Re: Anyone relying on "break-at" breakpoints?

[Neil Jerram]

address@hidden (Ludovic Courtès) writes:

> Hi Neil,
>
> Disclaimer: I'm not too familiar with the debugging infrastructure and
> I've never used `break-at'.  But...

Well thank you for reading through!

> Neil Jerram <address@hidden> writes:
>
>> By way of contrast, the other kind of breakpoint ("break-in") does not
>> suffer from this problem, because it is defined in a way that relates
>> more persistently to the code (even as the code changes).  A break-in
>> breakpoint is defined as
>>
>>   break-in <procedure-name> [<module-or-file-name>]
>>
>> and means break at the start of that procedure.
>
> That looks nice (I suppose it could also perform better than
> `scan-source-whash'), but would "let" count as a <procedure-name> in
> your example?  If so, how could we specify the scope referred to?

A priori, no, "let" wouldn't count as a procedure name.  The break-in
invocation means to break when evaluating the first form in the
relevant procedure's code, whatever that form happens to be.

There are (at least) three possibly interesting requirements that this
doesn't cover.  Right now I'm still wondering about these, so ideas
are welcome.

1. The Guile application is going to load a file that contains
   directly-executed code as well as procedure definitions, and you
   want to set a breakpoint (ahead of time) on some of the
   directly-executed code.

2. You want to set a breakpoint somewhere in the middle of a complex
   procedure, not right at the beginning of it.

3. You're using Guile interactively (e.g. using the GDS interface in
   Emacs) and want to step through the evaluation of some code (which
   isn't a procedure definition).

I think your question was aiming at (2) - is that right?

Regards,
        Neil