Hello
Here is the latest Caml Weekly News, for the week of 03 to 10 February, 2004.
Following Trevor's suggestions (see
http://caml.inria.fr/archives/200211/msg00163.html) I am now able to
get *my* labltk programs to run in native Mac OS X Aqua mode (using
TclTkAquaBI-8.4.5.0.dmg from
http://www.maths.mq.edu.au/~steffen/tcltk/TclTkAqua/). Thanks, Trevor!!
What follows is what I did to get ocamlbrowser to run as a native Aqua
app. First I followed Trevor's suggestions. That did not work if I
double-clicked on Ocamlbroswer.app. I then tried from the command line
open -a Ocamlbrowser
That at least let ocamlbrowser display its error message that the
options to the command line were at fault. All the Console showed in
the log was a dreaded "RegisterProcess failed (error -50)" message.
So I edited the source file ..../otherlibs/labltk/browser/main.ml and
essentially commented out the command line argument parsing step. I did
"make" and moved the new binary into OCamlbrowser.app/Contents/MacOS/
and everything works pretty nicely now. The only problem I have noticed
is that clicking in the scroll bar does not work. You have to catch the
scroll-button and move it with the mouse. Everything else seems to work
too.
If somebody needs the modified source I can email it. I hope some
similar hack can make labltk work too.
To make this complete we must find some way of passing the command line
options, but that is for somebody else to do.
Trevor Jim added:
I debugged the following when getting a version of Unison running in
Aqua:
/* When you click-start or use the open command, the program is
invoked with
a command-line arg of the form -psn_XXXXXXXXX. The XXXXXXXX is
a "process
serial number" and it seems to be important for Carbon programs.
We need
to get rid of it if it's there so the ocaml code won't exit.
Note, the
extra arg is not added if the binary is invoked directly from
the command
line without using the open command. */
if (argc == 2 && strncmp(argv[1],"-psn_",5) == 0) {
argc--;
argv[1] = NULL;
}
I just put that in main before calling caml. (I am calling caml from
ObjC.)
A simple-minded, O(N^2), floating-point, 2D Delaunay triangulator
without constraints is now available at
http://redwood.ucdavis.edu/~issac/software/ocamldelaunay-1.0.tar.gz
The license is BSD-style, to encourage including the code in other
projects.
MLpcap-0.7 has been released and can be downloaded from:
http://www.drugphish.ch/~jonny/mlpcap.html
MLpcap provides access to all libpcap functions from Ocaml.
This release includes following changes:
o added function pcap_findalldevs
o changed pcap_datalink so that it returns
directly a value of type datalink (e.g. DLT_EN10MB)
o IDL file is now included to generate the stub code
o changed Makefiles
o fixed example bugs
In my textual OCaml program, I would like to read a password. Currently,
I'm using read_line which is not very satisfying as the password is
display on screen.
let passwd = read_line () in
Any idea how I might read the password without displaying it?
I tried the following function, using input_char, but the password is
still displayed on screen:
let read_password () =
let password_chars = ref [] in
let loop = ref true in
while !loop do
let c = input_char stdin in
if c <> '\n' then (
password_chars := c :: !password_chars
) else (
loop := false
)
done;
let password = String.create (List.length !password_chars) in
let _, res = List.fold_right (fun c (i, s) -> s.[i] <- c; (i+1, s))
!password_chars (0, password) in
res
Many thanks in advance for any help
Maxence Guesdon suggested:
In Cash (http://pauillac.inria.fr/cash/), you can turn the echo
of the tty on and off. It may be what you need.
Alain Frisch also suggested and David Mentré replied:
> The field c_echo in the record type Unix.terminal_io might be the
> solution.
Thanks a lot Alain, you found the right solution.
Here is the working code:
open Unix
[...]
let read_password () =
let term_init = tcgetattr stdin in
let term_no_echo = { term_init with c_echo = false; } in
tcsetattr stdin TCSANOW term_no_echo;
let password = read_line () in
tcsetattr stdin TCSAFLUSH term_init;
password
David Brown added:
The only suggestion would be to put the read_line in a try clause, and
restore the terminal settings if an exception is raised. Otherwise,
pressing ^C leaves the terminal with echo off.
There is a new release of schoca at
http://sourceforge.net/project/showfiles.php?group_id=2598
Schoca --- Scheme for OCaml
---------------------------
Schoca is an implementation of the Scheme language. The primary
purpose of Schoca is the use as an embedded extension language in
OCaml applications (e.g. the ibgsclient).
Changes for 0.2.0
o Fix for call/cc. The implementation in schoca 0.1.0
made use of a simple try/catch-block.
Franklin Chen wrote this demo to show a general problem
with this approach:
(define retry #f)
(define factorial
(lambda (x)
(if (= x 0)
(call/cc (lambda (k) (set! retry k) 1))
(* x (factorial (- x 1))))))
(factorial 4)
(display (retry 2))
(newline)
o apply Philippe Audebaud's patch (typos/make clean)
o Fix typos in read_ini_file.ml (reported by Benjamin Geer)
o you can now write schoca-Scripts like
#!/usr/bin/schoca
(display "Hello World!\n")
(newline)
This was suggested by Benjamin Geer.
I hate to spam the list, but I thought that an ocaml-related job
posting might be welcomed. I run the (small) quantiative
research department at a trading company in New York City, called
Jane St. Capital. We do some technically very challenging work
in analyzing and improving trading strategies used by the firm.
It's an open and informal environment, and one that I've
personally felt very comfortable moving to from academia.
We're looking to fill one or two assistant researcher positions.
All of our research code is written in ocaml, and so experience
in ocaml is a plus. Here's the kind of skills I'm looking for:
- Strong unix/linux skills --- I'm looking for someone who
knows their way around the standard unix tools, can write a
makefile, is comfortable with shell scripts, etc. We've got
a small beowulf cluster for doing more compute-intensive
work, and administering that would be part of the job's
responsibilities.
- A well-rounded computer science background. Familiarity
with ideas from optimization, learning theory, NLP, and
algorithms, is something we're looking for.
- As part of the well-rounded CS background, we want someone
with a strong background in programming languages other than
ocaml, in particular C and Java/C#.
- One of the positions we're looking to fill will involve
taking a big role in testing some of the (non-ocaml)
in-house software that is developed here. We're not talking
about bang-on-the-GUI-type testing. We want someone with
good judgment and the ability to write and think carefully
about code. The testing work will involve building testing
systems including testing harnesses, simulators and
validation code. Some of this coding will be done in ocaml,
some in other languages such as C#.
We are mostly thinking about these as entry-level positions, but
we are also considering more experienced candidates. If you're
interested (or have any students you think might be a good match),
please send a cover-letter and resume to:
recruiter3@janestcapital.com
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.
If you happen to miss a CWN, you can send me a message and I'll mail it to you, or go take a look at the archive or the RSS feed of the archives.
If you also wish to receive it every week by mail, you may subscribe online.