Re: [lisp-snmp] Memory usage of ASN.1 library

[Chun T. (binghe) <bin...@gm...>]

Your version equal to this one: (and it works)

(defun oid-< (oid-1 oid-2)
  "test if oid-1 is oid-2's child"
  (unless (<= (oid-length oid-1) (oid-length oid-2))
    (loop for x-1 in (oid-number-list oid-1)
          for x-2 in (oid-number-list oid-2)
          always (= x-1 x-2))))

I'm so stupid in this function ... :)

Thank you, I'll commit it as ASN.1 4.16 and into trunk.

--binghe

在 2009-5-1，13:47， John Fremlin 写道：

> "Chun Tian (binghe)" <bin...@gm...> writes:
>
>> Great!
>>
>> And, please use my more updated version of ASN.1:OID-< as a work  
>> base:
>
> Sorry, I already made a new version, is it okay?
>
> (defun oid-< (oid-1 oid-2)
>  "test if oid-1 is oid-2's child"
>  (let ((o-1 (oid-number-list oid-1))
>        (o-2 (oid-number-list oid-2))
>        (o-1-len (oid-length oid-1))
>        (o-2-len (oid-length oid-2)))
>    (unless (<= o-1-len o-2-len)
>      (loop for x-1 in o-1
> 	    for x-2 in o-2
> 	    always (equal x-1 x-2)))))
>
> In the old version with O(n) lengths this is suboptimal but in the new
> version with O(1) lengths we are better off with checking the length  
> first
>
>>
>> (defun oid-< (oid-1 oid-2)
>>  "test if oid-1 is oid-2's child"
>>  (let ((o-1-len (oid-length oid-1))
>>        (o-2-len (oid-length oid-2)))
>>    (if (<= o-1-len o-2-len) nil
>>      (let ((o-1 (reverse (oid-number-list oid-1)))
>>            (o-2 (reverse (oid-number-list oid-2))))
>>        (equal o-2 (nthcdr (- o-1-len o-2-len) o-1))))))
>>
>> I believe it's more sufficient than before.
>
> if test nil else === unless test else
>
> [...]
>