[Oz] NewStat

[Peter Van Roy]

> Hi all.
> 
> I am exploring the distributed programming tutorial, and I am
> puzzled by NewStat. Are you supposed to define NewStat
> yourself? This seems like an important construct, is there
> a built in version? Knowing what is built in and what you
> have to define yourself is not always easy to tell from the tutorial.
> Anyone have pointers to other places in the documentation?
> 
> Best, Micke

The built-in support for distribution is very simple:

  Connection module: offering and taking tickets.  Because
  of transparent distribution, this covers (almost) all
  data types in the language.

  Fault module: reflective fault handling.  All you need
  to build fault tolerance abstractions in the language.

The Remote and Pickle modules are also useful for distribution.
The tutorial gives examples of how to write distributed
programs; you can cut and paste from it, but its definitions
(including NewStat) are not part of the system.

The Connection and Fault modules have been designed so that
users can define their own abstractions within the language.
We are working on redoing the distribution layer to give the
choice of mobile/stationary behavior for all stateful language
entities.  We are also working on fault tolerance abstractions
(a few exist already, cf. MOGUL).

But you are right, it would be nice to have a collection of
often-used definitions always available in the system right
now.  NewStat is one of the most useful, and right now the
only way to have it is to insert the definition in your
program.  I and others plan to make a collection eventually,
a superset of what exists in the tutorial (as part of a book
on programming techniques based on Mozart that is in the works),
but if you can't wait, you will have to collect the definitions
yourself (unless some noble soul has already done it).

Peter


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