Optimized Execution of FreeCHR

TL;DR

This paper introduces an optimized execution and matching algorithm for the FreeCHR framework, which standardizes embedding of CHR into various host languages, improving performance and correctness.

Contribution

It presents an improved execution and matching algorithm for FreeCHR, enhancing its efficiency and practical applicability.

Findings

Empirical evaluation shows performance improvements.

The algorithm maintains correctness of CHR semantics.

Enhanced matching efficiency reduces execution time.

Abstract

Constraint Handling Rules (CHR) is a rule-based programming language that rewrites collections of constraints. It is typically embedded into a general-purpose language. There exists a plethora of implementation for numerous host languages. However, the existing implementations often re-invent the method of embedding, which impedes maintenance and weakens assertions of correctness. To formalize and thereby standardize the embedding of a ground subset of CHR into arbitrary host languages, we introduced the framework FreeCHR and proved it to be a valid representation of classical CHR. For the sake of simplicity, abstract implementations of our framework did not yet include a concrete matching algorithm nor optimizations. In this paper, we introduce an improved execution and matching algorithm for FreeCHR. We also provide empirical evaluation of the algorithm.