biscuit

commit d69b7b8355737b7adb56bbf00c1ae5acfa519df0
parent 1652fefab72c92e892becda3d844c0dbd0e2bc9e
Author: Daniel Barlow <dan@telent.net>
Date:   Tue, 10 Mar 2026 00:14:39 +0000

handle json deciding errors

Diffstat:
M
pkgs/maps/tiles.fnl
 | 
13
+++++++++++--

1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/pkgs/maps/tiles.fnl b/pkgs/maps/tiles.fnl
@@ -135,13 +135,20 @@
 (fn tile-name [x y zoom]
   (.. x "_" y "_" zoom))
 
+(fn jsond [s]
+  (case (pcall json.decode s)
+    (true val) val
+    (false err) (values nil err)))
+
 (fn fetch [cq x y zoom cb]
   (let [k (tile-name x y zoom)
         pathname (.. "/tmp/tiles/" k ".json")]
     (if (file-exists? pathname)
         (let [payload (with-open [i (io.open pathname :r)] (i:read "*a"))]
           (when (not (= payload ""))
-            (cb (canvas (. (json.decode payload) :elements) zoom))))
+            (case (jsond payload)
+              val (cb (canvas (. val :elements) zoom))
+              (nil err) (print "json decode error" pathname))))
         (let [out (io.open pathname :w)]
           (cq:wrap (fn []
                      (print "getting " k)
@@ -154,7 +161,9 @@
                            (cqueues.sleep (math.random 2 6))))
                        (print "got " k)
                        (f:write payload)
-                       (cb (canvas (. (json.decode payload) :elements) zoom))
+                       (case (jsond payload)
+                         val (cb (canvas (. val :elements) zoom))
+                         (nil err) (print "json decode error" pathname))
                        true)))))))
 
 { : fetch : latlon->tile :name tile-name }