Algol 68 Dialect Conversion -- a Syntactic Approach

A syntax directed package for converting Revised Algol 68 programs into Algol 68-R form, (where possible) is being developed at Nottingham. The package makes use of J.M. Foster's Syntax Improving Device (SID) [1]. The experience gained has underlined the value of a syntactic approach to problems of this sort. A far wider range of constructs can be translated than would ever be possible by using ad hoc methods. In many respects the difficulties encountered are those of conventional compiler writing, but some intriguing new problems arise when, as in this case, the source language and target language differ relatively little in philosophy and appearance.

Compiling Exceptions Correctly

Exceptions are an important feature of modern programming languages, but their compilation has traditionally been viewed as an advanced topic. In this article we show that the basic method of compiling exceptions using stack unwinding can be explained and verified both simply and precisely, using elementary functional programming techniques. In particular, we develop a compiler for a small language with exceptions, together with a proof of its correctness.

Calculating an Exceptional Machine

In previous work we showed how to verify a compiler for a small language with exceptions. In this article we show how to calculate, as opposed to verify, an abstract machine for this language. The key step is the use of Reynold's defunctionalization, an old program transformation technique that has recently been rejuvenated by the work of Danvy et al.