monkey

README

Monkey Lang

Go implementation of the Monkey Programming language from the books Writing a Interpreter in Go and Writing a Compiler in Go.

Requirments

• go 1.22

Usage

Build Binary

$ go build -o bin/monkey main.go

Running the REPL

$ bin/monkey [-interpt]

Parse a file

$ bin/monkey [-interpt] -filename file_name

Example

The example.monkey is a sample program written in monkey lang.
It includes functions to map, filter, reduce and, search arrays and map operations!

Run this file with:

$ bin/monkey -filename example.monkey

Benchmark

A benchmark between the interpreter and bytecode compiler shows a 4x in performance of the bytecode compiler vs the interpreter.

Run benchmark

$ go build -o bin/fibonacci ./benchmark
$ ./bin/fibonacci
starting interpreter `fibonacci(35);`...
starting compiler `fibonacci(35);`...

engine=interpreter, result=9227465, duration=8.709372729s
engine=compiler, result=9227465, duration=2.431848157s

System Specs

CPU: 13th Gen Intel i7-13700K (24) @ 5.300GHz 
GPU: AMD ATI Radeon RX 6700/6700 XT/6750 XT / 6800M/6850M XT 
Memory: 3847MiB / 31863MiB 

Features

• C-like syntax
• Interger, boolean, and string primitive data types
• Array and hashtables
• Variable bindings
• If-else conditions
• First class higher order functions and closures
• Built-ins

Types

Type	Examples
int	0, -42, 99
boolean	true, false
strings	"Hello, World!
array	[], [1, 2 ,3], [true, "", fn(x) { x }]
hashes	{}, {"key": "value"}, {true: "yup!", 1: fn(x) { x + 1}}

Integer Arithmetis

>> let result = (5 + 10 * 2 + 15 / 3) * 2 + -10;
>> result;
55

Let and Return Statements

>> let one = 1;
1
>> return 42;
42

If-Else Conditionals

>> if(1 < 2) {
    return true;
} else {
    return "Borked."
}
true

Functions and Recursion

>> let factorial = fn(x) {
    if (x < 1) {
        return 1;
    }
    return factorial(x - 1) * x;
};
>> factorial(5);
125

Build-ins

>> len("abc")
3
>> len([1, 2])
2

>> push([1], 2)
[1, 2]

>> first([1, 2, 3])
1
 
>> last([1, 2, 3])
3

>> rest([1, 2, 3])
[2, 3]