Sketchup

New.rb

def self.stringify(input)
  if input.is_a? String
    input.dump    
  elsif input.is_a? Array
    "[" + input.collect{|object| stringify(object)}.join(",") + "]"
  elsif input.is_a? Hash
    "{" + input.to_a.collect{|key,value| "#{stringify(key)}:#{stringify(value)}"}.join(",") + "}"
  elsif input.is_a? Symbol
    input.to_s.dump
  else
    input.to_s
  end
end

Old.rb

def self.stringify(input)
  output = nil
  if input.class == String
    output = input.dump    
  elsif input.class == Array
    output = "[" + (input.collect{|object| stringify(object)}).join(",") + "]"
  elsif input.class == Hash
    output = "{" + (input.to_a.collect{|key,value| stringify(key) + ":" +  stringify(value)}).join(",") + "}"
  elsif input.class == Symbol
    output = input.to_s.dump
  else
    output = input.to_s
  end
  return output
end

Ah yes. My coding habbits have changed in favour of is_a?() and #{}.
I wrote this a year ago, so...
Looks much cleaner.