From: Michael Schuerig <michael@...>
Date: 2005-09-11T23:06:32+09:00
Subject: When an Array is not


(1) Under what circumstances is an array not an Array? I'm confronted
with such a case in one of my unit tests. The test failed when run in
conjunction with other tests and I narrowed it down to this: In the
tested code I use something.kind_of?(Array). I have a mixin module that
extends Array with additional methods. When this module is required
directly or indirectly in my test class then kind_of?(Array) doesn't
behave as expected anymore.

(2) Maybe I'm not understanding Ruby's object system well enough. That
appears to be true in another case, too. I have a mixin module for
Enumerable whose methods I want to use on arrays, too, of course. But
apparently it is not enough to include it in Enumerable

Enumerable.module_eval do
  include MyEnumExt
end

I have to do the same for Array to make it available there

Array.class_eval do
  include MyEnumExt
end

Incidentally, I get the idea that (1) and (2) are related. But still I
don't understand what's happening.

Michael

-- 
Michael Schuerig                       Face reality and stare it down
mailto:michael@schuerig.de        --Jethro Tull, Silver River Turning
http://www.schuerig.de/michael/