Re: [PATCH:MI] Return a subset of a variable object's children

Nick Roberts
2008-05-01T12:15:32Z

> > Again in scientific computing, arrays often have many more than 10000
> > elements. In image processing arrays are two dimensional 512x512 with
> > over 250,0000 elements. The user would have to identify the region of
> > interest for the display widget, e.g. [110:120][220:230] for a 10x10
> > square centred at (115,225).
>
> It seems to me that specialized widgets are more suitable for this purpose,
> like image viewer, or a charting component. Especially with image data,
> using varobjs is probably not going to work. Creating varobjs per each item
> will be just too slow -- we need some high-bandwidth interaction way, like
> the memory-reading commands. (And maybe those should have stride options).

Other debuggers, e.g., Totalview have this capability and it's not slow. In
England, I used it on a professional basis and found it useful.

>...
> > > Please feel free to implement generic list datastructure in C, or
> > > rewrite gdb in C++. So far, using vector proved to be big convenience.
> >
> > Clearly I'm not going to do either but we could simply go back to using
> > the linked list structures that were already in varobj.c. It's a question
> > of whether the convenience outweighs the handicap of having to work with
> > vectors all the time or not. IMHO it doesn't.
>
> I disagree, and I haven't yet seen a practical "handicap". We're not going
> back to hand-written data structures for MI implementation.

Well it's a shame that convenience should dictate the type of structures that
are used because I can get this patch to work with an old Gdb using linked
lists.

--
Nick http://www.inet.net.nz/~nickrob