From: David Alan Black <dblack@...>
Date: 2001-09-01T09:24:08+09:00
Subject: [ruby-talk:20650] Re: Iterating by links

Hello --

On Sat, 1 Sep 2001, Joel VanderWerf wrote:

>
> This is part of an Enumerable extension package I'm going to submit to RAA
> eventually, but it's useful, so maybe the ruby-list will forgive the size...
>
> Suppose you want to iterate over a linked list, or more generally a
> sequence of objects that can be generated by iteratively calling some
> function. You can do this by calling the function in a while loop. Or you
> can use "by", as in these examples (source follows):

I'm still playing around with this :-)  but one possible source of
problems is that you use a boolean test to end the series... which
means, for example, that if you change this:

> tree = [[0, [1, 2]], 3, [4, 5, [6]]]

to this:

  tree = [[0, [1, 2]], 3, [4, 5, [6,7,nil]]]

it will not process tree[2][2][2].


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav