Reusable Effects-Based Components
This OCaml library collects reusable effects-based components we have identified while developing our proof assistants based on algebraic effects.
Published: 07 Nov 2023
# 🦠 Reusable Effects-Based Components This library aims to collect reusable, general effects-based components we have seen when constructing our proof assistants using OCaml 5. All components here have appeared in various tutorials on algebraic effects; `algaeff` wraps these well-known components into an OPAM package. ## API Stability We use [semantic versioning.](https://semver.org/) Breaking changes will bump the major version number. ## Components - [Algaeff.State](https://redprl.org/algaeff/algaeff/Algaeff/State): mutable states - [Algaeff.Reader](https://redprl.org/algaeff/algaeff/Algaeff/Reader): read-only environments - [Algaeff.Sequencer](https://redprl.org/algaeff/algaeff/Algaeff/Sequencer): making a `Seq.t` - [Algaeff.Mutex](https://redprl.org/algaeff/algaeff/Algaeff/Mutex): simple locking to prevent re-entrance - [Algaeff.UniqueID](https://redprl.org/algaeff/algaeff/Algaeff/UniqueID): generating unique IDs Effects-based concurrency (cooperative lightweight threading) was already tackled by other libraries such as [Eio](https://github.com/ocaml-multicore/eio) and [Affect](https://erratique.ch/software/affect). This library focuses on the rest. There are a few other useful functions: - [Algaeff.Fun.Deep.finally](https://redprl.org/algaeff/algaeff/Algaeff/Fun/Deep/index.html#val-finally): call `continue` or `discontinue` accordingly. - [Algaeff.Fun.Shallow.finally_with](https://redprl.org/algaeff/algaeff/Algaeff/Fun/Shallow/index.html#val-finally_with): same as above, but for shallow effect handlers. ## How to Use It ### OCaml >= 5.0.0 You need OCaml 5. ### Example Code ```ocaml module S = Algaeff.State.Make (Int) let forty_two = S.run ~init:100 @@ fun () -> print_int (S.get ()); (* this will print out 100 *) S.set 42; S.get () ``` ### Documentation [Here is the API documentation.](https://redprl.org/algaeff/algaeff/Algaeff)