[ruby/set] Make Set#pretty_print IRB::ColorPrinter friendly

https://github.com/ruby/set/commit/f467028cdb

1 files changed, 6 insertions, 5 deletions

diff --git a/lib/set.rb b/lib/set.rb
index 50399309e3..7832c848cf 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -834,13 +834,14 @@ class Set
   alias to_s inspect
 
   def pretty_print(pp)  # :nodoc:
-    pp.text sprintf('#<%s: {', self.class.name)
-    pp.nest(1) {
-      pp.seplist(self) { |o|
-        pp.pp o
+    pp.group(1, sprintf('#<%s:', self.class.name), '>') {
+      pp.breakable
+      pp.group(1, '{', '}') {
+        pp.seplist(self) { |o|
+          pp.pp o
+        }
       }
     }
-    pp.text "}>"
   end
 
   def pretty_print_cycle(pp)    # :nodoc: