27 lines
774 B
Scheme
27 lines
774 B
Scheme
;;; -*-Scheme-*-
|
|
;;;
|
|
;;; Demonstrate the regular expression primitives.
|
|
|
|
(require 'regexp)
|
|
|
|
;; Returns a list of substrings of string `str' that match the
|
|
;; pattern `pat'
|
|
|
|
(define (matches str pat)
|
|
(let loop ((r (make-regexp pat '(extended))) (result '()) (from 0))
|
|
(let ((m (regexp-exec r str from)))
|
|
(if (regexp-match? m)
|
|
(loop r (cons (substring str (+ from (regexp-match-start m 0))
|
|
(+ from (regexp-match-end m 0)))
|
|
result)
|
|
(+ from (regexp-match-end m 0)))
|
|
(reverse result)))))
|
|
|
|
(cond
|
|
((feature? ':regular-expressions)
|
|
(print (matches "Hello, world!" "[a-zA-z]+"))
|
|
(print (matches "Hello, world!" ".")))
|
|
(else
|
|
(format #t "Regular expressions not supported by ~a-~a~%"
|
|
site-machine site-os)))
|