From fbb1776a35db50db19fc158381e74361d6e9b789 Mon Sep 17 00:00:00 2001
From: Christopher Allan Webber <cwebber@dustycloud.org>
Date: Fri, 27 Nov 2015 22:09:31 -0600
Subject: [PATCH 1/1] Add (catch-8sync) stuff

---
 eightsync/agenda.scm  | 18 ++++++++++++++++++
 tests/test-agenda.scm | 25 +++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/eightsync/agenda.scm b/eightsync/agenda.scm
index 68db42e..edade13 100644
--- a/eightsync/agenda.scm
+++ b/eightsync/agenda.scm
@@ -65,6 +65,8 @@
 
             %port-request %run %run-at %run-delay
             
+            catch-8sync catch-%8sync
+
             print-error-and-continue
 
             %current-agenda
@@ -543,6 +545,22 @@ return the wrong thing via (%8sync) and trip themselves up."
        (lambda ()
          body ...)))))
 
+(define-syntax-rule (catch-8sync exp (handler-key handler) ...)
+  (catch '%8sync-caught-error
+    (lambda ()
+      exp)
+    (lambda (_ orig-key orig-args orig-stacks)
+      (cond
+       ((or (eq? handler-key #t)
+            (eq? orig-key handler-key))
+        (apply handler orig-stacks orig-args)) ...
+       (else (raise '%8sync-caught-error
+                    orig-key orig-args orig-stacks))))))
+
+;; Alias...?
+(define-syntax-rule (catch-%8sync rest ...)
+  (catch-8sync rest ...))
+
 
 
 ;;; Execution of agenda, and current agenda
diff --git a/tests/test-agenda.scm b/tests/test-agenda.scm
index 6913109..6918c99 100644
--- a/tests/test-agenda.scm
+++ b/tests/test-agenda.scm
@@ -394,9 +394,34 @@
                  "in here now!\n"
                  "Well that was fun :)\n")))
 
+;; Make sure catching tools work
+
+(let ((speaker (speak-it))
+      (catch-result #f))
+  (catch-8sync
+   (begin
+     (speaker "hello")
+     (throw '%8sync-caught-error
+            'my-orig-key '(apple orange banana) '(*fake-stack* *fake-stack* *fake-stack*))
+     (speaker "no goodbyes"))
+   ('some-key
+    (lambda (stacks . rest)
+      (speaker "should not happen")))
+   ('my-orig-key
+    (lambda (stacks fruit1 fruit2 fruit3)
+      (set! catch-result
+            `((fruit1 ,fruit1)
+              (fruit2 ,fruit2)
+              (fruit3 ,fruit3))))))
+  (test-equal (speaker) '("hello"))
+  (test-equal catch-result '((fruit1 apple)
+                             (fruit2 orange)
+                             (fruit3 banana))))
+
 ;; End tests
 
 (test-end "test-agenda")
 
+;; @@: A better way to handle this at the repl?
 (test-exit)
 
-- 
2.31.1