Some publications in English

[o]

Syntactic Analysis of Technical Drawing Dimensions
Suzanne Collin and Dominique Colnet
International Journal of Pattern Recognition and Artificial Intelligence (IJPRAI)
October 1994
Volume 8 Number 5, pages 1131-1148.
Abstract:
The transfer of technical drawings from paper to CAD software data-bases and the construction of a 3D model of an object from several 2D views drawn on a draft, are topical problems. There are several different types of data in an industrial drawing, such as graphics, nomenclature and dimensioning. Dimensioning gives the measurement of the parts with more precision than direct scale measurements on the drawing. This article deals with the problem of dimension extraction and interpretation.
We present a syntactic approach to technical drawing dimensions analysis. A specific grammar is used to describe dimensions of drawings. This grammar can be graphically designed by combining different graphic primitives. The algorithm used for analysis can start at different points of the grammar. The analysis proceeds bottom-up and top-down according to previously obtained results.

[o]

Type Inference for Late Binding. The SmallEiffel Compiler
Suzanne Collin, Dominique Colnet and Olivier Zendra
Joint Modular Languages Conference 1997 (JMLC'97),
Volume 1204 of Lecture Notes in Computer Sciences, pages 67-81.
Abstract:
The SmallEiffel compiler uses a simple type inference mechanism to translate Eiffel source code to C code. The most important aspect in our technique is that many occurrences of late binding are replaced by static binding. Moreover, when dynamic dispatch cannot be removed, inlining is still possible. The advantage of this approach is that is speeds up execution time and decreases considerably the amount of generated code. SmallEiffel compiler source code itself is a large scale benchmark used to show the quality of our results. Obviously, this efficient technique can also be used for class-based languages without dynamic class creation: for example, it is possible for C++ or Java and not possible for Smalltalk.

[o]

Efficient Dynamic Dispatch without Virtual Function Tables. The SmallEiffel Compiler.
Olivier Zendra, Dominique Colnet, Suzanne Collin.
12th Annual ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications (OOPSLA'97),
Volume 32, Issue 10 - Atlanta, GA, USA, October 1997, pages 125-141.
Abstract:
SmallEiffel is an Eiffel compiler which uses a fast simple inference mechanism to remove most last binding calls, replacing them by static bindings. Starting from the system's entry point, it compiles only statically living code, which saves compiling and then removing dead code. As the whole system is analyzed at compile time, multiple inheritance and genericity do not cause any overhead.
SmallEiffel features a coding scheme which eliminates the need for virtual function tables. Dynamic dispatch is implemented without any array access but uses a simple static binary branch code. We show that this implementation makes it possible to use modern hardware very efficiently. It also allows to inline more calls even when dynamic dispatch is required. Some more dispatch sites are removed after the type inference algorithm has been performed, if the different branches of a dispatch site lead to the same code.
The advantage of this approach is that it greatly speeds up execution time and considerably decreases the amount of generated code.

[o]

Compiler Support to Customize the Mark and Sweep Algorithm.
Dominique Colnet, Philippe Coucaud and Olivier Zendra.
ACM SIGPLAN International Symposium on Memory Management (ISMM'98),
Vancouver, BC, Canada, October 17-19, 1998, pages 154-165.
Abstract:
Mark and sweep garbage collectors (GC) are classical but still very efficient automatic memory management systems. Although challenged by other kinds of systems, such as copying collectors, mark and sweep collectors remain among the best in terms of performance.
This paper describes our implementation of an efficient mark and sweep garbage collector tailored to each program. Compiler support provides the type information required to statically and automatically generate this customized garbage collector. The segregation of objects by type allows the production of a more efficient GC code. This technique, implemented in SmallEiffel, our compiler for the object-oriented language Eiffel, is applicable to other languages and other garbage collection algorithms, be they distributed or not.
We present the results obtained on programs featuring a variety of programming styles and compare our results to a well-know and high quality garbage collector.

[o]

Optimizations of Eiffel programs: SmallEiffel, The GNU Eiffel Compiler.
Dominique Colnet and Olivier Zendra.
29th conference on Technology of Object-Oriented Languages and Systems (TOOLS Europe'99), IEEE Computer Society
Nancy, France, June 7-10, 1999, pages 341--350.
Abstract:
The design of the Eiffel language makes it possible to perform global optimizations on Eiffel programs. In this paper, we describe some of the techniques we used in SmallEiffel, The GNU Eiffel Compiler, to generate highly efficient executables for Eiffel programs. Most of these techniques --- related to global analysis or not --- may also be applied to other object-oriented languages.

