X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsTypes.lhs;fp=compiler%2FhsSyn%2FHsTypes.lhs;h=806faf29dc0e9ffdc986fa6d9d74c20ad160c84d;hp=cb06a7f548d7e243585998156f349ce142c6d4f2;hb=fc7a2876f23510ab795ab2098bbac278d29d6356;hpb=b562edc69ed995644f195943d780b2e650021318

diff --git a/compiler/hsSyn/HsTypes.lhs b/compiler/hsSyn/HsTypes.lhs
index cb06a7f..806faf2 100644
--- a/compiler/hsSyn/HsTypes.lhs
+++ b/compiler/hsSyn/HsTypes.lhs
@@ -353,8 +353,16 @@ pprHsForAll exp tvs cxt
     forall_part = ptext (sLit "forall") <+> interppSP tvs <> dot
 
 pprHsContext :: (OutputableBndr name) => HsContext name -> SDoc
-pprHsContext []	 = empty
-pprHsContext cxt = ppr_hs_context cxt <+> ptext (sLit "=>")
+pprHsContext []	        = empty
+pprHsContext [L _ pred] 
+   | noParenHsPred pred = ppr pred <+> ptext (sLit "=>")
+pprHsContext cxt        = ppr_hs_context cxt <+> ptext (sLit "=>")
+
+noParenHsPred :: HsPred name -> Bool
+-- c.f. TypeRep.noParenPred
+noParenHsPred (HsClassP {}) = True
+noParenHsPred (HsEqualP {}) = True
+noParenHsPred (HsIParam {}) = False
 
 ppr_hs_context :: (OutputableBndr name) => HsContext name -> SDoc
 ppr_hs_context []  = empty