From: "trans.  (T. Onoma)" <transami@...>
Date: 2004-11-13T13:39:31+09:00
Subject: Re: Are +, -, +=, -=, etc. redefinable methods?

On Friday 12 November 2004 11:13 pm, itsme213 wrote:
| If so, is there some magic syntax to define them?
|
| Thanks!

-= and += are special forms that represent:

  y -= x   ~>   y = y - x
  y += x   ~>   y = y + x

A number of other infix operators can be used in the same way. So these are 
not redefinable independent of + and -.

+ and - on the otherhand has two forms, infix and unary. (Unary means prefix 
operator.)

Infix

  def +(x)
    #...
  end

  def -(x)
    #...
  end

Unary

  def +@
    #...
  end

  def -@
    #...
  end

HTH,
T