Most COM methods return an integer hresult to indicate success or failure, which can be checked using succeeded,. s_ok, hresult-equal or check-hresult.
In addition, after calling a COM method that provides extended error information, you can call the function get-error-info to obtain more details of any error that occurred. This is supplied with a list of fields , which should be keywords specifying the parts of the error information to obtain.
For example, in the session below,
is a COM interface pointer for the
CL-USER 186 > (call-com-interface (tt i-test-suite-1 fx))
"in fx" ;; implementation running
-2147352567 ;; the error code DISP_E_EXCEPTION
CL-USER 187 > (get-error-info :fields '(:description
CL-USER 188 >
LispWorks COM/Automation User Guide and Reference Manual - 19 Dec 2011