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#lang racket/base
(provide obj-maker
obj-set
obj-show)
(define (alist->obj alist)
(lambda key
(if (null? key)
alist
(cadr (assoc (car key) alist)))))
(define (obj-maker . fields)
(lambda inits
(define alist (map list fields inits))
(alist->obj alist)))
(define (obj-set record key value)
(define alist (record))
(define new-alist
(let loop ((new-list '()) (cur alist) (is-set #f))
(if (null? cur)
(if is-set
new-list
(cons (list key value) new-list))
(let ()
(if (eq? key (caar cur))
(loop (cons (list key value) new-list) (cdr cur) #t)
(loop (cons (car cur) new-list) (cdr cur) is-set))))))
(alist->obj new-alist))
(define (obj-show x) (x))
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