Tomáš Petříček: The origins of Monadic and Comonadic Computations

The widely known 1991 paper by Eugenio Moggi “Notions of computation and monads” [1] was the first paper that suggested how monads could be used to model the semantics of effectful computations, which later lead to the famous use of monads in Haskell and other programming languages. The less widely known 2008 paper by Tarmo Uustalu and Varmo Vene “Comonadic Notions of Computation” [2] used the dual structure called “comonads” for modelling context-dependent computations – similarly intriguing idea that has not (yet) been integrated into a programming language.

In this talk, I’m going to introduce the two dual ideas and I’ll say a few things about their later use in programming languages – and I’ll also explain what are effectful and context-dependent computations (and why they matter). I will introduce the content from the papers without the heavy category theory, so the talk will be accessible to everyone. Hopefully, you’ll get enough so that you can continue and read the full papers on your own!

Bio: Tomáš is an open-source developer and computer scientist who enjoys combining theory and practice. On the practical side, he writes about F#, runs trainings and provide consulting via F# Works (http://fsharpworks.com/). On the theory side, he works on various programming language topics (http://tomasp.net/academic).

[1] http://dl.acm.org/citation.cfm?id=116984

[2] http://dl.acm.org/citation.cfm?id=1379918.1380266