Re: [Repast-developer] batch language

[Mark R. D. <mdi...@la...>]

Nick Collier wrote:

>Hi,
>
>Any thoughts on a better batch description language? We have a sort of
>proto-XML format now together with the utterly confusing "}" based one.
>I'm thinking XML should do the job, but maybe something closer to a
>natural language would be better and then translate that into XML. Any
>thoughts? Examples?
>
>
>Nick
>
>  
>
I've discovered an Apache Jakarta Commons package called Jelly that 
really has caught my eye. Its similar in nature to Ant, but its built to 
be a "scripting" environment instead of a "build" environment. It can be 
embedded into any other java application (Servlet, Ant, "your 
application here"). It supports JSP style scripting (EL and tag 
libraries). I really was struggling with Ant in terms of writting tasks 
and passing around variables (getting the variables to update involved 
writting practically every task in another ant target), I think Jelly 
would really solve alot of my issues. Its supported and donated to to 
apache by a private company that promotes opensource release of its 
development projects. So I think it'll be around for awhile.

http://jakarta.apache.org/commons/sandbox/jelly/

donated by

http://www.werken.com/

So now I'm working twards implementing my batch stuff using this 
environment.

The other cool thing about Jelly, is that it can be bound to Java 
Objects. I can see actually calling the setters for my model parameters 
from within the Jelly script because I can instantiate the Model Object 
and manipulate it from within the script. Theoretically, by providing a 
sufficiently pluggable system of component Java Beans repast models 
could be "snapped" together using Jelly Script as well as utilizing 
Jelly's scripting env for batch processing.
 
-Mark

 p.s. I understand there's been some interest in my batch task in Ant. 
The Ant developers really "shun" any any development twards using Ant as 
a scripting environemnt, thus there are no <for-each>, <while> or any 
other conditional "type" tags in Ant.( This is where Jelly differs). My 
Batch task is simply an attempt to provide such conditional 
capabilities. It is in essance a simplified for loop.

Mostly what I was interested with Batch processing was to be able to 
"select" initial conditions from Probability Distributions (ie 
Beta(alpha,beta) or Normal(mean,std)). So I also wrote Distribution Rand 
Generator Tasks that can be used in Ant that are based on the Colt 
library (examples below).

Note: this code works with Ant 1.4.1 and isn't tested with Ant 1.5.x

-Mark