add space after -

list items start with -
but without the space one can’t distinguish from -1

lib/sof/array.rb

@@ -34,7 +34,7 @@ module Sof
 
     # The output of a Array can be a long or a short format
     # The short is used for 7 or less SimpleNodes
-    def out io , level = 0
+    def out io , level
       super
       short = true
       children.each do |c|