This is a friendly reminder that brocures for the Seattle conference
are due to RL and John Salasin ASAP.  Recall that the brocures or product
sheets should be a one page fact sheet which provides a brief description
of what the product does, why it is useful, what it runs on and how to get
it.

RL's fax    (315) 330-7989
John's fax  (703) 696-0564          

Demeter/Java and AP/Studio Fact Sheet

What does the product do?

Demeter/Java is a tool which allows you to write Java programs
which are easy to evolve and reuse. The product is the result
of 10 years of research/development in structure-shy programming which
started with the Law of Demeter. The techniques to achieve
structure-shy programming are to add
strategic information about traversals and objects to Java programs
and to follow style rules, such as the Law of Demeter.
http://www.ccs.neu.edu/research/demeter/demeter-method/LawOfDemeter

The program takes as input Java programs extended with additional 
aspect descriptions and translates the extended Java programs
to ordinary Java programs. Currently, an extended Java
program consists of a single layer of traversals and
visitors. Future extended Java programs are planned to have a layered
architecture where each layer is expressed adaptively in terms
of the layer below. This leads to a loose coupling between
the layers and each layer is very flexible regarding the 
structure of the objects which need to be processed.


Why is the product useful?

The product has the following benefits compared to unextended Java:

Programs become more flexible.
Programs are more readable since traversal strategies are a
part of the program, i.e., the programmer's high-level intentions
are encoded directly into the program code (as traversal strategies),
rather than having to be written as comments or external
documentation. This means that a part of the rationale
capture for the program is an integral part of the program itself.
Without the explicit traversal strategies, the programs are harder
to read since often a large number of function calls would need to be
studied to get the equivalent information in the strategies.
Programs become shorter.

The current version of the product supports adaptive object-oriented
programming with the following aspects using widely used notations:

The basic behavior is expressed in a
small language which has Java embedded in it. The small language supports
a traversal/visitor style of programming following the Visitor design pattern.
The object structure aspect is expressed in UML (Unified
Modeling Language of Rational et al.) and the domain-specific
language aspect is expressed in an extension to UML using
an EBNF style syntax.

Future versions of the product will include other aspects, including 
the synchronization aspect and the remote invocation aspect.

AP Studio is a graphical user interface for Demeter/Java.
It supports visualization of and visual development of Demeter/Java
programms, especially traversal strategies embedded in UML class diagrams.


Platforms

Demeter/Java is implemented in Demeter/Java and available in 100% pure
Java source form. It is running on all platform where Java
is running and is currently used under Solaris, SUNOS, DEC Alpha
with OSF, Windows,
Windows NT and Linux. Demeter/Java uses several libraries supplied
by Java and also the Java Compiler Compiler from SunTest.


How to get it.

We distribute the Demeter/Java tool for early experimentation.
It contains some bugs and lacks documentation. A beta release
will be announced at the end of August 1997.

The latest source code is in the youngest subdirectory of:
http://www.ccs.neu.edu/research/demeter/sources/DemeterJava/inJava/
(currently 0.4.6-JDK1.1). For general information on
Demeter/Java, see:
http://www.ccs.neu.edu/home/lieber/Demeter-and-Java.html

For AP Studio:
A beta release will be available at the end of August 1997. 

For theoretical foundations: See the book:
http://www.ccs.neu.edu/research/demeter/biblio/dem-book.html
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