From 5b0925033ec1fe15d0e37429325ed7fe98d1f11e Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Sat, 20 Oct 2012 21:10:38 -0700
Subject: [PATCH] Sketch out a very simple actor API

---
 src/servo/servo.rc      |   1 +
 src/servo/util/actor.rs | 109 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 src/servo/util/actor.rs

diff --git a/src/servo/servo.rc b/src/servo/servo.rc
index d9b6f2c5950..aac0dc3b43b 100755
--- a/src/servo/servo.rc
+++ b/src/servo/servo.rc
@@ -130,6 +130,7 @@ pub mod util {
     pub mod url;
     pub mod vec;
     pub mod range;
+    pub mod actor;
 }
 
 pub mod opts;
diff --git a/src/servo/util/actor.rs b/src/servo/util/actor.rs
new file mode 100644
index 00000000000..c13684836d9
--- /dev/null
+++ b/src/servo/util/actor.rs
@@ -0,0 +1,109 @@
+/*!
+An actor type
+*/
+
+use pipes::{Port, Chan, SharedChan, stream};
+
+/**
+The client reference to an actor
+
+Actors are only referred to by opaque handles parameterized
+over the actor's message type, which can be considered the
+actor's interface.
+*/
+struct ActorRef<M: Send> {
+    chan: Chan<M>,
+}
+
+impl<M: Send> ActorRef<M> {
+    fn send(msg: M) {
+        self.chan.send(move msg);
+    }
+}
+
+/// The local actor interface
+trait Actor<M> {
+    fn handle(msg: M) -> bool;
+}
+
+/// A helper function used by actor constructors
+fn spawn<A: Actor<M>, M: Send>(f: ~fn() -> A) -> ActorRef<M> {
+    let (chan, port) = stream();
+    do task::spawn |move f, move port| {
+        let actor = f();
+        loop {
+            let msg = port.recv();
+            if !actor.handle(move msg) {
+                break;
+            }
+        }
+    }
+
+    return ActorRef {
+        chan: move chan
+    }
+}
+
+struct SharedActorRef<M: Send> {
+    chan: SharedChan<M>
+}
+
+impl<M: Send> SharedActorRef<M> {
+    fn send(msg: M) {
+        self.chan.send(move msg);
+    }
+}
+
+fn SharedActorRef<M: Send>(actor: ActorRef<M>) -> SharedActorRef<M> {
+    let chan = match move actor {
+        ActorRef {
+            chan: move chan
+        } => {
+            move chan
+        }
+    };
+
+    SharedActorRef {
+        chan: SharedChan(move chan)
+    }
+}
+
+#[cfg(test)]
+mod test {
+
+    enum HelloMsg {
+        Exit(Chan<()>)
+    }
+
+    struct HelloActor {
+        name: ~str
+    }
+
+    impl HelloActor: Actor<HelloMsg> {
+        fn handle(msg: HelloMsg) -> bool {
+            match msg {
+                Exit(chan) => {
+                    chan.send(());
+                    return false;
+                }
+            }
+        }
+    }
+
+    fn HelloActor(name: ~str) -> ActorRef<HelloMsg> {
+        do spawn |move name| {
+            HelloActor {
+                name: copy name
+            }
+        }        
+    }
+
+
+    #[test]
+    fn test_exit() {
+        let actor = HelloActor(~"bob");
+        let (chan, port) = stream();
+        actor.send(Exit(move chan));
+        port.recv();
+    }
+}
\ No newline at end of file