Interpreter for a made-up language written in Go.

• Finish basic functions of the lexer
• A REPL
• Write a parser
  • AST
• Evaluate expressions
• Add more data types and built-in functions to the interpreter (arrays, hashes, etc.)

let five = 5;                 
let ten = 10;                 
let add = fn(x, y) {          
  x + y;                      
};                            
let result = add(five, ten);