Re: stepper-friendly macros

Hi list!

There is nice discussion about replacing C++. Modern C++ IDEs support stepping
through loops. Lispworks can't step through (loop :for i :from 1 to 10 :collect
(f i)). 

The only place one cat put stepper breakpoint to is a call to f. 
This is an issue I would like to address, but no one seem to care...

I've (seemingly) succeeded in making points in my macros "breakpointable".

Requirements for that are: 
- i) macroexpander function should "smash" original code so that steppizer would
be able to set up the correspondence between a point on the screen and a
breakpointable point in an expanded code. I think this is an unsafe practice,
but it looks like this is the only simple way. 
- ii) some fix to stepper info should be done. I do not understand completely
what I have done, but this seems to work. To be steppable, point must have
steppable (and visible) parent. So, I fix stepper info with the following code: 


(defun point-is-in-macro-call (point macro-name)
  "If point is in a subtree of macro-name, returns predecessor point"
  (let (parent)
    (setf parent (slot-value point 'lispworks-tools::parent))
    (cond
     ((null parent) nil)
     ((not (typep parent 'LISPWORKS-TOOLS::stepable-point)) nil)
     ((eq (slot-value parent 'lispworks-tools::operator) macro-name)
        parent
        )
     (t (point-is-in-macro-call parent macro-name)))))

(defun fix-parents-for-macro-in-context (context macro-name)
  "Updates parents for points in macro so that one can set breakpoints at them"
  (let (points grand-macro)
    (setf points
          (slot-value context 'lispworks-tools::stepable-points))
    (dolist (point points)
      (setf grand-macro
            (point-is-in-macro-call point macro-name))
      (when grand-macro
        (setf (slot-value point 'lispworks-tools::parent)
              grand-macro)))
  ))

(cl-user::defadvice (lispworks-tools::stepize fix-parents-for-perga-advice
:after :documentation "Makes perga clauses breakpointable")
    (context form)
  (declare (ignore form))
  (fix-parents-for-macro-in-context context 'perga))


Here "perga" is a name of my macro which I have made steppable. 


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