From: Avi Bryant <avi@...4.com>
Date: 2001-06-27T06:02:54+09:00
Subject: [ruby-talk:16934] Re: [Newbie] overload + operator for instance variable

On Wed, 27 Jun 2001, Jeff Putsch wrote:

>      def desc=(newDesc)
>        @desc = strToArray(newDesc)
>      end
>      def desc
>        @desc.join(', ')
>      end

>    c = Category.new
>    c.desc = "a,b,c"    # --> c's @desc = ["a", "b", "c"]
>    c.desc += "d,f,g"   # --> c's @desc = ["a", "b", "cd", "f", "g"]
> 
> As you can see, I'm attempting to store the desc as an array, yet pass
> in comma-delimited strings. 

Well, I'm not sure I would personally use operator overloading for this,
but if you really want it, you could maybe change your accessor to

def desc
  descString = @desc.join(',')
  def descString.+(str)
	"#{self}, #{str}"
  end
  descString
end

Note that it doesn't make sense to override an operator for a particular
instance variable - a variable is just a slot, it has no type, and no
methods.  What I'm doing here is overriding an operator for a particular
object - in this case, the string being returned from desc.

Avi