(defmacro deft (name &body slots)
  `(defstruct (,name (:conc-name)
                     (:constructor
                      ,name
                      ,(loop
                          for s in slots
                          collect (typecase s
                                    (symbol s)
                                    (cons (first s))))))
     ,@(loop
          for s in slots
          collect
            (append (typecase s
                      (symbol (list s nil))
                      (cons s))
                    (list :read-only t)))))