Atlisp

Atlisp is a minimal lisp that I created in my free time

The name is a portmanteau of atli and lisp.

Build

Requires go 1.18 or above.

After cloning the repo you can run:

go build

Usage

Prequisites: Build

To run a REPL of atlisp use ./atlisp

To run a file with atlisp use ./atlisp

Tutorial

To call a function use the following syntax (function_name parameter1 parameter2). Operations such as addition are functions ex:

 > (+ 1 2)
3
 > (* 10 9)
90

Variables

Variables and functions share a namespace. To define a variable use the following syntax

 > (def myvar "a string")
myvar
 > myvar
"a string"

Functions

Functions are defined with a similar syntax

 > (def factorial
..   (fn (n)
..     (if (eq n 1)
..         1
..         (* n (factorial (- n 1))))))

Here the fn keyword is used to create a function. To call this function we would say:

 > (factorial 5)
 120

Keywords / Special Forms

eq: checks for equality

progn: evaluate a series of expressions and returns the output of the last one.

fn: creates a function as seen earlier

def: define a variable as seen earlier

quote: return a symbol or variable unmodified or return an expression as a list of symbols

 > (quote test)
test

if: takes an expression which it evaluates. If the expression is truthy it evaluates the next expression otherwise it doesn't evaluate that one and instead evaluates the other. For example:

(if (eq 1 1) "this" "that")

evaluates to "this" and "that" is never evaluated.

Future work

Add eval
Add special characters to simplify common operations such as ' , `

Atli-A/atlisp