Safer Exceptions for Scala

by Martin Odersky, Aleksander Boruch-Gruszecki, Jonathan Immanuel Brachthäuser, Edward Lee, and Ondřej Lhoták

In Proceedings of the 12th ACM SIGPLAN International Symposium on Scala, pages 1–11. Association for Computing Machinery, 2021.

This publication is related to the Type- and Effect Systems research project.

Abstract

We describe a scheme for reflecting exceptions as capabilities in the Scala type system that keeps notational overhead to a minimum and avoids well-known problems with Java’s checked exceptions framework. The scheme makes exceptions safer but not fully safe since the capability for throwing an exception may still yet escape its enclosing try block. To address this limitation, we also propose a type system which prevents capabilities from escaping.

Citation as BibTeX

@inproceedings{odersky21safer,
  author = {Odersky, Martin and Boruch-Gruszecki, Aleksander and Brachthäuser, Jonathan Immanuel and Lee, Edward and Lhoták, Ondřej},
  title = {Safer Exceptions for Scala},
  year = {2021},
  isbn = {9781450391139},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  url = {https://doi.org/10.1145/3486610.3486893},
  doi = {10.1145/3486610.3486893},
  booktitle = {Proceedings of the 12th ACM SIGPLAN International Symposium on Scala},
  pages = {1–11},
  numpages = {11},
  keywords = {Scala, types, subtyping, effects, capture, references, exceptions, capabilities},
  location = {Chicago, IL, USA},
  series = {SCALA 2021}
}