[o]

Adding external iterators to an existing Eiffel class library.
Olivier Zendra and Dominique Colnet.
32nd conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'99), IEEE Computer Society
Melbourne, Australia, 22-25 November 1999, pages 188--199.
Abstract:
This paper discusses common iteration schemes and highlights the interest of using explicit iterators. The advantages of external iterators are compared to those of internalized iterators. The integration of an iterator class hierarchy to an existing library without modifying the latter is detailed. This integration brings an extra level of abstraction to the library, which thus becomes more flexible, more adapted to certain design patterns and hence can be used in a higher-level way. Such an integration is not only possible, but can even be done in an optimized way, taking into account the specific structure of the collection traversed. A slight extension of existing class libraries can also be implemented that does not cause any compatibility problem and does not break existing code, but allows even further abstraction and makes it easier for the developer to use high-level, optimized, external iterators.

[o]

Match-O, a Dialect of Eiffel with Match-Types.
Dominique Colnet and Luigi Liquori.
35th conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'2000), IEEE Computer Society
Sydney, Australia, November 2000, pages 190--201.
Abstract:
It is well known that the Eiffel language allows covariant redefinition. Regardless of system-level validity rules, Eiffel is not type safe. In this paper, we present a dialect of Eiffel called Match-O, which prohibits covariant redefinition. We introduce a new kind of types, the match-types, inspired by the papers of Kim Bruce. The scope of this project is many-fold: -- allowing binary methods; -- keeping sound ``mytype method specialization'', i.e. anchored type using Current; -- allowing subtyping in all other sound cases. We claim that match-types can be added in the Eiffel type system to eliminate type unsoundness without blocking many interesting Eiffel programs (e.g. the ones with ``binary methods''). We have implemented a compiler for Match-O and we have experimented our dialect on a large system using the original source code of SmallEiffel itself.

[o]

Coping with aliasing in the GNU Eiffel Compiler implementation.
Olivier Zendra and Dominique Colnet.
Software Practice and Experience, 2001, Volume 31, No 6, pages 601-613
Abstract:
This paper report our experience about aliasing usage in the implementation of SmallEiffel, the GNU Eiffel Compiler. The SmallEiffel compiler source code makes intensive use of aliasing in order to achieve very good performance both in terms of memory and execution time. Thanks to the design by contract capabilities of the Eiffel language, aliasing can be handled very safely. The singleton pattern appears to be crucial in implementing alias provider objects. We propose an efficient implementation of this pattern made easy by some Eiffel idioms. This technique, which requires no language modification, is very appropriate for compilation, but can also be applied to a wide range of applications.

[o]

Lisaac: the power of simplicity at work for operating system.
Benoīt Sonntag and Dominique Colnet.
Proceedings of the fortieth conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'2002), Sydney, Australia, February 2002, Australian Computer Society, pages 45-52, James Noble and John Potterm, Eds,
Abstract:
The design as well as the implementation of the Isaac operating system (http://www.isaacOS.com) led us to set up a new programming language named Lisaac. Many features from the Lisaac language come from the Self programming language. Comparing to Self's skills, Lisaac integrates communications protection mechanisms as well as other tools related to operating systems' design. System interruptions support as well as drivers memory mapping have been considered in the design of Lisaac. The use of prototypes and especially dynamic inheritance, fits a flexible operating system in the making. First benchmarks of our compiled objects show that it is possible to obtain high-level prototype-based language's executables as fast as C programs are.

[o]

Reconciling Subtyping and Code Reuse in Object-Oriented Languages: Using inherit and insert in SmartEiffel, The GNU Eiffel Compiler.
Dominique Colnet and Guillem Marpons and Frederic Merizen.
Proceedings of the 9th International Conference on Software Reuse, Turin, june 2006, Lecture Notes in Computer Sciences, Springer-Verlag, Volume 4039, pages 203-216, ISBN 3-540-34606-6.
Abstract:
SmartEiffel has been enjoying two different mechanisms to express subtyping and implementation inheritance for one year. After large scale practical tests and thanks to user feedback, this paper finalises the new typing policy of SmartEiffel, which combines two forms of multiple inheritance with genericity in one statically-checked, object-oriented language. Having two forms of inheritance allows the designer to capture more design decisions in the source code. It is now straightforward to share reusable code between otherwise unrelated types. The new mechanism allows to reuse code from an existing class without polluting the reuser's interface. It also enables an elegant implementation of some design patterns. Furthermore, this mechanism helps compilers to statically remove more dynamic dispatch code. It can also be used to add a no-penalty and no-risk multiple-inheritance-like construct to a single-inheritance language such as Java.

