(defun to-camel-case (string)
  (cl-ppcre:regex-replace
   "([a-z])[_-]([a-z])"
   (string-downcase string)
   (lambda (TARGET-STRING START END MATCH-START MATCH-END REG-STARTS REG-ENDS)
     (declare (ignore START END REG-STARTS REG-ENDS))
     (format nil "~C~C" (aref target-string match-start)
             (char-upcase (aref target-string (1- match-end)))))))