This class is used to customize the way the evaluator resolves
variable references. For example, instances of this class can
implement their own variable lookup mechanisms, or introduce the
notion of "implicit variables" which override any other variables.
An instance of this class should be passed to the evaluator's
constructor.
Whenever the evaluator is invoked, it is passed a "context"
Object from the application. For example, in a JSP environment,
the "context" is a PageContext. That context object is eventually
passed to this class, so that this class has a context in which to
resolve variables. |