Dominique Colnet

Last modified: Sun Mar 10 18:10:11 MET 2002

	Syntactic Analysis of Technical Drawing Dimensions Suzanne Collin and Dominique Colnet International Journal of Pattern Recognition and Artificial Intelligence (IJPRAI) October 1994 Volume 8 Number 5, pages 1131-1148. Abstract: The transfer of technical drawings from paper to CAD software data-bases and the construction of a 3D model of an object from several 2D views drawn on a draft, are topical problems. There are several different types of data in an industrial drawing, such as graphics, nomenclature and dimensioning. Dimensioning gives the measurement of the parts with more precision than direct scale measurements on the drawing. This article deals with the problem of dimension extraction and interpretation. We present a syntactic approach to technical drawing dimensions analysis. A specific grammar is used to describe dimensions of drawings. This grammar can be graphically designed by combining different graphic primitives. The algorithm used for analysis can start at different points of the grammar. The analysis proceeds bottom-up and top-down according to previously obtained results.
	Type Inference for Late Binding. The SmallEiffel Compiler Suzanne Collin, Dominique Colnet and Olivier Zendra Joint Modular Languages Conference 1997 (JMLC'97), Volume 1204 of Lecture Notes in Computer Sciences, pages 67-81. Abstract: The SmallEiffel compiler uses a simple type inference mechanism to translate Eiffel source code to C code. The most important aspect in our technique is that many occurrences of late binding are replaced by static binding. Moreover, when dynamic dispatch cannot be removed, inlining is still possible. The advantage of this approach is that is speeds up execution time and decreases considerably the amount of generated code. SmallEiffel compiler source code itself is a large scale benchmark used to show the quality of our results. Obviously, this efficient technique can also be used for class-based languages without dynamic class creation: for example, it is possible for C++ or Java and not possible for Smalltalk.
	Efficient Dynamic Dispatch without Virtual Function Tables. The SmallEiffel Compiler. Olivier Zendra, Dominique Colnet, Suzanne Collin. 12th Annual ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications (OOPSLA'97), Volume 32, Issue 10 - Atlanta, GA, USA, October 1997, pages 125-141. Abstract: SmallEiffel is an Eiffel compiler which uses a fast simple inference mechanism to remove most last binding calls, replacing them by static bindings. Starting from the system's entry point, it compiles only statically living code, which saves compiling and then removing dead code. As the whole system is analyzed at compile time, multiple inheritance and genericity do not cause any overhead. SmallEiffel features a coding scheme which eliminates the need for virtual function tables. Dynamic dispatch is implemented without any array access but uses a simple static binary branch code. We show that this implementation makes it possible to use modern hardware very efficiently. It also allows to inline more calls even when dynamic dispatch is required. Some more dispatch sites are removed after the type inference algorithm has been performed, if the different branches of a dispatch site lead to the same code. The advantage of this approach is that it greatly speeds up execution time and considerably decreases the amount of generated code.
	Compiler Support to Customize the Mark and Sweep Algorithm. Dominique Colnet, Philippe Coucaud and Olivier Zendra. ACM SIGPLAN International Symposium on Memory Management (ISMM'98), Vancouver, BC, Canada, October 17-19, 1998, pages 154-165. Abstract: Mark and sweep garbage collectors (GC) are classical but still very efficient automatic memory management systems. Although challenged by other kinds of systems, such as copying collectors, mark and sweep collectors remain among the best in terms of performance. This paper describes our implementation of an efficient mark and sweep garbage collector tailored to each program. Compiler support provides the type information required to statically and automatically generate this customized garbage collector. The segregation of objects by type allows the production of a more efficient GC code. This technique, implemented in SmallEiffel, our compiler for the object-oriented language Eiffel, is applicable to other languages and other garbage collection algorithms, be they distributed or not. We present the results obtained on programs featuring a variety of programming styles and compare our results to a well-know and high quality garbage collector.
	Optimizations of Eiffel programs: SmallEiffel, The GNU Eiffel Compiler. Dominique Colnet and Olivier Zendra. 29th conference on Technology of Object-Oriented Languages and Systems (TOOLS Europe'99), IEEE Computer Society Nancy, France, June 7-10, 1999, pages 341--350. Abstract: The design of the Eiffel language makes it possible to perform global optimizations on Eiffel programs. In this paper, we describe some of the techniques we used in SmallEiffel, The GNU Eiffel Compiler, to generate highly efficient executables for Eiffel programs. Most of these techniques --- related to global analysis or not --- may also be applied to other object-oriented languages.
