From: Christopher Dicely <cmdicely@...>
Date: 2008-04-23T05:07:36+09:00
Subject: Re: A couple of questions regarding class design

On Mon, Apr 21, 2008 at 11:35 AM, Michael W. Ryder
<_mwryder@worldnet.att.net> wrote:
> Joel VanderWerf wrote:
>
> > Michael W. Ryder wrote:
> >
> > > I am part way through implementing a Rational math class to further my
> understanding of Ruby and had a couple of questions that I can't find the
> answer to in Pickaxe.
> > > The first question regards creating a new instance of the class.  The
> initialize method expects two integer values.  While I have no problem
> making sure that they are integers I am not sure what to do if they are not.
> Do I return nil or some other result?
> > >
> >
> > You could raise an exception:
> >
> > unless ...
> >   raise ArgumentError, "Rational arguments must be integers"
> > end
> >
> >
>  That worked except for a minor problem.  I first tried a.class == Integer
> and it failed.  I had to use Fixnum to get it to work.  I thought that
> Integer being the super class for Fixnum and Bignum I could just test for
> Integer without having to test for both of the subclasses.  Is there any way
> to do this?
>

You could use a.kind_of? Integer, but why not just call a.to_int? to
get the value to use
instead?