From: Eric Bennett <ericb@...>
Date: 2001-04-13T22:07:08+09:00
Subject: [ruby-talk:13651] Re: operator +

On Fri, 13 Apr 2001, ts wrote:

>  You'll have a problem with -

Oh, that's what that mirror stuff was about - so you can seperate the
forward and reverse forms:

class Two
  class Mirror < Two
    def - (x)
      x - 2
    end
  end

  def coerce(x)
    [ Mirror.new, x ]
  end

  def + (x)
    2 + x
  end

  def - (x)
    2 - x
  end
end

a = Two.new

[ a + 2, 2 + a, a - 1, 1 - a ]   #=> [3, 3, 1, -1]


Thank you.  Greatly enlightened.

   - Eric B.

--
"Work is highly commutative"