This is a simple and easy to use Actor system in Common Lisp.
Requires Bordeaux threads. http://common-lisp.net/project/bordeaux-threads/ 2. Just load actors.lisp and start using it.
If you have Quicklisp, (ql:quickload "cl-actors")
An small manual can be found at : http://www.cs.rpi.edu/~govinn/actors.pdf
-
Creating an actor class or template
(defactor Actor-Class (state) (message-vars) behavior)
-
Creating an actor instance
(setq my-actor (Actor-Class (:state-var_1 value_1 ... :state-var_n value_n)))
-
Sending a message
(send my-actor message_args)
- Concurrency using the actors model.
- Dynamic behavior change of actors.
-
A ticker: Keeps printing out a count every 2 seconds, starting from 0 and incrementing it every 2 seconds.
;create the ticker template (defactor ticker ((counter 0)) (m) (sleep 2) (pr counter) (incf counter) (send self nil) next) ; Create an instance (setf t1 (ticker)) ; send a message (async) (send t1 nil) ; to stop use (stop-actor t1)
- A print actor: Prints the message which was sent to it. A very useful utility actor.
```lisp
;create the actor template
(defactor print-actor () (val) (pr val) next)
; initialize a new instance
(setf printer (print-actor))
;send values for printing
(send printer "hello, world")
-
A factorial computing actor : The name says it all :)
;create the template (defactor fact ((temp 1)) (n cust) (if (equal 1 n) (progn (send cust (* temp 1)) (setf temp 1) next) (progn (setf temp (* n temp)) (send self (- n 1) cust) next))) ;create a new instance (setf f (fact)) ; send a value (send f 4 print-actor)
- A nagger for fun : Works only in Mac OS X. Keeps saying out aloud "please work" every 10 seconds :)
```lisp
(defactor nagger () ()
(sleep 10)
(trivial-shell:shell-command "say please work")
(send self) next)
; anonymous actor , no way to stop the nagging
(send (nagger))
```
## More Resources
1. [Meta-Circular Adventures in Functional Abstraction –Challenging Clojure in Common Lisp] (http://chriskohlhepp.wordpress.com/metacircular-adventures-in-functional-abstraction-challenging-clojure-in-common-lisp/)