Monkey Programming Language

This is a simple editor for a programming language I am building following along with the book Writing an Interpreter in Go. There are a few differences in my implementation which can be found at the github repo for the project.

Data types

Right now my implementation of Monkey supports positive and negative integers, strings, booleans, null values, arrays, hashes (maps) and functions. Monkey has first class functions so functions can be variables or arguments to other functions. Monkey also supports recursion.

Operators

Monkey supports:

• arithmetic operators (+ - / *)
• boolean operators for all data types (! == != < >)
• string operators: + concatenates strings. Negative string returns the string reversed

Data structures

• Arrays let arr = ["a", 2, fn(x) { return x + 1; }]; arr[2](arr[1]);
• Hashes { "key": "value", 1: "cool", true: 1, 5: false }

Built-in functions

• len() for strings and arrays
• first, rest, last, and join for arrays
• toUpperCase, toLowerCase, split for strings

Syntax

• let statements: let x = 5;
• functions: let foo = fn(x) { return x + 2; }
• if/else statements: if (x == y) { return true; } else { return false; };
• # for single line comments
• while loops: let i = 0; while (i < 10) { let i = i + 1; }; i;