XFUNC (Sbxname, arg1,...,argn)
XFUNC$ (Sbxname, arg1,...,argn)
XFUNC executes an external function, returning a value. It is similar to XCALL (in that it loads and calls an external function) except that it is an expression (which returns a value) rather than a statement (which does not). Sbxname is the name of an SBX subroutine which implements the function, and arg1 through argn are the arguments passed to the SBX routine. The only special requirement for the SBX routine is that it return a value (numeric for XFUNC and string for XFUNC$) via a special form of the RETURN statement (which see above).
See Also