Let Emacs simulate Acme by creating clickable regexp links in the buffer.

uu-re-link.el

;; Simulates Acme by creating clickable regexp links in the buffer.
;;
;; You can use it for instance to create an index:
;;
;; :/uu-re-link-mode/ : entry point.
;;

(defcustom uu-re-link-re ":/\\(.+\\)/" "Regular expression for regular expression links.")
(defcustom uu-re-link-re-initial "[[:space:]]:/" nil)
(defcustom uu-re-link-isearch t "Use isearch to find the expression interactively.")

(defun uu-re-text-search-forward ()
  "moves the point to the next regexp in buffer."
  (interactive)
  (if (re-search-forward uu-re-link-re nil t)
      (match-beginning 0)))

(defun uu-re-text-search-backward ()
  (if (re-search-backward uu-re-link-re nil t)
      (match-beginning 0)))

(defun uu-re-link--mouse-click (event)
  "Follow the regular expression search."
  (interactive "e")
  (let ((window (posn-window (event-end event)))
	(pos (posn-point (event-end event))))
    ;; move pos to beginning of link
    (with-current-buffer (window-buffer window)
      (let ((re))
	(goto-char pos)
	(save-excursion
	  (if (progn (re-search-backward uu-re-link-re-initial) (uu-re-text-search-forward))
	      (setq re (buffer-substring-no-properties (match-beginning 1) (match-end 1)))))
	(if (not uu-re-link-isearch)
	    (re-search-forward re)
	  (progn
	    (isearch-mode t t)
	    (let ((isearch-regexp nil))
	      (isearch-yank-string re))
	    (isearch-repeat-forward)))))))

(setq uu-re-text-map
  (let ((map (make-sparse-keymap)))
    (define-key map [mouse-2] 'uu-re-link--mouse-click)
    (define-key map (kbd "<C-mouse-1>") 'uu-re-link--mouse-click)
    (define-key map [follow-link] t)
    map))

(defun uu-re-link--make-links ()
  (save-excursion
    (goto-char (point-min))
      (while (uu-re-text-search-forward)
	(let ((link-start (match-beginning 1))
	      (link-end (match-end 1)))
	  (with-silent-modifications
	    (add-text-properties
	     link-start link-end
	     '(mouse-face highlight
			  help-echo "mouse-2: search forward for regular expression."))
	    (put-text-property link-start link-end
			       'keymap uu-re-text-map))))))


(defun uu-re-link--after-change (begin end length)
  (uu-re-link--make-links))

(define-minor-mode uu-re-link-mode
  "Mode in which :/.../ defines a clickable regular expression."
  :group uu
  :init-value nil :lighter nil :keymap nil

  (uu-re-link--make-links)
  (add-hook 'after-change-functions #'uu-re-link--after-change t t))

(define-globalized-minor-mode global-uu-re-link-mode uu-re-link-mode (lambda () (uu-re-link-mode)))