# FreeST: Context-free Session Types in a Functional Language

## TL;DR

FreeST introduces a novel concurrent programming language with a unique type system based on context-free session types, enabling safe communication in a functional setting with a new type equivalence algorithm.

## Contribution

It presents a new language, FreeST, with a novel type system and a unique algorithm for type equivalence of context-free session types, advancing session type research.

## Key findings

- Implemented a prototype compiler for FreeST.
- Validated the language through a series of communication protocols.
- Demonstrated the effectiveness of the type equivalence algorithm.

## Abstract

FreeST is an experimental concurrent programming language. Based on a core linear functional programming language, it features primitives to fork new threads, and for channel creation and communication. A powerful type system of context-free session types governs the interaction on channels. The compiler builds on a novel algorithm for deciding type equivalence of context-free session types. This abstract provides a gentle introduction to the language and discusses the validation process and runtime system.