Added generic function UNBOUND-VALUE

[clg] / glib / proxy.lisp

diff --git a/glib/proxy.lisp b/glib/proxy.lisp
index 0efe3792c9b163b7eecd32a1ccf29a5c662a2c2c..587158bd9844149883f2e064c9abdf57aed89cca 100644 (file)
--- a/glib/proxy.lisp
+++ b/glib/proxy.lisp
@@ -15,7 +15,7 @@
 ;; License along with this library; if not, write to the Free Software
 ;; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
-;; $Id: proxy.lisp,v 1.16 2004/12/19 23:33:57 espen Exp $
+;; $Id: proxy.lisp,v 1.17 2004/12/26 11:40:14 espen Exp $
 
 (in-package "GLIB")
 
@@ -84,23 +84,20 @@ (defmethod initialize-internal-slot-functions ((slotd effective-virtual-slot-def
                  (setf (slot-value slotd 'reader-function)
                        #'(lambda (object)
                            (unless reader
-                           (setq reader
-                            (mkbinding getter 
-                             (slot-definition-type slotd) 'pointer)))
+                             (setq reader
+                              (mkbinding getter 
+                               (slot-definition-type slotd) 'pointer)))
                            (funcall reader (proxy-location object))))))))))
 
       (setf 
        (slot-value slotd 'boundp-function)
        (cond
-       ((and 
-         (not (slot-boundp slotd 'unbound))
-         (not (slot-boundp slotd 'boundp)))
-        #'(lambda (object) (declare (ignore object)) t))  
        ((slot-boundp slotd 'unbound)
         (let ((unbound-value (slot-value slotd 'unbound)))
-          (lambda (object)
-            (not (eq (funcall getter-function object) unbound-value)))))
-       ((let ((boundp (slot-value slotd 'boundp)))
+          #'(lambda (object)
+              (not (eq (funcall getter-function object) unbound-value)))))
+       ((slot-boundp slotd 'boundp)
+        (let ((boundp (slot-value slotd 'boundp)))
           (etypecase boundp
             (function boundp)
             (symbol #'(lambda (object)
@@ -111,7 +108,13 @@ (defmethod initialize-internal-slot-functions ((slotd effective-virtual-slot-def
                             (setq reader
                              (mkbinding boundp
                               (slot-definition-type slotd) 'pointer)))
-                          (funcall reader (proxy-location object))))))))))
+                          (funcall reader (proxy-location object))))))))
+       ((multiple-value-bind (unbound-p unbound-value)
+            (unbound-value (slot-definition-type slotd))
+          (when unbound-p
+            #'(lambda (object)
+                (not (eq (funcall getter-function object) unbound-value))))))
+       (#'(lambda (object) (declare (ignore object)) t))))
 
       (setf
        (slot-value slotd 'reader-function)
@@ -119,17 +122,26 @@ (defmethod initialize-internal-slot-functions ((slotd effective-virtual-slot-def
        ((slot-boundp slotd 'unbound)
         (let ((unbound (slot-value slotd 'unbound))
               (slot-name (slot-definition-name slotd)))
-          (lambda (object)
-            (let ((value (funcall getter-function object)))
-              (if (eq value unbound)
-                  (slot-unbound (class-of object) object slot-name)
-                value)))))
+          #'(lambda (object)
+              (let ((value (funcall getter-function object)))
+                (if (eq value unbound)
+                    (slot-unbound (class-of object) object slot-name)
+                  value)))))
        ((slot-boundp slotd 'boundp)
         (let ((boundp-function (slot-value slotd 'boundp-function)))
-          (lambda (object)
-            (and
-             (funcall boundp-function object)
-             (funcall getter-function object)))))
+          #'(lambda (object)
+              (and
+               (funcall boundp-function object)
+               (funcall getter-function object)))))
+       ((multiple-value-bind (unbound-p unbound-value)
+            (unbound-value (slot-definition-type slotd))
+          (let ((slot-name (slot-definition-name slotd)))
+            (when unbound-p
+              #'(lambda (object)
+                  (let ((value (funcall getter-function object)))
+                    (if (eq value unbound-value)
+                        (slot-unbound (class-of object) object slot-name)
+                        value)))))))
        (getter-function)))))
 
   (setf 
@@ -457,6 +469,9 @@ (defmethod destroy-function ((class proxy-class) &rest args)
   #'(lambda (location &optional (offset 0))
       (unreference-foreign class (sap-ref-sap location offset))))
 
+(defmethod unbound-value ((class proxy-class) &rest args)
+  (declare (ignore type args))
+  (values t nil))
 
 (defgeneric ensure-proxy-instance (class location)
   (:documentation "Returns a proxy object representing the foreign object at the give location."))