A visitor for declarations, in the style of the standard visitor
design pattern. Classes implementing this interface are used to
operate on a declaration when the kind of declaration is unknown at
compile time. When a visitor is passed to a declaration's
Declaration.accept accept method, the most specific
visitXxx method applicable to that declaration is
invoked.
author: Joseph D. Darcy author: Scott Seligman version: 1.3 04/04/20 since: 1.5