Completely flatten a hash

gistfile1.rb

# From: http://www.samlown.com/en/recursive_lambdas_and_how_to_completely_flatten_a_hash_in_ruby

flatten = lambda do |r|
  case r
  when Hash
    r.to_a.map { |v| flatten.call(v) }.flatten
  when Array
    r.flatten.map { |v| flatten.call(v) }
  else
    r
  end
end

flatten.call(hash)