Go Interpreter

A tree-walking Go Interpreter written in ... Go :)

Features

• Integer arithmetic
• Boolean expressions
• Variable bindings (let)
• Conditional expressions (if/else)
• Functions
• Closures
• Recursive functions
• Arrays
• Hash maps
• Strings
• Built-in functions

Architecture

Source code goes through multiple stages:

Raw input -> Lexer -> Tokens -> Parser -> AST -> Evaluator

Usage/Examples

Basic arithmetic

5+3
((5*3) / (4-2)) * 3

Functions

let a = 5
let b = 4
let add = fn(x, y) { x + y };
let result = add(a, b)
result

Recursive Fibonacci

let fibonacci = fn(x) {
    if (x < 2) {
        x
    } else {
        fibonacci(x - 1) + fibonacci(x - 2)
    }
};

fibonacci(10);

Closures

let newAdder = fn(x) {
    fn(y) { x + y };
};

let addTwo = newAdder(2);

addTwo(5);

Running Tests

To run tests, run the following command (after cloning the project)

  go test ./nameofthefolder (e.g. ./ast)

Run Locally

Clone the project

  git clone https://github.com/CoderFaris/gointerpreter.git

Build the project

  go build main.go

Run the project

  go run main.go

Acknowledgements

This project was inspired by and built while studying the book:

Writing an Interpreter in Go by Thorsten Ball.