Research

Here is an interesting selection of recent publications.

2010

CLoX: Common Lisp Objects for XEmacs

Verna, D. (2010). In Proceedings of the 3rd European Lisp Symposium.

• Paper
• CLoX is an ongoing attempt to provide a full Emacs Lisp implementation of the Common Lisp Object System, including its underlying meta-object protocol, for XEmacs. This paper describes the early development stages of this project. CLoX currently consists in a port of Closette to Emacs Lisp, with some additional features, most notably, a deeper integration between types and classes and a comprehensive test suite. All these aspects are described in the paper, and we also provide a feature comparison with an alternative project called Eieio.

Revisiting the Visitor: the Just Do It Pattern

Verna, D. (2010). In Journal of Universal Computer Science, Volume 16, Issue 2, Pages 246 -- 271.

• Paper
• Lisp Code
• While software design patterns are a generally useful concept, they are often (and mistakenly) seen as ready-made universal recipes for solving common problems. In a way, the danger is that programmers stop thinking about their actual problem, and start looking for pre-cooked solutions in some design pattern book instead. What people usually forget about design patterns is that the underlying programming language plays a major role in the exact shape such or such pattern will have on the surface. The purpose of this paper is twofold: we show why design pattern expression is intimately linked to the expressiveness of the programming language in use, and we also demonstrate how a blind application of them can in fact lead to very poorly designed code.

2009

CLOS Efficiency: Instantiation -- On the Behavior and Performance of Lisp, Part 2.1

Verna, D. (2009). In Proceedings of the International Lisp Conference , MIT, Cambridge, Massachusetts, USA.

• Paper
• Slides
• Benchmarks
• This article reports the results of an ongoing experimental research on the behavior and performance of CLOS, the Common Lisp Object System. Our purpose is to evaluate the behavior and performance of the 3 most important characteristics of any dynamic object oriented system: class instantiation, slot access and dynamic dispatch. This paper describes the results of our experiments on instantiation. We evaluate the efficiency of the instantiation process in both C++ and Lisp under a combination of parameters such as slot types or classes hierarchy. We show that in a non-optimized configuration where safety is given priority on speed, the behavior of C++ and Lisp instantiation can be quite different, which is also the case amongst different Lisp compilers. On the other hand, we demonstrate that when compilation is tuned for speed, instantiation in Lisp can become faster than in C++.

2008

Binary Methods Programming: the CLOS Perspective.

Verna, D. (2008). In Journal of Universal Computer Science, Volume 14, Issue 20, Pages 3389 - 3411.

• Paper
• Implementing binary methods in traditional object-oriented languages is difficult: numerous problems arise regarding the relationship between types and classes in the context of inheritance, or the need for privileged access to the internal representation of objects. Most of these problems occur in the context of statically typed languages that lack multi-methods (polymorphism on multiple arguments). The purpose of this paper is twofold: first, we show why some of these problems are either non-issues, or easily solved in Common-Lisp. Then, we demonstrate how the Common-Lisp Object System (CLOS) allows us not only to implement binary methods in a straightforward way, but also to support the concept directly, and even enforce it at different levels (usage and implementation).

2006

Verna, D. (2006). In The PracTeX Journal, number 3, August 2006.

• Paper
• This paper presents CurVe, a curriculum vitae class for LaTeX2e, in a progressive approach going from a first contact with the class, through concrete examples of customization, and some aspects of advanced usage.

Beating C in Scientific Computing Applications -- On the Behavior and Performance of Lisp, Part I.

Verna, D. (2006). In Third European LISP Workshop at ECOOP , Nantes, France.

• Best paper award winner
• Paper
• Slides
• This paper presents an ongoing research on the behavior and performance of LISP with respect to C in the context of scientific numerical computing. Several simple image processing algorithms are used to evaluate the performance of pixel access and arithmetic operations in both languages. We demonstrate that the behavior of equivalent LISP and C code is similar with respect to the choice of data structures and types, and also to external parameters such as hardware optimization. We further demonstrate that properly typed and optimized LISP code runs as fast as the equivalent C code, or even faster in some cases.

2003

Verna D. (2003). In TugBoat, volume 22, number 4, December 2001, pages 361 -- 364.

• Paper
• This paper relates the history of the development of Curve, a LaTeX2e class package for typesetting curricula vitae, and describes its specificities as well as the main aspects of it use.