The LISP70 pattern matching system

Abstract

LISP70 is a descendant of LISP which emphasizes pattern-directed computation and extensibility. A function can be defined by a set of pattern rewrite rules as well as by the normal LAMBDA method. New rewrite rules can be added to a previously defined function; thus a LISP70 function is said to be extensible. It is possible to have new rules merged in automatically such that special cases are checked before general cases. Some of the facilities of the rewrite system are described and a variety of applications are demonstrated.