[cwn] Attn: Development Editor, Latest Caml Weekly News
Alan Schmitt
alan.schmitt at polytechnique.org
Tue Nov 29 00:05:54 PST 2005
Hello,
Here is the latest Caml Weekly News, for the week of 22 to 29
November, 2005.
1) Mandelbrot renderer
2) polymorphic fixpoints operator in Ocaml
3) Interface to Boom SMS (text message service)
4) HDCaml 0.2.5 -- SystemC Support
5) Physical compare
6) Library for reading and writing CSV (comma-separated values) files
7) findlib-1.1.1 released
8) ile ou un remplacement?
========================================================================
1) Mandelbrot renderer
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31458>
------------------------------------------------------------------------
** Jon Harrop announced:
Following Oliver's objections regarding the lack of serious software
written
in OCaml (e.g. web servers), I have written a very serious Mandelbrot
renderer. The program is 35 lines of OCaml and renders using OpenGL.
This
page breaks it down and describes how it works:
<http://www.ffconsultancy.com/free/fractal>
I've written a simple, recursive C++ version as well. It weighs in at
45 lines
but only 6% more bytes. If you specialise the complex-number
arithmetic in
the OCaml:
let rec mandelbrot i cx cy zx zy =
if i = 63 || zx *. zx +. zy *. zy > 4. then i else
let zx = zx *. zx -. zy *. zy and zy = 2. *. zx *. zy in
mandelbrot (i+1) cx cy (zx +. cx) (zy +. cy)
then, with only -O3, the C++ is actually significantly slower. The
performance
of the C++ improves considerably with -ffast-math so that it is slightly
faster. The performance of the C++ can be further improved by using an
imperative style. This is on both AMD64 and x86.
========================================================================
2) polymorphic fixpoints operator in Ocaml
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31459>
------------------------------------------------------------------------
** Jacques Carette announced:
Inspired by Julien Signoles' code for Omega, (<http://www.lri.fr/
~signoles/prog/misc/lambda.ml.html>) Oleg K explores different ways
to create a *fully polymorphic* fixpoint operator in Ocaml. See
<http://pobox.com/~oleg/ftp/packages/fixpoints.ml>
for details.
========================================================================
3) Interface to Boom SMS (text message service)
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31476>
------------------------------------------------------------------------
** Richard Jones announced:
Not likely to be of wide interest, but we have implemented a simple
interface to the commercial Boom SMS (text message sending) service.
We use this to generate alerts when significant things happen while
automatically bidding on Google Adwords.
<http://merjis.com/developers/boomsms>
License is LGPL + OCaml linking exception.
Interface: <http://resources.merjis.com/developers/boomsms/BoomSMS.html>
Read more about the commercial service here. If you want to test it,
they will give you up to 50 free text messages (if you ask them).
<http://sms.boom-sms.co.uk/>
========================================================================
4) HDCaml 0.2.5 -- SystemC Support
Archive: <http://thread.gmane.org/gmane.comp.lang.confluence/405>
------------------------------------------------------------------------
** Tom Hawkins announced:
HDCaml is a hardware design and verification language embedded in OCaml.
With release 0.2.5, HDCaml now produces cycle and bit accurate C models
for simulation. In addition to the logic primitives, the C models also
support basic assertions of the form:
assertion "label" (always (prop (some_signal)));
The C models include a SystemC wrapper for integration into any SystemC
environment. The wrapper is currently untested, so feedback from any
SystemC user is appreciated. Thanks!
<http://www.confluent.org/>
========================================================================
5) Physical compare
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31485>
------------------------------------------------------------------------
** Tom Hawkins asked and Nicolas Cannasse answered:
> Is their a version of "compare" that is based on physical
equality? If
> not, how can I define one? I tried:
>
> let compareq a b = if a == b then 0 else if a > b then 1 else (-1)
>
> But unfortunately, (>) is a structural comparison.
>
> I need to make a Map where the keys are distinguished by the physical
> instance.
It's not possible.
One of the reason is that the GC might move your memory addresses around
and then break your Map constitency. You need to attribute an unique id
to each of your items and use it for comparison.
** Jon Harrop suggested:
Tag every key with a unique integer using something like this:
module Tag : sig
type 'a t
val make : 'a -> 'a t
val compare : 'a t -> 'a t -> int
end = struct
type 'a t = int * 'a
let i = ref 0
let make x =
incr i;
!i, x
let compare (a, _) (b, _) = compare a b
end;;
Then use the Tag.compare function to perform physical comparison with
a total
ordering.
** Jean-Christophe Filliatre also suggested:
Others already gave the right answer i.e. that you need to tag your
values with unique integers to do that.
Just to mention it, I wrote a little hash-consing library that does
precisely this, together with specialized versions of Set and Map for
these tagged values (based on Patricia trees). There is even a short
article describing the technique. All is available on this page:
<http://www.lri.fr/~filliatr/software.en.html>
========================================================================
6) Library for reading and writing CSV (comma-separated values) files
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31509>
------------------------------------------------------------------------
** Richard Jones announced:
Version 1.1.0 has been released.
Download: <http://merjis.com/developers/csv>
Documentation: <http://resources.merjis.com/developers/csv/Csv.html>
========================================================================
7) findlib-1.1.1 released
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31531>
------------------------------------------------------------------------
** Gerd Stolpmann announced:
there is a new version of findlib (1.1.1) with two minor bug fixes,
especially for O'Caml 3.09.
See <http://www.ocaml-programming.de/packages/documentation/findlib/>
for documentation and links. See
<http://www.ocaml-programming.de/packages/>
for downloads.
========================================================================
8) ile ou un remplacement?
Archive: <http://thread.gmane.org/gmane.comp.lang.caml.general/31535>
------------------------------------------------------------------------
** Christopher Alexander Stein asked:
J'avais l'habitude d'avoir une utilité très commode pour Caml; la
ligne éditant
"ile" qui envelopperait l'interprèteur. Je puis plus ne le trouver
sur le web.
N'importe qui savent où il est ou suggèrent un remplacement?
(Editor's translation: the poster is looking for the line editor
"ile" or a
remplacement that would allow him, when using it with the toplevel,
to have a
better line editing experience.)
** Eric Cooper suggested:
Try ledit, available as a Debian package or from
<ftp://ftp.inria.fr/INRIA/cristal/Daniel.de_Rauglaudre/Tools/>
** Michael Wohlwend suggested:
there is also rlwrap which is easier to use. (readline wrap)
** Martin Jambon suggested:
There is some useful information there, and you are welcome to
contribute
too:
<http://wiki.cocan.org/tips_for_using_the_ocaml_toplevel>
** Alain Frisch said:
Google donne ce lien:
<http://ocaml.info/ocaml_sources/ile-2.7/>
========================================================================
Using folding to read the cwn in vim 6+
------------------------------------------------------------------------
Here is a quick trick to help you read this CWN if you are viewing it
using
vim (version 6 or greater).
:set foldmethod=expr
:set foldexpr=getline(v:lnum)=~'^=\\{78}$'?'<1':1
zM
If you know of a better way, please let me know.
========================================================================
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========================================================================
Alan Schmitt, <http://sardes.inrialpes.fr/~aschmitt/>
--
Alan Schmitt <http://sardes.inrialpes.fr/~aschmitt/>
The hacker: someone who figured things out and made something cool
happen.
.O.
..O
OOO
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