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Combining structural subtyping and external dispatch

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OOPSLA '07: Companion to the 22nd ACM SIGPLAN conference on Object-oriented programming systems and applications companion

Pages 951 - 952

https://doi.org/10.1145/1297846.1297961

Published: 20 October 2007 Publication History

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Abstract

By-name subtyping (or user-defined subtyping) and structural subtyping each have their own strengths and weaknesses. By-name subtyping allows programmers to explicitly express design intent, and, when types are associated with run time tags, enables run-time "type" tests and external/multimethod dispatch. On the other hand, structural subtyping is flexible and compositional, allowing unanticipated reuse. To date, nearly all object-oriented languages fully support only one subtyping paradigm or the other.

I propose a language that combines the key aspects of by-name and structural subtyping in a unified framework. The goal is to provide the flexibility of structural subtyping while still allowing static typechecking of external methods. The work offers a clean foundation for the designof future languages that enjoy the benefits of both by-name and structural subtyping.

I also propose a language extension to Java that combines by-name and structural subtyping, and includes parametric polymorphism. The practical utility of this language will be illustrated through case studies that show that code written in the new language is more flexible and easier to modify than the original code.

References

[1]

Grzegorz Czajkowski, Laurent Dayn`es, and Ben Titzer. A multi-user virtual machine. In Proceedings of the General Track: 2003 USENIX Annual Technical Conference, pages 85--98, San Antonio, Texas, USA, June 2003. USENIX.

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[2]

Galen Hunt et al. An overview of the Singularity project. Microsoft Research Technical Report MSR-TR-2005-135 MSR-TR-2005-135, Microsoft Research, 2005.

Google Scholar

[3]

Georgios Gousios. Jikesnode: A Java operating system. Master's thesis, University of Manchester, September 2004.

Google Scholar

[4]

Matthew Hertz, Yi Feng, and Emery D. Berger. Garbage collection without paging. In PLDI '05: Proceedings of the 2005 ACM SIGPLAN conference on Programming language design and implementation, pages 143--153, New York, NY, USA, 2005. ACM Press.

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Malayeri DAldrich J(2008)Integrating Nominal and Structural SubtypingProceedings of the 22nd European conference on Object-Oriented Programming10.1007/978-3-540-70592-5_12(260-284)Online publication date: 7-Jul-2008
https://dl.acm.org/doi/10.1007/978-3-540-70592-5_12
Reppy JTuron A(2007)Metaprogramming with TraitsECOOP 2007 – Object-Oriented Programming10.1007/978-3-540-73589-2_18(373-398)Online publication date: 2007
https://doi.org/10.1007/978-3-540-73589-2_18

Index Terms

Combining structural subtyping and external dispatch
1. Software and its engineering
  1. Software notations and tools
    1. General programming languages
      1. Language features

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Published In

OOPSLA '07: Companion to the 22nd ACM SIGPLAN conference on Object-oriented programming systems and applications companion

October 2007

241 pages

ISBN:9781595938657

DOI:10.1145/1297846

General Chair:
Richard P. Gabriel
IBM Research, USA
,
Program Chairs:
David F. Bacon
IBM Research, USA
,
Cristina Videira Lopes
University of California, Irvine, USA
,
Guy L. Steele
Sun Labs, USA

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected]

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Association for Computing Machinery

New York, NY, United States

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Published: 20 October 2007

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OOPSLA07: ACM SIGPLAN Object Oriented Programming Systems and Applications Conference

October 21 - 25, 2007

Quebec, Montreal, Canada

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Malayeri DAldrich J(2008)Integrating Nominal and Structural SubtypingProceedings of the 22nd European conference on Object-Oriented Programming10.1007/978-3-540-70592-5_12(260-284)Online publication date: 7-Jul-2008
https://dl.acm.org/doi/10.1007/978-3-540-70592-5_12
Reppy JTuron A(2007)Metaprogramming with TraitsECOOP 2007 – Object-Oriented Programming10.1007/978-3-540-73589-2_18(373-398)Online publication date: 2007
https://doi.org/10.1007/978-3-540-73589-2_18

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