From: Joel VanderWerf <vjoel@...>
Date: 2001-09-26T07:26:43+09:00
Subject: [ruby-talk:21690] Re: manipulating "immutable" objects such as Fixnum from within callbacks & al...


Guillaume Cottenceau wrote:
> Here's the problem: it happens often that you need to pass "references" to
> objects so that callbacks/functions/etc may modify these objects to their
> convenience, and you will need the modified value afterwards.

What about using a closure that references local vars in the caller's scope?
(This is discussed a bit on pp.47-8 of the Pickaxe book.)

def doit
  yield 1
end

t = 3
doit { |i| t += i }
puts t
  ==> 4

> Guillaume Cottenceau - http://people.mandrakesoft.com/~gc/