anchor.diff:  (defmacro setup-libraries-for-feeds (&body body)
     `(let ((plump:*tag-dispatchers* plump:*xml-tags*)
   	 (drakma:*drakma-default-external-format* :utf-8)
  -         (drakma:*text-content-types* 
  -           (pairlis '("application" "application")
  -                    '("atom+xml"    "rss+xml")
  -                    drakma:*text-content-types*)))
  +	 (drakma:*text-content-types* 
  +	  (pairlis '("application" "application" "application")
  +		   '("atom+xml"    "rss+xml"     "xml")
  +		   drakma:*text-content-types*)))
        ,@body))
   
   (defvar *user-agent* "alimenta/0.0")
  
positive.code:   (let-bind-special-var-macro-body '*user-agent* user-agent body))
  
  (defun fetch-doc-from-url (url)
    (setup-libraries-for-feeds 
      (plump:parse (drakma:http-request url :user-agent *user-agent*))))
  
  (define-condition fetch-error () ())
  (define-condition feed-ambiguous (fetch-error) ((choices :initarg :choices :initform nil)))
  (define-condition no-feed (fetch-error) ((url :initarg :url :initform nil)))
  
  (defun feed-ambiguous (choices)
    (error 'feed-ambiguous
           :choices choices))
  
  (defun no-feed (url)
    (cerror "Skip this feed" 'no-feed :url url))
  
negative.code:     (let* ((feeds (alimenta.discover:discover-feed (drakma:http-request url
  									:user-agent *user-agent*
  									:decode-content t)))
  	   (feeds (if type (remove-if-not (lambda (x) (eql type (car x)))
  					  feeds)
  		      feeds)))
        (if (not feeds)
  	  (no-feed url)
  	  (fetch-doc-from-url
  	   (cdar 
  	    (restart-case
  		(if (cdr feeds) (feed-ambiguous feeds) feeds)
  	      (take-first-feed nil
  		:report (lambda (s) (format s "Take the first feed"))
  		feeds)
  	      (take-nth-feed (n)
  		:report (lambda (s) (format s "Take the nth feed"))
  		(list (elt feeds n)))
  	      (select-feed (selector)
  		:report (lambda (s) (format s "Provide a function to select the right feed"))
  		(find-if selector feeds)))))))))
  
  (defun pull-feed (url &key detect type)
    (to-feed
     (if detect
         (fetch-feed-from-url url)
         (fetch-doc-from-url url)) 
     :type type))
  