Clean — A language for functional graph rewriting

Abstract

Abstract.Clean is an experimental language for specifying functional computations in terms of graph rewriting. It is based on an extension of Term Rewriting Systems (TRS) in which the terms are replaced by graphs. Such a Graph Rewriting System (GRS) consists of a, possibly cyclic, directed graph, called the data graph and graph rewrite rules which specify how this data graph may be rewr~en. Clean is designed to provide a firm base for functional programming. In particular, Clean is suitable as an intermediate language between functional languages and (parallel) target machine architectures. A sequential implementation of Clean on a conventional machine is described and its performance is compared with other systems. The results show that Clean can be efficiently implemented.

ViSSh: A Data Visualisation Spreadsheet

“…However, it was not until the functional paradigm was used in conjunction with spreadsheets that the compatibility of spreadsheets and the functional paradigm was demonstrated. De Hoon [4] has constructed a text-based spreadsheet, which uses the functional language Clean [1] as its underlying formula language. This spreadsheet has some interesting properties, such as the ability to evaluate functional expressions symbolically.…”

High Level Specification of I/O in Functional Languages

“…Concurrent Clean [5], [13], [17] is a lazy functional programming language based on Term Graph Rewriting [4]. Here is an example of a Clean function defining the well-known fibonacci function.…”

“…In this paper we present Clean's Event I/O, a new solution for the I/O problem that has been implemented in the lazy functional graph rewriting language Concurrent Clean [5], [13], [17] developed at the University of Nijmegen. This solution not only deals with the problems mentioned above but it also allows the specification of complicated window based I/O on a very high-level of abstraction.…”

Functional Programming and Lambda Calculus

“…In the early eighties things went faster and rather good sequential implementations of functional languages were developed, e.g. the G-machine [3,49] or the compiler described in [15]. Presently, several research groups are working towards fast parallel reduction machines.…”