能否新建一个数据类型？

喵呜喵5

[pre lang="ruby"]class Fraction
  attr_accessor :numerator, :denominator  
  def initialize(array)
    @numerator = array[0].to_i   
    @denominator = array[1].to_i
    raise "分母不为0" if @denominator == 0
    reduction
  end
  # 极其简陋的约分（破坏性）
  def reduction
    @denominator = 1 if @numerator == 0
    [@denominator, @numerator, 2, 3, 5, 7].each do |i|
      next if i == 1 || i == -1 || i == 0
      while @numerator % i == 0 && @denominator % i == 0        
        @denominator /= i; @numerator /= i
      end
    end
    self
  end
  # 取负数（破坏性）
  def -@; self.numerator = -self.numerator; self; end
  # 取倒数（破坏性）
  def reciprocal
    self.numerator ,self.denominator = self.denominator, self.numerator
    self
  end  
  # 将整数转换为分数
  def change_to_fraction(number)
    return Fraction.new([number,1]) if number.class != Fraction
    number
  end
  # 加
  def +(number)
    r = self.clone
    n = change_to_fraction(number)
    r.numerator *= n.denominator
    r.numerator += n.numerator * r.denominator
    r.denominator *= n.denominator   
    r.reduction   
  end
  # 乘
  def *(number)
    n = change_to_fraction(number)
    r = self.clone
    r.denominator *= n.denominator
    r.numerator *= n.numerator
    r.reduction
  end
  # 减
  def -(number); self.+(-number); end
  # 除
  def /(number); self.*(change_to_fraction(number).reciprocal); end
  
  # 数据类型的转换
  def to_f; @numerator.to_f / @denominator; end
  def to_i; @numerator / @denominator; end
  def to_s
    return @numerator.to_s if @denominator == 1
    "#{@numerator}/#{@denominator}"
  end
end
  
  
a = Fraction.new([1,4])
b = Fraction.new([2,3])

p a + b
p a - 1
p b * 3
p b / a
[/pre]