Wed 17 Jun 2026 16:50 - 17:10 at Flatirons 4 - Type Systems Chair(s): Eleftherios Ioannidis

We introduce a type system that provides strong types for exception tracking in ML-style languages. Our type system employs a rich notion of row polymorphism and subtyping to ensure backwards compatibility, making sure that code without exception tracking continues to work and can be generalized gracefully to support exception tracking. We study the safety and abstraction guarantees of our type system, in particular the role of local exceptions for data abstraction. We formulate these claims using binary logical relations in a novel relational separation logic for exceptions, an independent contribution of this paper. We support a realistic subset of features from ML-style languages, such as extensible variant types, local exceptions, and concurrency. We exercise our type system and logic on a number of challenging examples taken from the OCaml standard library, from one of Jane Street's OCaml libraries, and from Filinski's PhD thesis. All our results are mechanized in the Rocq prover using Iris.

Wed 17 Jun

Displayed time zone: Mountain Time (US & Canada) change

16:10 - 17:50
Type SystemsPLDI Research Papers at Flatirons 4
Chair(s): Eleftherios Ioannidis Microsoft Research
16:10
20m
Talk
[SIGPLAN PLDI’25] Probabilistic Refinement Session Types
PLDI Research Papers
Qiancheng Fu Boston University, Ankush Das Boston University, Marco Gaboardi Boston University
16:30
20m
Talk
[SIGPLAN OOPSLA’25] Complete the Cycle: Reachability Types with Expressive Cyclic References
PLDI Research Papers
Haotian Deng Purdue University, Siyuan He Purdue University, Songlin Jia Purdue University, Yuyan Bao Augusta University, Tiark Rompf Purdue University
16:50
20m
Talk
Backwards-Compatible Row-Based Exceptions in ML
PLDI Research Papers
Simcha van Collem Radboud University Nijmegen, Paulo Emílio de Vilhena University of Surrey, Robbert Krebbers Radboud University Nijmegen
DOI
17:10
20m
Talk
Typestate via Revocable Capabilities
PLDI Research Papers
Songlin Jia Purdue University, Craig Liu Purdue University, Siyuan He Purdue University, Haotian Deng Purdue University, Yuyan Bao Augusta University, Tiark Rompf Purdue University
DOI
17:30
20m
Talk
Syntactic Implicit Parameters with Static Overloading
PLDI Research Papers
Daan Leijen Microsoft Research, Tim Whiting Brigham Young University
DOI Pre-print