I think this is a bug in SBCL, and should be reported with its maintainers.
Pascal
On 10 Jun 2011, at 16:53, Tamas K Papp wrote:
Hi,
I tried to save a supplied-p parameter from a BOA constructor like this:
(defstruct (delayed-iseq (:constructor iseq (start-or-end &optional (end 0 end?) (by 1) strict-direction?))) "Delayed index sequence evaluation." start-or-end end end? by strict-direction?)
but SBCL complained that end? was not used. After rereading the CLHS page for defstruct, I am still not 100% sure why this is. My intepretation is that END? is an argument like any other, but probably I am not getting something.
Anyhow, instead I used
(defstruct delayed-iseq "Delayed index sequence evaluation." start-or-end end end? by strict-direction?)
(defun iseq (start-or-end &optional (end 0 end?) (by 1) strict-direction?) (make-delayed-iseq :start-or-end start-or-end :end end :end? end? :by by :strict-direction? strict-direction?))
Is there a way to do it in a single defstruct definition?
Best,
Tamas
PS.: (eq end nil) is different from when it is not supplied, hence the need to save end?.
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