Implemented beh hierarchy and behaviour macros.
authorTim Vaughan <plugd@thelambdalab.xyz>
Sun, 2 May 2021 21:15:02 +0000 (23:15 +0200)
committerTim Vaughan <plugd@thelambdalab.xyz>
Sun, 2 May 2021 21:15:02 +0000 (23:15 +0200)
Makefile
chat_client.scm
sam-macros.scm [new file with mode: 0644]
sam.scm
simple_test.scm

index 34bd08b..ee8239e 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -3,5 +3,5 @@ all: sam
 %.so: %.scm
        csc -s -J $<
 
-sam: sam.scm fifo.so
+sam: sam.scm fifo.so sam-macros.so
        csc sam.scm
index d500579..e6e205d 100644 (file)
@@ -1,70 +1,68 @@
-(import matchable
-        srfi-13
-        (chicken process-context))
+(import sam-macros srfi-13 matchable)
 
 (define (make-client-beh system)
   (let ((name "name")
         (recipients '()))
-    (lambda (self . message)
-      (match message
-        (('start)
-         (send-message system 'print "Welcome to chat!\n"
-                       "Your client address is " (address->string self) ".\n"
-                       "Type '/help' for a list of commands.\n")
-         (send-message system 'read self))
-        (('show-msg from text)
-         (send-message system 'print from "> " text))
-        (((? string? str))
-         (if (string-prefix? "/" str)
-             (let* ((maybe-idx (string-index str #\space))
-                    (idx (if maybe-idx maybe-idx (string-length str)))
-                    (cmd (substring str 1 idx))
-                    (arg (string-trim (substring str idx))))
-               (match cmd
-                 ((or "h" "help")
-                  (send-message system 'print
-                                "Command          | Description\n"
-                                "------------------------------\n"
-                                "/help              List commands\n"
-                                "/name Name         Set name to use in chat.\n"
-                                "/join <address>    Join chat with specified client\n"
-                                "/clear             Clear recipients\n"
-                                "/list              List current recipients\n"
-                                "/quit              Quit chat"))
-                 ((or "j" "join")
-                  (if (string-null? arg)
-                      (send-message system 'print "Missing address of client.")
-                      (begin
-                        (set! recipients (cons (string->address arg) recipients))
-                        (send-message system 'print "Added recipient to chat."))))
-                 ((or "c" "clear")
-                  (set! recipients '())
-                  (send-message system 'print "Cleared recipient list."))
-                 ((or "n" "name")
-                  (set! name arg)
-                  (send-message system 'print "Name now set to '" name "'."))
-                 ((or "l" "list")
-                  (if (null? recipients)
-                      (send-message system 'print "Recipients list empty.")
-                      (begin
-                        (send-message system 'print "Current recipients:")
-                        (let loop ((recipients-left recipients))
-                          (unless (null? recipients-left)
-                            (send-message system 'print (address->string (car recipients-left)))
-                            (loop (cdr recipients-left)))))))
-                 ((or "q" "quit")
-                  (send-message system 'shutdown))
-                 (else
-                  (send-message system 'print "Unrecognised command '" cmd "'"))))
-             (if (null? recipients)
-                 (send-message system 'print "Speaking to the void.")
-                 (let loop ((recipients-left recipients))
-                   (unless (null? recipients-left)
-                     (send-message (car recipients-left) 'show-msg name str)
-                     (loop (cdr recipients-left))))))))
-      (send-message system 'read self)
-      'sleep)))
+    (make-beh (self)
+              (('start) =>
+               (send-message system 'print "Welcome to chat!\n"
+                             "Your client address is " (address->string self) ".\n"
+                             "Type '/help' for a list of commands.\n"))
+              (('show-msg from text) =>
+               (send-message system 'print from "> " text))
+              (((? string? str)) =>
+               (if (string-prefix? "/" str)
+                   (let* ((maybe-idx (string-index str #\space))
+                          (idx (if maybe-idx maybe-idx (string-length str)))
+                          (cmd (substring str 1 idx))
+                          (arg (string-trim (substring str idx))))
+                     (match cmd
+                       ((or "h" "help")
+                        (send-message system 'print
+                                      "Command          | Description\n"
+                                      "------------------------------\n"
+                                      "/help              List commands\n"
+                                      "/name Name         Set name to use in chat.\n"
+                                      "/join <address>    Join chat with specified client\n"
+                                      "/clear             Clear recipients\n"
+                                      "/list              List current recipients\n"
+                                      "/quit              Quit chat"))
+                       ((or "j" "join")
+                        (if (string-null? arg)
+                            (send-message system 'print "Missing address of client.")
+                            (begin
+                              (set! recipients (cons (string->address arg) recipients))
+                              (send-message system 'print "Added recipient to chat."))))
+                       ((or "c" "clear")
+                        (set! recipients '())
+                        (send-message system 'print "Cleared recipient list."))
+                       ((or "n" "name")
+                        (set! name arg)
+                        (send-message system 'print "Name now set to '" name "'."))
+                       ((or "l" "list")
+                        (if (null? recipients)
+                            (send-message system 'print "Recipients list empty.")
+                            (begin
+                              (send-message system 'print "Current recipients:")
+                              (let loop ((recipients-left recipients))
+                                (unless (null? recipients-left)
+                                  (send-message system 'print (address->string (car recipients-left)))
+                                  (loop (cdr recipients-left)))))))
+                       ((or "q" "quit")
+                        (send-message system 'shutdown))
+                       (else
+                        (send-message system 'print "Unrecognised command '" cmd "'"))))
+                   (if (null? recipients)
+                       (send-message system 'print "Speaking to the void.")
+                       (let loop ((recipients-left recipients))
+                         (unless (null? recipients-left)
+                           (send-message (car recipients-left) 'show-msg name str)
+                           (loop (cdr recipients-left)))))))
+              (finally
+               (send-message system 'read self)
+               'sleep))))
 
