Alignment Elimination from Adams' Grammars

TL;DR

This paper introduces a method to eliminate the alignment construct from Adams' grammars, simplifying indentation-sensitive parsing by transforming well-formed grammars without losing their expressive power.

Contribution

It presents the first detailed transformation process to remove alignment from Adams' grammars, enhancing their usability and understanding.

Findings

Alignment can be systematically eliminated from Adams' grammars.

The transformation preserves the original grammar's semantics.

The method simplifies the grammar structure for easier implementation.

Abstract

Adams' extension of parsing expression grammars enables specifying indentation sensitivity using two non-standard grammar constructs --- indentation by a binary relation and alignment. This paper proposes a step-by-step transformation of well-formed Adams' grammars for elimination of the alignment construct from the grammar. The idea that alignment could be avoided was suggested by Adams but no process for achieving this aim has been described before.