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(define (make-wrapper-comparator type-test unwrap contents-comparator)
(make-comparator
type-test
(lambda (a b)
((comparator-equality-predicate contents-comparator)
(unwrap a)
(unwrap b)))
(if (comparator-ordering-predicate contents-comparator)
(lambda (a b)
((comparator-ordering-predicate contents-comparator)
(unwrap a)
(unwrap b)))
#f)
(if (comparator-hash-function contents-comparator)
(lambda (x)
((comparator-hash-function contents-comparator) x))
#f)))
(define (make-product-comparator type-test . comparators)
(make-comparator
type-test
(if (every comparator-equality-predicate comparators)
(lambda (a b)
(every (lambda (cmp)
((comparator-equality-predicate cmp) a b))
comparators))
#f)
(if (every comparator-ordering-predicate comparators)
(lambda (a b)
(let ((gen (list->generator comparators)))
(let loop ((cmp (gen)))
(cond ((eof-object? cmp) #f)
(((comparator-ordering-predicate cmp) a b) #t)
(((comparator-equality-predicate cmp) a b) (loop (gen)))
(else #f)))))
#f)
(if (every comparator-hash-function comparators)
(lambda (x)
(generator-fold bitwise-xor
0
(gmap (lambda (cmp)
((comparator-hash-function cmp) x))
(list->generator comparators))))
#f)))
(define (comparison-procedures comparator)
(values
(lambda args (apply <? comparator args))
(lambda args (apply <=? comparator args))
(lambda args (apply =? comparator args))
(lambda args (apply >=? comparator args))
(lambda args (apply >? comparator args))))
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