-(define (main-beh self system)
-  (send-message (make-actor (make-client-beh system)) 'start)
-  'done)
+(define-beh main-beh (self)
+  ((system) =>
+   (send-message (make-actor (make-client-beh system)) 'start)
+   'done))
diff --git a/sam-macros.scm b/sam-macros.scm
new file mode 100644 (file)
index 0000000..16faba3
--- /dev/null
@@ -0,0 +1,32 @@
+;; Macro definitions used for SAM behaviour definition
+;;
+
+(module sam-macros
+    (make-beh define-beh)
+
+  (import scheme
+          (chicken base)
+          matchable)
+
+  (define-syntax make-beh
+    (syntax-rules (: => finally)
+      ((make-beh : parent (self) (pat => body ...) ... (finally after ...))
+       (cons (lambda (self . message)
+               (match message
+                 (pat body ...)
+                 ...
+                 (else 'pass))
+               after ...)
+             parent))
+      ((make-beh (self) (pat => body ...) ... (finally after ...))
+       (make-beh : root-beh (self) (pat => body ...) ... (finally after ...)))
+      ((make-beh : parent (self) (pat => body ...) ...)
+       (make-beh : parent (self) (pat => body ...) ... (finally)))
+      ((make-beh (self) (pat => body ...) ...)
+       (make-beh : root-beh (self) (pat => body ...) ... (finally)))))
+
+  (define-syntax define-beh
+    (syntax-rules ()
+      ((_ name rest ...)
+       (define name (make-beh rest ...))))))
+
diff --git a/sam.scm b/sam.scm
index 8f2741f..846561c 100644 (file)
--- a/sam.scm
+++ b/sam.scm
@@ -18,7 +18,8 @@
         uuid ; ids for actors
         uri-generic
         udp
-        fifo)
+        fifo
+        sam-macros)
 
 ;; Global variables
 
 
 (define sam-version "0.1")
 
-;; Actors
+;; Logging
+
+(define (log-msg . args)
+  (with-output-to-port (current-error-port)
+    (lambda ()
+      (apply print (cons "## " args)))))
+
+(define (log-trace . args)
+  (with-output-to-port (current-error-port)
+    (lambda ()
+      (if trace (apply log-msg args)))))
+
+;; Behaviours
+
+(define (beh-proc beh)
+  (car beh))
+(define (beh-parent beh)
+  (cdr beh))  
 
+(define root-beh
+  (make-beh : #f (self)
+            (('ping recipient) =>
+             (send-message recipient 'pong)
+             'sleep)))
+
+;; Actors
 
 (define (make-address host port id)
   (list id host port))
     address))
 
