From: Bob Hutchison <hutch@...>
Date: 2005-09-28T01:24:42+09:00
Subject: Re: Class and Iterator Design Question


On Sep 27, 2005, at 11:49 AM, Jim Freeze wrote:

> This may be a silly design question, but I always balk at
> the right answer when I am confronted with it.

I don't think this is a silly question at all. I'm having to deal  
with it myself right now. I never seem to come up with the same  
answer twice in a row.

[snip]


> In other words, for classes that manage a list of items,
> do people prefer to see a custom iterator, such as #each_<item>,
> or do they prefer getting back an array and iterating
> over it themselves, such as #<items>.each?
>
>   Pea.new.each_pod  { |pod| ..do stuff.. }
>   Pea.new.pods.each { |pod| ..do stuff.. }
>


There is another possibility, have the pods accessor return a  
(shallow) copy of the original.

I've done all three.

These days I just return the array and let the user do what they  
want. This saves me a lot of work at the risk of potentially ruining  
the integrity of the object structure. Seemed like a good idea at the  
time, but putting it that way... :-) Actually I don't think it is  
that bad. If I was worried, I'd return a copy. I don't think I'd go  
the each_pod route. Who knows what I'm going to think tomorrow.

Cheers,
Bob

> Cheers
> --
> Jim Freeze
>
>

----
Bob Hutchison          -- blogs at <http://www.recursive.ca/hutch/>
Recursive Design Inc.  -- <http://www.recursive.ca/>
Raconteur              -- <http://www.raconteur.info/>