oh yeah define* not define

[8sync.git] / loopy.scm

diff --git a/loopy.scm b/loopy.scm
index 09034f409a65c341bec53fcaa954631cb68c3aad..1b5e29dea7510e139ad591d81367646962446785 100644 (file)
--- a/loopy.scm
+++ b/loopy.scm
@@ -4,21 +4,57 @@
              (ice-9 match))
 
 ;; @@: Using immutable agendas here, so wouldn't it make sense to
-;;   replace this
+;;   replace this queue stuff with using pfds based immutable queues?
 
 (define-immutable-record-type <agenda>
-  (make-agenda-intern queue)
+  (make-agenda-intern queue prompt-tag port-mapping)
   agenda?
-  (queue agenda-queue))
+  (queue agenda-queue)
+  (prompt-tag agenda-prompt-tag)
+  (port-mapping agenda-port-mapping))
 
-(define* (make-agenda #:key (queue (make-q)))
-  (make-agenda-intern queue))
+(define (make-async-prompt-tag)
+  (make-prompt-tag "prompt"))
+
+(define* (make-agenda #:key
+                      (queue (make-q))
+                      (prompt (make-prompt-tag))
+                      (port-mapping (make-port-mapping)))
+  (make-agenda-intern queue prompt port-mapping))
+
+(define (make-port-mapping)
+  (make-hash-table))
+
+(define* (port-mapping-set! port-mapping port #:optional read write except)
+  "Sets port-mapping for reader / writer / exception handlers"
+  (if (not (or read write except))
+      (throw 'no-handlers-given "No handlers given for port" port))
+  (hashq-set! port-mapping port
+              `#(,read ,write ,except)))
+
+(define (port-mapping-remove! port-mapping port)
+  (hashq-remove! port-mapping port))
+
+;; TODO: This is O(n), I'm pretty sure :\
+;; ... it might be worthwhile for us to have a
+;;   port-mapping record that keeps a count of how many
+;;   handlers (maybe via a promise?)
+(define (port-mapping-empty? port-mapping)
+  "Is this port mapping empty?"
+  (eq? (hash-count (const #t) port-mapping) 0))
+
+(define (port-mapping-non-empty? port-mapping)
+  "Whether this port-mapping contains any elements"
+  (not (port-mapping-empty? port-mapping)))
 
 (define %current-agenda (make-parameter #f))
 
 (define* (start-agenda agenda #:optional stop-condition)
   (let loop ((agenda agenda))
-    (let ((new-agenda
+    (let ((new-agenda   
+           ;; @@: Hm, maybe here would be a great place to handle
+           ;;   select'ing on ports.
+           ;;   We could compose over agenda-run-once and agenda-read-ports
            (parameterize ((%current-agenda agenda))
              (agenda-run-once agenda))))
       (if (and stop-condition (stop-condition agenda))
@@ -28,11 +64,19 @@
 (define (agenda-run-once agenda)
   "Run once through the agenda, and produce a new agenda
 based on the results"
+  (define (call-proc proc)
+    (call-with-prompt
+        (agenda-prompt-tag agenda)
+      (lambda ()
+        (proc))
+      ;; TODO
+      (lambda (k) k)))
+
   (let ((queue (agenda-queue agenda))
         (next-queue (make-q)))
     (while (not (q-empty? queue))
       (let* ((proc (q-pop! queue))
-             (proc-result (proc))
+             (proc-result (call-proc proc))
              (enqueue
               (lambda (new-proc)
                 (enq! next-queue new-proc))))
@@ -44,7 +88,9 @@ based on the results"
            (for-each
             (lambda (new-proc)
               (enqueue new-proc))
-            new-procs)))))
+            new-procs))
+          ;; do nothing
+          (_ #f))))
     ;; TODO: Selecting on ports would happen here?
     ;; Return new agenda, with next queue set
     (set-field agenda (agenda-queue) next-queue)))