       1mtry_eval 4m22mcode24m 4mcatch24m ?4mfinally24m?
              The 1mtry_eval 22mcommand evaluates 4mcode24m in the current context.

       If  an  error occurs during the evaluation and 4mcatch24m is not empty, then
       4mcatch24m is evaluated to handler the error.  The result  of  the  command,
       containing  the  error  message,  will  be  stored in a global variable
       1merrorResult22m.  The global variables 1merrorResult22m, 1merrorInfo 22mand 1merrorCode0m
       will  be imported into the current scope, there is no need to execute a
       1mglobal 22mcommand.  The result of the 4mcatch24m command becomes the result  of
       the  1mtry_eval 22mcommand.  If the error that caused the 4mcatch24m to be evalu-
       ate is to be continued, the following command should be used:
            1merror $errorResult $errorCode $errorInfo0m

       If the 4mfinally24m argument is supplied and  not  empty,  it  is  evaluated
       after  the  evaluation of the 4mcode24m and the 4mcatch24m commands.  If an error
       occurs during the evaluation of the 4mfinally24m  command,  it  becomes  the
       result  of  the 1mtry_eval 22mcommand.  Otherwise, the result of either 4mcode0m
       or 4mcatch24m is preserved, as described above.