	Adding external iterators to an existing Eiffel class library. Olivier Zendra and Dominique Colnet. 32nd conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'99), IEEE Computer Society Melbourne, Australia, 22-25 November 1999, pages 188--199. Abstract: This paper discusses common iteration schemes and highlights the interest of using explicit iterators. The advantages of external iterators are compared to those of internalized iterators. The integration of an iterator class hierarchy to an existing library without modifying the latter is detailed. This integration brings an extra level of abstraction to the library, which thus becomes more flexible, more adapted to certain design patterns and hence can be used in a higher-level way. Such an integration is not only possible, but can even be done in an optimized way, taking into account the specific structure of the collection traversed. A slight extension of existing class libraries can also be implemented that does not cause any compatibility problem and does not break existing code, but allows even further abstraction and makes it easier for the developer to use high-level, optimized, external iterators.
	Match-O, a Dialect of Eiffel with Match-Types. Dominique Colnet and Luigi Liquori. 35th conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'2000), IEEE Computer Society Sydney, Australia, November 2000, pages 190--201. Abstract: It is well known that the Eiffel language allows covariant redefinition. Regardless of system-level validity rules, Eiffel is not type safe. In this paper, we present a dialect of Eiffel called Match-O, which prohibits covariant redefinition. We introduce a new kind of types, the match-types, inspired by the papers of Kim Bruce. The scope of this project is many-fold: -- allowing binary methods; -- keeping sound ``mytype method specialization'', i.e. anchored type using `Current`; -- allowing subtyping in all other sound cases. We claim that match-types can be added in the Eiffel type system to eliminate type unsoundness without blocking many interesting Eiffel programs (e.g. the ones with ``binary methods''). We have implemented a compiler for Match-O and we have experimented our dialect on a large system using the original source code of SmallEiffel itself.
	Coping with aliasing in the GNU Eiffel Compiler implementation. Olivier Zendra and Dominique Colnet. Software Practice and Experience, 2001, Volume 31, No 6, pages 601-613 Abstract: This paper report our experience about aliasing usage in the implementation of SmallEiffel, the GNU Eiffel Compiler. The SmallEiffel compiler source code makes intensive use of aliasing in order to achieve very good performance both in terms of memory and execution time. Thanks to the design by contract capabilities of the Eiffel language, aliasing can be handled very safely. The singleton pattern appears to be crucial in implementing alias provider objects. We propose an efficient implementation of this pattern made easy by some Eiffel idioms. This technique, which requires no language modification, is very appropriate for compilation, but can also be applied to a wide range of applications.
	Lisaac: the power of simplicity at work for operating system. Benoīt Sonntag and Dominique Colnet. Proceedings of the fortieth conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific'2002), Sydney, Australia, February 2002, Australian Computer Society, pages 45-52, James Noble and John Potterm, Eds, Abstract: The design as well as the implementation of the Isaac operating system (http://www.isaacOS.com) led us to set up a new programming language named Lisaac. Many features from the Lisaac language come from the Self programming language. Comparing to Self's skills, Lisaac integrates communications protection mechanisms as well as other tools related to operating systems' design. System interruptions support as well as drivers memory mapping have been considered in the design of Lisaac. The use of prototypes and especially dynamic inheritance, fits a flexible operating system in the making. First benchmarks of our compiled objects show that it is possible to obtain high-level prototype-based language's executables as fast as C programs are.
	Reconciling Subtyping and Code Reuse in Object-Oriented Languages: Using `inherit` and `insert` in SmartEiffel, The GNU Eiffel Compiler. Dominique Colnet and Guillem Marpons and Frederic Merizen. Proceedings of the 9th International Conference on Software Reuse, Turin, june 2006, Lecture Notes in Computer Sciences, Springer-Verlag, Volume 4039, pages 203-216, ISBN 3-540-34606-6. Abstract: SmartEiffel has been enjoying two different mechanisms to express subtyping and implementation inheritance for one year. After large scale practical tests and thanks to user feedback, this paper finalises the new typing policy of SmartEiffel, which combines two forms of multiple inheritance with genericity in one statically-checked, object-oriented language. Having two forms of inheritance allows the designer to capture more design decisions in the source code. It is now straightforward to share reusable code between otherwise unrelated types. The new mechanism allows to reuse code from an existing class without polluting the reuser's interface. It also enables an elegant implementation of some design patterns. Furthermore, this mechanism helps compilers to statically remove more dynamic dispatch code. It can also be used to add a no-penalty and no-risk multiple-inheritance-like construct to a single-inheritance language such as Java.