LispE: Lisp Elémentaire

Hello,

Welcome to Lisp Elémentaire, a version of Lisp that is both compact and offers a remarkable variety of functional and array language features. The code also comes with a small internal editor from another NAVER's project: TAMGU.

The main goal of LispE is to provide a multi-platform language that can harness the power of functional languages with array languages. The real strength of the Lisp language, of which LispE is a dialect, is its very simple but incredible versatile formalism that helps combining all these programming trends together in one single language.

I based a large part of this work on the following article: The Root of Lisp.

• The description of the language is available here: Introduction to LispE
• LispE provides a large set of functions, see the index here.
• A help to the available functions is here: LispE Language Description
• The wiki index is here: HOME

CHECK binaries

We have stashed here precompiled versions for Window and Mac OS (including M1)...

A Lisp with all the bells and whistles

LispE is a true Lisp with all the traditional operators that one can expect from such a language:

(cons 'a '(b c)) ; (a b c)
(cdr '(a b c d e)) ; '(b c d e)
(car '(a b c d e)) ; 'a

(+ 10 20 (* 3 4)) ; 42

(list 'a 'b 'c 'd 'e) ; (a b c d e)

; It also provides some built-in types to handle numbers

(setq l1 (integers 1 2 3))
(setq l2 (integers 4 5 6))

; We can then add these lists together
(+ l1 l2) ; 5 7 9

; or strings

(setq s1 (strings "a" "b" "c"))
(setq s2 (strings "d" "e" "f"))

; We can then add these lists together
(+ s1 s2) ; ("ad" "be" "cf")

; Lists are treated as vectors

(@ s1 1) ; "b"
(@ l1 2) ; 3

; You can loop in a list
(loop i s1 (println i))

You can easily run threads

; Variables in threadspace are protected against
; value concurrencies.
(threadspace
   (seth titi 10)
   (seth toto (rho 2 10 '(0)))
)

; You declare a thread with the keyword: dethread
(dethread tst(x y)
   (threadspace
      (+= titi x)
      (set@ toto 0 y titi)
   )
)

; We launch 10 threads
(loop i (range 1 10 1)
   (tst (+ i 10) i)
)

; We wait for the threads to terminate
(wait)

; threadspace is actually a specific name space
(space thread
   (println titi) ; 145
   ; Note that the order of values is random, due to thread execution
   (println toto) ; ((0 21 46 34 60 75 108 92 126 145) (0 0 0 0 0 0 0 0 0 0))
)

Modern Functional Properties

LispE provides an alternative to parentheses with the composition operator: ".":

(sum (numbers 1 2 3)) can be written (sum . numbers 1 2 3)

LispE provides a powerfull built-in pattern matching mechanism:

; You can call a function in the pattern definition of the function
(defun checking (x y) (eq 0 (% y x)))

; the argument should be an integer, whose value is a multiple of 15
; The argument is stored in x
(defpat fizzbuzz ((integer_ (checking 15 x))) 'fizzbuzz)
(defpat fizzbuzz ((integer_ (checking 3 x))) 'fizz)
(defpat fizzbuzz ((integer_ (checking 5 x))) 'buzz)
(defpat fizzbuzz (x) x)
(mapcar 'fizzbuzz (range 1 100 1))

LispE provides also some interesting properties such as: Data Structures

; First we define some data structures
; nil or _ this is the same value

(data (Point integer_ integer_) (Pixel _ _) (Circle (Point _ _)  _) (Rectangle (Point _ _)  _ nil))

; Then some pattern methods
(defpat Surface ((Circle (Point x y) r)) (* _pi r r))
(defpat Surface ((Rectangle _ h w)) (* h w))
(defpat Surface (true) 'wrong)

(println "Circle:" (Surface (Circle (Point 12 32) 10)))
(println "Rectangle:" (Surface (Rectangle (Point 21 20) 10 20)))

(setq x 10)
(setq y 20)
(setq r 12)

(setq cercle (Circle (Point x y) r))

(println "Circle:" (Surface cercle))
(println "Point:" (Surface (Point 10 20)))
(println "Circle:" (Surface ((atom "Circle") (Point 20 30) 3)))

(data Shape (Triangle _) (Square _))

(defpat dimension ( (Shape x))
   (println 'Dimension x)
)
(dimension (Triangle 10))
(dimension (Square 20))

But also array language capabilities

Thanks to an internal structure implemented with arrays, we also provide some array operators.

For instance, here is how Game of life can be solved in one single instruction:

(defmacro ⊖(l n) (rotate l n true))

(defun lifeinit(x y) (rho x y . random_choice (* x y) (integers 0 1) 17))

(setq r (lifeinit 20 40))
(defun gol8(⍵) ((λ(⍺) (| (& (== ⍺ 4) r) (== ⍺ 3))) (⌿ '+ (⌿  '+ (° (λ (x ⍺) (⊖ ⍺ x)) '(1 0 -1) (↑ (λ (x) (⌽ ⍵ x)) '(1 0 -1)))))))

(println . prettify (gol8 r) 20)

See: Array Operators

Play with it

Finally, LispE can also be used as a Shell: Shell

Come and discover LispE: the Lisp Elémentaire.

We provide a fun little program to discover some of the most interesting aspects of LispE: minizork

Have a look and try it

License

BSD 3-Clause License

LispE
Copyright (c) 2020-present NAVER Corp.

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