rox

Tree walk interpreter for the Lox language in Rust, following the book Crafting Interpreters. Work in progress.

Features

• Evaluate expressions (upon numbers, strings and booleans)
• Variable declaration and assignment
• Scopes
• Control Flow (if statements, while and foor loops)
• Functions
• Closures
• Classes
• Inheritance

Examples

Fibonacci numbers (naive implementation)

fun fib(n) {
    if (n < 2) {
	return n;
    }
    return fib(n - 1) + fib(n - 2);
}

var result = fib(10);
print(result);

Closures

fun makeCounter() {
    var i = 0;
    fun count() {
        i = i + 1;
        print i;
    }
    return count;
}

var counter = makeCounter();
counter(); // 1
counter(); // 2

OOP and inheritance

class Doughnut {
  cook() {
    print "Fry until golden brown.";
  }
}

class BostonCream < Doughnut {}

BostonCream().cook();