RosettaCodeData/Task/Exceptions-Catch-an-exception-thrown-in-a-nested-call/BBC-BASIC/exceptions-catch-an-exception-thrown-in-a-nested-call.basic

      REM Allocate error numbers:
      U0& = 123
      U1& = 124

      PROCfoo
      END

      DEF PROCfoo
      ON ERROR LOCAL IF ERR = U0& THEN PRINT "Exception U0 caught in foo" ELSE \
      \              RESTORE ERROR : ERROR ERR, REPORT$
      PROCbar
      PROCbar
      ENDPROC

      DEF PROCbar
      PROCbaz
      ENDPROC

      DEF PROCbaz
      PRIVATE called%
      called% += 1
      CASE called% OF
        WHEN 1: ERROR U0&, "Exception U0 thrown"
        WHEN 2: ERROR U1&, "Exception U1 thrown"
      ENDCASE
      ENDPROC