jisp is a project of mine to implement an interpreted lisp-like language in Java. Below is an example program of jisp.
Some test cases are written in the lisp directory of this repository.
;; 'simple' program that reads an integer (or even a string!)
;; from stdin and prints its value doubled
; doubles the input value, i
(define double
(lambda [i]
(* i 2)))
; note this is deliberately contrived to demonstrate
; the (awesome) let-binding functionality
(define main
(lambda []
(print "enter a value to double [string or integer]: ")
(let [n (read-string)
n-doubled (let [parsed (parse-integer n)]
(if (nil? parsed)
(double n)
(double parsed)))]
(print-line n " * 2 = " n-doubled))))