Koka is a research programming language with algebraic effects and handlers, built by Leijen et al. Algebraic effects are a feature generalising exceptions, generators, and async/await. I like to think of them as resumable exceptions; precisely, they are delimited continuations.
Koka Zero is my implementation of a subset of Koka. It compiles to LLVM-IR, and its type system is based on algebraic subtyping, which provides precise subexpression effect information to the optimiser.
Use the language playground to explore algebraic effects by writing and running Koka Zero programs.