[Oz] Oz complaints

[Denys Duchier]

rsmotrzyk at mikroplan.com.pl (Rafa³ Smotrzyk) writes:

> Basically, I'd be really interested to learn: what _don't_ people
> like about Oz?

The one recurring complaint from newcomers is that Oz has very unusual
syntax.  This state of affairs is due partly to development history
and partly to the fact that it combines many programming paradigms for
which concrete linguistic support must be devised.  After a while, one
gets used to it and the compromise is really not so bad :-)

> What is the speed when dealing with extremely large data sets. Is
> there some kind of support for large arrays, external databases,
> ODBC, etc. ?

Oz supports very large arrays but the core system was never intended
for number-crunching.  If you need a module that provides extremely
efficient number-crunching capabilities, then (much like in Python)
you may consider writing a "native functor" in C++... That is what the
system was designed for (among other things): dynamic extensibility.
The system is component-based and components may be written in Oz or
in C++.  In this aspect, it is very much like Java.

Regarding databases.  The system currently comes with an interface to
GDBM.  This illustrates how easy it is to create interfaces for native
library services.  Our library does not yet contain an interface for
other databases, but we would welcome submissions :-)

As for the speed.  I have used the GDBM interface to implement a
browser for a fairly large linguistic corpus of annotated syntax
trees.  Search was implemented by looping through the database,
unpickling each entry, and applying to it a continuation passing
search test, and it was very reasonably speedy.  I' not sure if that's
what you wanted to know, though.

> What is the support for COM (Win32). Could I create OLE servers or
> connect to COM servers with OZ?  Is there possibility to use Oz as
> one of the Active Scripting languages?

This is something that we have been talking about for some time, but,
so far, I don't believe that we have found the manpower to put into
the COM idea.  Maybe Leif can comment on this issue.

> Where is the common repository of algorithms, contributed modules,
> etceteras?

Funny you should ask...  At this very moment, we are in the process of
creating the administrative infrastructure to support such a
repository, and we are testing, on the contributions from our groups,
the package development support that we want to make available for
general user contributions.

> What exactly do you mean when you write about distributed garbage
> collection? How stable is it?

Oz supports distributed computations where Oz processes arbirarily
located in the network may transparently operate on the same
data-structures, as if they were sharing the same memory store.  Thus,
a data-structure (a term) may span more than one site.  Distributed
garbage collection refers to the collection of such data when it is no
longer referenced by any site.

Perhaps Peter can elaborate on this issue.

> And now the most important question: could I recompile Oz with
> Microsoft Visual Studio 6, and use it as embedded scripting language
> in application written in C++?

Leif?

If you succeed in your enterprise, please, do share your experience
with us so that we may improve the system in subsequent releases.

Sincerely,

-- 
Dr. Denys Duchier			Denys.Duchier at ps.uni-sb.de
Forschungsbereich Programmiersysteme	(Programming Systems Lab)
Universitaet des Saarlandes, Geb. 45	http://www.ps.uni-sb.de/~duchier
Postfach 15 11 50			Phone: +49 681 302 5618
66041 Saarbruecken, Germany		Fax:   +49 681 302 5615
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