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Hello Lucian,

On Fri, 25 Jun 2010 16:36:39 +0100
Lucian Smith <lpsmith@spod-central.org> wrote:

> * shoops <shoops@vbi.vt.edu> [2010-06-25 14:14] writes:
> > Hello Lucian,
> >
> > On Fri, 25 Jun 2010 07:06:24 +0100
> > Lucian Smith <lpsmith@spod-central.org> wrote:
> >
> > > > 3) Some simultaneously executed events have the priority object
> > > > and some not.
> > > > Not defined as in L2V4 and L3 currently
> > >
> > > Yes, except that in #3, those events with priorities must execute
> > > in priority order. It's only the events without priorities that
> > > may execute in any order.
> >
> > This is not possible. You have a set of elements of which some can
> > be ordered and some not. This leads to the situation that the set
> > cannot be ordered, i.e., the behavior is undefined. Every other
> > interpretation would have to introduce some defaults which are
> > strictly prohibited. Note that executing the events in a random
> > order or partially random order as yu usggest is different than the
> > order being undefined. People can easily avoid this situation by
> > specifying the priority attribute for all events.
>
> I think you're misunderstanding me. If you have six events, three
> with priorities and three without:
>
> 10 7 2 X X X
>
> The X's can be inserted anywhere, *but* the 10 must fire before the 7
> which must fire before the 2.
>
> X X X 10 7 2
> X 10 X X 7 2
> 10 X 7 X 2 X
> 10 7 2 X X X
>
> but not:
>
> 7 2 X 10 X X
>
> There are no defaults, and the overall behavior is undefined... but
> the priority-flagged events still fire in a defined order with
> respect to each other.

No you are misunderstanding me! I was afraid that the above was your
intend. What you propose is that we change the undefined behavior to
random insertions into a sorted set. I fact you are saying that the
default for the optional object priority is a random number if and only
if it happens simultaneously with events that have a priority object.
You however do not specify from which distribution the random number
shall be drawn. We should avoid all this mess and simply leave this as
undefined. If people want the above they need to define the proper
priorities for all events. This proper definition could include a
distribution package as suggested by Darren if you want a random order.

Please avoid shortcuts and overloaded semantics at all costs. We made
such an effort to become very clear and specific in L3. We should not
haste the introduction of new features. This does not mean that I am
against the priority object in fact I am very much in favor of it.
However I can not stress enough that we should make its semantics as
simple as possible.

Thanks,
Stefan


>
> -Lucian
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--
Stefan Hoops, Ph.D.
Senior Project Associate
Virginia Bioinformatics Institute - 0477
Virginia Tech
Bioinformatics Facility II
Blacksburg, Va 24061, USA

Phone: (540) 231-1799
Fax: (540) 231-2606
Email: shoops@vbi.vt.edu
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