From: Brian Candler <B.Candler@...>
Date: 2003-05-19T16:21:26+09:00
Subject: Re: ruby-dev summary #20159-20200

On Mon, May 19, 2003 at 02:17:36PM +0900, Joel VanderWerf wrote:
> >However Python behaves bit differently on numbers.
> 
> I hope so...
> 
>   p [1, "1", 1.5, 2].sort_by {|v| [v.class.name, v] }
> 
>     # ==> [1, 2, 1.5, "1"]
> 
> How about using class.name as a fallback, so that Floats and Integers 
> get sorted together?

Surely if you have a mixed bag of objects, it should be your responsibility
to define the ordering? i.e. if they are "like numbers" then

   p [2, 1, "1", 1.5].sort { |x,y| x.to_f <=> y.to_f }

   # ==> ["1", 1, 1.5, 2]

and if they are "like strings" then use x.to_s <=> y.to_s

If you don't do that, then I'd much prefer an exception to be raised (i.e.
"you are trying to do something stupid") than have "sorted" arrays returned
with a strange ordering just because 1 <=> "2" returns nil. And I certainly
wouldn't want the automatic equivalence between numbers and
strings-with-digits which Perl applies.

Regards,

Brian.