Subtyping constraints for incomplete objects

Extended abstract
  • Viviana Bono
  • Michele Bugliesi
  • Mariangiola Dezani-Ciancaglini
  • Luigi Liquori
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1214)


We extend the type system for the Lambda Calculus of Objects [14] to account for a notion of width subtyping. The main novelties over previous work are the use of bounded quantification to achieve a new and more direct rendering of MyType polymorphism, and a uniform treatment for other features that were accounted for via different systems in subsequent extensions [7, 6] of [14]. In particular, the new system provides for (i) appropriate type specialization of inherited methods, (ii) static detection of errors, (iii) width subtyping compatible with object extension, and (iv) complete freedom in the order of method addition.


Type System Method Addition Operational Semantic Typing Rule Object Extension 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Viviana Bono
    • 1
  • Michele Bugliesi
    • 2
  • Mariangiola Dezani-Ciancaglini
    • 1
  • Luigi Liquori
    • 1
  1. 1.Dip. InformaticaUniversità di TorinoTorinoItaly
  2. 2.Dip. MatematicaUniversità di PadovaPadovaItaly

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