gouf
9/24/2014 - 3:48 AM

Try to use instance method Module#refine お試しでつかってみる。スコープを限定させてクラスのメソッドを改変・拡張する Ref: http://www.ruby-doc.org/core-2.1.1/doc/syntax/refinement

Try to use instance method Module#refine お試しでつかってみる。スコープを限定させてクラスのメソッドを改変・拡張する Ref: http://www.ruby-doc.org/core-2.1.1/doc/syntax/refinements_rdoc.html

module_refine.rb
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module FizzBuzzExtension
  refine Fixnum do
    def fizz?
      modulo(3).zero?
    end
 
    def buzz?
      modulo(5).zero?
    end
 
    def fizz_buzz?
      fizz? && buzz?
    end
  end
end
 
class FizzBuzz
  using FizzBuzzExtension

  def fizz_buzz(n)
    1.upto(n).map{ |num| fizz_buzz_out(num) }
  end

  private

  def fizz_buzz_out(n)
    if n.fizz_buzz?
      'FizzBuzz'
    elsif n.fizz?
      'Fizz'
    elsif n.buzz?
      'Buzz'
    else
      n
    end
  end
end

f = FizzBuzz.new
p result = f.fizz_buzz(10) # => [1, 2, "Fizz", 4, "Buzz", "Fizz", 7, 8, "Fizz", "Buzz"]
p result.join(', ') # => "1, 2, Fizz, 4, Buzz, Fizz, 7, 8, Fizz, Buzz"

p 10.fizz? # => undefined method `fizz?' for 10:Fixnum (NoMethodError)