Functional description of the contextual analysis in block-structured programming languages: a case study of tree transducers

Abstract

This paper provides a functional way of describing the analysis of contextual constraints in block-structured, imperative programming languages. As auxiliary formal framework for the intended description, the general concept of many-sorted tree transducer is defined; such transducers are special left-linear, confluent, and noetherian term-rewriting systems in which both sides of the rewrite rules are applicative terms. Then, the contextual analysis is described by five different instances of the auxiliary framework where these instances are known from the literature, viz., top-down tree transducers, macro tree transducers, modular tree transducers, high-level tree transducers, and high-level modular tree transducers. Hence, this paper provides a nontrivial example for each of the mentioned families of tree transducers and it shows how features involved in these tree transducers can be exploited.