Implementation of Visit-Oriented Attribute Evaluators

A large class of attribute evaluators (AE) are controlled by visit-sequences describing the computations during a tree walk. In this paper it is shown how such a control structure is implemented systematically. An AE has to provide storage for the attribute values associated to the tree nodes. Naive storage allocation techniques are not tolerable for practical applications. An introduction to well elaborated methods of attribute storage optimization is given. They are applied automatically by practical AG systems.