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Diffstat (limited to 'lib/obj.rkt')
| -rw-r--r-- | lib/obj.rkt | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/lib/obj.rkt b/lib/obj.rkt new file mode 100644 index 0000000..8ffc401 --- /dev/null +++ b/lib/obj.rkt @@ -0,0 +1,32 @@ +#lang racket + +(provide obj-maker + obj-set + obj-show) + +(define (alist->obj alist) + (λ key + (if (null? key) + alist + (cadr (assoc (car key) alist))))) + +(define (obj-maker . fields) + (λ 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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