Past Meetup

#10 Ben Darwin on Programming with Algebraic Effects and Handlers

This Meetup is past

38 people went

Location image of event venue


Important: please arrive before 7pm, which is when the front door locks! If you arrive after 7pm, use the keypad beside the outside door and buzz 8882 to be let in.


Ben will be presenting Programming with Algebraic Effects and Handlers ( by Andrej Bauer and Matija Pretnar.


Handlers for algebraic effects are a promising development in managing complexity in software. In addition to the prototypal implementation in Eff ( ), they've also been implemented variously as a Haskell library, in the experimental functional languages Idris, Koka, and F-star, and in an experimental branch of the Ocaml compiler ( ). I'll begin by looking for some intuitive motivation for the concept as a generalization of familiar ideas like exceptions. After looking at the syntax and semantics of the new constructs, we'll consider a number of examples (in Eff and/or Ocaml) from the paper including implementing probabilistic programming and thread scheduling. I'll briefly compare such effect systems against Haskell's monad transformers without getting into details of the latter.

Paper Link:

Doors open at 6:30 pm, presentation will begin at 7:00 pm. There will be food and refreshments provided by Shopify.


Ben Darwin is a programmer at Sick Kids Hospital's Mouse Imaging Centre.