(defconst regex-tests
  '(;; From GNU libc's runptests
    ("\\([a-c]*\\)\\{2,\\}" . "abcdefg")
    ;; Misc
    ("^[^a]*[^b]c$" . "xc")

    ("^[^ab]*[abc]c$" . "cc")
    ("^[abc]*[^ab]c$" . "cc")

    ("[éa]*" . "éaé")
    ("[1[:alpha:]]*" . "é1aé a")
    ("[1[:Multibyte:]]*" . "é1aé a")
    ("[1[:nonascii:]]*" . "é1aé a")
    ("[^é]+" . "é1aé a")
    ("\\(1+\\)\\{2\\}" . "11")
    ("1\\{2\\}" . "11")
    ("1\\{0,2\\}" . "111")
    ("1\\{1,2\\}" . "11")
    ("1\\{1,2\\}" . "111")
    ("\\(1\\)\\{2,4\\}" . "11")
    ("\\(1\\|1\\)\\{2,4\\}" . "11")
    ("\\(1\\|1\\)\\{2,4\\}" . "1")
    ("\\(\\(a\\)*\\(b\\)*\\)*" . "aabb")
    (".\\(..\\)f\\|1a.c" . "1abc")
    ("\\(\\(a*\\)*\\(b*\\)*\\)*" . "aba")
    ;; Tests that require shy-groups or non-greedy ops
    ("\\(?:\\(a*\\)*\\(b*\\)*\\)*" . "aba")
    ("[[:alpha:]]" . "a")
    ))

(if (fboundp 'match-string) nil
  (defun match-string (n str)
    (if (match-end n)
	(substring str (match-beginning n) (match-end n)))))

(defun regex-test ()
  (interactive)
  (while regex-tests
    (message "%s %s - %s"
	     (car (car regex-tests)) (cdr (car regex-tests))
	     (condition-case err
		 (if (string-match (car (car regex-tests)) (cdr (car regex-tests)))
		     (list (match-string 0 (cdr (car regex-tests)))
			   (match-string 1 (cdr (car regex-tests)))
			   (match-string 2 (cdr (car regex-tests)))
			   (match-string 3 (cdr (car regex-tests)))
			   (match-string 4 (cdr (car regex-tests))))
		   "No match")
	       (error err)))
    (setq regex-tests (cdr regex-tests))))

(regex-test)