NAME

       throw - Generate a machine-readable error

SYNOPSIS

       throw type message
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DESCRIPTION

       This command causes the current evaluation to be unwound with an error. The error created is described by
       the  type and message arguments: type must contain a list of words describing the error in a form that is
       machine-readable (and which will form the error-code part of the result dictionary), and  message  should
       contain text that is intended for display to a human being.

       The  stack  will  be unwound until the error is trapped by a suitable catch or try command. If it reaches
       the event loop without being trapped, it will be reported through the bgerror mechanism.  If  it  reaches
       the  top  level  of  script  evaluation  in  tclsh, it will be printed on the console before, in the non-
       interactive case, causing an exit (the behavior in other programs will depend on the details of  how  Tcl
       is embedded and used).

       By convention, the words in the type argument should go from most general to most specific.

EXAMPLES

       The  following produces an error that is identical to that produced by expr when trying to divide a value
       by zero.

              throw {ARITH DIVZERO {divide by zero}} {divide by zero}

SEE ALSO

       catch(3tcl), error(3tcl), errorCode(3tcl), errorInfo(3tcl), return(3tcl), try(3tcl)

KEYWORDS

       error, exception

Tcl                                                    8.6                                           throw(3tcl)