[POPL'26] Local Contextual Type Inference скачать в хорошем качестве

[POPL'26] Local Contextual Type Inference

Local Contextual Type Inference (Video, POPL 2026) Xu Xue, Chen Cui, Shengyi Jiang, Bruno C. d. S. Oliveira (University of Hong Kong, China; University of Hong Kong, China; University of Hong Kong, China; University of Hong Kong, China) Abstract: Type inference is essential for programming languages, yet complete and global inference quickly becomes undecidable in the presence of rich type systems like System~F. Pierce and Turner proposed local type inference (LTI) as a scalable, partially annotated alternative by relying on information local to applications. While LTI has been widely adopted in practice, there are significant gaps between theory and practice, with its theory being underdeveloped and specifications for LTI being complex and restrictive. We propose \emph{Local Contextual Type Inference}, a principled redesign of LTI grounded in contextual typing—a recent formalism which captures type information flow. We present \emph{Contextual System~F} (Fc), a variant of System~F with implicit and first-class polymorphism. We formalize Fc using a declarative type system, prove soundness, completeness, and decidability, and introduce matching subtyping as a bridge between declarative and algorithmic inference. This work offers the first mechanized treatment of LTI, while at the same time removing important practical restrictions and also demonstrating the power of contextual typing in designing robust, extensible and simple to implement type inference algorithms. Article: https://doi.org/10.1145/3776653 Supplementary archive: https://doi.org/10.5281/zenodo.17491013 (Badges: Artifacts Available, Artifacts Evaluated — Reusable) ORCID: https://orcid.org/0009-0008-2165-3330, https://orcid.org/0009-0002-8351-2679, https://orcid.org/0000-0002-4443-0753, https://orcid.org/0000-0002-1846-7210 Video Tags: Type Inference, Contextual Typing, Local Type Inference, doi:10.1145/3776653, doi:10.5281/zenodo.17491013, orcid:0009-0008-2165-3330, orcid:0009-0002-8351-2679, orcid:0000-0002-4443-0753, orcid:0000-0002-1846-7210, Artifacts Available, Artifacts Evaluated — Reusable Presentation at the POPL 2026 conference, Jan 11-17, 2026, https://popl26.sigplan.org/ Sponsored by ACM SIGPLAN.