monkeylang

Interpreter written in Go.

Build

make build

Usage

To run you can use the binary built in previous step

monkey

OR

make run

This will start monkey repl

language

• C-like syntax
• Dynamic typing
• Variable bindings
• Integers and booleans
• Arithmetic expressions
• Arrays and maps
• Built-in functions
• First-class and higher-order functions
• Closures - TODO

Sample snippets

let age = 1;
let name = "Monkey";
let result = 10 * (20 / 2);
let add = fn(a, b) { return a + b; };
add(1, 2);

let fibonacci = fn(x) {
    if (x == 0) {
        0
    } else {
        if (x == 1) {
            1
        } else {
            fibonacci(x - 1) + fibonacci(x - 2);
        }
    }
};

fn(x,Y){ x+y ;} (3,4) 
let firstname = "Nishanth"
let lastname= "Shetty"
let fullname = firstname + " " + lastname

let ar = [1,2, "hello", 2/2, fn(x) { x* 2; }(3)]
ar[2]
len(ar)
let a = {1:"1", 2:"2", 3:"3"};
a[1]
a[4]
let map = {1:"one", 2:"two", 3:"three"}
map[1]

all the above snippets are valid monkey lang, try executing them in a repl

REPL commands

repl provides helper commands to inspect and more. They start with : (colon)

1. :env Inspect environment

   Prints out the variables, functions declared in the current environment

2. :exit or :quit

   Exit the repl

Developement and Testing

Test

make test   

Reference

This implementation is based on the Thorsten Ball Book. Writing Interpreter In Go