Refactoring Pattern Matching

Journal article

Defining functions by pattern matching over the arguments is advantageous for understanding and reasoning, but it tends to expose the implementation of a datatype. Significant effort has been invested in tackling this loss of modularity; however, decoupling patterns from concrete representations while maintaining soundness of reasoning has been a challenge. Inspired by the development of invertible programming, we propose an approach to program refactoring based on a right-invertible language RINV - every function has a right (or pre-) inverse. We show how this new design is able to permit a smooth incremental transition from programs with algebraic datatypes and pattern matching, to ones with proper encapsulation, while maintaining simple and sound reasoning.

Authors: Wang, M; Gibbons, J; Matsuda, K; Hu, Z

• Journal: Science of Computer Programming
• Volume: 78
• Issue: 11
• Pages: 2216-2242
• Publication date: 2012-01-01
• DOI: 10.1016/j.scico.2012.07.014