Welcome

The official website for the Varphi programming language.

Welcome to the Varphi user documentation! Here you'll get an overview of all the amazing features Varphi offers to help you build, simulate, and debug Turing machines and finite automata.

What is Varphi?

Varphi is a modern, domain-specific language designed for defining, simulating, and studying Turing machines and finite automata.

While Turing machines are the fundamental model of computation, defining them has historically been tedious, relying on verbose state tables or fragile graphical simulators. Varphi bridges the gap between theoretical computer science and modern software engineering, providing a concise syntax, a robust compiler, and high-quality developer tooling.

Why Varphi?

Varphi treats Turing Machines as code, not diagrams. It introduces modern language features to the theoretical domain:

• Concise Syntax: Define complex state transitions using pattern matching and variables instead of listing every single symbol combination.
• Native Multi-Tape Support: Write algorithms for $k$-tape machines as easily as single-tape ones. The compiler handles the complexity.
• First-Class Tooling: Debug your machines with a dedicated VS Code Extension, complete with syntax highlighting, live error reporting, and a step-by-step debugger (DAP).

Jump right in

Installation

Install Varphi on your machine

The Varphi Language Reference

Learn about Varphi's syntax

Examples

See some of what you can do with Varphi