From: Dave Thomas <Dave@...>
Date: 2002-03-21T23:19:56+09:00
Subject: Re: Windows version of Ruby (proposals)

Paul Brannan <paul@atdesk.com> writes:

> On Thu, Mar 21, 2002 at 11:04:55PM +0900, Dave Thomas wrote:
> > Then, we provide a set of environment support modules for those
> > classes that currently contain non-portable methods. We could have
> > (for example)
> > 
> >     module SysdepFilePosix
> >       ...
> >     end
> > 
> >     module SysdepFileWin32
> >       ...
> >     end
> > 
> > Mix one of these into class File and you'll get all the system
> > dependent calls. You'll also be explicitly marking your code as
> > non-portable.
> 
> This would be a global change, and may not be desirable.  What are the
> advantages of mixing a module into File over subclassing from File?

I view it as changing the underlying semantics of a File object. I
thought it would be confusing to have two file objects in the same
program, one with portable semantics, and the other with (say)
Window's-specific semantics.  However, I'd be happy to be argued out
of that idea. Mixin vs. subclassing is really a detail in the overall
idea.


Cheers


Dave