57 lines
2.1 KiB
Plaintext
57 lines
2.1 KiB
Plaintext
;;;;
|
|
;;;; a c t i v e - s l o t . s t k l o s -- Active slots metaclass
|
|
;;;;
|
|
;;;; Copyright © 1996-1998 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
|
|
;;;;
|
|
;;;; Permission to use, copy, and/or distribute this software and its
|
|
;;;; documentation for any purpose and without fee is hereby granted, provided
|
|
;;;; that both the above copyright notice and this permission notice appear in
|
|
;;;; all copies and derived works. Fees for distribution or use of this
|
|
;;;; software or derived works may only be charged with express written
|
|
;;;; permission of the copyright holder.
|
|
;;;; This software is provided ``as is'' without express or implied warranty.
|
|
;;;;
|
|
;;;; $Id: active-slot.stklos 1.1 Tue, 03 Feb 1998 10:13:08 +0000 eg $
|
|
;;;;
|
|
;;;; Author: Erick Gallesio [eg@unice.fr]
|
|
;;;; Creation date: 17-Oct-1996 18:16
|
|
;;;; Last file update: 3-Feb-1998 10:13
|
|
|
|
(select-module STklos)
|
|
|
|
(define-class <Active-metaclass> (<class>)
|
|
())
|
|
|
|
(define-method compute-get-n-set ((class <Active-metaclass>) slot)
|
|
(if (eq? (get-slot-allocation slot) :active)
|
|
(let* ((index (slot-ref class 'nfields))
|
|
(name (car slot))
|
|
(s (cdr slot))
|
|
(env (class-environment class))
|
|
(before-ref (make-closure (get-keyword :before-slot-ref s #f) env))
|
|
(after-ref (make-closure (get-keyword :after-slot-ref s #f) env))
|
|
(before-set! (make-closure (get-keyword :before-slot-set! s #f) env))
|
|
(after-set! (make-closure (get-keyword :after-slot-set! s #f) env))
|
|
(unbound (make-unbound)))
|
|
(slot-set! class 'nfields (+ index 1))
|
|
(list (lambda (o)
|
|
(if before-ref
|
|
(if (before-ref o)
|
|
(let ((res (%fast-slot-ref o index)))
|
|
(and after-ref (not (eqv? res unbound)) (after-ref o))
|
|
res)
|
|
(make-unbound))
|
|
(let ((res (%fast-slot-ref o index)))
|
|
(and after-ref (not (eqv? res unbound)) (after-ref o))
|
|
res)))
|
|
|
|
(lambda (o v)
|
|
(if before-set!
|
|
(when (before-set! o v)
|
|
(%fast-slot-set! o index v)
|
|
(and after-set! (after-set! o v)))
|
|
(begin
|
|
(%fast-slot-set! o index v)
|
|
(and after-set! (after-set! o v)))))))
|
|
(next-method)))
|