[project @ 2001-07-25 08:04:00 by simonpj]

[ghc-hetmet.git] / ghc / compiler / basicTypes / NewDemand.lhs

diff --git a/ghc/compiler/basicTypes/NewDemand.lhs b/ghc/compiler/basicTypes/NewDemand.lhs
index 291cf07..735c5ef 100644 (file)
--- a/ghc/compiler/basicTypes/NewDemand.lhs
+++ b/ghc/compiler/basicTypes/NewDemand.lhs
@@ -66,9 +66,11 @@ instance Outputable DmdType where
   ppr (DmdType fv ds res) 
     = hsep [text "DmdType",
            hcat (map ppr ds) <> ppr res,
-           braces (fsep (map pp_elt (ufmToList fv)))]
+           if null fv_elts then empty
+           else braces (fsep (map pp_elt fv_elts))]
     where
       pp_elt (uniq, dmd) = ppr uniq <> text "->" <> ppr dmd
+      fv_elts = ufmToList fv
 
 instance Outputable DmdResult where
   ppr TopRes = empty     -- Keep these distinct from Demand letters