use util:mv-bind for evaluating return values of action handlers

csys/csys.lisp

@@ -74,13 +74,13 @@
   (lambda (msg) (funcall (proc scope) msg scope)))
 
 (defun std-proc (msg scope &key (default #'remember) params actions)
-  (destructuring-bind (nmsg nscope) 
+  (util:mv-bind (nmsg &optional (nscope scope)) 
       (handle-action msg scope :default default :actions actions :params params)
     (forward nmsg (syns nscope))
     (update nscope)))
 
 (defun eff-proc (msg scope &key params actions)
-  (destructuring-bind (nmsg nscope) 
+  (util:mv-bind (nmsg &optional (nscope scope)) 
       (handle-action msg scope :default #'no-op :actions actions :params params)
     (notify nmsg nscope)
     (update nscope)))
@@ -112,9 +112,8 @@
 
 ;;;; predefined neuron actions
 
-(defun no-op (msg scope)
-  (list msg scope))
+(defun no-op (msg scope) msg)
 
 (defun remember (msg scope)
   (setf (value scope) (shape:data-value msg :value))
-  (list msg scope))
+  (values msg scope))

csys/environ.lisp

@@ -32,12 +32,12 @@
          (addr (getf data :addr)))
     (when addr
       (register-cell (cells scope) addr (getf data :new)))
-    (list msg scope)))
+    msg))
 
 (defun forward (msg scope)
   (dolist (cell (find-cells (cells scope) (message:addr msg))) 
     (actor:send cell msg))
-  (list msg scope))
+  msg)
  
 ;;;; helpers
 

test/test-csys.lisp

@@ -36,7 +36,7 @@
 
 (defun proc-env (msg scope)
   (let ((t:*test-suite* (csys:environ scope))) 
-    (destructuring-bind (nmsg scope) 
+    (util:mv-bind (nmsg &optional (scope scope)) 
         (csys:handle-action msg scope :actions (environ:actions))
       (util:lgi nmsg (tc:receiver t:*test-suite*))
       (actor:send (core:mailbox (tc:receiver t:*test-suite*)) nmsg))))