[CfP] Dynamic Languages Day @ Brussels
- Dynamic Languages Day @ Vrije Universiteit Brussel
Monday, February 13, 2006, VUB Campus Etterbeek
The VUB (Programming Technology Lab, System and Software Engineering
Lab), ULB (deComp) and the Belgian Association for Dynamic Languages
(BADL) are very pleased to invite you to a whole day of presentations
about the programming languages Self, Smalltalk and Common Lisp by
experts in these languages. Besides some introductory material for
each language, the reflective facilities in the respective
programming environments will be highlighted. The presentations will
be especially interesting for people with good knowledge about
current mainstream object-oriented languages like Java, C# and C++
who want to get a deeper understanding about the expressive power of
Self, Smalltalk and Common Lisp. In order to prepare the ground for
these presentations, Professor Viviane Jonckers will introduce the
day by an overview of the benefits of teaching dynamic languages to
undergraduate students in computer science. She will especially
discuss the specific advantages of using Scheme as an introductory
language instead of the more widely employed Java language.
Attendance is free and open to the public. Please make sure to
register for the event by sending an e-mail to Pascal Costanza
(pascal.costanza@...), so we can plan ahead. The number of
places will be limited according to the exact location of the event
and will be allocated on a first-come, first-serve basis. Watch the
website for the exact schedule, location and any news at http://
Abstracts of the Talks
Scheme as an introductory language (Viviane Jonckers)
The VUB has a rich history in dynamic programming language teaching
and research. Ever since the late 80's, compulsory courses on Lisp
and Smalltalk have played an important role in the last two years of
the computer science curriculum. Since the early 90's, this role was
further intensified by selecting Scheme as the introductory course in
the first year and by promoting Scheme as the lingua franca for most
courses in the first two years. Professor Jonckers' introductory talk
to the dynamic languages day explains how this early exposure to the
dynamic paradigm is the seed that gives students the skills to fully
grasp and appreciate the more advanced dynamic paradigms (such as
Lisp, CLOS, Smalltalk and Self) in subsequent courses of their
computer science training.
Self (Ellen Van Paesschen)
Self is a prototype-based object-oriented programming language where
everything is an object and all manipulation of objects is initiated
through message sending. A prototype-based language eschews classes
and allows object creation ex-nihilo or by cloning prototypes. Self
resembles Smalltalk in both its syntax and semantics. Other
characteristics of Self are delegation (object-centered inheritance),
parent sharing and child sharing (multiple inheritance), and dynamic
parent modification. Further the Self environment includes a powerful
mechanism for reflective meta-programming based on mirror objects.
The Self group were also the first to introduce traits objects that
gather shared and reusable behavior between objects in order to
program in a more efficient and structured way.
After a brief introduction to the highly interactive Self environment
the language's basics and its syntax and semantics are presented.
Next the most important advanced features such as mirrors and dynamic
parent modification are illustrated.
Smalltalk (Johan Brichau, Roel Wuyts)
Smalltalk is class-based object-oriented programming language.
Everything in Smalltalk is an object and these objects communicate
through messages. The Smalltalk language itself offers only very few
programming constructs and is thus easy to learn and grasp.
Therefore, the expressive power of Smalltalk lies in its huge library
of frameworks, which includes an extensive metaobject protocol that
enables powerful dynamic (runtime) reflection. Furthermore, perhaps
one of the most significant advantages of Smalltalk outside of the
language itself is that software development is a truly dynamic
experience. The Smalltalk environment features the incremental
development of an application where there is no strict separation
between development and execution cycles, leading to an interactive
and dynamic development process.
Besides a short introduction to the Smalltalk programming language,
this presentation will focus on the dynamic reflective facilities of
Smalltalk. We will demonstrate the power of its metaobject protocol
through a number of tools that extensively rely on it. Furthermore,
we will provide some insight in the dynamic nature of Smalltalk
development through a live demonstration.
Generic Functions and the CLOS Metaobject Protocol (Pascal Costanza)
The Common Lisp Object System (CLOS) is unique in two ways.
