std.pattern..mixin temptes..std.concurrency

[BLS]

On 09/07/2010 01:04, Andrei Alexandrescu wrote:
> I think Observer is a very difficult pattern to make generic. There's
> very much variability. Here's an article I wrote about it:
>
> http://docs.google.com/viewer?url=http://erdani.com/publications/cuj-2005-04.pdf
>
>
> http://docs.google.com/viewer?url=http://erdani.com/publications/cuj-2005-06.pdf
>
>
>
> Andrei

OK, got the message, Still not a Murder-Death-Kill argument.

The biggest problem I (just me) see is, to push or to pull.
I am not kidding. Using std.concurreny for message passing, the thing is 
quit clear.. and anyway pull is sometimes too late, and furthermore hard 
to make thread safe.

In example ..
I am watching a list []  Whenever the list class gets an delete, insert, 
update event it triggers the delegate , no problem so far, even if I 
want to know which data was added, respective deleted.
My  (without std.concurrency message passing)

void delegate(const ref msg) callback;
callback[] CallBack;
is keeping me informed ..

struct Message {T}{
T data;
string msg;
}
BUT  What if I add a list to my list ?

...if we have a look at std.concurrency  receive(), things are more 
shiny.. what do you think Andrei ?
bjoern