Reference Mutability for DOT

Authors Vlastimil Dort , Ondřej Lhoták

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Author Details

Vlastimil Dort
  • Charles University, Prague, Czech Republic
Ondřej Lhoták
  • University of Waterloo, Canada

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Vlastimil Dort and Ondřej Lhoták. Reference Mutability for DOT. In 34th European Conference on Object-Oriented Programming (ECOOP 2020). Leibniz International Proceedings in Informatics (LIPIcs), Volume 166, pp. 18:1-18:28, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Reference mutability is a type-based technique for controlling mutation that has been thoroughly studied in Java. We explore how reference mutability interacts with the features of Scala by adding it to the Dependent Object Types (DOT) calculus. Our extension shows how reference mutability can be encoded using existing Scala features such as path-dependent, intersection, and union types. We prove type soundness and the immutability guarantee provided by our calculus.

Subject Classification

ACM Subject Classification
  • Software and its engineering → Formal language definitions
  • Software and its engineering → Object oriented languages
  • Reference Mutability
  • Read-only References
  • DOT Calculus


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