cos-scheme

basic implementation of Scheme in InterSystems ObjectScript

Algorithm is taken from http://norvig.com/lispy.html

USER>do ##class(Scheme.Main).repl()
lisp> (define circle-area (lambda (r) (* pi (* r r))))
lisp> (circle-area 3)
28.27433388230813914
lisp> (define fact (lambda (n) (if (<= n 1) 1 (* n (fact (- n 1))))))
lisp> (fact 10)
3628800
lisp> (circle-area (fact 10))
41369087205782.69341
lisp> (define twice (lambda (x) (* 2 x)))
lisp> (define repeat (lambda (f) (lambda (x) (f (f x)))))
lisp> ((repeat twice) 10)
40
lisp> ((repeat (repeat twice)) 10)
160
lisp> ((repeat (repeat (repeat twice))) 10)
2560
lisp>:q
USER>

Supported special forms:

1. (quote exp)
2. (if test conseq alt)
3. (define var exp)
4. (set! var exp)
5. (lambda (var...) body)

Embedded functions:

1. (abs num)
2. (car list)
3. (cdr list)
4. (cons x y)
5. (equal? x y)
6. (procedure? x)