On Sun, Aug 23, 2020 at 09:34:11PM +0100, Aaron Sloman wrote:
> Waldek's changes for pop11+motif now allow poplog graphic windows to be
> deleted (using mouse) without killing the whole process.
>
> Many thanks for this!
Thanks for the report
> This works only if poplog is started by invoking not pop11, but xved
> (extendable multi-window ved with menu buttons: File Edit View Compile).
Have you tried the following in pop11:
uses rc_graphic;
uses rclib;
uses rc_mousepic;
rc_start();
And click on window delete button? Before fix this reliably killed
Poplog process. Now for me most of the time this is no-op,
sometimes works as expected. One possibility is that this
depends on window manager, so I would like to know what happens
in different setups.
Also, before typing:
rc_destroy_widget(rc_window);
for me killed Poplog process. For me now this reliably closes
the window, and Poplog continues to run.
Concerning your comment about rc_menu + rc_graphic
>
> There are now dozens/hundreds/thousands? of graphical programming teaching
> systems on the internet. I wonder if any are as flexible as this system,
> which can be extended at run time by by using Pop-11's incremental compiler
> to generate machine code with call-backs to previously created
> data-structures or previously compiled code.
>
> Perhaps machines are so much faster now that for educational tools the
> difference in speed between compiled and interpreted code is irrelevant??
>
> An evaluation of the current relevance of Poplog could be a good PhD
> project???
>
> But I no longer teach.
I do not think that compiled versus interpreted code makes much
difference to possible speed. I would expect that in well-tuned
system most work is spent in highly optimized low-level libraries.
Given speed of current machine it is possible that educational
tool does not try to optimize at all. I know of at least to
systems which claim rich graphic capabilities and have strong
educational motivation: Squeak (a Smalltalk implementation)
and Racket (former DrScheme). Both are interpreted and
there are technical reasons that limit speed of Smalltalk
implementations, yet I have not heard complaints about their
speed. At low level both offer comparable flexibility to
Poplog. So it really boils down how well the systems are
designed and implemented. Also, a lot depends on educational
goals. In basic programming course (using C) I wanted
to have some graphics. The course was for math students
who were supposed to have good grasp of coordinate
geometry. I provided a simple template using basic
X capabilites, so that students could give simple
commands generating line drawings. By delaying and
rewriting they could do simple animations. Technicaly
the code was quite crude, but it was fit for the
purpose.
--
Waldek Hebisch
