BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Andrej Bauer (University of Ljubljana) DTSTART:20201007T140000Z DTEND:20201007T150000Z DTSTAMP:20260423T021137Z UID:OWLS/7 DESCRIPTION:Title: Eff ects in the real world\nby Andrej Bauer (University of Ljubljana) as p art of Online Worldwide Seminar on Logic and Semantics (OWLS)\n\n\nAbstrac t\nJoint work with Danel Ahman\, University of Ljubljana (https://danel.ah man.ee/).\n\nIn modern languages\, computational effects are often structu red using monads or algebraic effects and handlers. These mechanisms excel at implementation of computational effects within the language itself. Fo r instance\, the familiar implementation of mutable state in terms of stat e-passing functions requires no native state\, and can be implemented eith er as a monad or using handlers. One is naturally drawn to using these tec hniques also for dealing with actual effects\, such as manipulation of nat ive memory and access to hardware. These are represented inside the langua ge as algebraic operations or a monad\, but treated specially by the langu age's top-level runtime\, which invokes corresponding operating system fun ctionality. While this approach works in practice\, one wishes that the in genuity of the language implementors were better supported by a more flexi ble methodology with a sound theoretical footing.\n\nWe address the issue by showing how to design a programming language based on runners of algebr aic effects. We review runners\, recast them as a programming construct\, and present a calculus that captures the core ideas of programming with th em. Through examples of runners we show how they capture both the interact ion between the program and the external world\, and encapsulation of prog rams in virtual environments that tightly control access to external resou rces and provide strong guarantees of proper resource finalization.\n\nWe accompanied our work with a prototype programming language Coop (https://g ithub.com/andrejbauer/coop) and a Haskell library for runners (https://git hub.com/danelahman/haskell-coop).\n\nReferences:\n\n - https://arxiv.org/a bs/1910.11629\n\n - https://github.com/andrejbauer/coop\n\n - https://gith ub.com/danelahman/haskell-coop\n LOCATION:https://researchseminars.org/talk/OWLS/7/ END:VEVENT END:VCALENDAR