+ (class-info (type-class-or-lose 'member))
+ (enumerable t))
+ (:copier nil)
+ (:constructor %make-member-type (xset fp-zeroes))
+ #-sb-xc-host (:pure nil))
+ (xset (missing-arg) :type xset)
+ (fp-zeroes (missing-arg) :type list))
+(defun make-member-type (&key xset fp-zeroes members)
+ (unless xset
+ (aver (not fp-zeroes))
+ (setf xset (alloc-xset))
+ (dolist (elt members)
+ (if (fp-zero-p elt)
+ (pushnew elt fp-zeroes)
+ (add-to-xset elt xset))))
+ ;; if we have a pair of zeros (e.g. 0.0d0 and -0.0d0), then we can
+ ;; canonicalize to (DOUBLE-FLOAT 0.0d0 0.0d0), because numeric
+ ;; ranges are compared by arithmetic operators (while MEMBERship is
+ ;; compared by EQL). -- CSR, 2003-04-23
+ (let ((unpaired nil)
+ (union-types nil))
+ (do ((tail (cdr fp-zeroes) (cdr tail))
+ (zero (car fp-zeroes) (car tail)))
+ ((not zero))
+ (macrolet ((frob (c)
+ `(let ((neg (neg-fp-zero zero)))
+ (if (member neg tail)
+ (push (ctype-of ,c) union-types)
+ (push zero unpaired)))))
+ (etypecase zero
+ (single-float (frob 0.0f0))
+ (double-float (frob 0.0d0))
+ #!+long-float
+ (long-float (frob 0.0l0)))))
+ ;; The actual member-type contains the XSET (with no FP zeroes),
+ ;; and a list of unpaired zeroes.
+ (let ((member-type (unless (and (xset-empty-p xset) (not unpaired))
+ (%make-member-type xset unpaired))))
+ (cond (union-types
+ (make-union-type t (if member-type
+ (cons member-type union-types)
+ union-types)))
+ (member-type
+ member-type)
+ (t
+ *empty-type*)))))
+
+(defun member-type-size (type)
+ (+ (length (member-type-fp-zeroes type))
+ (xset-count (member-type-xset type))))
+
+(defun member-type-member-p (x type)
+ (if (fp-zero-p x)
+ (and (member x (member-type-fp-zeroes type)) t)
+ (xset-member-p x (member-type-xset type))))
+
+(defun mapcar-member-type-members (function type)
+ (declare (function function))
+ (collect ((results))
+ (map-xset (lambda (x)
+ (results (funcall function x)))
+ (member-type-xset type))
+ (dolist (zero (member-type-fp-zeroes type))
+ (results (funcall function zero)))
+ (results)))
+
+(defun mapc-member-type-members (function type)
+ (declare (function function))
+ (map-xset function (member-type-xset type))
+ (dolist (zero (member-type-fp-zeroes type))
+ (funcall function zero)))
+
+(defun member-type-members (type)
+ (append (member-type-fp-zeroes type)
+ (xset-members (member-type-xset type))))