Language Extensions - Modal Methods

Service programmers annotate methods with a “when” clause, to make them modal. The clause declares a named property, e.g.
class SearchEngine { Vector query(String searchTerm) when CAN_SEARCH { ... } }
To control use of the modal query method, policies are written that define exactly when the SearchEngine service has the CAN_SEARCH property and when it does not.

Service programmers annotate methods with a “when” clause, to make them modal. The clause declares a named property, e.g.