:art: add digit separator

diff --git a/ast b/ast
index 76ba56280e16bbef295c8496a50d079cce7fa1f9..f8589bde72faa61d9552ca6fbce4a2ba541031f9 160000 (submodule)
--- a/ast
+++ b/ast
@@ -1 +1 @@
-Subproject commit 76ba56280e16bbef295c8496a50d079cce7fa1f9
+Subproject commit f8589bde72faa61d9552ca6fbce4a2ba541031f9