- (unless (member-type-p x-type)
- (mapc-member-type-members
- (lambda (member)
- (multiple-value-bind (ok sure) (ctypep member x-type)
- (when (or (not sure) ok)
- (return-from type-difference nil))))
- y-mem)))))
- (apply #'type-union (res)))))
+ (if (member-type-p x-type)
+ (let ((xset (alloc-xset))
+ (fp-zeroes nil))
+ (mapc-member-type-members
+ (lambda (elt)
+ (multiple-value-bind (ok sure) (ctypep elt y)
+ (unless sure
+ (return-from type-difference nil))
+ (unless ok
+ (if (fp-zero-p elt)
+ (pushnew elt fp-zeroes)
+ (add-to-xset elt xset)))))
+ x-type)
+ (unless (and (xset-empty-p xset) (not fp-zeroes))
+ (res (make-member-type :xset xset :fp-zeroes fp-zeroes))))
+ (dolist (y-type y-types (res x-type))
+ (multiple-value-bind (val win) (csubtypep x-type y-type)
+ (unless win (return-from type-difference nil))
+ (when val (return))
+ (when (types-equal-or-intersect x-type y-type)
+ (return-from type-difference nil))))))
+ (let ((y-mem (find-if #'member-type-p y-types)))
+ (when y-mem
+ (dolist (x-type x-types)
+ (unless (member-type-p x-type)
+ (mapc-member-type-members
+ (lambda (member)
+ (multiple-value-bind (ok sure) (ctypep member x-type)
+ (when (or (not sure) ok)
+ (return-from type-difference nil))))
+ y-mem)))))
+ (apply #'type-union (res))))))