Add queue helpers, with tests

[8sync.git] / eightsync / agenda.scm

diff --git a/eightsync/agenda.scm b/eightsync/agenda.scm
index 7ee0ec4d9dd11d24350905eabcb90f2199e18896..ede753fee409eb4a3f88b6728876fc77b079e74d 100644 (file)
--- a/eightsync/agenda.scm
+++ b/eightsync/agenda.scm
@@ -30,6 +30,8 @@
             
             make-async-prompt-tag
 
+            list->q make-q*
+
             <time-segment>
             make-time-segment time-segment?
             time-segment-time time-segment-queue
@@ -146,6 +148,19 @@ Generally done automatically for the user through (make-agenda)."
          "Can't get current agenda prompt if there's no current agenda!")
         (agenda-prompt-tag current-agenda))))
 
+;; helper for making queues for an agenda
+(define (list->q lst)
+  "Makes a queue composed of LST items"
+  (let ((q (make-q)))
+    (for-each
+     (lambda (x)
+       (enq! q x))
+     lst)
+    q))
+
+(define (make-q* . args)
+  "Makes a queue and populates it with this invocation's ARGS"
+  (list->q args))
 
 \f
 ;;; Schedule
@@ -442,12 +457,6 @@ Will produce (0 . 0) instead of a negative number, if needed."
 ;;; Asynchronous escape to run things
 ;;; =================================
 
-(define (agenda-on-error agenda)
-  (const #f))
-
-(define (agenda-on-fail agenda)
-  (const #f))
-
 (define-syntax-rule (%8sync async-request)
   "Run BODY asynchronously at a prompt, passing args to make-future.
 
@@ -700,12 +709,27 @@ return the wrong thing via (%8sync) and trip themselves up."
 
 (define (print-error-and-continue key . args)
   "Frequently used as pre-unwind-handler for agenda"
-  (format (current-error-port)
-          "\n*** Caught exception with key '~s and arguments: ~s ***\n"
-          key args)
-  (display-backtrace (make-stack #t 1 0)
-                     (current-error-port))
-  (newline (current-error-port)))
+  (cond
+   ((eq? key '8sync-caught-error)
+    (match args
+      ((orig-key orig-args stacks)
+       (display "\n*** Caught async exception. ***\n")
+       (format (current-error-port)
+               "* Original key '~s and arguments: ~s *\n"
+               orig-key orig-args)
+       (display "* Caught stacks below (ending with original) *\n\n")
+       (for-each
+        (lambda (s)
+          (display-backtrace s (current-error-port))
+          (newline (current-error-port)))
+        stacks))))
+   (else
+    (format (current-error-port)
+            "\n*** Caught exception with key '~s and arguments: ~s ***\n"
+            key args)
+    (display-backtrace (make-stack #t 1 0)
+                       (current-error-port))
+    (newline (current-error-port)))))
 
 (define-syntax-rule (maybe-catch-all (catch-handler pre-unwind-handler)
                                      body ...)