From: Paul Brannan <pbrannan@...>
Date: 2003-02-04T07:28:53+09:00
Subject: Re: ruby-dev summary 19437-19455

On Tue, Feb 04, 2003 at 03:56:03AM +0900, Daniel Berger wrote:
> Paul Brannan wrote:
> > > [ruby-dev:19441] Integer#gcd
> > >
> > >   Masaki requested a new method Integer#gcd.
> > >   Shugo Maeda suggested alternative name, Math.gcd(m,n).
> >
> > With Math#gcd know how to handle bignums and GMP integers?
> 
> Should it be expected to?  I know that the gcd method is listed as a
> TODO item in Tomasz Wegrzanowski's ruby-gmp module.

No, I'm just pointing out that using Math.gcd instead of Integer#gcd
means that I lose the ability to easily write a function that works on
both GMP integers and regular integers:

  # A function that returns 10 times the gcd of x and 5, for whatever
  # stupid reason
  def foo(x)
    case x
    when Integer
      return 10 * Math.gcd(x, 5)
    else
      return 10 * x.gcd(5)
    end
  end

I would much rather write:

  def foo(x)
    return 10 * x.gcd(5)
  end

instead of having to write a special case for Integers.

Paul