On Sun, Sep 22, 2013 at 9:53 AM, Pascal Costanza <pc@p-cos.net> wrote:

Hi,

It seems to me that ASSERT and CHECK-TYPE are not as convenient as they could be. In particular, ISLISP seems to have a better alternative in ASSURE.

ASSURE is easy to define:

(defmacro assure (type form)
  (let ((object (copy-symbol 'object)))
    `(let ((,object ,form))
       (check-type ,object ,type)
       ,object)))

Yeah, this is really useful. One question -- is it also worth putting

in (declare (type ,object ,type)) after the let-binding? Or does every

competent compiler do the right thing once it's seen 'check-type'?