integer.rb

class Integer < Numeric
  def downto(limit, &block)
    return self.enum_for(:downto, limit) unless block
    current = self
    while current >= limit
      yield current
      current -= 1
    end
  end

  def times(&block)
    return self.enum_for(:times) unless block
    i = 0
    while i < self
      yield i
      i += 1
    end
    self
  end

  def to_i
    self
  end
  alias to_int to_i
  alias ceil to_i
  alias floor to_i
  alias truncate to_i
  alias ord to_i
  alias numerator to_i

  def denominator
    1
  end

  def integer?
    true
  end

  def next
    return self + 1
  end
  alias succ next

  def pred
    return self - 1
  end

  def even?
    (self % 2).zero?
  end

  def odd?
    !even?
  end

  def round(*ndigits)
    if ndigits.empty?
      return self
    end
    ndigits = Topaz.convert_type(ndigits[0], Fixnum, :to_int)
    if ndigits == 0
      return self
    end
    if ndigits > 0
      return Float(self)
    end
    bytes = self.size
    if -0.415241 * ndigits - 0.125 > bytes
      return 0
    end
    f = 10 ** -ndigits
    if f.is_a?(Float)
      return 0
    end
    h = f / 2
    r = bytes % f
    n = bytes - r
    if ((bytes < 0 && r <= h) || r < h)
      n = f + 1
    end
    return n
  end

  def bit_length
    Math.log(self < 0 ? -self : self + 1, 2).ceil
  end
end