MODULE TExceptTrap;
(* M4: compiler-emitted index and subrange traps are catchable language
   exceptions with the right M2EXCEPTION values. *)
FROM M2EXCEPTION IMPORT
  M2Exception, IsM2Exception, indexException, rangeException;

TYPE
  Small = [0..7];
VAR ExitCode : INTEGER;
VAR a : ARRAY [0..2] OF INTEGER;
VAR s : Small;
VAR i : INTEGER;

PROCEDURE IndexTrap;
BEGIN
  i := 3;
  a[i] := 1;
  ExitCode := 1
EXCEPT
  IF IsM2Exception() AND (M2Exception() = indexException) THEN
    ExitCode := 2
  ELSE
    ExitCode := 3
  END
END IndexTrap;

PROCEDURE RangeTrap;
BEGIN
  i := 9;
  s := i;
  ExitCode := 4
EXCEPT
  IF IsM2Exception() AND (M2Exception() = rangeException) THEN
    ExitCode := 42
  ELSE
    ExitCode := 5
  END
END RangeTrap;

BEGIN
  ExitCode := 0;
  IndexTrap;
  IF ExitCode = 2 THEN RangeTrap END
END TExceptTrap.