s3json / s3j

Modern Scala 3 JSON library

s3j

s3j is a general-purpose JSON library for Scala 3, heavily focused on macros.

Goals

As JSON is a data exchange format, we define the term 'general purpose' as 'being able to easily interact with most remote systems', adapting to their serialization formats. Accordingly, this library specifies the following goals:

• Safety, mainly concerning the resilience to DoS attacks. It should not be possible for specially crafted inputs to cause significant performance degradation.
• Usability: there is no such thing as 'canonical JSON encoding'; every service is different. In some cases, JSON trees are more convenient than case classes. Sometimes case class has an untyped piece. More complex projects may require more fine-grained control over JSON serialization. Both the runtime code and the macro engine should be able to handle all of this.
• Composability: when some abstraction fails, it should be possible to dig one level down and implement your idea.
• Performance: the library should deliver the best possible performance at chosen abstraction level. However, it's not a goal to be the fastest library in the world and to count every femtosecond. Every abstraction comes with a price.

Usage

Full documentation is located at <TODO LINK HERE>. Here is just a quick example of library usage:

First, enable the library in your project:

// project/plugins.sbt
addSbtPlugin("io.s3j" % "s3j-sbt" % "VERSION")


// build.sbt
enablePlugins(S3jPlugin)

Then, use it in your code:

import s3j.*

object Test extends App {
  case class Foo(x: Int, y: String, z: Boolean) derives JsonFormat

  println(Foo(123, "test", z = true).toJsonString)
  // => {"x":123,"y":"test","z":true}

  println("""{ "x": 456, "y": "foo", "z": false }""".fromJson[Foo])
  // => Foo(456,foo,false)
}