* In most OOP languages, methods belong to classes and are invoked by
sending messages. In CLOS, methods belong to generic functions
instead of classes, and those generic functions select and execute
the correct method according to the types of the arguments they receive.
* The CLOS Metaobject Protocol (MOP) specifies how its essential
building blocks are to be implemented in CLOS itself. This allows
extending its object model with metaclasses that change important
aspects of CLOS for a well-defined scope.
This presentation introduces these two notions. The code for an
interpreter for generic functions that performs selection and
execution of methods will be developed live during the presentation.
This will be followed by a discussion how that code can be extended
to introduce, for example, multimethods and AOP-style advices, and a
sketch how generic functions are implemented efficiently in the
"real" world. In the second part, the extensibility of the CLOS MOP
will be illustrated by implementing - live - the (hashtable-based)
Python object model as a metaclass. Other practical extensions based
on the CLOS MOP are also sketched, like object-relational mappings,
interfaces to foreign-language objects, and domain-specific
annotations in classes.
Viviane Jonckers received a master degree in Computer Science from
the Vrije Universiteit Brussel in 1983 and a Ph.D. degree in Sciences
from the same university in 1987. Since 1987 she is a professor both
in the Computer Science Department of the faculty of Sciences as in
the Computer Science group of the Engineering Faculty. Currently, she
is the director of the System and Software Engineering Lab. Her
current research interests are in integrated software development
methods with a focus on component based software development and
aspect oriented software development. She participated in and has
been project manager of several national and international R&D projects.
Roel Wuyts is professor at the University Libre de Bruxelles, where
he leads the deComp group. His fields of interest are logic meta
programming, forms of reflection and language design. On the side he
also dabbles in development environments. Quite a lot his development
is done in Smalltalk, extensively using the reflective facilities in
that language to do research in language symbiosis, development
environments and for rapid programming in gneral. From the moment he
realized that dynamicity was what he really liked in all of his
favourite programming languages (Smalltalk, Prolog and Scheme), he
has been trying to grow the dynamic languages field again. Part of
this endavour was the organization of the first Dynamic Language
Symposium, a symposium co-organized with OOPSLA'2005 in San Diego.
Johan Brichau currently holds a postdoc position at the Laboratoire
d'Informatique Fondamentale de Lille (LIFL). He is also associated
with the Programming Technology Lab at the Vrije Universiteit
Brussel, where he obtained a Ph.D. degree in Computer Sciences in
2005. Johan's research is focusing on the use of metaprogramming in
the context of generative programming techniques and aspect-oriented
programming languages. To this extent, he has been extensively using
the Smalltalk metaobject protocol for the creation and development of
(generative) logic metaprogramming techniques as well as aspect-
oriented language extensions to Smalltalk.
Pascal Costanza has a Ph.D. degree from the University of Bonn,
Germany. His past involvements include specification and
implementation of the languages Gilgul and Lava, and the design and
application of the JMangler framework for load-time transformation of
Java class files. He has also implemented ContextL, the first
programming language extension for Context-oriented Programming based
on CLOS, and aspect-oriented extensions for CLOS, which all heavily
rely on the CLOS MOP. He is furthermore the initiator and lead of
Closer, an open source project that provides a compatibility layer
for the CLOS MOP across multiple Common Lisp implementations.
Ellen Van Paesschen obtained a master degree in computer science at
the Vrije Universiteit Brussel in 2000. Currently she is a Ph.D.
student at the Programming Technology Lab. Ellen's research is
focusing on using dynamic and prototype-based languages for model-
driven development and round-trip engineering (RTE). She has created
a research prototype of a dynamic prototype-based RTE environment in
Self which is the main implementation language in her research. This
environment differs from other existing tools at the level of
synchronisation, run-time objects and constraint enforcement steered
from an analysis model. Her other interests include (the analysis
phase during) software engineering and role modelling.
Pascal Costanza, mailto:pc@..., http://p-cos.net
Vrije Universiteit Brussel, Programming Technology Lab
Pleinlaan 2, B-1050 Brussel, Belgium