Tiny Lisp Interpreter in Zig

This repository contains a simple Lisp interpreter written in Zig. It is designed to demonstrate core Lisp concepts and serve as a learning tool for both Lisp and Zig programming. This implementation supports basic Lisp functionality, making it an excellent starting point for exploring both languages.

Features

• Basic Lisp Data Types:

  • Atom types: Numbers, Symbols, Strings, and Booleans
  • List types: Standard Lisp lists

• Parsing:

  • Parses input strings into an Abstract Syntax Tree (AST)
  • Handles numbers, strings, symbols, and lists
  • Detects and reports syntax errors (e.g., unmatched parentheses)

• Built-in Functions:

  • Arithmetic operations: +, -, *, /, mod
  • Comparison operations: =, <=, >=
  • Logical operations: and
  • Conditional branching: if, cond
  • Variable definition and assignment: define, set!
  • Loops: while
  • Output: print

• Environment and Scope:

  • Supports variable management and name resolution
  • Implements lexical scoping for functions and variables

• Error Handling:

  • Parses errors (e.g., invalid syntax, unmatched parentheses)
  • Evaluation errors (e.g., type errors, unknown symbols)
  • Meaningful error messages for debugging

Example Script

Here's an example of a FizzBuzz implementation in Lisp, which the interpreter can evaluate:

(define i 1)
(while (<= i 100)
    (cond
        (and (= (mod i 3) 0) (= (mod i 5) 0)) (print "FizzBuzz")
        (= (mod i 3) 0)                       (print "Fizz")
        (= (mod i 5) 0)                       (print "Buzz")
        #t                                    (print i))
    (set! i (+ i 1)))

Compatibility

This project has been tested and confirmed to work on the following environment:

• Zig 0.14.0-dev.2178+bd7dda0c5
• Gentoo Linux 6.6.32 (x86_64)

This project has been tested on Gentoo Linux. While it should work on other Linux distributions, macOS, and Windows, these platforms have not been thoroughly tested.

Getting Started

Prerequisites

• Zig Compiler version 0.13.0 or later

Build and Run

• Clone the repository:

git clone https://github.com/keix/tiny-lisp.git
cd tiny-lisp

Build the interpreter:

zig build

Run a Lisp script:

./zig-out/bin/lisp script/fizzbuzz.lisp

Acknowledgments

Inspired by the simplicity and elegance of Lisp and the modern design of Zig. Thanks to the Zig and Lisp hackers for their support and resources.

License

This project is licensed under the MIT License. Copyright (c) 2024 Kei Sawamura a.k.a. keix