Paul J. Kwiatkowski

Forwarding in Attribute Grammars for Modular Language Design

Forwarding is a technique for providing default attribute definitions in attribute grammars that is helpful in the modular implementation of programming languages. It complements existing techniques such as default copy rules. This paper introduces forwarding and shows how it is but a small extension of standard higher-order attribute grammars. The usual tools for manipulating higher-order attribute grammars, including the circularity check (which tests for cyclic dependencies between attribute values), carry over without modification. The closure test (which checks that each attribute has a defining equation) needs modification, however, because the resulting higher-order attribute grammars may contain spurious attributes that are never evaluated and indeed that need not be defined.

Transformation in intentional programming

Intentional programming is a new paradigm in software engineering that allows programming languages to be implemented in a highly extensible manner. In particular, the programmer can specify new abstractions that are specific to his problem domain, while simultaneously recording any domain specific optimizations that may apply to such new abstractions. This paper describes a system that implements intentional programming, focusing on the facilities for program transformation. The key difference with other approaches lies in the way the order of transformation is controlled: emphasis is placed on specifying that order in a compositional fashion, so that transformations are easily re-used.