Verbose calculator

calc.rb

class MyNum < Struct.new(:n)
  NUMBERS = {
    zero:   0,
    one:    1,
    two:    2,
    three:  3,
    four:   4,
    five:   5,
    six:    6,
    seven:  7,
    eight:  8,
    nine:   9,
  }

  [:plus, :minus, :by, :divide_by].each do |op|
    define_method(op) do
      MyOp.new(n, op)
    end
  end

  alias to_i n
end

class MyOp < Struct.new(:n, :op)
  OPERATIONS = {
    plus:       :+,
    minus:      :-,
    by:         :*,
    divide_by:  :/,
  }

  MyNum::NUMBERS.keys.each do |i|
    define_method(i) do
      res = n.send(OPERATIONS[op], MyNum::NUMBERS[i])

      MyNum.new(res)
    end
  end
end

MyNum::NUMBERS.keys.each do |n|
  define_method(n) do
    MyNum.new(MyNum::NUMBERS[n])
  end
end

raise unless one.plus.one.to_i == 2
raise unless two.minus.one.to_i == 1
raise unless three.by.two.to_i == 6
raise unless four.divide_by.two.to_i == 2

puts 'Works!'