A small footprint GUI for OCaml

A small footprint GUI for OCaml

[Alexsandro Soares]

My collaborators and I wrote a small footprint graphics.cmxa based GUI for OCaml.  It works well on Windows, but not so well on Linux. In fact, in most Linux installations the program turns out to be unbearably slow; to make it usable, I am forced to use powerful and well tuned video cards. However, if I compile the program on  Windows, and use CEDEGA, I am able to run it on Linux.  I would appreciate if members of the list take a look at the sources, and make suggestion to run the program on Linux. You can download the sources from

http://www.discenda.org/ocaml/bed.zip

After downloading, you can compile it thus:

ocamlopt graphics.cmxa wid.ml nw.ml -o nw

If you run the program, and click on a tab (for instance, on the "blabla" tab), you will find yourself on a Emacs like editor. You can type text, and use Emacs commands, like:

1-- Ctrl-b  : Back step
2-- Ctrl-f  : Step forward
3-- Ctrj-j  : Break a line
4-- Ctrl-p : Previous line
5-- Ctrl-n : Next line
6-- Ctrl-d : Delete a char
7-- Ctrl-q : Toggle Backspace from backerase to backstep
8-- Ctrl-e : Beginning of line
9-- Ctrl-a : End of line
10-- Esc-space + Esc w : Put text between mark and point in the kill ring.
11-- Ctrl-y : yank
12-- Ctrl-w Ctrl-s : Save buffer
13-- Ctrl-w Ctrl-w <file name> : Save as
14-- Ctrl-x Ctrl-f : Visit file
15-- Ctrl-t : Execute OCaml funcion on text
16-- Ctrl-r : Toggle between result of the execution and original text

There are two kinds of text. One is just a text. The other is a data entry form. Please test the program on Linux, and make suggestion about how to change it in order to make it run as well on Linux as on Windows.


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Re: [Caml-list] A small footprint GUI for OCaml

[Eric Cooper]

On Sat, May 26, 2007 at 03:09:43PM -0700, Alexsandro Soares wrote:
> My collaborators and I wrote a small footprint graphics.cmxa based
> GUI for OCaml.  It works well on Windows, but not so well on
> Linux. In fact, in most Linux installations the program turns out to
> be unbearably slow; to make it usable, I am forced to use powerful
> and well tuned video cards.

I tried your program briefly and noticed (using a load monitor) that
it was constantly using CPU cycles even when it should be idle.  So I
ran it under "strace" and saw that it was continually reading data
from the connection to the X server.  This occurs inside a signal
action, probably triggered by a timer interrupt.

Compare that to a real Emacs process, which is almost always in a
blocking select() system call when idle.

I haven't looked at your source code, or the Graphics implementation,
but I conclude that you need to find a way to block, rather than poll,
for input events.

-- 
Eric Cooper             e c c @ c m u . e d u