;;;; cl-scopes/core/actor - basic actor definitions

(defpackage :scopes/core/actor
  (:use :common-lisp)
  (:local-nicknames (:util :scopes/util))
  (:export #:actor #:become #:create #:send
           #:echo #:inc #:lgi))

(in-package :scopes/core/actor)

;;;; basic actor and message implementation

(defclass actor ()
  ((behavior :accessor behavior :initarg :behavior :initform #'no-op)))

(defun become (ac bhv)
  (setf (behavior ac) bhv))

(defun create (bhv &optional (cls 'actor))
  (make-instance cls :behavior bhv))

(defun send (addr msg &key customer)
  (let ((ac addr)) 
    ;(setf (customer msg) customer)
    (funcall (behavior ac) ac msg)))

;;;; predefined behaviors

(defun no-op (ac msg))

(defun lgi (ac msg)
  (util:lgi msg))

(defun echo (ac msg)
  (send (customer msg) msg))

(defun inc (&optional (val 0))
  #'(lambda (ac msg) 
      (if msg ; (payload msg)
        (become ac (inc (+ msg val)))
        (send (create #'lgi) val))))