Ruby script that uses NoMethodError and Object#send to get to an existing method

test.rb

#!/usr/bin/env ruby

class Class
  def foo
    puts "FOO!!"
    return false
  end
end

str = "foa"
c = Class.new
flag = true
while flag
  begin
    flag = c.send str
  rescue
    puts "nope"
    str.next!
  end
end