Re: Low level things in C or Scheme

[Mikael Djurfeldt]

Thamer Al-Harbash <address@hidden> writes:

> It's funny you should talk about layering. I've recently started
> writing a project at work (or re-writing for the Nth time thanks
> to changes being requested), and I chose doing the high level
> work in guile just so I could say "ok done," and get back to more
> important things.
>
> The funny thing is, thanks to guile's seamless use of arbitrarily
> big numbers (its numerical tower), I don't know if I *want* to do
> my number crunching in C anymore. This project is slowly becoming
> 100% scheme as I remove the final bits of C from it.

I've been through something similar.  I've written a neuron simulator
which I've used in my research for several years.

Originally, a lot of things was done with C++.  Guile was only used as
a scripting language, gluing pieces together.  Then, during the years,
I tended to do more and more on the Scheme level.

Now, I write almost everything in Scheme.

> I have not noticed any significant penalty in performance.

For me, there would be a penalty if the inner loops were on the Scheme
level.  Now, however, I do most computations using my Matlab-like
GOOPS-based matrix library
(http://kvast.blakulla.net/mdj/matrix-1.2.0.tar.gz).  So, even though
the algorithms are written in Guile Scheme, the overhead gets drowned
by the heavy crunching vector and matrix loops on the C level in the
library.

(BTW, if any of the people who have written to me regarding this
library and possible collaboration with other projects, I have to
apologize for not getting back to you quickly.  I will do that soon.)

Best regards,
Mikael D.