fluentCalculator.rb

=begin

		Source:  Codewars
		Difficulty:  4 kyu
		Title:  Fluent Calculator

		Description:
		The goal is to implement simple calculator which uses fluent syntax:

		Calc.new.one.plus.two             # Should return 3
		Calc.new.five.minus.six           # Should return -1
		Calc.new.seven.times.two          # Should return 14
		Calc.new.nine.divided_by.three     # Should return 3

		There are only four operations that are supported (plus, minus, times, divided_by)
		and 10 digits (zero, one, two, three, four, five, six, seven, eight, nine).

		Each calculation consists of one operation only.

=end



class Calc
	def initialize
    @first, @op, @result = nil
  end

  [:zero, :one, :two, :three, :four,
  :five, :six, :seven, :eight, :nine].each_with_index do |method, value|
    define_method("#{method}") do
      if @first
        @result = @first.send(@op, value)
      else
        @first = value
        self
      end
    end
  end
  
  {:plus => :+, :minus => :-, :times => :*, :divided_by => :/ }.each do |key, value|
    define_method("#{key}") do
      @op = value
      self
    end
  end
end