get multiple JSON messages working

tools/cmd/list_fonts/main.go

@@ -12,8 +12,16 @@ import (
 
 var _ = fmt.Print
 var debugprintln = tty.DebugPrintln
+
 var json_decoder *json.Decoder
 
+func json_decode(v any) error {
+	if err := json_decoder.Decode(v); err != nil {
+		return fmt.Errorf("Failed to decode JSON from kitty with error: %w", err)
+	}
+	return nil
+}
+
 func main() (rc int, err error) {
 	json_decoder = json.NewDecoder(os.Stdin)
 	lp, err := loop.New()

tools/cmd/list_fonts/ui.go

@@ -187,7 +187,7 @@ func (h *handler) initialize() {
 	h.rl = readline.New(h.lp, readline.RlInit{DontMarkPrompts: true, Prompt: "Family: "})
 	h.draw_screen()
 	go func() {
-		h.set_worker_error(json_decoder.Decode(&h.fonts))
+		h.set_worker_error(json_decode(&h.fonts))
 		h.lp.WakeupMainThread()
 	}()
 }