Hash#shape

hash_shape.rb

class Hash

  def shape
    self.class.shape_of self
  end

  def self.shape_of(hash)
    hash.sort_by{|k,v| k.to_s }.map do |k,v|
      v = case v
      when Array
        v.map{|e| shape_of(e) }
      when Hash
        shape_of(v)
      else
        v.class
      end

      [k,v]
    end.to_h
  end

end