From: Mathieu Bouchard <matju@...>
Date: 2004-03-07T01:17:43+09:00
Subject: Re: Possible strangeness in Numeric


On Sat, 6 Mar 2004, Yukihiro Matsumoto wrote:

> In message "Possible strangeness in Numeric"
>     on 04/03/06, Dave Thomas <dave@pragprog.com> writes:
> |I suggest that the to_int implementation should be moved from Numeric 
> |to Integer.
> This has been changed several times.  Some feel just like you, whereas
> others feel integer arguments should accept floating point values.
> I'm happy to discuss and get the final decision.

Have you tried something like this?:

class Numeric
  def to_int
    x=self.to_i
    raise "not a representation of an integer" if x!=self
    x
  end
end

class Float; remove_method :to_int; end
class Integer; remove_method :to_int; end


So (2.5).to_int raises, but (2.0).to_int returns 2, and
Rational(4,3).to_int raises, but Rational(6,3).to_int returns 2.

Complex(2.0,0.0).to_int, however, doesn't work, because Complex doesn't
have a #to_f nor a #to_i at all. I am wondering what a good default #to_f
for Complex would be. It wouldn't be modulus because then
Complex(-2.0,0).to_f == +2.0, which would be really bad. Taking the real
part sounds more reasonable. I don't really have any other ideas.

________________________________________________________________
Mathieu Bouchard                       http://artengine.ca/matju