Staging with Class: A Specification for Typed Template Haskell
Multi-stage programming using typed code quotation is an established technique for writing optimizing code generators with strong type-safety guarantees. Unfortunately, quotation in Haskell interacts poorly with type classes, making it difficult to write robust multi-stage programs.
We study this unsound interaction and propose a resolution, staged type class constraints, which we formalize in a source calculus λ^〚⇒〛 that elaborates into an explicit core calculus F^〚〛. We show type soundness of both calculi, establishing that well-typed, well-staged source programs always elaborate to well-typed, well-staged core programs, and prove beta and eta rules for code quotations.
Our design allows programmers to incorporate type classes into multi-stage programs with confidence. Although motivated by Haskell, it is also suitable as a foundation for other languages that support both overloading and quotation.
Thu 20 JanDisplayed time zone: Eastern Time (US & Canada) change
15:05 - 16:20
MetaprogrammingPOPL at Salon III
Chair(s): Stephanie Weirich University of Pennsylvania
|Staging with Class: A Specification for Typed Template HaskellInPerson|
Ningning Xie University of Cambridge, Matthew Pickering Well-Typed LLP, Andres Löh Well-Typed LLP, Nicolas Wu Imperial College London, Jeremy Yallop University of Cambridge, Meng Wang University of BristolDOI Media Attached
|Mœbius: Metaprogramming using Contextual Types: The Stage Where System F Can Pattern Match on ItselfRemote|
Junyoung Jang McGill University, Samuel Gélineau SimSpace, Stefan Monnier Université de Montréal, Brigitte Pientka McGill UniversityDOI Media Attached
|Type-Level Programming with Match TypesRemote|
Olivier Blanvillain EPFL, Jonathan Immanuel Brachthäuser University of Tübingen, Maxime Kjaer EPFL, Martin Odersky EPFLDOI Media Attached