From: Yohanes Santoso <ysantoso@...>
Date: 2002-04-05T11:53:19+09:00
Subject: Re: Question abt. Operation of Iterators

Dennis Newbold <dennisn@pe.net> writes:

> This may be a dumb question, but I've been unable to determine for
> sure from the Pickaxe book:
> 
>      When an iterator is applied to an object which is an aggregate
> of ordered subcomponents (e.g., a string, an array), does the
> formal language definition, or the implementation, guarantee that
> the elements are iterated through in a given order (i.e.,
> first element 0, then element 1, etc. or possibly the reverse,
> from last to first)?  If so, does the programmer have any control
> over this, or is it hardwired into the code?

Both Array and String fall under the mathematical list category, not
 mathematical set. So, their iterators travel in a definite order. In
 the case of #each, the traversal is from the first subcomponent to
 the last in that order. That is why there is #reverse on both Array
 and String.

YS.