M2compiler-V3/compiler/tests/t_ptrsentinel.mod

MODULE TPtrSentinel;
(* Integer-to-ADDRESS conversion supports C sentinel values. *)
FROM SYSTEM IMPORT ADDRESS, VAL;
VAR ExitCode : INTEGER;
    p : ADDRESS;
BEGIN
  p := VAL(ADDRESS, -1);
  IF p # NIL THEN ExitCode := 42 ELSE ExitCode := 1 END
END TPtrSentinel.