unikernel/duniverse/ppxlib/test/pprintast/oldschool-constraints/pprint_pvb_constraint.ml

@@ -0,0 +1,35 @@
+open Ppxlib
+
+let loc = Location.none
+
+let ast =
+  let vbs =
+    let pat = [%pat? f] in
+    let expr = [%expr fun _ -> ()] in
+    let constraint_ =
+      Pvc_constraint
+        {
+          locally_abstract_univars = [];
+          typ =
+            Ast_builder.Default.ptyp_poly ~loc
+              [ Loc.make ~loc "a" ]
+              [%type: 'a -> unit];
+        }
+    in
+    [ Ast_builder.Default.Latest.value_binding ~loc ~pat ~expr ~constraint_ () ]
+  in
+  Ast_builder.Default.pstr_value ~loc Nonrecursive vbs
+
+let print_source () = Format.printf "%a\n" Pprintast.structure_item ast
+let print_ast () = Format.printf "%a\n" Pp_ast.Default.structure_item ast
+
+let () =
+  match Sys.argv with
+  | [| _exec |] -> print_source ()
+  | [| _exec; _flag |] ->
+      print_ast ();
+      Format.printf "------- PRINTED AS -------\n";
+      print_source ()
+  | _ ->
+      Printf.eprintf "Invalid usage!";
+      exit 1