Add default game loop error handler.

* chickadee.scm (default-error-handler): New procedure.
(run-game): Set default value for 'error' arg to
'default-error-handler'.
* chickadee/sdl.scm (run-game/sdl): Ditto.

2 files changed, 11 insertions, 5 deletions

diff --git a/chickadee.scm b/chickadee.scm
index 09212fe..4176b5d 100644
--- a/chickadee.scm
+++ b/chickadee.scm
@@ -16,7 +16,8 @@
 ;;; <http://www.gnu.org/licenses/>.
 
 (define-module (chickadee)
-  #:export (run-game
+  #:export (default-error-handler
+            run-game
             abort-game))
 
 
@@ -43,11 +44,14 @@
         (set! stack (make-stack #t 3))))))
 
 (define-syntax-rule (with-error-handling handler body ...)
-  (call-with-error-handling handler  (lambda () body ...)))
+  (call-with-error-handling handler (lambda () body ...)))
+
+(define (default-error-handler stack key args)
+  (apply throw key args))
 
 
 ;;;
-;;; Game loop core
+;;; Game loop kernel
 ;;;
 
 (define game-loop-prompt-tag (make-prompt-tag 'game-loop))
@@ -55,7 +59,9 @@
 (define (abort-game)
   (abort-to-prompt game-loop-prompt-tag #f))
 
-(define* (run-game #:key update render time error (update-hz 60))
+(define* (run-game #:key update render time
+                   (error default-error-handler)
+                   (update-hz 60))
   (let ((timestep (round (/ 1000 update-hz))))
     (call-with-prompt game-loop-prompt-tag
       (lambda ()
diff --git a/chickadee/sdl.scm b/chickadee/sdl.scm
index bb8d5e3..b00e30e 100644
--- a/chickadee/sdl.scm
+++ b/chickadee/sdl.scm
@@ -85,7 +85,7 @@
                        (controller-press (const #t))
                        (controller-release (const #t))
                        (controller-move (const #t))
-                       (error (const #t)))
+                       (error default-error-handler))
   (sdl-init)
   (false-if-exception (mixer-init))
   (open-audio)