preliminary read support

diff --git a/src/prolog/parser b/src/prolog/parser
index 3fb28efa315852734613fcf34ee3467c5be8545c..6a7545257bbfc660b37a0bc3d7a72edb244dda86 160000 (submodule)
--- a/src/prolog/parser
+++ b/src/prolog/parser
@@ -1 +1 @@
-Subproject commit 3fb28efa315852734613fcf34ee3467c5be8545c
+Subproject commit 6a7545257bbfc660b37a0bc3d7a72edb244dda86