From: Austin Ziegler <austin@...>
Date: 2002-11-08T08:47:47+09:00
Subject: Re: understanding modules/classes

On Fri, 8 Nov 2002 05:49:14 +0900, Eric Schwartz wrote:
> Austin Ziegler <austin@halostatue.ca> writes:
>> On Thu, 7 Nov 2002 10:27:02 +0900, Eric Schwartz wrote:
>>> Okay, that's not a problem. But I can't figure out how to export
>>> classes from my module into the global namespace. In Perl, I'd
>>> just add the functions to @EXPORT, and be done with it. Can this
>>> be done in Ruby as well, or am I just thinking about it the
>>> wrong way? Should I be creating my CGI executable in that same
>>> module as well? Or am I just over-organizing here?
>> Easily enough to do:
> <snip> 
> 
> Okay, thanks to you and Gavin. One last question: is it good style
> to put that in the class files? That is, do I put the 'include
> Foo' in bar.rb, or in the file that 'require's it? I understand it
> doesn't matter; I'm trying to get an idea for good Ruby style.

It does matter where you put it, to a degree. "include" simply
includes the methods and classes from a module into the current
object scope. The "standard" object scope is (more or less) the
Object object.

Thus, when I do:

  include MIME::Types

Then I have made it so that I can call the MIME::Types functions
without any specifiers (although it may not be a good idea to do
so).

On the other hand, when I do:

  class Foo
    include MIME::Types
  end

I have made it so that I can call the MIME::Types functions within
the context of Foo, and would automagically gain Foo#[] behaving
like MIME::Types::[]. More or less.

I've probably goofed on some of the specifics, but the gist is
there.

-austin
-- Austin Ziegler, austin@halostatue.ca on 2002.11.07 at 18.42.38