[Ns-developers] [ns3] topology API

[Mathieu Lacage]

On Tue, 2008-01-15 at 17:14 +0000, Gustavo Carneiro wrote:

>         > This example seems a bit inconsistent.  On one hand you have
>         > container.Add (mobility.GetByBoundingBox (...)), on the
>         other hand
>         > application.AddOnOff(container, ...), two different
>         styles... which 
>         > one is it?
>         
>         I am not really sure I understand this comment: I fail to see
>         what is
>         different between these two styles:
>           - GetByBoundingBox returns a NodeContainer and we invoke
>         NodeContainer::Add (const NodeContainer & c) to add it to the
>         original 
>         container.
> 
> OK, I completely missed the point of "mobility.GetByBoundingBox" :|
> Something doesn't add up.  Why 'mobility.GetByBoundingBox()'?
> Shouldn't it be a function or static method, rather than an instance
> method?  And what does it have to do with "mobility"?  So, yes, I
> agree with the idea, but the naming is not so good and got me
> confused.  Yes, I get easily confused, I know :P 
> 
> It should have been a GetNodesInsideBoundingBox function, not method. 
>  And IMHO this sort of API is not needed in NS-3 and can even be
> distracting.  But, well, apparently I'm the only one who thinks that
> way, so... 

I don't have a definite answer here: I understand your concerns and I
partly agree with them. I don't like very much either solution myself.

[snip]

>         Sure. The goal, here, however, is to provide syntactical
>         conveniance. If
>         you want "simplicity", you can use the low-level API.
> 
> Fine, but we need to be careful to make sure that NS-3 does not become
> like some systems where there is a nice and easy frontend that does
> common things, but when you want something less common you have to go
> to a lower layer where everything is incredibly complex and
> unforgiving to small errors.  In some ways NS-2 is like that: you
> start softly with oTCL, but to do real research you have to go to the
> C++ level and start hacking it.  If we start relying too much on high
> level interfaces I am afraid we might unconsciously start neglecting
> the intermediate layers because the front end hides the "uglyness"
> inside.
> 
> I am not saying this  is the case _now_, just something that may
> happen in the future, to be aware of.

Yes, I agree. We need to be careful.

[snip]

>         > Finally I prefer the naming NodeGroup rather than
>         NodeContainer 
>         > because container sounds like simulating a physical entity
>         that
>         > actually contains nodes, while group is obviously a purely
>         logical
>         > entity.
>         
>         I don't really agree but I don't feel very strongly about it.
> 
> I don't feel very strongly about it either.

Another option is NodeSet.

Mathieu