The KnowledgeWorks Listener has already been shown to function as a Lisp Listener. However it extends this with the ability of the Objects Browser to match objects. When using the Objects Browser the
Query
pane contained patterns which could be matched against the Object Base. These same patterns can be entered into the KnowledgeWorks Listener. Enter
(node ?object)
into the Listener. This asks "Are there any node objects?". A
NODE
object will be returned. To ask for more solutions press the
Next
button. If there are more you will be shown another, otherwise the listener displays the word
NO
and the listener prompt reappears. If you do not want to see any more, just press
Return
.
Try entering some of the other expressions from the Objects Browser, for example
(and (node ?n animal ?a) (test ?a))
. If the input is not recognised it is treated as Lisp.