unikernel/duniverse/ppxlib/ast/pp/pp_rewrite.mll

@@ -0,0 +1,27 @@
+{
+open Printf
+
+let print_ocaml_version version =
+  let patt_len = String.length "OCAML_VERSION" in
+  (* Note: the spaces in the replacements are to preserve locations *)
+  printf "%-*s" patt_len version
+}
+
+rule rewrite ocaml_version = parse
+  | "OCAML_VERSION"
+    { print_ocaml_version ocaml_version;
+      rewrite ocaml_version lexbuf
+    }
+  |          "(*IF_AT_LEAST " ([^'*' ' ']* as v) " " ([^'*']* as s) "*)"
+    { let chunk = if (v <= ocaml_version)
+        then "              " ^ String.make (String.length v + 1) ' ' ^ s ^          "  "
+        else Lexing.lexeme lexbuf
+      in
+      print_string chunk;
+      rewrite ocaml_version lexbuf
+    }
+  | _ as c
+    { print_char c;
+      rewrite ocaml_version lexbuf
+    }
+  | eof { () }