From: Tanaka Akira <akr@...17n.org>
Date: 2005-02-04T17:02:45+09:00
Subject: Re: 'example.com' == 'example.com.' => false... is this intended?

In article <20050204052951.GA2531@ensemble.local>,
  Sam Roberts <sroberts@uniserve.com> writes:

> Why? When are they not the same?

For example, if you have a machine named "museum", it is confusing with
"museum." domain.

> They are equivalent in the DNS, Resolv::DNS#getaddress() would return
> the same A record for both.

There are several top-domains which have A record: ac, museum, etc.
If your local domain have a machine named "ac", it is important to
distinguish a relative "ac" domain and the absolute "ac" domain.

> Name doesn't have any comparison operators, so they occupy empty space.
>
> Do you have another idea on what Name < Name could mean?

For example, lexical order.

> I found it necessary to find whether a Name was a sub-domain of another.
> How would you recommend to do this, if there is no method?
>
>   lhs.length > rhs.length && lhs.to_a[-rhs.length, rhs.length] == rhs.to_a
>
> is the best I came up with, and its not the kind of thing I would want
> to type regularly.

Adding some method (not operator) is acceptable if it has a good name.
-- 
Tanaka Akira