The Scala Toolkit

What else can uPickle do?

Language

    Using Scala CLI, you can require the entire toolkit in a single line:

    //> using toolkit latest

    Alternatively, you can require just a specific version of UPickle:

    //> using dep com.lihaoyi::upickle:3.1.0

    In your build.sbt file, you can add the dependency on the Toolkit:

    lazy val example = project.in(file("."))
  .settings(
    scalaVersion := "3.3.4",
    libraryDependencies += "org.scala-lang" %% "toolkit" % "0.1.7"
  )

    Alternatively, you can require just a specific version of UPickle:

    libraryDependencies += "com.lihaoyi" %% "upickle" % "3.1.0"

    In your build.sc file, you can add the dependency to the upickle library:

    object example extends ScalaModule {
  def scalaVersion = "3.3.4"
  def ivyDeps =
    Agg(
      ivy"org.scala-lang::toolkit:0.1.7"
    )
}

    Alternatively, you can require just a specific version of UPickle:

    ivy"com.lihaoyi::upickle:3.1.0"

    Construct a new JSON structure with uJson

    val obj: ujson.Value = ujson.Obj(
  "library" -> "upickle",
  "versions" -> ujson.Arr("1.6.0", "2.0.0", "3.1.0"),
  "documentation" -> "https://com-lihaoyi.github.io/upickle/",
)

    Learn more about constructing JSON in the uJson documentation.

    Defining custom JSON serialization

    You can customize the ReadWriter of your data type by mapping the ujson.Value, like this:

    import upickle.default._

case class Bar(i: Int, s: String)

object Bar {
  implicit val barReadWriter: ReadWriter[Bar] = readwriter[ujson.Value]
    .bimap[Bar](
      x => ujson.Arr(x.s, x.i),
      json => new Bar(json(1).num.toInt, json(0).str)
    )
}

val bar = Bar(5, "bar")
val json = upickle.default.write(bar)
println(json)
// prints: [5, "bar"]

    import upickle.default.*

case class Bar(i: Int, s: String)

object Bar:
  given ReadWriter[Bar] = readwriter[ujson.Value]
    .bimap[Bar](
      x => ujson.Arr(x.s, x.i),
      json => new Bar(json(1).num.toInt, json(0).str)
    )

val bar = Bar(5, "bar")
val json = upickle.default.write(bar)
println(json)
// prints: [5, "bar"]

    Learn more about custom JSON serialization in the uPickle documentation.

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