Recursion equations as a programming language

Abstract

This paper was written in 1981 and published in Darlington Henderson and Turner (1982) pp 1-28. The volume comprised the lecture notes from a summer school on Functional Programming held at Newcastle University in July 1981, attended by 80 people. The paper includes an overview of Kent Recursive Calculator, a simple functional programming system based on higher order recursion equations and a series of programming examples. It is probably the earliest paper using list comprehensions applied to lazy lists and has the first published account of the “list of successes” method of eliminating backtracking, here applied to the eight queens problem. The method didn’t yet have a name. It was Phil Wadler who saw its importance and coined the phrase “list of successes” in his 1985 paper. It was also Phil who invented the term “list comprehensions” for what are here called “ZF expressions”.