[project @ 1997-10-06 09:52:41 by simonm]

fix for qualified Prelude / () bug

diff --git a/ghc/compiler/reader/ReadPrefix.lhs b/ghc/compiler/reader/ReadPrefix.lhs
index 8e41450..3ce008b 100644 (file)
--- a/ghc/compiler/reader/ReadPrefix.lhs
+++ b/ghc/compiler/reader/ReadPrefix.lhs
@@ -33,7 +33,7 @@ import FiniteMap      ( elemFM, FiniteMap )
 import Name            ( OccName(..), SYN_IE(Module) )
 import Lex             ( isLexConId )
 import Outputable      ( Outputable(..), PprStyle(..) )
-import PrelMods
+import PrelMods                ( pRELUDE )
 import Pretty
 import SrcLoc          ( mkGeneratedSrcLoc, noSrcLoc, SrcLoc )
 import Util            ( nOfThem, pprError, panic )
@@ -75,14 +75,22 @@ wlkEntId = wlkQid (\occ -> if isLexConId occ
                           else VarOcc occ)
 
 wlkQid :: (FAST_STRING -> OccName) -> U_qid -> UgnM RdrName
+
+-- There are three kinds of qid:
+--     qualified name (noqual)         A.x
+--     unqualified name (aqual)        x
+--     special name (gid)              [], (), ->, (,,,)
+-- The special names always mean "Prelude.whatever"; that's why
+-- they are distinct.  So if you write "()", it's just as if  you
+-- had written "Prelude.()".  NB: The (qualified) prelude is always in scope,
+-- so the renamer will find it.
+
 wlkQid mk_occ_name (U_noqual name)
   = returnUgn (Unqual (mk_occ_name name))
 wlkQid mk_occ_name (U_aqual  mod name)
   = returnUgn (Qual mod (mk_occ_name name) HiFile)
-
-       -- I don't understand this one!  It is what shows up when we meet (), [], or (,,,).
 wlkQid mk_occ_name (U_gid n name)
-  = returnUgn (Unqual (mk_occ_name name))
+  = returnUgn (Qual pRELUDE (mk_occ_name name))
 
 rdTCId  pt = rdU_qid pt `thenUgn` \ qid -> wlkTCId qid
 rdVarId pt = rdU_qid pt `thenUgn` \ qid -> wlkVarId qid