LiScript

Lisp dialect written in Python

Installation

sudo pip3 install liscript

Usage

lirepl            # open liscript repl
lirun <filename>  # run liscript code

Overview

Syntax

;; Atoms
x         ; will return the value of variable `x'

;; Getters & properties
(:x obj)  ; will return property `x' of object (or dictionary) `obj'
obj:x     ; the same as above

;; Numbers
1
1.5
-1

;; Strings
"Hello, world!"

;; Expressions (lists)
(+ 1 2)                 ; apply function `+' to 1 and 2; will return 3

;; Quoted lists
'(1 (+ 1 1) (+ 1 1 1))  ; elements are evaluated when the list is initialized; will return '(1 2 3)

;; Lazy lists
[1 (+ 1 1) (+ 1 1 1)]   ; elements are evaluated manually; will return [1 (+ 1 1) (+ 1 1 1)]  

;; Dictionaries
{:x 1
 :y 2
 :z 3}

Standard functions

let, modify

> (let [x d] 0 {:a 1 :b 2})
> (let [d:c] 3)
> x
  -> 0
> d:c
  -> 3
> (modify [x] [+ 1])  ; same as `(let [x] (+ 1 x))'
> x
  -> 1

fn, def

> (def [sqr x] [* x x])   ; same as `(let [sqr] (fn [x] [* x x]))'
> (sqr 9)
  -> 81

class, new

> (class [Point] {:constructor (fn [self x y] [let [self:x] x] [let [self:y] y])})
> (let [p] (new Point 3 5))
> p:x
  -> 3
> p:y
  -> 5

+, -, *, /

> (+ 1 2)
  -> 3
> (- 5 1)
  -> 4
> (* 2 3)
  -> 6
> (/ 5 2)
  -> 2.5

>, <, =, !=

> (> 1 2)
  -> #f
> (< 5 1)
  -> #f
> (= 2 2)
  -> #t
> (!= 5 2)
  -> #t

if, unless, case

> (if #t [say "true"] [say "false"])
true
> (unless #t [say "true"] [say "false"])
false
> (case [= 1 0] [say "1 = 0"] [> 1 0] [say "1 > 0"] otherwise [say "1 < 0"])
1 > 0

list, cons

> (list 1 2 3)
  -> '(1 2 3)
> (cons 1 '(2 3))
  -> '(1 2 3)

head, tail

> (head '(1 2 3))
  -> 1
> (tail '(1 2 3))
  -> '(2 3)

push

> (push 3 '(1 2))
  -> '(1 2 3)

!!, slice

> (!! '(1 2 3) 1)
  -> 2
> (slice '(1 2 3 4 5 6 7 8 9 10) 5)
  -> '(6 7 8 9 10)
> (slice '(1 2 3 4 5 6 7 8 9 10) 1 5)
  -> '(2 3 4 5)

eval-list

> (eval-list '(+ 1 2))
  -> 3
> (eval-list [* 2 2])
  -> 4

say, read

> (read)
user input
  -> "user input"
> (say "hello, world")
hello, world

exit

> (exit)  ; exit with code 0