(set-macro-character
#\[
(lambda (stream char)
(declare (ignore char))
(let ((*readtable* (copy-readtable *readtable* nil)))
(set-macro-character #\] (get-macro-character #\)))
(set-macro-character #\, (lambda (stream char)
(declare (ignore stream char))
(values)))
(set-macro-character #\~ (get-macro-character #\,))
(let ((contents (read-delimited-list #\] stream t)))
`(vector ,@contents)))))