r4943: 2.8.2

[hyperobject.git] / mop.lisp

diff --git a/mop.lisp b/mop.lisp
index b24c4b477dac3b1852e894fc3f11c10ffd9d2962..c9fb4f2e89be8863dd4ec747eb1a16b0b23999e6 100644 (file)
--- a/mop.lisp
+++ b/mop.lisp
@@ -11,7 +11,7 @@
 ;;;; in Text, HTML, and XML formats. This includes hyperlinking
 ;;;; capability and sub-objects.
 ;;;;
-;;;; $Id: mop.lisp,v 1.71 2003/05/14 05:36:22 kevin Exp $
+;;;; $Id: mop.lisp,v 1.72 2003/05/15 06:05:46 kevin Exp $
 ;;;;
 ;;;; This file is Copyright (c) 2000-2003 by Kevin M. Rosenberg
 ;;;; *************************************************************************
@@ -371,6 +371,38 @@
                   ':function (compile nil method-lambda)
                   init-args-values)))))
 
+#+(or allegro scl)
+(progn
+  ;; One entry for each class with lazy readers defined.  The value is a plist mapping
+  ;; slot-name to a lazy reader, each of which is a list of a function and slot-names.
+  (defvar *lazy-readers* (make-hash-table))
+
+(defmethod slot-unbound :around ((class hyperobject-class) instance slot-name)
+    (let ((lazy-reader (loop for super in (mop:class-precedence-list class)
+                            as lazy-reader = (getf (gethash super *lazy-readers*) slot-name)
+                            when lazy-reader return it)))
+      (if lazy-reader
+         (setf (slot-value instance slot-name)
+               (apply (car lazy-reader)
+                      (loop for arg-slot-name in (cdr lazy-reader)
+                            collect (slot-value instance arg-slot-name))))
+         ;; No lazy reader -- defer to regular slot-unbound handling.
+         (call-next-method))))
+
+  ;; The reader is a function and the reader-keys are slot names.  The slot is lazily set to
+  ;; the result of applying the function to the slot-values of those slots, and that value
+  ;; is also returned.
+  (defun ensure-lazy-reader (class-name slot-name reader &rest reader-keys)
+    (setf (getf (gethash (find-class class-name) *lazy-readers*) slot-name)
+         (list* reader (copy-list reader-keys))))
+
+  (defun remove-lazy-reader (class-name slot-name)
+    (setf (getf (gethash (find-class class-name) *lazy-readers*) slot-name)
+         nil))
+  
+  ) ;; #+(or allegro scl)
+
+
 (defun finalize-subobjects (cl)
   "Process class subobjects slot"
   (setf (subobjects cl)
@@ -389,12 +421,12 @@
                                                    nil
                                                    (cdr subobj-def)))))
               (unless (eq (lookup subobject) t)
-                #-(or sbcl cmu lispworks)
+                #+ignore ;; #-(or sbcl cmu lispworks)
                 (eval
                  `(hyperobject::def-lazy-reader ,(name-class subobject)
                    ,(name-slot subobject) ,(lookup subobject)
                    ,@(lookup-keys subobject)))
-                #+(or sbcl cmu lispworks)
+                #+(or sbcl cmu lispworks allegro scl)
                 (apply #'ensure-lazy-reader 
                        (name-class subobject) (name-slot subobject)
                        (lookup subobject) (lookup-keys subobject)))