From: Tanaka Akira <akr@...17n.org>
Date: 2006-03-28T02:22:46+09:00
Subject: Re: PATCH: A subclassable Pathname

In article <92f5f81d0603270903g2fb02244i6a395be708dfffa3@mail.gmail.com>,
  "Evan Phoenix" <evan@fallingsnow.net> writes:

> Quite right on the .glob and .getwd. I guess the tests don't test hit
> those methods, I'll add some quick tests for those. Also, why is it
> not so simple when a Pathname is an argument?
>
> For instance, the code for join tests that each argument is a Pathname
> (which will come up as true for subclasses). The it simply uses
> self.class.new to create the return value.

The class of an argument may be different from
self.class.new.

For example, if P inherits Pathname,
Pathname.new("...") + P.new("...") returns an instance of
Pathname.

Is it useful? intuitive? ...

Note that Array has a similar issue too.

% ruby -ve '
class A1 < Array; end
class A2 < Array; end
p((A1.new + A2.new).class)
'
ruby 1.9.0 (2006-03-04) [i686-linux]
Array
-- 
Tanaka Akira