twittering-connection-type-table as a defcustom entry

twittering-connection-build-customize-option

;; First attempt:

(defun twittering-connection-build-customize-option ()
  (list 'repeat
        (list
         'list :tag "Configure connection method"
	 '(repeat
	   :tag "Name"
	   (choice
	    (cons :tag "Check test method"
		  (const :format "" :check)
		  (set (const :tag "No matter what" t)
		       function))
	    (cons :tag "Display name"
		  (const :format "" :display-name)
		  string)
	    (cons :tag "HTTPS connection method"
		  (const :format "" :https)
		  (set (const :tag "None" nil)
		       function))
	    (cons :tag "Send HTTP request function"
		  (const :format "" :send-http-request)
		  function)
	    (cons :tag "Pre process buffer"
		  (const :format "" :pre-process-buffer)
		  function))))))

twittering-connection-type-table

(defcustom twittering-connection-type-table
  '((native (check . t)
	    (https . twittering-start-http-session-native-tls-p)
	    (send-http-request . twittering-send-http-request-native)
	    (pre-process-buffer . twittering-pre-process-buffer-native))
    (curl (check . twittering-start-http-session-curl-p)
	  (https . twittering-start-http-session-curl-https-p)
	  (send-http-request . twittering-send-http-request-curl)
	  (pre-process-buffer . twittering-pre-process-buffer-curl))
    (wget (check . twittering-start-http-session-wget-p)
	  (https . t)
	  (send-http-request . twittering-send-http-request-wget)
	  (pre-process-buffer . twittering-pre-process-buffer-wget))
    (urllib-http
     (display-name . "urllib")
     (check . twittering-start-http-session-urllib-p)
     (https . nil)
     (send-http-request . twittering-send-http-request-urllib)
     (pre-process-buffer . twittering-pre-process-buffer-urllib))
    (urllib-https
     (display-name . "urllib")
     (check . twittering-start-http-session-urllib-p)
     (https . twittering-start-http-session-urllib-https-p)
     (send-http-request . twittering-send-http-request-urllib)
     (pre-process-buffer . twittering-pre-process-buffer-urllib)))
  "A list of alist of connection methods."
  :group 'twittering-mode
  :type (twittering-connection-build-customize-option))

Here is another attempt:

(defun twittering-connection-build-customize-option ()
  (list 'repeat 
    (list
     'cons
     '(symbol :tag "Connection symbol" :value "")
     '(repeat
       :tag "Connection method defintion"
       (choice
        (cons :tag "Check test method"
          (const :format "" check)
          (choice :value t (const :tag "Do not check" t)
              (function :tag "Check function")))
        (cons :tag "Display name"
          (const :format "" display-name)
          string)
        (cons :tag "HTTPS connection method"
          (const :format "" https)
          (choice :value nil (const :tag "Same as HTTP" nil)
              (function :tag "HTTPS function")))
        (cons :tag "Send HTTP request function"
          (const :format "" send-http-request)
          function)
        (cons :tag "Pre process buffer"
          (const :format "" pre-process-buffer)
          function))))))

This will generate an acceptable value. Could it be better written ?