Refactoring = Substitution + Rewriting

TL;DR

This paper introduces a language-independent framework for describing code refactorings through substitution and rewriting, connecting to API migration research and enabling broader application.

Contribution

It proposes an abstract, class-based approach to refactoring that separates substitution from rewriting, facilitating language-independent transformations.

Findings

Framework unifies refactoring and API migration concepts

Implementation demonstrates language-independent substitution

Rewrites incorporate language-specific details

Abstract

We present an approach to describing refactorings that abstracts away from particular refactorings to classes of similar transformations, and presents an implementation of these that works by substitution and subsequent rewriting. Substitution is language-independent under this approach, while the rewrites embody language-specific aspects. Intriguingly, it also goes back to work on API migration by Huiqing Li and the first author, and sets refactoring in that general context.