[racket] Can impersonator be a cache?

 > Why not just define a new version of object-a that does that?

(set! object-a 
    (let ([old object-a])
       (lambda (x) 
          (if (reference? x) 
              (ref-get old x)
              (old x)))))

Like that for every accessor? + prop:impersonator-of... Maybe shall work.


Fri, 15 Aug 2014 08:45:59 -0400 от "Alexander D. Knauth" <alexander at knauth.org>:
>
>Why not just define a new version of object-a that does that?
>You probably have a good reason, but what is it? 
>Is it to change the result of struct->vector, allow (object a b c) as a match pattern to match ref, or what? 
>
>On Aug 15, 2014, at 6:42 AM, Roman Klochkov < kalimehtar at mail.ru > wrote:
>
>> I have
>> (struct object (a b c))
>> (struct reference (id data))
>> 
>> Let `ref' -- an instance of `reference'.
>> 
>> I want, that (object-a ref) call my own (ref-get object-a ref)
>> 
>> (define (ref-get accessor ref)
>>   (unless (weak-box-value (ref-data ref))
>>      (set-ref-data! ref (make-weak-box (load-data (ref-id ref)))))
>>   (accessor (weak-box-value (ref-data ref))))
>> 
>> Is it possible? 
>> I found `impersonate-struct', but it is not struct itself (no `id' field). 
>> I can add `prop:impersonator-of',. but how to redirect accessors?
>> 
>> -- 
>> Roman Klochkov
>> ____________________
>>  Racket Users list:
>>  http://lists.racket-lang.org/users
>


-- 
Roman Klochkov
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