Method: (PROCESS-DIRECTIVE COMMENT-PART)

Source

(defmethod process-directive ((part comment-part))
  (declare (special *source-file*))
  (multiple-value-bind (matchp strings)
      (cl-ppcre:scan-to-strings (load-time-value (cl-ppcre:create-scanner "^@include (.*)"))
                                (text part))
    (if matchp
        (return-from process-directive
          (read-source-file
           (merge-pathnames (let ((*readtable* (copy-readtable nil)))
                              (read-from-string (aref strings 0)))
                            (truename *source-file*))))
        (return-from process-directive (list part)))))