From: Kristof Bastiaensen <kristof@...>
Date: 2006-08-09T00:00:06+09:00
Subject: Re: For performance, write it in C - Part 3, Source code now available

On Tue, 08 Aug 2006 10:54:53 +0100, Jon Harrop wrote:

> Peter Hickman wrote:
>> Isaac Gouy wrote:
>> > D and Clean are other languages you might look at, but using a
>> > different language won't make what you're trying to do any more
>> > feasible.
>>
>> True,
> 
> Even for such a simple task, the ability to use sophisticated data
> structures, higher-order functions and other constructs can make a solution
> practically feasible in some languages and infeasible in others.
> 
> Simulated annealing solution to the travelling salesman problem is another
> seemingly simple task that benefits enormously from high-level constructs.
> The naive Fortran code given in Numerical Recipies (the de-facto standard
> monologue) has an O(n) bottleneck that can be trivially reduced to O(sqrt
> N) using closures or O(ln n) using balanced trees, neither of which are
> feasible in C/Fortran for most science students.
> 
>> but as I've said before C is a fragile language to work in if 
>> you've come from a scripting background. A program will compile and then
>> crash with not the slightest hint at what went wrong, so any language
>> that will allow me to get that sort of performance with a better support
>> is a good thing. I will be learning Ocaml for this reason alone.
> 
> Absolutely, C is a systems programming language. People are abusing it when
> they advocate it for tasks like this. C++ is slightly better but, as I've
> shown, you've lost the performance advantage that you thought you had once
> you start using its features. OCaml's great. It's succinct, safe and fast.
> The main downside is probably that you have to get to grips with its type
> system.
> 
> Here are my benchmarks for the final versions:
> 
> 0.368s gcc -O2
> 0.458s ocamlopt -inline 100 -unsafe
> 0.605s g++ -O2
> 0.644s java
> 
> I can't seem to run the Perl or Ruby out of the box: how do I get the extra
> packages that I need?

For my and Simon Kroegers version you need the permutation.rb file, which
you can install with rubygems, or extract it from the sourcepackage at
http://permutation.rubyforge.org/ (which I did).  Perhaps it would be
better to include the permutation.rb file on the webpage?

Kristof