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(lset-union): Rewrite to accumulate result by consing in

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the order specified by the SRFI.
This commit is contained in:
Kevin Ryde 2005-04-01 23:47:42 +00:00
parent 6507b83189
commit 62a8750001
1 changed files with 11 additions and 9 deletions
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20
srfi/srfi-1.scm
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@ -673,15 +673,17 @@
(lp (cdr l) (cons (car l) acc))))))
(define (lset-union = . rest)
(let lp0 ((l rest) (acc '()))
(if (null? l)
(reverse! acc)
(let lp1 ((ll (car l)) (acc acc))
(if (null? ll)
(lp0 (cdr l) acc)
(if (member (car ll) acc (lambda (x y) (= y x)))
(lp1 (cdr ll) acc)
(lp1 (cdr ll) (cons (car ll) acc))))))))
(let ((acc '()))
(for-each (lambda (lst)
(if (null? acc)
(set! acc lst)
(for-each (lambda (elem)
(if (not (member elem acc
(lambda (x y) (= y x))))
(set! acc (cons elem acc))))
lst)))
rest)
acc))
(define (lset-intersection = list1 . rest)
(let lp ((l list1) (acc '()))