From: Graham Wideman <checkforrealaddress@...>
Date: 2006-08-26T04:25:05+09:00
Subject: Re: Collections of structured-data objects: what approach?

Robert:

Question and then a comment:

Question: What does the keyword "self" do when sitting on a line by itself, 
as in several of your methods?

Comment:

> For the sake of discussion I present a different approach.  As long as
> you don't need 4 (lookup by key) an Array is perfect.  However, with the
> lookup IMHO a new data structure is preferred because then consistency
> can be handled internally.  I'll attach a half grown quick hack to
> demonstrate what I mean.

If I'm reading you correctly, you are saying a bit more than this:

1. For lookup (or for that matter if one want to implement a 
SortedCollection), then it's desirable to have an index for the array on the 
key field(s), which can be a ruby hash. (Ie: one *could* use Enumerable#find 
or find_all, but on larger collections that's slow?)

2. But if you are going to implement an index using a helper hash, then you 
want a way to keep the hash up-to-date as items are inserted or deleted from 
the array.

3. So you advocate a class to wrap these together so that "consistency can 
be handled internally".

Thanks for your reply,

Graham
-- 
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Graham Wideman
Microsoft Visio MVP
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