From 76b16f298e6e6d99e4fda17ba9b38bb181792ecc Mon Sep 17 00:00:00 2001
From: Johannes Mey <johannes.mey@tu-dresden.de>
Date: Sat, 4 Jan 2020 13:30:00 +0100
Subject: [PATCH] fix printing of null-valued (i.e., optional or empty list)
 relations

---
 scope4m/src/main/jastadd/ASTPrinting.jadd | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scope4m/src/main/jastadd/ASTPrinting.jadd b/scope4m/src/main/jastadd/ASTPrinting.jadd
index ce00afc..67099c0 100644
--- a/scope4m/src/main/jastadd/ASTPrinting.jadd
+++ b/scope4m/src/main/jastadd/ASTPrinting.jadd
@@ -14,7 +14,8 @@ aspect Debugging {
           } else {
             name += ":= ";
           }
-          result += "|--" + name + method.invoke(this).toString().split("\\r?\\n")[0];
+          Object value = method.invoke(this);
+          result += "|--" + name + (value == null ? "<null>" : value.toString().split("\\r?\\n")[0]);
         } catch (IllegalAccessException e) {
           e.printStackTrace();
         } catch (java.lang.reflect.InvocationTargetException e) {
-- 
GitLab