Re: [Vtd-xml-users] Random Access Proposal (take 2)

[Jimmy Z. <cra...@co...>]

Rodrigo, How about add a method (tentatively called set()) that basically
does pop() and push() in one shot , so your
example

 push();
 // do something
 pop();
 push();
 // do something
 pop();
 push();
 // do something
 pop();
 push();
 // do something
 pop();

becomes

push();
// do something
set();
// do something
set();
// do something
set();
// do something
pop();


----- Original Message ----- 
From: "Rodrigo Cunha" <rn...@gm...>
To: "Mark Swanson" <ma...@Sc...>; "Jimmy Zhang" 
<cra...@co...>
Cc: <vtd...@li...>
Sent: Tuesday, March 06, 2007 9:24 AM
Subject: Re: [Vtd-xml-users] Random Access Proposal (take 2)


> Hum, thanks for the hint also Mark. I normally use java.util collections, 
> but i'll give fastutils a look, since they might be better for some of my 
> problems.
>
> Jimmy, a context can be imported/exported as an array of integers, this 
> being a bit raw perhaps... and leaving the programmer with the job of 
> storing that array. I just created SimpleContext as a way of abstracting 
> that implementation detail, but since you like performance, perhaps you 
> could leave that raw. I still prefer the abstracted version... besides, 
> the internal representation might change and the abstracted version would 
> still work.
>
> So, yes, go ahead with my API even if you decide to change it later.
>
> Just as a little silly footnote I found my API is also useful in cases 
> where you have:
>
> push();
> // do something
> pop();
> push();
> // do something
> pop();
> push();
> // do something
> pop();
> push();
> // do something
> pop();
>
> Can be abreviated to:
>
> setCtxFromNav(ctx);
> // do something
> setNavFromCtx(ctx);
> // do something
> setNavFromCtx(ctx);
> // do something
> setNavFromCtx(ctx);
> // do something
> setNavFromCtx(ctx);
>
> This is both faster and more readable.
>
> It's also useful for things like:
>
> xpto = getComplexToFindTransmissionPath(VTDNav n, String s); // might even 
> use caching!
> push();
> nav.setNavFromCtx(xpto);
> // Do something
> pop();
>
> and also for exception handling:
>
> {
> setCtxFromNav(xpto);
> // do something complex and error-prone,
> // so I won't use the stack, but a few locally declared contexts instead
> // oops! crash! go to handler!
> finally {
>    setNavFromCtx(xpto)
>    // we are now clean
> }
>
> So, it made using VTD much more enjoyable to me, even in rather trivial 
> situations.
>
> Mark Swanson wrote:
>> Jimmy Zhang wrote:
>>>
>>>> Just a FYI: I have cases where the key is an Integer, and cases where
>>>> it's a string.
>>>
>>> By Integer is it a java class? or just a primitive data type? Maybe I 
>>> can
>>> modify Rodrigo's class and put it into CVS so you guys can use 
>>> immediately...
>>> however, I can't guarantee that it will be included in the next 
>>> release...
>>> Would that work?
>>
>> Oh, I always use native ints and fastutil wherever possible.
>>
>> Just a thought: I use autojar on my code to build a tiny fastutil jar 
>> that just has the code I need. You could do the same thing to get 
>> excellent native collections instead of writing your own. I see you 
>> already wrote your own, but in case you need more.. Fastutil uses the 
>> LGPL.
>>
>> Cheers.
>>
>
>