 (define (deliver-message address . message)
-  (if trace (print "Delivering to " address ": " message))
   (let ((id (address-id address)))
-    (let ((behaviour (hash-table-ref/default actor-table id '())))
-      (if (null? behaviour)
-          (print "## Warning: discarded message " message
-                 " to unknown actor id " id)
+    (log-trace "DELIVERING to " id ": " message)
+    (let loop ((beh (hash-table-ref/default actor-table id #f)))
+      (if beh
           (condition-case
-              (match (apply behaviour (cons address message))
+              (match (apply (beh-proc beh) (cons address message))
                 ('done (hash-table-delete! actor-table id))
                 ('sleep 'do-nothing)
-                (new-beh (hash-table-set! actor-table id new-beh)))
-            ((exn)
-             (print "## Warning: actor id " id " crashed evaluating message " message)))))))
+                ('pass
+                 (log-trace "Passing to parent behaviour...")
+                 (loop (beh-parent beh)))
+                ((? procedure? new-beh) (hash-table-set! actor-table id new-beh))
+                (else
+                 (log-msg "Warning: behaviour of actor " id " returned invalid value.")))
+            (o (exn)
+             (log-msg "Warning: actor " id " crashed evaluating message " message)
+             (print-error-message o)))
+          (log-msg "Warning: DISCARDING message to unknown actor " id ": " message)))))
 
 ;; Scheduler
 
 (define local-queue (make-fifo))
 
 (define (send-message address . message)
+  (log-trace "SENDING to " address ": " message)
   (apply (if (address-local? address)
              send-local-message
              send-network-message)
              ((address message ...)
               (apply send-message (cons address message)))
              (else
-              (print "Warning: received badly formatted message string '" str "'"))))
+              (log-msg "Warning: received badly formatted message string '" str "'"))))
          (loop))))))
 
 ;; System interface
 
 ;; System initialization
 
-(define (system-beh self . message)
-  (match message
-
-    (('shutdown)
-     (print "## System actor received shutdown message.")
-     (exit 0)
-     'done)
+(define system-beh
+  (make-beh (self)
+            (('shutdown) =>
+             (log-msg "System actor received shutdown message.")
+             (exit 0)
+             'done)
 
-    (('print strings ...)
-     (apply print strings)
-     'sleep)
+            (('print strings ...) =>
+             (apply print strings)
+             'sleep)
 
-    (('read reader)
-     (mutex-lock! reader-queue-mutex)
-     (fifo-push reader-queue reader)
-     (mutex-unlock! reader-available-mutex)
-     (mutex-unlock! reader-queue-mutex)
-     'sleep)))
+            (('read reader) =>
+             (mutex-lock! reader-queue-mutex)
+             (fifo-push reader-queue reader)
+             (mutex-unlock! reader-available-mutex)
+             (mutex-unlock! reader-queue-mutex)
+             'sleep)))
 
 (define (boot-sam)
   (start-console)
         (begin
           (set! main (make-actor main-beh)))
       ((exn)
-       (print "## Error starting main actor. Is main-beh defined?")
+       (log-msg "Error starting main actor. Is main-beh defined?")
        (exit 1)))
     (send-message main system))
   (start-scheduler))
          "Usage: sam -h|--help\n"
          "       sam [-n hostname] [-p port] source-file-1 [source-file-2 [...]] "))
 
-
 (let loop ((args (cdr (argv))))
   (match args
     (((or "-h" "--help"))
     (((or "-n" "--hostname") hstr rest ...)
      (set! sam-host hstr)
      (loop rest))
+    (((or "-t" "--trace") rest ...)
+     (log-msg "Enabling trace debugging")
+     (set! trace #t)
+     (loop rest))
     (((? file-exists? filename) rest ...)
-     (print* "## Loading " filename "...")
+     (log-msg "Loading " filename)
      (load filename)
-     (print " done.")
      (loop rest))
     (()
-     (print "## Booting SAM\n")
+     (log-msg "Booting SAM\n")
      (boot-sam))
     (else
      (print "Unrecognised argument '" (car args) "'.\n")
index f20d203..35c9d48 100644 (file)
@@ -1,14 +1,18 @@
-(import matchable
-        (chicken process-context)
-        srfi-18)
+(import sam-macros)
 
-(define (main-beh self system)
-  (send-message system 'print "Hello, what is your name?")
-  (send-message system 'read
-                (make-actor (lambda (self . message)
-                              (match message
-                                ((name)
-                                 (send-message system 'print "Hello, " name "!")
-                                 'done)))))
-
-  (send-message-later system 10 'print "Boo!"))
+(define-beh main-beh (self)
+  ((system) =>
+   (send-message system 'print "Hello, what is your name?")
+   (send-message system 'read
+                 (make-actor (make-beh (self)
+                                       ((name) =>
+                                        (send-message system 'print "Hello, " name "!")
+                                        'done))))
+   (send-message system 'ping
+                 (make-actor (make-beh (self)
+                                       (('pong) =>
+                                        (send-message system 'print
+                                                      "Received pong from system!")
+                                        'done))))
+   (send-message-later system 10 'print "Boo!")
+   'done))