:art: Improve concatenation

diff --git a/ast b/ast
index 7971b912bbdd6271afd1df5aa8e218b5284d6a44..750eae810b8603f1229a93d6bbf856ce8f9f9bd7 160000 (submodule)
--- a/ast
+++ b/ast
@@ -1 +1 @@
-Subproject commit 7971b912bbdd6271afd1df5aa8e218b5284d6a44
+Subproject commit 750eae810b8603f1229a93d6bbf856ce8f9f9bd7