Skip to content
Fetching contributors…
Cannot retrieve contributors at this time
57 lines (45 sloc) 1.58 KB
#lang typed/racket/base
(provide Setof new-set new-seteq
set-insert! set-remove! set-contains?
set-for-each set-map
set->list list->set)
(define-struct: (A) set ([ht : (HashTable A Boolean)]))
(define-type (Setof A) (set A))
(: new-set (All (A) (-> (Setof A))))
(define (new-set)
(make-set ((inst make-hash A Boolean))))
(: new-seteq (All (A) (-> (Setof A))))
(define (new-seteq)
(make-set ((inst make-hasheq A Boolean))))
(: set-insert! (All (A) ((Setof A) A -> Void)))
(define (set-insert! s elt)
(hash-set! (set-ht s) elt #t)
(void))
(: set-remove! (All (A) ((Setof A) A -> Void)))
(define (set-remove! s elt)
((inst hash-remove! A Boolean) (set-ht s) elt)
(void))
(: set-contains? (All (A) ((Setof A) A -> Boolean)))
(define (set-contains? s elt)
(hash-has-key? (set-ht s) elt))
(: set-for-each (All (A) ((A -> Any) (Setof A) -> Void)))
(define (set-for-each f s)
((inst hash-for-each A Boolean Any)
(set-ht s)
(lambda: ([k : A] [v : Boolean])
(f k)))
(void))
(: set-map (All (A B) ((A -> B) (Setof A) -> (Listof B))))
(define (set-map f s)
((inst hash-map A Boolean B) (set-ht s) (lambda: ([k : A] [v : Boolean])
(f k))))
(: set->list (All (A) ((Setof A) -> (Listof A))))
(define (set->list a-set)
(set-map (lambda: ([k : A]) k) a-set))
(: list->set (All (A) ((Listof A) -> (Setof A))))
(define (list->set a-lst)
(let: ([a-set : (Setof A) (new-set)])
(for-each (lambda: ([k : A])
(set-insert! a-set k))
a-lst)
a-set))
Something went wrong with that request. Please try again.