SRFI-119 Wisp: simpler indentation-sensitive Scheme.

The languages shipped in Guile include SRFI-119, also referred to as Wisp (for “Whitespace to Lisp”), an encoding of Scheme that allows replacing parentheses with equivalent indentation and inline colons. See the specification of SRFI-119. Some examples:

display "Hello World!"         ⇒  (display "Hello World!")

define : factorial n           ⇒  (define (factorial n)
    if : zero? n               ⇒      (if (zero? n)
       . 1                     ⇒          1
       * n : factorial {n - 1} ⇒    (* n (factorial {n - 1}))))

To execute a file with Wisp code, select the language and filename extension .w vie guile --language=wisp -x .w.

In files using Wisp, See SRFI-105 Curly-infix expressions. (Curly Infix) is always activated.