[Xotcl] Collections

[MichaelL at frogware.com]

I must admit that I was only thinking about elegance, and hadn't thought 
about memory and performance implications.

One option, I suppose, is to use a flyweight approach. In other words, 
pass the list in as a parameter to some function/object. This is roughly 
analogous to using the existing list commands in pure Tcl. The difference 
is simply that it would be possible to add a number of convenience 
functions in an XOTcl implementation. For example, Tcl doesn't have a 
simple "add only if it isn't there" command or a simple "copy list" 
command (you use lrange with specific arguments) or a simple "delete 
element" command (you use lreplace with specific arguments). Such an 
approach would only be a small improvement, but maybe it would be enough. 
It would certainly be easier than a full implementation of lightweigt 
objects. :-)

You do, however, hint that there may be plans for ongoing development. Are 
there specific plans, or just a general interest is evolving it "somehow"?

Gustaf Neumann <neumann at wu-wien.ac.at> wrote on 05/12/2003 12:39:44 PM:

> On Monday 12 May 2003 17:36, Uwe Zdun wrote:
> > This corresponds to the idea of making filters etc themselves objects.
> > I like this idea from a conceptual point of view. Implementation-wise
> > it could be a larger undertaking ... the problem is that these
> > "collections" manage different things at the C-code level (Tcl_Obj*s, 
Cmds,
> > etc) in lists and hashtables and that some parts are not under control 
of
> > XOTcl's C code (children are managed by Tcl in Namespaces). So really 
a 2.0
> > issue :)
> 
>  same opinon here; we had already some discussion some time ago about 
>  transforming e.g. methods into objects, etc. We did a big step in 
> this direction when 
>  we implemented our "light-weight objects", which require namespaces
>  etc on demand (please note, that lightweight is relative; see also
>  http://media.wu-wien.ac.at/download/mem.log). But still, objects
>  are costly in terms of time and memory.
> 
>  I am pondering since a while about a simple thing: transforming 
>  xotcl parameters into objects. Conceptually, this is quite simple, but 
>  has disadvantages from benchmarks etc, whenmultiple objects are created
>  on the fly, in situations where the users expects one class/object 
> to be created. 
>  Maybe we are able to provide object facades, or to create these 
interface 
>  objects on demand, while keeping low-fat memory strucutures....... but 
this 
>  will take a few releases...
> 
>  greetings
> -gustaf
> 
> -- 
> Univ.Prof. Dr.Gustaf Neumann
> Abteilung für Wirtschaftsinformatik
> WU-Wien, Augasse 2-6, 1090 Wien
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://alice.wu-wien.ac.at/pipermail/xotcl/attachments/20030512/5914b306/attachment.html