[clisp-list] CLOS: class-wide slots defined at compile-time?

[Hoehle, Joerg-C. <Joe...@t-...>]

Hi,

I'm seeking help with CLOS. I want to define a slot that all instances =
of a class will share. This sounds like typical :allocation :class. But =
read on.

One of these special slots is supposed to contain a function (closure) =
that I want compiled at file-compilation time. Another will be set at =
run-time. Another will contain the lambda expression to compile at =
run-time and ought to be defined at file-compilation time as well.

I thought about the following macro to declare the code:
(define-analyse-line ((analyse durchsatz))
  (incf (gethash key (analyse-top-table analyse)))
  (princ #\; (analyse-outstream analyse)))

which would macroexpand to:

(let ((*columns-used* '()))
 (setf (analyse-line-function (find-class 'durchsatz))
  (lambda (analyse .line. .start-positions. .stop-positions.)
    (macrolet ((log-line-universal-time () ;TODO? flet
		 (or (analyse-universal-time analyse) #))
	       (log-line-sql-time ()
		 (format nil #)))
      body...))
  (setf (analyse-used-columns #) *columns-used*)))

and here's something which cannot work
(defmacro define-analyse-line ((var class) &body body)
  (let* ((*precompile* nil)
	  (*columns-used* '()))
    (setf (analyse-line-function (find-class ',class))
       (lambda (,var .line. .start-positions. .stop-positions.)
	   ,@body))
    (setf (analyse-line-lambda (find-class ',class)) ',body)
    (setf (analyse-used-columns (find-class ',class)) *columns-used*)))

The reason it cannot work is that analyse-line-lambda and =
-line-function are not typically slots of (find-class 'analyse), but =
rather shared slots of each instance.

Need I got MOP here or is that overshoot? Am I misguided?

Maybe all I need is a wrapper around defclass and some initform =
instead?
This could become weird as well, since the closure body may reference =
slots to be defined in this same DEFCLASS form (e.g. analyse-top-table =
above).

Thanks for your help,
	J=F6rg H=F6hle.