MIT/GNU Scheme

Implementation of programming language Lisp

MIT/GNU Scheme is Scheme implementation which contains interpreter, compiler, debugger, built-in Emasc-style editor and a massive standard library. It is developed in Massachusetts Institute of Technology, and distributed under GNU GPl, though it was free software even before this license existed.

MIT/GNU Scheme implements version of language compatible with R5RS.

MIT/GNU Scheme logo
MIT/GNU Scheme logo

Links:

Examples:

Hello, World!:

Example for versions JScheme 7.2, MIT/GNU Scheme 7.7.9, guile 1.8.5

Printing a message is a side effect of this command. Depending on the chosen implementation, the command will return either the message printed, or Unspecified return value. 

(write "Hello, World!")

Factorial:

Example for versions JScheme 7.2, MIT/GNU Scheme 7.7.9, guile 1.8.5

This example uses tail-recursive factorial calculation. Note that GNU Guile and MIT/GNU Scheme print correct result, while JScheme has values of factorial starting with 13! wrong due to overflow. 

(define (factorial x)
  (if (< x 2)
    1
    (* x (factorial (- x 1)))))

(do ((i 0 (+ i 1)))
  ((> i 16))
    (display (string-append (number->string i) "! = "))
    (display (number->string (factorial i)))
    (newline))

Fibonacci numbers:

Example for versions JScheme 7.2, MIT/GNU Scheme 7.7.9, guile 1.8.5

This example uses recursive definition of Fibonacci numbers. 

(define (fibonacci x)
  (if (< x 2)
    x
    (+ (fibonacci (- x 1)) (fibonacci (- x 2)))))

(do ((i 1 (+ i 1)))
  ((> i 16))
    (display (string-append (number->string (fibonacci i)) ", ")))
(display "...")
(newline)