MODULE TExceptLib;
(* M3: EXCEPTIONS / M2EXCEPTION over user RAISE and SYSTEM.THROW. *)
FROM EXCEPTIONS IMPORT
  ExceptionSource, ExceptionNumber, AllocateSource, RAISE,
  CurrentNumber, GetMessage, IsCurrentSource, IsExceptionalExecution;
FROM M2EXCEPTION IMPORT
  M2Exception, IsM2Exception, wholeDivException, exException;
FROM SYSTEM IMPORT THROW;

VAR ExitCode : INTEGER;
VAR src      : ExceptionSource;
VAR other    : ExceptionSource;
VAR msg      : ARRAY [0..63] OF CHAR;
VAR n        : ExceptionNumber;

PROCEDURE UserRaise;
BEGIN
  RAISE(src, 7, "boom");
  ExitCode := 1
EXCEPT
  IF IsExceptionalExecution() AND IsCurrentSource(src)
     AND NOT IsCurrentSource(other)
     AND NOT IsM2Exception() AND (CurrentNumber(src) = 7) THEN
    GetMessage(msg);
    IF msg = "boom" THEN ExitCode := 42 ELSE ExitCode := 2 END
  ELSE
    ExitCode := 3
  END
END UserRaise;

PROCEDURE AskWrongSource;
BEGIN
  n := CurrentNumber(other);
  ExitCode := 1
EXCEPT
  IF IsM2Exception() AND (M2Exception() = exException) THEN
    ExitCode := 42
  ELSE
    ExitCode := 6
  END
END AskWrongSource;

PROCEDURE LanguageRaise;
BEGIN
  THROW(6)
EXCEPT
  IF IsM2Exception() AND (M2Exception() = wholeDivException) THEN
    ExitCode := 42
  ELSE
    ExitCode := 4
  END
END LanguageRaise;

BEGIN
  AllocateSource(src);
  AllocateSource(other);
  ExitCode := 0;
  UserRaise;
  IF ExitCode = 42 THEN
    GetMessage(msg);
    IF msg = "" THEN ExitCode := 0 ELSE ExitCode := 5 END
  END;
  IF ExitCode = 0 THEN AskWrongSource END;
  IF ExitCode = 42 THEN LanguageRaise END
END TExceptLib.