From: Mathieu Bouchard <matju@...>
Date: 2005-10-27T15:08:09+09:00
Subject: Re: Time for built-in Rational and Complex classes?

On Thu, 27 Oct 2005, Charles Mills wrote:
> I don't see why not.  But using GCD as an example the C version would
> have to handle fixnums, bignums and arbitrary types that respond to
> +,-,*,/,etc.  You could just do a straight translation into C using
> rb_funcall(), but if you wanted to see a speed up for the common case
> (fixnum and bignum) than it would require handling those cases specially
> (using arithmetic in C and the rb_big_*() functions).
> Is there a more straight forward solution?

The case of gcd and Rational is different from the case of Complex in that 
I'm not too sure Rationals make sense with anything non-integer.

Anyone tried using the current Rational class with some kind of Polynomial 
class? did it work, or did it break some assumptions of Rational?

A first step would be to make gcd a method in Integer (or in both Fixnum 
and Bignum) and make it use #coerce.

I can provide some C implementations of gcd for Fixnums.

But first, is there anyone who has profiled Rational and can tell that gcd 
really is a major time consumer ? What do commonly used denominators look 
like and how do they affect the speed of gcd ?

____________________________________________________________________
Mathieu Bouchard - t�l:+1.514.383.3801 - http://artengine.ca/matju
Freelance Digital Arts Engineer, Montr�al QC Canada