Climb

It appears that if all the projects of the LRDE involve various application areas, a common underlying problem is how to reconcile two aspects that are usually contradictory: performance and genericity.

This issue has led the lab's teams to develop a long-term software engineering based on technical C++ with many templates. This approach has its drawbacks. Disadvantages include the fact that C++ is a heavy language with an extremely complex and ambiguous syntax, that the template system is actually a completely different language from standard C++, and finally that it is a static language. This last point has significant implications on the application, insofar as it imposes a strict chain of Compilation => Development => Run => Debug, making for example rapid prototyping or human-machine interfacing activities difficult. It becomes therefore essential to equip the involved projects with a third language infrastructure that is rather based on scripting languages.

Facing these problems, another team of the laboratory has chosen to focus on the persistent question of performance and genericity with a transversal approach, that is to say focused on alternative languages rather than on a particular application domain. The purpose of this research is therefore to examine the solutions offered by languages other than C++, especially dynamic languages, and we chose Common Lisp.

Perfomance

At first glance, it seems paradoxical indeed to use, for performance issues, a language which is legitimately expected to deteriorate them. Almost by definition, a dynamic language does less at compile-time and more at run-time (eg, type checking). Most modern dynamic languages like Python and Ruby match these preconceived notions. Common Lisp, however, has this ability to let you static type pieces of the code you write, and let the rest be dynamically typed. A compiler that is properly informed about such types is then free to perform any possible optimization, even to produce a weakly typed executable as a C compiler would do.

Therefore, one goal of this research focuses on comparing the performance obtained by some Common Lisp compilers with those of equivalent programs written in C or C++. This work involves a substantial set of performance measurements on micro-benchmarks to evaluate the cost of some basic operations (arithmetic, object instantiation, access to their members, dynamic dispatch, etc.).

Genericity

Once the issue of performance is resolved, we still have to demonstrate the benefits of a dynamic language for genericity. The basis of this approach lies in a fact that is this time widely recognized: dynamic languages are more expressive. By eliminating especially the static typing, and consequently, by expanding the scope of polymorphism, dynamic languages provide paradigms that are impossible or difficult to obtain in static languages. If we take simply the paradigm of object-oriented programming, Common Lisp goes further than other (static or dynamic) languages if that the object layer is based on a so-called meta-object protocol: a reflexive architecture that implements the object layer in itself, and that also allows to modify or extend it. Thus, far from the classical OO approach of traditional languages, the object-oriented layer of Common Lisp includes natively multimethods, and allows the use (and mix) of traditional classes-based, prototype-based, context-oriented approaches, etc.

The second line of research in this work consists in the study of all these new programming paradigms in terms of what they bring to the notion of genericity. To do this, we have chosen to clone one of the oldest projects of the laboratory (Olena) and to express the same issues following an axis of dynamic genericity.

Finally, a longer-term perspective will be to reconcile these aspects of dynamic genericity with the performances of a dedicated code. This step should also be made significantly easier than the manipulation of C++ templates because of the structural reflexivity of Lisp (code and data are represented in the same way). The system of macros in Common Lisp is unique because it can perform any function written in Lisp itself during the compilation, these functions themselves having access to the code to compile. This allows in particular to rewrite the code on the fly and provides for native JIT-compilation.

