On Mon, Feb 11, 2013 at 1:05 PM, bearophile <bearophileHUGS@lycos.com> wrote:

And isn't it better for the Rational constructor to simplify the arguments (calling an optimized GCD)? See this implementation (that doesn't use an optimized GCD):

http://rosettacode.org/wiki/Arithmetic/Rational#D

Bye,
bearophile

I ran some benchmarks, and I don't see how the rosetta version is more optimized: https://gist.github.com/Arlen/4947368

And the results on my 64-bit system, compiled with '-O -inline -release':

Rosetta            rational + rational: 3333 ms
Rosetta immutable rational + rational: 3358 ms
std                rational + rational: 2348 ms
std immutable      rational + rational: 2197 ms

Rosetta            rational - rational: 2822 ms
Rosetta immutable rational - rational: 2720 ms
std                rational - rational: 1668 ms
std immutable      rational - rational: 1583 ms

Rosetta            rational * rational: 1628 ms
Rosetta immutable rational * rational: 1579 ms
std                rational * rational: 1603 ms
std immutable      rational * rational: 1500 ms

Rosetta            rational / rational: 1636 ms
Rosetta immutable rational / rational: 1614 ms
std                rational / rational: 1664 ms
std immutable      rational / rational: 1534 ms

Rosetta            rational == rational: 180 ms
Rosetta immutable rational == rational: 176 ms
std                rational == rational: 90 ms
std immutable      rational == rational: 80 ms

Arlen