(let ((*read-intern*
       (lambda (x)
         (let* ((result nil)
                (s (string x))
                (end-char (char s (1- (length s)))))
           (when (equalp end-char #\i)
             (let ((ss (ppcre:split "[-+]" (subseq s 0 (1- (length s)))))
                   real imag)
               (when (and ss (= (length ss) 2)
                          (setf real (parse-integer (first ss)))
                          (setf imag (parse-integer (second ss))))
                 (setf result (complex real imag)))))
           (or result (intern x))))))
           (read-from-string "0+1i"))