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Thu 23 Jan 2020 14:21 - 14:43 at Ile de France II (IDF II) - Type Systems Chair(s): Peter Thiemann

Path dependent types have long served as an expressive component of the Scala programming language. They allow for the modelling of both bounded polymorphism and a degree of nominal subtyping. Nominality in turn provides the ability to capture first class modules. Thus a single language feature gives rise to a rich array of expressiveness. Recent work has proven path dependent types sound in the presence of both intersection and recursive types, but unfortunately typing remains undecidable, posing problems for programmers who rely on the results of type checkers. The Wyvern programming language is an object oriented language with path dependent types, recursive types and first class modules. In this paper we define two variants of Wyvern that feature decidable typing, along with machine checked proofs of decidability. Despite the restrictions, our approaches retain the ability to encode the parameteric polymorphism of Java generics along with many idioms of the Scala module system.

Thu 23 Jan

Displayed time zone: Saskatchewan, Central America change

14:00 - 15:05
Type SystemsResearch Papers at Ile de France II (IDF II)
Chair(s): Peter Thiemann University of Freiburg, Germany
14:00
21m
Talk
Undecidability of D<: and Its Decidable FragmentsDistinguished Paper
Research Papers
Jason Z.S. Hu McGill University, Ondřej Lhoták University of Waterloo
Link to publication DOI Media Attached File Attached
14:21
21m
Talk
Decidable Subtyping for Path Dependent Types
Research Papers
Julian Mackay Victoria University of Wellington, Alex Potanin Victoria University of Wellington, Jonathan Aldrich Carnegie Mellon University, Lindsay Groves Victoria University of Wellington
Link to publication DOI Media Attached
14:43
21m
Talk
Dependent Type Systems as Macros
Research Papers
Stephen Chang Northeastern University, Michael Ballantyne PLT @ Northeastern University, Milo Turner PLT @ Northeastern University, William J. Bowman University of British Columbia
Link to publication DOI Media Attached File Attached