SPLASH 2023
Sun 22 - Fri 27 October 2023 Cascais, Portugal
Thu 26 Oct 2023 15:12 - 15:30 at Room I - type systems 2 Chair(s): Max S. New

Creating good type error messages for constraint-based type inference systems is difficult. Typical type error messages reflect implementation details of the underlying constraint-solving algorithms rather than the specific factors leading to type mismatches. We propose using subtyping constraints that capture data flow to classify and explain type errors. Our algorithm explains type errors as faulty data flows, which programmers are already used to reasoning about, and illustrates these data flows as sequences of relevant program locations. We show that our ideas and algorithm are not limited to languages with subtyping, as they can be readily integrated with Hindley-Milner type inference. In addition to these core contributions, we present the results of a user study to evaluate the quality of our messages compared to other implementations. While the quantitative evaluation does not show that flow-based messages improve the localization or understanding of the causes of type errors, the qualitative evaluation suggests a real need and demand for flow-based messages.

Thu 26 Oct

Displayed time zone: Lisbon change

14:00 - 15:30
type systems 2OOPSLA at Room I
Chair(s): Max S. New University of Michigan
14:00
18m
Talk
Greedy Implicit Bounded Quantification
OOPSLA
Chen Cui University of Hong Kong, Shengyi Jiang University of Hong Kong, Bruno C. d. S. Oliveira University of Hong Kong
DOI
14:18
18m
Talk
Structural Subtyping as Parametric Polymorphism
OOPSLA
Wenhao Tang University of Edinburgh, Daniel Hillerström Huawei Zurich Research Center, James McKinna Heriot-Watt University, Michel Steuwer TU Berlin; University of Edinburgh, Ornela Dardha University of Glasgow, Rongxiao Fu University of Edinburgh, Sam Lindley University of Edinburgh
DOI Pre-print
14:36
18m
Talk
Simple Reference Immutability for System F<:
OOPSLA
Edward Lee University of Waterloo, Ondřej Lhoták University of Waterloo
DOI
14:54
18m
Talk
Mutually Iso-Recursive Subtyping
OOPSLA
Andreas Rossberg Independent
DOI
15:12
18m
Talk
Getting into the Flow: Towards Better Type Error Messages for Constraint-Based Type Inference
OOPSLA
Ishan Bhanuka Hong Kong University of Science and Technology, Lionel Parreaux Hong Kong University of Science and Technology, David Binder University of Tübingen, Jonathan Immanuel Brachthäuser University of Tübingen
DOI Pre-print