From: "James H." <james.herdman@...>
Date: 2006-03-15T01:03:45+09:00
Subject: Re: Writing Good #each Methods?

Concerning ordered elements, what is the best way to ascertain the
order wherein the structure is not an array?  For instance, suppose you
had a link list.  You *could* have a class variable that kept track of
the beginning, but this would mean difficulties when you had more than
one link list in play.

In trying to solve the order issue (naively), I wrote a method like:

def each(&block)
  current = self.previous
  until current.previous.nil?
    current = current.previous
  end

  # ...
end

This obviously doesn't work because on each call of #each, the focus is
rewound to the intial element in the list.

Any advice on the matter?