return(TCL)

return -- return from a procedure

Synopsis

return [-code code] [-errorinfo info] [-errorcode code] [string]

Description

Returns immediately from the current procedure (or top-level command or source command), with string as the return value. If string is not specified then an empty string will be returned as result.

Exceptional returns

In the usual case where the -code option is not specified the procedure returns normally (with a completion code of TCL_OK). However, the -code option may be used to generate an exceptional return from the procedure. code may have any of the following values:

ok: Normal return: the same as if the option were omitted.
error: Error return: the same as if the error command were used to terminate the procedure, except for handling of errorInfo and errorCode variables (see below).
return: The current procedure returns with a completion code of TCL_RETURN, so that the procedure that invoked it returns also.
break: The current procedure returns with a completion code of TCL_BREAK, which terminates the innermost nested loop in the code that invoked the current procedure.
continue: The current procedure returns with a completion code of TCL_CONTINUE, which terminates the current iteration of the innermost nested loop in the code that invoked the current procedure.
value: value must be an integer; it is returned as the completion code for the current procedure.

The -code option is rarely used. It is provided so that procedures that implement new control structures can reflect exceptional conditions back to their callers.

Two additional options, -errorinfo and -errorcode, may be used to provide additional information during error returns. These options are ignored unless code is error.

The -errorinfo option specifies an initial stack trace for the errorInfo variable; if it is not specified then the stack trace left in errorInfo includes the call to the procedure and higher levels on the stack but it does not include any information about the context of the error within the procedure. Typically the info value is supplied from the value left in errorInfo after a catch command traps an error within the procedure.

If the -errorcode option is specified then code provides a value for the errorCode variable. If the option is not specified then errorCode defaults to NONE.