Re: BeanShell JDJ Article

[Pat <pat@pat.net>]

I have to apologize for the lack of info on BeanShell lately.  I've had
some personal stuff going on that's prevented me from getting out a new
release.

Anyway, I thought you might be interested in my response to someone who
is writing an article about bsh for the JDJ.

As for those of you who have been patiently waiting for me to get back to
you about your bug fixes and major enhancements (you know who you are ;) )
I hope this indicates that I am going to try to get to them now.

In the future when we have moved development over to sourceforge.net it
will be easier to distribute the development process and things shouldn't
block on me as often.

Thanks to everyone,
Pat Niemeyer


----- Forwarded message from Pat <pat@pat.net> -----
Message-ID: <20000510093643.11167@pat.net>
Date: Wed, 10 May 2000 09:36:43 -0500
From: Pat <pat@pat.net>
To: RICKHIGH@aol.com
Subject: Re: BeanShell JDJ Article
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On Wed, May 10, 2000 at 03:41:53AM -0400, RICKHIGH@aol.com wrote:
> 
> Hi Pat. How is it going? I like BeanShell and I have showed it to many 
> people. It is a good way to learn Java in an interactive manner.
> I am writing a series of articles highlighting various scrpting languages 
> that run in the 
> JVM. I've decided to highlight BeanShell in the July issue of the JDJ.

Excellent.  That's very exciting.

I have been meaning for some time to write an article myself, but something
always pulls me away ;)

> What is the future RoadMap for BeanShell, i.e., what features do you plan for 
> BeanShell?

Well, there is a brief "wishlist" on the web site that perhaps you've seen
(http://www.beanshell.org/wishlist.html)

Some features which will almost certainly be in the next release are:

- More dynamic class loading and class reloading.

- Taking advantage of the API that allows introspection of private 
  and fields/methods.

- Better error reporting...  a more complete test suite.

I also have submissions from sommeone right now that add regular expression 
support on par with Perl...  We've concocted a way to add this without 
deviating too much from standard Java syntax...  That's always been a goal, 
to maintain as much real Java syntax as possible and simply extend /loosen it.

I think there is a need for a language that scales semantically between
scripting and rigorous, static typing.  I think that loose Java is 
"the natural scripting language" for Java.  It requires almost no learning
curve.

One feature that bsh got in the latest version takes advantage of a new
reflection capability in JDK1.3 - dynamic proxy creation.  This allows bsh
to emulate any type of interface... You've always been able to script event
listeners, etc. in bsh, however the types were limited to the known types
in AWT and Swing.  Now with 1.3 you can script any kind of interface.

In the future I'd like to extend the capability to be able to generate 
arbitrary types... e.g. extend existing types as subclasses or script 
abstract base classes.  This may sound more archane, but it's important for
one reason...  It would allow the bsh syntax to be extended to cover class
definitions as well...  Right now bsh only understands statements and 
expressions as well as it's own extended method closures (as in Perl or
JavaScript... methods that return 'this' and act like objects).  It would be
nice if bsh could interpret 100% of the Java syntax including classes.

I'd also like to be able to have bsh spew out compilable code someday...
(not that bsh isn't reasonably fast... it's really just limited by the speed
of the reflection API right now).  But it would make a lot of people happy
if they could flip a switch and turn their bsh script into a compileable java
file.

I also think bsh should provide better support for serving as a JavaBean
inside of various IDEs...  to wire together sophisticated connections.

> I see that you have made BeanShell opensource. How many developers are 
> working to extend BeanShell features?

There are a couple of hundred people on the developer's list.  I'm currently
in the process of moving development over from the beanshell.org ISP to
sourceforge.net (an open source facility with lots of neat features like
public CVS, etc.)

I have been really bad lately about getting any work done on bsh for personal
reasons... and some of the developers are bugging me ;)  So I really do
have to get to work on the next release soon.

I think I'll do a maintenance release for bug fixes and then start working
on a 2.0 with the new features.

By the way, there will be a brief section on BeanShell in the third edition
of my book: Exploring Java, O'Reilly & Associates - The book is to be 
retitled "Learning Java" (for some reason).

I mention this because it will probably prompt me to get back to work on
the next release... we've been stuck at 1.0 for a long time.

> How would you compare BeanShell to DynamicJava?

I'm afraid I don't know much about DynamicJava.  The most popular alternative
that I've heard about is of course JPython.  I have a lot of respect for
Python (although I can't digest it's syntax... I need my curly braces ;) )
but I see it as more of a full blown language that's not necessarily as nice
a match for Java.  BeanShell is something like 150K in size...  It mates
well with Java.  I'd like to see it as a standard extension someday (hah ;) ).
JPython is probably much more powerful, but much bigger.


> Do you know of any commercial products that use BeanShell as their scripting 
> language?

I started maintaining a list... but it's incomplete.  

First, everyone should know that BeanShell is distributed with Emacs as part
of Paul Kinnucan's JDE to serve as a Java interpreter.. I believe he also
uses it internally.

Various other IDE's are providing plug-ins for it:

Sun's NetBeans has been interested (they did a poll recently and JPython and
BeanShell were the top choices).

I believe the ElixirIDE (http://elixirtech.com/ElixirIDE/) has a plug in now.

And someone just wrote one for JBuilder  
http://www.multimania.com/bjb/index.en.html

CERN - The physics people use it in a sophisticated visualization app.

Two years ago on Corel (The Word Perfect peole) contributed a lot of bug fixes
and help...  but then their Java efforts sort of dried up.

I am aware of some Jigsaw integration
and the JOS (www.jos.org) people are considering it for their shell language.

I am probably forgetting some important ones...  Tens of thousands of people
have downloaded the code and I have perhaps a thousands license forms
(It's just a request, the code is LGPL of course).

I hope to put a better list together when I update the web site.


> Any guess as to the number of people that are using BeanShell?

It's very hard to say...  I'm sure there are hundreds of commercial products
using or at least evaluating BeanShell right now.    But because of the
free license they don't generally have to give me much feedback ;)  

> When will be the next major release of BeanShell? What will that release 
> include?

Well, as I said the pressure is building to get the new features going...
so I hope to start again in the next few weeks.  Usually that creates a 
flurry of releases.  Also, with moving to sourceforge.net I hope that I can
distribute the load now...  Currently I've been doing everything from fixes
to running the mailing list manually.

> What special features set BeanShell apart from other scripting languages?

I hope I addressed a few in the first part of this email.  (And I hope I 
haven't ranted too much...)  

Other interesting thigns to mention are that:

BeanShell can be easily embedded in Java or vice-versa bsh scritps can call
any Java app or API seamlessly...  By seamlessly I mean that live Java objects
can be passed into and return from scripts.

Bsh also has a "server mode" which allows you to run bsh inside a running app
and then open a console from your web browser (or telnet) into the application
and poke around like a debugger...  (This features is shakey in some releases).

I'm sure I'm forgetting things...

I'd be happy to elaborate or try to give you some more eloquent quotes if
you need them ;)  It's still early for me ;)

Please don't hesitate to ask for more info.  If anything, your article will
probably prompt me to get back to work on bsh ;)


Thanks,
Pat Niemeyer


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