[REBOL] Re: Hack
From: sunandadh:aol at: 28-Dec-2001 19:35
Hi Joel,
> Knowing that I happened to have accessed the function via the
> (temporary!) reference in a word named FF is of little use, if what
> I am really trying to do is find (and, presumably, fix) the defective
> code.
(Replying to several emails in one go, and may losing part of the thread in
the process).
Absolutely, I agree. I want first-class diagnostic information, and some of
my questions over the past couple of weeks have been about this (e.g. the
thread on "Better Error Messages?"
We probably have different sets of priorities. I'll tell you mine, so you can
see where I'm coming from (and then you can tell me where to go!). I'm still
trying out Rebol, wanting to see if it is possible to build largish
applications with this basic structure:
Rebol []
Do Preparation
ShutDown: false
While [not ShutDown]
[
if Error? Try [Do RunApplication]
[If Error? Try [Do ReportIncident
Do AttemptRecovery
] ;try
[ShutDown: True]
] ;if
] ;while
Where:
--Preparation does what ever is necessary in advance for error recovery and
quality control (For example, I've built one pilot application which
checksums the *.r sources to ensure the distribution set is consistent and
untampered with).
RunApplication is the payload (the pilot is about 6,000 lines of Rebol as
measured out of Mold).
ReportIncident should dump (or email or whatever) scads of useful stuff about
where and why we've failed: failing function name, complete call stack,
status of ports, maybe molds of crucial data structures). This is the weakest
part of the pilot. it doesn't do much more than print the error object. And
that gives barely a hint of where in the 6000 lines we're a-pumping mud.
AttemptRecovery is application-specific code to repair (or direct the user to
repair) the damage.
I've been conscientiously putting bugs into code for over 30 years now, and
even back then the first thing a diagnostic tool would tell me is "last known
function call was X. Call stack is ...". Maybe I'm hopelessly old-fashioned
butI can't believe the programming world has made so much progress that these
things are now impossible <wry g>.
I've toyed with ideas like object identifiers (as suggested in another of you
emails), but that only works for my objects, not for any third-party ones I
might be using (unless it becomes a standard method). And I've experimented
with hand-coding a call stack:
Anyfunc: [...] [
Stack "AnyFunc"
....
Unstack
Return true
]
Where Stack and Unstack simple append/remove the string in a global block.
But it's a real hassle to remember to do it for every return statement.
I think maybe the real problem (from my perspective) is that RT haven't
delivered what is needed in the field as opposed to the lab. But they are not
far off: if they action a couple of feedback requests, I'll be very happy.
Sunanda.
