call acedEvaluateLisp and put the result on the stack
Hmm, you might be on to something there, a little further digging...
http://www.intellicad.net/forum/topics/intellicad-lisp-debugger?page=1&commentId=2285825%3AComment%3A3361&x=1#2285825Comment3361
and that's your 'noggin / avatar
Now go up 2 messages to the post made by iCadSalescom Jan 27, 2009 at 11:28am.
He gives 2 links to lisp debuggers, these things are OLD, but they shed some light on
a possible approach.
Wheels are turning.
Ok, given this some more thought and I'm not feeling it for acedEvaluateLisp. It was worth the mental
exercise, but I keep coming up with scenarios that would break the process and have no easy fix.
As for the 2 files mentioned from the Intellicad board, it's kind of a neat trick from what I can understand,
however, the user debugging a lisp app will not have fine control with stepping into and out of code.
For VLIdE, here is my best "birds eye view" guess on implementation
1) I think it implements its own lisp interpreter, some functionality may be passed along to VL.arx and VLLib.dll.
A) When a file is pushed to AutoCAD it is probably.
a) building a linked list of s-expressions, also provides paren matching and checking.
b) builds a stack of break points.
c) calcs a hash on the file in the editor.
B) From the AutoCAD command line, the command entered is intercepted and control given to the VLisp interpreter
where it then -
a) calcs a new hash and comparing against the old. If they match then the file is clean (unmodified).
b) tracks the current s-expression pointer to be evaluated.
If pointer matches a break point in the stack then the run loop is paused.
2) It is built with and relies heavily on LPP,
http://www.interhack.net/projects/lpp/Again this is skimpy on details, more just gathering / posting thoughts and ideas.