Ruby

There are two ways to find out what fields an OpenStruct instance has. One is through inspect,
however that returns a String that needs to be parsed.

The second is by white box engineering, looking at OpenStructs source code and seeing that in
fact, it has a hash and getting the keys of that hash...

The second way is faster, more robust, but will break once OpenStruct will be re-engineered...

So I suggest to add an explicit method to return a list of fields in an OpenStruct instance:

--- ostruct.rb.old	2009-04-23 15:26:45.000000000 +0200
+++ ostruct.rb	2009-04-23 15:32:41.000000000 +0200
@@ -110,6 +110,15 @@
     @table.delete name.to_sym
   end
 
+  #
+  # Returns an Array containing the fields of an OpenStruct instance
+  #
+  # p record.fields # -> [:age, :pension, :name]
+  #
+  def fields
+    @table.keys
+  end
+
   InspectKey = :__inspect_key__ # :nodoc:
 
   #