# Jolie Static Type Checker: a prototype

## TL;DR

This paper presents a prototype static type checker for Jolie, utilizing an SMT solver to improve software reliability by detecting errors at compile time, complementing its existing dynamic type system.

## Contribution

The paper introduces the first implementation of a static type checker for Jolie, based on formal theory and SMT solving techniques.

## Key findings

- Prototype successfully detects type errors before runtime
- Integrates static analysis with Jolie's dynamic type system
- Enhances software reliability by reducing runtime errors

## Abstract

Static verification of a program source code correctness is an important element of software reliability. Formal verification of software programs involves proving that a program satisfies a formal specification of its behavior. Many languages use both static and dynamic type checking. With such approach, the static type checker verifies everything possible at compile time, and dynamic checks the remaining. The current state of the Jolie programming language includes a dynamic type system. Consequently, it allows avoidable run-time errors. A static type system for the language has been formally defined on paper but lacks an implementation yet. In this paper, we describe a prototype of Jolie Static Type Checker (JSTC), which employs a technique based on a SMT solver. We describe the theory behind and the implementation, and the process of static analysis.