Re: How to make GNU Guile more successful

[Linas Vepstas]

On Mon, Feb 13, 2017 at 2:28 PM, Panicz Maciej Godek <address@hidden
> wrote:

>
> someone
> responded critically: "are there out of the box libraries to estimate a
> zero inflated negative
> binomial regression model in guile". Of course, if I knew what a
> zero-inflated
> negative binomial regression model, I could deliver an implementation by
> just explaining
> the notions used in that phrase.


Caution: the message below sounds negative.  Sorry, I use guile daily and
almost exclusively now. So there ...

Lack of decent science libraries for scheme is a major stumbling block, for
me. Simply having sine and cosine is not enough.   I got excited (a decade
ago) when I realized that guile supported GnuMP, and then rapidly deflated
when I realized it only supported integers and rationals in GnuMP .. I work
with arbitrary-precision floats.  Or, I did back then.

Maybe more important is making guile work well with large-RAM setups.
Currently, I do data analysis, every day, in guile, on datasets that take
20GB or 40GB -- my current one is 110GB when loaded in RAM, and guile
starts getting buggy, crashy and slow when working at that size.
Sometimes, it starts calling GC half-a-dozen times per second, for no
apparent reason, eating up 6 cores (or more!) doing nothing but GC. Why?
Who knows? Who can tell?

Yes, I have a machine with 256 GB RAM and a few dozen cores, and SSD's that
hold the data, but every time guile crashes, I have to wait an hour for the
data to reload.  I can live with it, but its a dirty secret I would not
share with guile wannabe users.

String handling in guile is a disaster area: If I give it a
10-megabyte-long string in utf8, it promptly tries to convert all of that
string in utf32, for utterly pointless reasons. This just makes it slow.

There are still bugs between GC and the compiler: if call (eval "(some
stuff) (other stuff)")  the compiler will try to compile that string (after
it was converted ti utf32!) and if GC happens to run at just that moment,
guile crashes or hangs.  These bugs need to be fixed.

So although its a good start, there's a lot of work left until it can get
to "the next level". And that work can't happen until guile is more
popular. So it's very much chicken-and-egg scenario.

--linas