[plt-scheme] DrScheme Debug button

The teaching languages do set it (you can see the code in
plt/collects/lang/htdp-langs.ss). They override the eval-handler to add
tracing & debugging annotations to the source code. 

The teaching languages eval-handler does call whatever eval-handler was
installed before continuing, however.

Robby

At Tue, 13 Sep 2005 22:02:25 -0400 (EDT), Gregory Cooper wrote:
> 
> I'm guessing that the HtDP languages install their own eval-handler that 
> bypasses the one installed by the debug tool.  That would explain why the 
> button behaves identically to Execute.
> 
> On Tue, 13 Sep 2005, Prabhakar Ragde wrote:
> 
> > Gregory Cooper wrote:
> >> 
> >> Could you send me the code you are trying to debug.  Which language level 
> >> are you using?
> >
> > I just typed something in to try it out, something like
> >
> > (define (f x) (* x x))
> >
> > (f 3)
> > (f 5)
> >
> > I had tried something a little more elaborate (solutions to the first 
> > assignment in the HtDP course I'm teaching, five questions using a teachpack) 
> > and got the same sort of behaviour.
> >
> > I think I was running Beginning Student, but I tried it with Intermediate 
> > with Lambda also.
> >
> > My immediate purpose is to be able to answer student questions of the form 
> > "What does that 'Debug' button do?" So I'm not really looking for full 
> > functionality; on the other hand, "It appears to do nothing" is not that 
> > satisfactory an answer. --PR
> >
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