67 lines
1.2 KiB
Scheme
67 lines
1.2 KiB
Scheme
|
|
(declare (unit util-bst-lset))
|
|
|
|
(import duck)
|
|
|
|
(module*
|
|
util-bst-lset
|
|
#:doc ("Reimplementation of old lset using new BST backend.")
|
|
(
|
|
make-lset
|
|
lset?
|
|
lset-empty?
|
|
lset-member?
|
|
lset-count
|
|
lset-add
|
|
lset-remove
|
|
list->lset
|
|
lset->list
|
|
lset-merge
|
|
lset-intersect
|
|
lset-subtract
|
|
lset=?
|
|
)
|
|
(import scheme
|
|
util-bst
|
|
racket-kwargs
|
|
util-bst-ldict
|
|
util-list)
|
|
|
|
(define* (make-lset (equality? equal?))
|
|
(make-bst 'lset equality? ldict<?))
|
|
|
|
(define lset? (bst? 'lset))
|
|
|
|
(define lset-empty? bst-empty?)
|
|
(define lset-member? bst-contains?)
|
|
(define lset-count bst-count)
|
|
|
|
(define (lset-add ls e)
|
|
(bst-set ls e #t))
|
|
|
|
(define lset-remove bst-remove)
|
|
|
|
(define* (list->lset lst (equality? equal?))
|
|
(foldl lset-add (make-lset equality?) lst))
|
|
|
|
(define lset->list bst-keys)
|
|
|
|
(define (lset=? ls1 ls2)
|
|
(bst-equal? ls1 ls2))
|
|
|
|
(define (lset-merge ls1 ls2)
|
|
(foldl lset-add ls1 (lset->list ls2)))
|
|
|
|
(define (lset-intersect ls1 ls2)
|
|
(list->lset
|
|
(filter (lambda (el)
|
|
(lset-member? ls2 el))
|
|
(lset->list ls1))
|
|
(bst-EQ? ls1)))
|
|
|
|
(define (lset-subtract ls1 ls2)
|
|
(foldl (lambda (ls e)
|
|
(lset-remove ls e #t))
|
|
ls1 (lset->list ls2)))
|
|
|
|
)
|