anchor.diff:                            :base-url "https://en.wikipedia.org/w/api.php?action=opensearch&format=json&search=~a"
                             :processing-function
                             #'(lambda (results)
  -                              (when results
  -                                (second (json:decode-json-from-string results))))))
  +                              (alex:when-let* ((results results)
  +                                               (results (json:decode-json-from-string results)))
  +                                (mapcar #'list (second results) (fourth results))))))
             (make-instance 'search-engine
                            :shortcut "ddg"
                            :search-url "https://duckduckgo.com/?q=~a"
  
positive.code:                                  ;; return garbage in response to an empty request.
                                   (when (and engine-completion-p
                                              (completion-function engine) (rest terms))
                                     (mapcar (alex:curry #'make-instance 'new-url-query
                                                         :engine      engine
                                                         :check-dns-p check-dns-p
                                                         :query)
                                             (with-protect ("Error while completing search: ~a" :condition)
                                               (funcall (completion-function engine)
                                                        (str:join " " (rest terms))))))))
  
negative.code: (define-class new-url-query ()
    ((query ""
            :documentation "Either a URL or a string query passed to `engine'.")
     (label nil
            :type (or null string)
            :documentation "The meaningful text for the query, if query is a URL.")
     (engine nil
             :type (or null search-engine)))
    (:export-class-name-p t)
  