[plt-scheme] Debugger: How much work to implement?

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Tue Oct 12 08:59:00 EDT 2004

On Oct 12, 2004, at 7:24 AM, Eric Kidd wrote:

>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> On Thu, 7 Oct 2004 18:10:31 +0200, ifconfig nslookup
> <configurator at gmail.com> wrote:
>> On Wed, 6 Oct 2004 13:23:57 -0400, John Clements
>> <clements at brinckerhoff.org> wrote:
>>> Let me clarify: the problem is not that performance would suffer 
>>> while
>>> single-stepping: as you point out, performance doesn't matter at that
>>> point.  The problem is that the performance of the target program 
>>> would
>>> suffer (probably seriously) even when not in single-stepping mode.
>> A simple (maybe not programmatically simple, but logically simple)
>> solution exists for that problem: Create two Execute buttons, one with
>> single-stepping enabled and one that can't single-step but runs much
>> faster.
> Yeah, we're perfectly happy to have single-stepping only work in a
> low-performance mode.  Most of our running time is in optimized C++
> code, so a factor-of-10 hit to PLT performance could be bearable.  Our
> users are having significant problems debugging their scripts, though,
> and even an imperfect stepper could be an enormous win.

Eric, if this is the case, we need to study what kinds of scripts
your users write and what their problems are. Perhaps we can come
up with even better targeted help. Debuggers are crude tools.

> (The problem comes up most often when people with minimal Scheme
> skills have to debug code written by people with medium-level Scheme
> skills who aren't available.)

Share examples, at least with the core PLT group. -- Matthias

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