobalAvails `thenRn` \ avail_env ->
+ case lookupNameEnv avail_env cls_name of
+ -- The class itself isn't in scope, so cls_name is unboundName
+ -- e.g. import Prelude hiding( Ord )
+ -- instance Ord T where ...
+ -- The program is wrong, but that should not cause a crash.
+ Nothing -> returnRn (mkUnboundName rdr_name)
+ Just (AvailTC _ ns) -> case [n | n <- ns, nameOccName n == occ] of
+ (n:ns)-> ASSERT( null ns ) returnRn n
+ [] -> failWithRn (mkUnboundName rdr_name)
+ (unknownNameErr rdr_name)
+ other -> pprPanic "lookupInstDeclBndr" (ppr cls_name)
+ where
+ occ = rdrNameOcc rdr_name
+
-- lookupOccRn looks up an occurrence of a RdrName
lookupOccRn :: RdrName -> RnMS Name
lookupOccRn rdr_name
-> Bool -- True <=> want unqualified import
-> (Name -> Provenance)
-> Avails -- Whats imported
- -> Avails -- What's to be hidden
- -- I.e. import (imports - hides)
-> Deprecations
-> GlobalRdrEnv
-mkGlobalRdrEnv this_mod unqual_imp mk_provenance avails hides deprecs
- = gbl_env3
+mkGlobalRdrEnv this_mod unqual_imp mk_provenance avails deprecs
+ = gbl_env2
where
-- Make the name environment. We're talking about a
-- single module here, so there must be no name clashes.
-- (Qualified names are always imported)
gbl_env1 = foldl add_avail emptyRdrEnv avails
- -- Delete (qualified names of) things that are hidden
- gbl_env2 = foldl del_avail gbl_env1 hides
-
-- Add unqualified names
- gbl_env3 | unqual_imp = foldl add_unqual gbl_env2 (rdrEnvToList gbl_env2)
- | otherwise = gbl_env2
+ gbl_env2 | unqual_imp = foldl add_unqual gbl_env1 (rdrEnvToList gbl_env1)
+ | otherwise = gbl_env1
add_unqual env (qual_name, elts)
= foldl add_one env elts
-- the module (multiple bindings for the same name) we may get
-- duplicates. So the simple thing is to do the fold.
- del_avail env avail
- = foldl delOneFromGlobalRdrEnv env rdr_names
- where
- rdr_names = map (mkRdrQual this_mod . nameOccName)
- (availNames avail)
-
-
add_avail :: GlobalRdrEnv -> AvailInfo -> GlobalRdrEnv
add_avail env avail = foldl add_name env (availNames avail)
= foldl add emptyRdrEnv m_avails
where
add env (mod,avails) = plusGlobalRdrEnv env (mkGlobalRdrEnv mod True
- (\n -> LocalDef) avails [] NoDeprecs)
+ (\n -> LocalDef) avails NoDeprecs)
-- The NoDeprecs is a bit of a hack I suppose
\end{code}
\begin{code}
unQualInScope :: GlobalRdrEnv -> Name -> Bool
--- True if 'f' is in scope, and has only one binding
+-- 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')
+--
+-- This fn is only efficient if the shared
+-- partial application is used a lot.
unQualInScope env
= (`elemNameSet` unqual_names)
where
addAvail :: AvailEnv -> AvailInfo -> AvailEnv
addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail
-emptyAvailEnv = emptyNameEnv
unitAvailEnv :: AvailInfo -> AvailEnv
unitAvailEnv a = unitNameEnv (availName a) a
n1 `lt` n2 = nameOccName n1 < nameOccName n2
\end{code}
+\begin{code}
+pruneAvails :: (Name -> Bool) -- Keep if this is True
+ -> [AvailInfo]
+ -> [AvailInfo]
+pruneAvails keep avails
+ = mapMaybe del avails
+ where
+ del :: AvailInfo -> Maybe AvailInfo -- Nothing => nothing left!
+ del (Avail n) | keep n = Just (Avail n)
+ | otherwise = Nothing
+ del (AvailTC n ns) | null ns' = Nothing
+ | otherwise = Just (AvailTC n ns')
+ where
+ ns' = filter keep ns
+\end{code}
%************************************************************************
%* *