Method overloading and overriding cause encapsulation flaw: an experiment on assembly of heterogeneous components

ABSTRACT

Based on an experiment using three languages under .NET, this paper argues that the semantic differences between these languages regarding method overloading and overriding give rise to significant complexity and break encapsulation. We first recalls the various interpretations of overriding and overloading in object oriented languages through what we call language signatures. Then, we realize an experimentation with .NET components coded in different programming languages in order to observe the global behavior. From this, we show that overriding and overloading are not compatible with a key property of components: encapsulation. We conclude that, in the current state of the art, in order to build predictable assembly, components must expose their internal structure! We propose a solution to this problem.

REFERENCES

• 1: D. Ancona, S. Fagorzi, and E. Zucca. A calculus for dynamic linking. In Springer, editor, ICTCS'03 - Italian Conference on Theoretical Computer Science, Lecture Notes in Computer Science 2841, 2003.
• 2: D. Ancona and E. Zucca. Sound and complete inter-checking (the very essence of principal typings). Technical report, Universita di Genova, 2004.
• 3: A. Beugnard. Comparison of various oo languages relatively to their late-binding semantics. http://perso-info.enst-bretagne.fr/~beugnard/papiers/lb-sem.shtml.
• 4: A. Beugnard. OO languages late-binding signature. In FOOL 9 (The Ninth International Workshop on Foundations of Object-Oriented Languages), Portland, Oregon, January 19 2002.
• 5: Antoine Beugnard , Jean-Marc Jézéquel , Noël Plouzeau , Damien Watkins, Making Components Contract Aware, Computer, v.32 n.7, p.38-45, July 1999 [doi>10.1109/2.774917]
• 6: Martin Buchi , Wolfgang Weck, The Greybox Approach: When Blackbox Specifications Hide Too Much, Turku Centre for Computer Science, 1999
• 7: A. Capouillez, P. Crescenzo, and P. Lahire. Le modèle ofl au service du métaprogrammeur - application à java. L'objet, LMO'2002, pages 11--24, 8 2002.
• 8: Sophia Drossopoulou , Susan Eisenbach , David Wragg, A Fragment Calculus Towards a Model of Separate Compilation, Linking and Binary Compatibility, Proceedings of the 14th Annual IEEE Symposium on Logic in Computer Science, p.147, July 02-05, 1999
• 9: R. Ducournau. Spécialisation et sous-typage: thème et variations. Technique et Science Informatique, 21(10):1305--1342, 2002.
• 10: ECMA. Standard-ecma334, C# language specification. http://www.ecma-international.org/publications/standards/Ecma-334.htm.
• 11: M. D. McIlroy. Mass produced software components. In NATO Conference on Software Engineering, Garmisch, Germany, 1968.
• 12: B. Meyer. Overloading vs. object technology. Journal of Object-Oriented Programming, pages 3--7, October/November 2001.
• 13: Microsoft. Microsoft .NET. http://www.microsoft.com/net.
• 14: Microsoft Corporation, Microsoft® Visual Basic® .NET Language Reference, Microsoft Press, Redmond, WA, 2002
• 15: OMG. site mda. http://www.omg.org/mda.
• 16: Bjarne Stroustrup, The C++ Programming Language, Third Edition, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1997
• 17: Clemens Szyperski, Component software: beyond object-oriented programming, ACM Press/Addison-Wesley Publishing Co., New York, NY, 1998

INDEX TERMS

Primary Classification:
  D. Software
  D.1 PROGRAMMING TECHNIQUES
      D.1.5 Object-oriented Programming

Additional Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
        D.2.12 Interoperability
      D.2.3 Coding Tools and Techniques

Keywords:
encapsulation, objet oriented language interoperability, software component