Implement pre-increment / pre-decrement
diff --git a/libacc/tests/test.py b/libacc/tests/test.py
index 5f9a71e..0249695 100644
--- a/libacc/tests/test.py
+++ b/libacc/tests/test.py
@@ -293,6 +293,10 @@
 1
 2
 1
+1
+2
+1
+0
 result: 0
 ""","""""")