hash nested iteration

hash_nested_iteration.rb

# In /lib/rails_extensions.rb

class Hash

  ##
  # Iterate over a hash, motified so we have the breadcrumb of keys
  # http://stackoverflow.com/questions/9279768/how-do-i-loop-over-a-hash-of-hashes-in-ruby
  # Example:
  # {"root"=>{:a=>"tom", :b=>{:c => 1, :x => 2}}}.nested_each_pair{|k,v|
  #   puts k
  #   puts v
  # }
  def nested_iterate(keys=[])
    self.each_pair do |k,v|
      local_keys = keys.clone
      if v.is_a?(Hash)
        local_keys.push(k)
        v.nested_iterate(local_keys) {|k, v, local_keys| yield k, v, local_keys}
      else
        yield(k,v,local_keys)
      end
    end
  end
end