util: separated the monadic traverse into a utility module

lib/compiler/syntactic_ast.ml

@@ -34,13 +34,7 @@ type top_level =
 
 (* we use result here to make things nicer *)
 let ( let* ) = Result.bind
-let traverse f l =
+let traverse = Util.traverse
-  let rec aux acc = function
-    | x :: xs ->
-       let* result = f x in
-       aux (result :: acc) xs
-    | [] -> Ok (List.rev acc) in
-  aux [] l
 let map = List.map
 
 

lib/compiler/util.ml

@@ -0,0 +1,9 @@
+let ( let* ) = Result.bind
+
+let traverse f l =
+  let rec aux acc = function
+    | x :: xs ->
+       let* result = f x in
+       aux (result :: acc) xs
+    | [] -> Ok (List.rev acc) in
+  aux [] l