pokedex.rb

class Pokemon
  def initialize(&block)
    @var = []
    instance_eval &block
  end

  def method_missing(m, *args, &block)
    if args.any?
      args = args.first if args.length == 1
      @var << { m => args }
      instance_variable_set "@#{m}", args
    else
      return instance_variable_get "@#{m}"
    end
  end

  def to_s
    ''.tap { |s|
        #len_max = 1

        #@var.each { |h|
        #  curr_max = h.keys.max.length
        #  len_max  = curr_max if curr_max > len_max
        #}

        @var.each { |h|
          s << "%-5s: %s\n" % [ h.keys.first, h.values.first ]
        }
      }
  end

end

puts [].tap { |pokedex|
  pokedex << Pokemon.new do
    id    1
    name  :Bulbasaur
  end

  pokedex << Pokemon.new do
    id    2
    name  :Ivysaur
  end

}.join "\n"