gistfile1.builder

class Hash

  def hash_from(*keys)
    keys.inject({}) { |memo, obj| memo.merge(obj => self[obj]) }
  end

end

# example:
# >> a = {:foo => 1, :bar => 2, :foobar => 3}
# => {:bar=>2, :foobar=>3, :foo=>1}
# >> b = a.hash_from(:foo,:bar)
# => {:bar=>2, :foo=>1}