Grammatical Aspects for Language Descriptions

TL;DR

This paper introduces Grammatic, an aspect-oriented approach to describing programming languages that enhances grammar readability and reduces duplication, facilitating the automatic generation of tools like parsers and pretty-printers.

Contribution

It presents a novel aspect-oriented method for language description that improves readability and minimizes duplication compared to traditional annotated grammars.

Findings

Implemented in open-source tool Grammatic

Enables automatic generation of pretty-printers and syntax highlighters

Reduces grammar duplication and improves readability

Abstract

For the purposes of tool development, computer languages are usually described using context-free grammars with annotations such as semantic actions or pretty-printing instructions. These descriptions are processed by generators which automatically build software, e.g., parsers, pretty-printers and editing support. In many cases the annotations make grammars unreadable, and when generating code for several tools supporting the same language, one usually needs to duplicate the grammar in order to provide different annotations for different generators. We present an approach to describing languages which improves readability of grammars and reduces the duplication. To achieve this we use Aspect-Oriented Programming principles. This approach has been implemented in an open-source tool named Grammatic. We show how it can be used to generate pretty-printers and syntax highlighters.