assembler: Avoid NoneError

check result

1 files changed, 3 insertions, 0 deletions

diff --git a/nandgame/assembler/assembler_main.py b/nandgame/assembler/assembler_main.py
index 881b8fe..9871a31 100644
--- a/nandgame/assembler/assembler_main.py
+++ b/nandgame/assembler/assembler_main.py
@@ -7,6 +7,9 @@ from py_nand_ass import assembler as ass  # pyright: ignore[reportImplicitRelati
 
 if __name__ == "__main__":
     result = parse_file(sys.argv[1])
+    if not result:
+        print("Parsing returned an empty result")
+        sys.exit(1)
     errors = ass.check_instructions(result)
     errors = list(errors)