- (let* ((not-type (specifier-type typespec))
- (spec (type-specifier not-type)))
- (cond
- ;; canonicalize (NOT (NOT FOO))
- ((and (listp spec) (eq (car spec) 'not))
- (specifier-type (cadr spec)))
- ;; canonicalize (NOT NIL) and (NOT T)
- ((eq not-type *empty-type*) *universal-type*)
- ((eq not-type *universal-type*) *empty-type*)
- ((and (numeric-type-p not-type)
- (null (numeric-type-low not-type))
- (null (numeric-type-high not-type)))
- (make-negation-type :type not-type))
- ((numeric-type-p not-type)
- (type-union
- (make-negation-type
- :type (modified-numeric-type not-type :low nil :high nil))
- (cond
- ((null (numeric-type-low not-type))
- (modified-numeric-type
- not-type
- :low (let ((h (numeric-type-high not-type)))
- (if (consp h) (car h) (list h)))
- :high nil))
- ((null (numeric-type-high not-type))
- (modified-numeric-type
- not-type
- :low nil
- :high (let ((l (numeric-type-low not-type)))
- (if (consp l) (car l) (list l)))))
- (t (type-union
- (modified-numeric-type
- not-type
- :low nil
- :high (let ((l (numeric-type-low not-type)))
- (if (consp l) (car l) (list l))))
- (modified-numeric-type
- not-type
- :low (let ((h (numeric-type-high not-type)))
- (if (consp h) (car h) (list h)))
- :high nil))))))
- ((intersection-type-p not-type)
- (apply #'type-union
- (mapcar #'(lambda (x)
- (specifier-type `(not ,(type-specifier x))))
- (intersection-type-types not-type))))
- ((union-type-p not-type)
- (apply #'type-intersection
- (mapcar #'(lambda (x)
- (specifier-type `(not ,(type-specifier x))))
- (union-type-types not-type))))
- ((and (cons-type-p not-type)
- (eq (cons-type-car-type not-type) *universal-type*)
- (eq (cons-type-cdr-type not-type) *universal-type*))
- (make-negation-type :type not-type))
- ((cons-type-p not-type)
- (type-union
- (make-negation-type :type (specifier-type 'cons))
- (cond
- ((and (not (eq (cons-type-car-type not-type) *universal-type*))
- (not (eq (cons-type-cdr-type not-type) *universal-type*)))
- (type-union
- (make-cons-type
- (specifier-type `(not ,(type-specifier
- (cons-type-car-type not-type))))
- *universal-type*)
- (make-cons-type
- *universal-type*
- (specifier-type `(not ,(type-specifier
- (cons-type-cdr-type not-type)))))))
- ((not (eq (cons-type-car-type not-type) *universal-type*))
- (make-cons-type
- (specifier-type `(not ,(type-specifier
- (cons-type-car-type not-type))))
- *universal-type*))
- ((not (eq (cons-type-cdr-type not-type) *universal-type*))
- (make-cons-type
- *universal-type*
- (specifier-type `(not ,(type-specifier
- (cons-type-cdr-type not-type))))))
- (t (bug "Weird CONS type ~S" not-type)))))
- (t (make-negation-type :type not-type)))))