(loop for e in list
maximizing e into max
minimizing e into min
finally (return (values min max)))

In one pass, find the largest number and
the smallest number.

Even better: in one pass, find the smallest number,
the largest number, the sum, and the product.

(multi-reduce min max + * '(3 2 9 8 4 5 6 7))

2
9
44
362880

Given:

(define (multi-fold* funcs knils the-list)
(let loop ((the-list the-list)
(accums knils))
(if (null? the-list)
(apply values accums)
(loop (cdr the-list)
(map (lambda (fn acc) (fn (car the-list) acc))
funcs
accums)))))

(define (multi-fold . args)
(let ((rev (reverse args)))
(multi-fold* (reverse (cddr rev)) (cadr rev) (car rev))))

(define (multi-reduce* funcs the-list)
(multi-fold* funcs (map (lambda _ (car the-list)) funcs) (cdr the-list)))

(define (multi-reduce . args)
(let ((rev (reverse args)))
(multi-reduce* (reverse (cdr rev)) (car rev))))

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