# HG changeset patch
# User wenzelm
# Date 1527274911 -7200
# Node ID 53788963c4dccf3a0e3cfad7c5fa0b3eae178390
# Parent  ddeb6847451a06476f217edaf8d8c46c1a4ec54a
pretty-print according to defaults of input syntax;

diff -r ddeb6847451a -r 53788963c4dc src/Pure/Syntax/mixfix.ML
--- a/src/Pure/Syntax/mixfix.ML	Fri May 25 21:00:47 2018 +0200
+++ b/src/Pure/Syntax/mixfix.ML	Fri May 25 21:01:51 2018 +0200
@@ -97,12 +97,18 @@
 
 fun pretty_mixfix NoSyn = Pretty.str ""
   | pretty_mixfix (Mixfix (s, ps, p, _)) =
-      parens (Pretty.breaks [quoted s, brackets (Pretty.commas (map int ps)), int p])
+      parens
+        (Pretty.breaks
+          (quoted s ::
+            (if null ps then [] else [brackets (Pretty.commas (map int ps))]) @
+            (if p = 1000 then [] else [int p])))
   | pretty_mixfix (Infix (s, p, _)) = parens (Pretty.breaks [keyword "infix", quoted s, int p])
   | pretty_mixfix (Infixl (s, p, _)) = parens (Pretty.breaks [keyword "infixl", quoted s, int p])
   | pretty_mixfix (Infixr (s, p, _)) = parens (Pretty.breaks [keyword "infixr", quoted s, int p])
   | pretty_mixfix (Binder (s, p1, p2, _)) =
-      parens (Pretty.breaks [keyword "binder", quoted s, brackets [int p1], int p2])
+      parens
+        (Pretty.breaks
+          ([keyword "binder", quoted s] @ (if p1 = p2 then [] else [brackets [int p1]]) @ [int p2]))
   | pretty_mixfix (Structure _) = parens [keyword "structure"];
 
 end;