[project @ 2003-10-22 16:25:42 by simonpj]

[ghc-hetmet.git] / ghc / compiler / rename / RnTypes.lhs

diff --git a/ghc/compiler/rename/RnTypes.lhs b/ghc/compiler/rename/RnTypes.lhs
index cf998b6..227cce5 100644 (file)
--- a/ghc/compiler/rename/RnTypes.lhs
+++ b/ghc/compiler/rename/RnTypes.lhs
@@ -167,11 +167,22 @@ rnHsTypes doc tys = mappM (rnHsType doc) tys
 
 
 \begin{code}
+rnForAll doc exp [] [] ty = rnHsType doc ty
+       -- One reason for this case is that a type like Int#
+       -- starts of as (HsForAllTy Nothing [] Int), in case
+       -- there is some quantification.  Now that we have quantified
+       -- and discovered there are no type variables, it's nicer to turn
+       -- it into plain Int.  If it were Int# instead of Int, we'd actually
+       -- get an error, because the body of a genuine for-all is
+       -- of kind *.
+
 rnForAll doc exp forall_tyvars ctxt ty
   = bindTyVarsRn doc forall_tyvars     $ \ new_tyvars ->
     rnContext doc ctxt                 `thenM` \ new_ctxt ->
     rnHsType doc ty                    `thenM` \ new_ty ->
     returnM (HsForAllTy exp new_tyvars new_ctxt new_ty)
+       -- Retain the same implicit/explicit flag as before
+       -- so that we can later print it correctly
 \end{code}