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throw(n)                     Tcl Built-In Commands                    throw(n)

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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(n), error(n), errorCode(n), errorInfo(n), return(n), try(n)

KEYWORDS
       error, exception

Tcl                                   8.6                             throw(n)