Publications

Conference papers

	Title	Authors	Published in	Date
esteban.22.gpce	The Cost of Dynamism in Static Languages for Image Processing	Baptiste Esteban, Edwin Carlinet, Guillaume Tochon, Didier Verna	Proceedings of the 21st International Conference on Generative Programming: Concepts & Experiences (GPCE 2022)	10 October 2022
esteban.22.gretsi.1	Estimation de la fonction de niveau de bruit pour des images couleurs en utilisant la morphologie mathématique	Baptiste Esteban, Guillaume Tochon, Edwin Carlinet, Didier Verna	28e Colloque sur le traitement du signal et des images	15 June 2022
esteban.22.gretsi.2	Généricité dynamique pour des algorithmes morphologiques	Baptiste Esteban, Edwin Carlinet, Guillaume Tochon, Didier Verna	28e Colloque sur le traitement du signal et des images	15 June 2022
esteban.22.icpr	Estimation of the noise level function for color images using mathematical morphology and non-parametric statistics	Baptiste Esteban, Guillaume Tochon, Edwin Carlinet, Didier Verna	Proceedings of the 26th International Conference on Pattern Recognition	8 April 2022
verna.22.els	ETAP: Experimental Typesetting Algorithms Platform	Didier Verna	15th European Lisp Symposium	1 March 2022
hacquard.21.els	A Corpus Processing and Analysis Pipeline for Quickref	Antoine Hacquard, Didier Verna	Proceedings of the 14th European Lisp Symposium (ELS)	1 May 2021
verna.19.tug	Quickref: Common Lisp Reference Documentation as a Stress Test for Texinfo	Didier Verna	TUGboat	6 November 2019
verna.19.els	Parallelizing Quickref	Didier Verna	12th European Lisp Symposium	1 April 2019
valais.19.els	Implementing Baker's SUBTYPEP decision procedure	Léo Valais, Jim Newton, Didier Verna	12th European Lisp Symposium	1 April 2019
newton.19.els	Finite Automata Theory Based Optimization of Conditional Variable Binding	Jim Newton, Didier Verna	European Lisp Symposium	14 January 2019
newton.18.meta	Recognizing Heterogeneous Sequences by Rational Type Expression	Jim Newton, Didier Verna	Proceedings of the Meta'18: Workshop on Meta-Programming Techniques and Reflection	14 September 2018
newton.18.els	Approaches in Typecase Optimization	Jim Newton, Didier Verna	European Lisp Symposium	5 April 2018
verna.18.els	Method Combinators	Didier Verna	11th European Lisp Symposium	25 March 2018
newton.17.els	Programmatic Manipulation of Common Lisp Type Specifiers	Jim Newton, Didier Verna, Maximilien Colange	European Lisp Symposium	6 February 2017
newton.16.els	Type-Checking of Heterogeneous Sequences in Common Lisp	Jim Newton, Akim Demaille, Didier Verna	European Lisp Symposium	25 March 2016
verna.15.cop	Context-Oriented Image Processing	Didier Verna, François Ripault	Context-Oriented Programming Workshop	1 January 2015
verna.13.tug-1	The incredible tale of the author who didn't want to do the publisher's job	Didier Verna	TUGboat	1 January 2013
verna.13.tug-2	TiCL: the Prototype (Star TeX: the Next GenerationSeason 2)	Didier Verna	TUGboat	1 January 2013
senta.12.els	Generic Image Processing with Climb	Laurent Senta, Christopher Chedeau, Didier Verna	European Lisp Symposium	1 May 2012
verna.12.tug	Star TeX : the Next Generation	Didier Verna	TUGboat	1 January 2012
verna.11.onward	Biological Realms in Computer Science: the Way You Don't (Want To) Think About Them	Didier Verna	Onward! 2011	1 January 2011
verna.11.tug	Towards LaTeX Coding Standards	Didier Verna	TUGboat	1 January 2011
verna.10.tug	Classes, Styles, Conflicts: the Biological Realm of LaTeX	Didier Verna	TUGboat	9 March 2010
verna.10.els	CLoX: Common Lisp objects for XEmacs	Didier Verna	Proceedings of the 3rd European Lisp Symposium	9 March 2010
verna.08.els	Binary Methods Programming: the CLOS Perspective	Didier Verna	Proceedings of the First European Lisp Symposium	31 March 2009
verna.09.ilc	CLOS Efficiency: Instantiation	Didier Verna	Proceedings of the International Lisp Conference	13 January 2009
verna.09.accu	Revisiting the Visitor: the Just Do It Pattern	Didier Verna	Proceedings of the ACCU Conference 2009	29 December 2008
verna.08.lncs	Report on the 5th Workshop ELW at ECOOP 2008	Didier Verna, Charlotte Herzeel, Christophe Rhodes, Hans Hübner	Object-Oriented Technology. ECOOP 2008 Workshop Reader	1 July 2008
verna.06.imecs	How to make Lisp go faster than C	Didier Verna	Proceedings of the International MultiConference of Engineers and Computer Scientists	11 June 2007
verna.07.imecs	CLOS solutions to binary methods	Didier Verna	Proceedings of the International MultiConference of Engineers and Computer Scientists	22 January 2007
verna.06.ecoop	Beating C in Scientific Computing Applications	Didier Verna	Third European Lisp Workshop at ECOOP	11 July 2006
verna.01.sci	Virtual reality and tele-operation: a common framework	Didier Verna	Proceedings of the 5th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI)—Emergent Computing and Virtual Engineering	1 July 2001
verna.00.vsmm	Action recognition: how intelligent virtual environments can ease human-machine interaction	Didier Verna	Proceedings of the 6th International Conference on Virtual Systems and MultiMedia (VSMM)—Intelligent Environments Workshop	1 October 2000
fabre.00.vsmm	Urbi et Orbi: unusual design and implementation choices for distributed virtual environments	Yoann Fabre, Guillaume Pitel, Didier Verna	Proceedings of the 6th International Conference on Virtual Systems and MultiMedia (VSMM)—Intelligent Environments Workshop	1 October 2000

Journal papers

	Title	Authors	Published in	Date
newton.18.tocl	A Theoretical and Numerical Analysis of the Worst-Case Size of Reduced Ordered Binary Decision Diagrams	Jim Newton, Didier Verna	ACM Transactions on Computational Logic	28 August 2018
verna.18.programming	Lisp, Jazz, Aikido	Didier Verna	The Art, Science and Engineering of Programming Journal	5 February 2018
verna.10.jucs	Revisiting the Visitor: the Just Do It Pattern	Didier Verna	Journal of Universal Computer Science	1 January 2010
verna.08.jucs	Binary Methods Programming: the CLOS Perspective (extended version)	Didier Verna	Journal of Universal Computer Science	1 January 2008
verna.06.ijcs	How to make Lisp go faster than C	Didier Verna	IAENG International Journal of Computer Science	1 December 2006

PHD Theses and Habilitations

	Title	Authors	Published in	Date
verna.20.hdr	(Dynamic (Programming Paradigms)) ;; Performance and Expressivity	Didier Verna		10 July 2020

Book chapters

	Title	Authors	Published in	Date
verna.12.dsl	Extensible languages: blurring the distinction between DSLs and GPLs	Didier Verna	Formal and Practical Aspects of Domain-Specific Languages: Recent Developments	1 September 2012

Technical reports

	Title	Authors	Published in	Date
chedeau.12.tr	JSPP: Morphing C++ into JavaScript	Christopher Chedeau, Didier Verna		1 January 2012