Yet another event streams library (signals3, v1.2.0)
Hey,
I've just published an update to an event streaming library I'm working on. It's called signals3 and its main purpose is to be a lightweight solution for distributing and processing data in Android apps and video games.
Which is exactly what Scala is not used for, I know ;) But once upon a time it was. signals3 is a rewrite + plus lots of additional functionality added to a codebase taken from Wire Android - an end-to-end encrypted messenger. The old version of its Android client was written in Scala 2.11 and published as open source. I worked on it 2017-2022 and later decided to rewrite a part of its functionality in Scala 3. So it might be claimed that signals3 is already battle-tested :)
Repo: https://github.com/makingthematrix/signals3
sbt: libraryDependencies += "io.github.makingthematrix" %% "signals3" % "1.2.0"
Anyway. The main idea here is that you can get events from different sources - be it the end user clicking and typing, the server, or the operating system, and you can easily create a chain of transformations that results in updates to the GUI, the database, or a request being sent back to the server. Streams and signals (i.e. streams with a cache for the last event) can be used pretty intuitively because their API is inspired by Scala standard collections library and comes with similarly working (and named) methods, as well as the support for the for/yield syntax. You can think of them as collections that are possibly infinite and accessing the next element is asynchronous and you might need to wait, but otherwise it's (almost) like standard collections.
v1.2.0 comes with the support for virtual threads, fallback strategy (i.e. what to do when a transformation throws an exception), support for Java's try-with-resources, should you ever need it, and stream "chaining" and decomposition with the `::` operator.
On top of that, there are lots of tests and documentation, so if you want to learn about event streams, you can clone the repo and experiment with it. It might actually make sense to treat v1.2.0 this way, as it's a non-LTS version (I use Scala 3.8.4). The next LTS version will be 1.3.0, but I want to wait till Scala 3.9 comes out. That also should give me enough time to add lightweight actors to the library :)