Author Description

This volume contains the notes of the lectures given at the Fourth Inter- national School on Advanced Functional Programming, held August 19–24, 2002, at St. Anne’s College in Oxford, UK. This School was preceded by earlier ones in B? astad (1995, Sweden, LNCS 925), Olympia, WA (1996, USA, LNCS 1129), and Braga (1998, Portugal, LNCS 1608). The goal of this series of schools is to make recent developments in the area of functional programming widely available. The notes are published to enable individuals, small groups of students, and lecturers to study recent work in the rapidly developing area of functional programming. The lectures in this School introduce tools, language features, domain-speci?c languages, problem domains, or programming methods. All lectures are accompanied by software, and all lectures contain exercises and practical assignments. Most of the resources can be downloaded via the website of the School: http://www.functional-programming.org/afp/afp4/. The Lectures Richard Bird and Jeremy Gibbons show how to construct a program for arithmetic coding. They use the theory of folds and unfolds to develop both a program for arithmetic coding and decoding, and a proof of correctness. The elegant result shows that using theory can make a difficult proof digestible. Manuel Chakravarty and Gabriele Keller tackle the performance problem of Haskell’s standard arrays. They introduce an array library with which arr-centric algorithms can be coded elegantly, which has very good performance. Koen Claessen and Colin Runciman show how to use QuickCheck to specify program properties and to test these properties on functional programs, and how to use Hat to trace computations. The combination of the two tools which can be used to trace computations of unexpected results is a powerful debugging tool. Matthias Felleisen explains how to develop interactive Web programs in functional Scheme with continuations, using DrScheme and its built-in Web server.