Programming Research Group Technical Monograph PRG-55

Mark B Josephs

D.Phil. thesis, June 1986, 101 pages, ISBN 0-902928-36-8

In this thesis functional and logic programming languages are combined into a new declarative language. This allows for lazy single assignment to logical variables in an otherwise purely functional language. Efficient solutions to various programming problems are developed. It is also shown that these programs with side-effects can be derived by means of transformational programming. On implementations that support parallelism, further interesting possibilities arise.

The formal semantics of this extension to functional programming is investigated. Both denotational and axiomatic semantic descriptions of the language are presented. Programming with side-effects is particularly attractive because it can be supported by graph reduction based implementations of functional programming languages. Details of a prototype implementation are given.