+ fun-name
+ :lambda-list lambda-list
+ :definition-source `((defgeneric ,fun-name) ,*load-truename*)
+ initargs))
+
+;;; As per section 3.4.2 of the ANSI spec, generic function lambda
+;;; lists have some special limitations, which we check here.
+(defun check-gf-lambda-list (lambda-list)
+ (flet ((ensure (arg ok)
+ (unless ok
+ (error
+ ;; (s/invalid/non-ANSI-conforming/ because the old PCL
+ ;; implementation allowed this, so people got used to
+ ;; it, and maybe this phrasing will help them to guess
+ ;; why their program which worked under PCL no longer works.)
+ "~@<non-ANSI-conforming argument ~S ~_in the generic function lambda list ~S~:>"
+ arg lambda-list))))
+ (multiple-value-bind (required optional restp rest keyp keys allowp
+ auxp aux morep more-context more-count)
+ (parse-lambda-list lambda-list)
+ (declare (ignore required)) ; since they're no different in a gf ll
+ (declare (ignore restp rest)) ; since they're no different in a gf ll
+ (declare (ignore allowp)) ; since &ALLOW-OTHER-KEYS is fine either way
+ (declare (ignore aux)) ; since we require AUXP=NIL
+ (declare (ignore more-context more-count)) ; safely ignored unless MOREP
+ ;; no defaults allowed for &OPTIONAL arguments
+ (dolist (i optional)
+ (ensure i (or (symbolp i)
+ (and (consp i) (symbolp (car i)) (null (cdr i))))))
+ ;; no defaults allowed for &KEY arguments
+ (when keyp
+ (dolist (i keys)
+ (ensure i (or (symbolp i)
+ (and (consp i)
+ (or (symbolp (car i))
+ (and (consp (car i))
+ (symbolp (caar i))
+ (symbolp (cadar i))
+ (null (cddar i))))
+ (null (cdr i)))))))
+ ;; no &AUX allowed
+ (when auxp
+ (error "&AUX is not allowed in a generic function lambda list: ~S"
+ lambda-list))
+ ;; Oh, *puhlease*... not specifically as per section 3.4.2 of
+ ;; the ANSI spec, but the CMU CL &MORE extension does not
+ ;; belong here!
+ (aver (not morep)))))