From: Farrel Lifson <farrel.lifson@...>
Date: 2006-03-14T16:16:16+09:00
Subject: Re: Writing Good #each Methods?

> So, this got me thinking: what makes a good #each method?  I'd love to
> hear any pearls of wisdom if any of you have the time.

I think an each method should have the following properties
 * All elements must be yielded
 * Each element must be yielded exactly once
 * If the container has some order associated with it (ie Array or
SortedSet) the elements should be yielded in order
 * If there is more than ordering (such as a post, pre or in order
walk round a binary tree) then the elements should be yielded
according to the ordering that is as closest to 'natural' ordering
(inorder in the case of a binary tree). each methods for the other
orderings (each_preorder, each_postorder) must also be provided.

That's my opinion, I'm sure other people might disagree with me here.

Farrel