[plt-scheme] Handin Server checkers for v4?

From: Eli Barzilay (eli at barzilay.org)
Date: Thu Aug 7 21:31:43 EDT 2008

On Aug  6, Keith S. Decker wrote:
> I was playing around with the handin-server using the full
> distribution, and was able to get everything work except the example
> checker; I wondered if anyone had a few working checker examples, as
> the checker source has a lot of Scheme macros and I admit my macro
> experience is Common Lisp only :-).

There are some issues that are still open with the handin server,
especially around its testing framework.  I hope that this semester
I'll get to make things work again.  So there will probably be changes
to it through the semester.  (Last semester I ended up using it only
to receive submissions, but not to evaluate them.)

> 1) For future-Google-searching posterity, if you are new to PLT and
> are trying to install the handin server, the magic incantation
> (after getting the full distribution) is
> 	setup-plt -l handin-server
> The documentation will then be in your local library, so for example  
> on a Mac it is in ~/Library/PLTScheme/

Yes.  And the installation is only needed if you want this manual.

> 2) There are 2 errors in the (otherwise very nice) handin
>    documentation.
> First, the Quick Start works great until you get to the last line:
> "Check the status of your submission by pointing a web browser at
> https://localhost:7980/servlets/status.ss. " Unfortunately, the
> status server is disabled by default, so you need to add
> (https-port- number 7980) to the config.ss file before trying the
> web browser bit.  Took me a while to figure that one out (basically
> by giving up and reading the rest of the doc :-)

I think that there is either a bug report on this, or a mail that John
sent me when he noticed it.

> Second, by default the Master Password is disabled, and set to #f.  
> However, this interacts badly with unix or plaintext passwords because  
> the #f (first in the passwords list) causes the good? test inside the  
> ormap inside has-password? to throw an immediate error. Works fine if  
> you just set a master password.

There shouldn't be any default master passwords.  Can you explain more
how you got this problem?

> 3) submission directories must be created by hand prior to entry in
> active-dirs in config.ss. The error message was quite clear, but you
> might want to note that in the doc (since all the other directories
> are created on-the-fly by the server code).

I'm not sure about making it create the directories, perhaps it's a
good idea.

On Aug  7, Grant Rettke wrote:
> Hi folks,
> In this thread:
> http://groups.google.com/group/plt-scheme/browse_thread/thread/552ef9d1d529db72/bedc174f564d138b?hl=en&lnk=gst&q=Commenting+code+for+teaching#
> I see that the server and client are not included with "stable"
> releases; instead they are only available from SVN or pre-releases.
> Why is that the case?

Because the handin client is not intended to be used as is -- it is
intended instead to be customized for your own class.  If I had the
time, I'd get rid of the handin client altogether, then make some
wizard code that would create it for you and set the right options in

On Aug  7, Grant Rettke wrote:
> After reading that thread, I downloaded the nightly build;
> the handin server and client aren't in there.

It's only included in the "Full" distribution, which contains the
complete PLT tree.

          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!

Posted on the users mailing list.