Re: [q-lang-users] newbie question

[Albert G. <Dr....@t-...>]

Álvaro Castro Castilla wrote:
> I saw Q related to K, which are supposed to be good
> languages for matrix multiplication, and somewhere said that it was
> faster than plain C (well, because it vectorizes).

That Q and K are completely different languages, they have nothing to do
with my Q.

> In a couple of days I'll make a Gentoo ebuild for Pure, as I couldn't
> find one.

That will be much appreciated. :) Please let me know when it's
available, so I can add a note to the Pure website.

> My machine is amd64, I tried to compile Q but I couldn't.

Q won't work there as it's never been ported to 64 bit. That was planned
for Q 8.0, but instead I decided to start Pure, so updates to Q will
probably be limited to bugfixes and applying user-supplied patches in
the future.

> Anyway, Q (pure) first got my attention because of the concept of
> rewriting. I'll check the code when I have time to try to understand
> how is it implemented, and what "rewriting" means here.

It's basically just term rewriting in the sense of universal algebra,
i.e., your programs are collections of rules of the form l -> r (where l
and r are terms with variables) which are used to reduce terms to normal
form (using eager evaluation by default). But I've added some
conveniences, e.g. Pure also has guards, lambdas and lexical block
structure with local functions and variables (much like Haskell and ML,
but it's a dynamically typed language like Lisp), and will soon also
have Lisp-like macros.

I'll let you find out about the rest on your own. ;-) The Pure manual is
still a bit terse, so if you have any questions just ask.

Cheers,
Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag