Re: Libraries in Obj C vs. Java

[Marcus G. Daniels]

>>>>> "RS" == Ralf Stephan <address@hidden> writes:

RS> I think the 'problem of choice' (German: Qual der Wahl) here is
RS> using one language for all parts of development (Agent,
RS> Scheduling, UI) and having all of the benefits and none of the
RS> quirks.

The architecture of a model will be described by XML, or rather,
interactive manipulation of nodes on a palette.  Simple agent rules
can be stated using a EXPR element that has a simple calculator
syntax. 

For non-trivial rules, Java's not bad.  It's easy to learn, popular,
fairly fast, safe, has garbage collection, and a freely-redistributable
implementation available.

So we'll support the usual stuff, but it will not be limited to the
usual stuff. 

RS> Scheme is the one I missed until now.  But is it readable by
RS> humans as naturally as --- was Obj-C?  How efficiently compilable
RS> is it /wrt other choices?

Scheme is useful in models where evolution of agent behaviors is 
desirable.  For open-minded people, it is easy to learn.  There are
compilers that generate fast code like Stalin and MIT Scheme.
IMT uses Guile. 

RS> There are free Java-to-C translators, presumably, but are there
RS> Javascript compilers? 

Compiling Javascript is not a goal.  I don't anticipate modelers using
JavaScript -- it's a language we can use internally to develop parts of
the Swarm/IMA IDE because it is tightly integrated with the browser, and
since performance isn't an issue in this context.  

JavaScript is a nifty little language, though.

As for the general question of how to make fast models, it ought to be
possible to take all the agent-rules nodes and compile it down to native
code COM objects.  That won't be in the first release, but we may have
a agent-rule node type that is for COM objects so that people can
write high-performance rules which don't rely on an interpreter. 

RS> And, has security with Javascript become better?  Haven't looked
RS> for years.

Mozilla has a highly-configurable security system.  A number of people
at Netscape are thinking hard about security.  

Swarm users will simply need to be warned categorically about loading
simulations from web pages, just as they should be cautious when
compiling and running Objective C or Java Swarm models.

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