RosettaCodeData/Task/Metaprogramming/Racket/metaprogramming-1.rkt
2017-09-25 22:28:19 +02:00

10 lines
186 B
Racket

#lang racket
(define-syntax-rule (list-when test body)
(if test
body
'()))
(let ([not-a-string 42])
(list-when (string? not-a-string)
(string->list not-a-string)))