ValAsp: a tool for data validation in Answer Set Programming

TL;DR

ValAsp introduces a formalized approach and a tool for data validation in Answer Set Programming, enabling fail-fast detection of invalid data to improve software reliability without impacting performance.

Contribution

It formalizes data validation in ASP, proposes a validation language using YAML, ASP, and Python, and provides a tool to integrate validation seamlessly into existing programs.

Findings

Formalization of data validation for ASP

Development of ValAsp tool for validation injection

Supports validation in ASP, YAML, and Python

Abstract

The development of complex software requires tools promoting fail-fast approaches, so that bugs and unexpected behavior can be quickly identified and fixed. Tools for data validation may save the day of computer programmers. In fact, processing invalid data is a waste of resources at best, and a drama at worst if the problem remains unnoticed and wrong results are used for business. Answer Set Programming (ASP) is not an exception, but the quest for better and better performance resulted in systems that essentially do not validate data. Even under the simplistic assumption that input/output data are eventually validated by external tools, invalid data may appear in other portions of the program, and go undetected until some other module of the designed software suddenly breaks. This paper formalizes the problem of data validation for ASP programs, introduces a language to specify data validation, and presents \textsc{valasp}, a tool to inject data validation in ordinary programs. The proposed approach promotes fail-fast techniques at coding time without imposing any lag on the deployed system if data are pretended to be valid. Validation can be specified in terms of statements using YAML, ASP and Python. Additionally, the proposed approach opens the possibility to use ASP for validating data of imperative programming languages. Under consideration for acceptance in TPLP.