Packages

•  package root

  Definition Classes

  root

•  package endpoints4s
  • algebras are in the algebra package,
  • interpreters are in the other packages (e.g., pekkohttp, http4s, openapi, etc.),
  • Types defined in this package are utility classes (e.g., Validated, Tupler).

  Definition Classes

  root

•  package algebra

  Algebra interfaces

  Algebra interfaces

  Definition Classes

  endpoints4s

•  trait JsonSchemas extends TuplesSchemas with PartialInvariantFunctorSyntax

  An algebra interface for describing algebraic data types.

  An algebra interface for describing algebraic data types. Such descriptions can be interpreted to produce a JSON schema of the data type, a JSON encoder, a JSON decoder, etc.

  A description contains the fields of a case class and their type, and the constructor names of a sealed trait.

  For instance, consider the following record type:

  case class User(name: String, age: Int)

  Its description is the following:

  object User {
    implicit val schema: JsonSchema[User] = (
      field[String]("name") zip
      field[Int]("age")
    ).xmap((User.apply _).tupled)(Function.unlift(User.unapply))
  }

  The description says that the record type has two fields, the first one has type String and is named “name”, and the second one has type Int and name “age”.

  To describe sum types you have to explicitly “tag” each alternative:

  sealed trait Shape
  case class Circle(radius: Double) extends Shape
  case class Rectangle(width: Double, height: Double) extends Shape
  
  object Shape {
    implicit val schema: JsonSchema[Shape] = {
      val circleSchema = field[Double]("radius").xmap(Circle)(Function.unlift(Circle.unapply))
      val rectangleSchema = (
        field[Double]("width") zip
        field[Double]("height")
      ).xmap((Rectangle.apply _).tupled)(Function.unlift(Rectangle.unapply))
      (circleSchema.tagged("Circle") orElse rectangleSchema.tagged("Rectangle"))
        .xmap[Shape] {
          case Left(circle) => circle
          case Right(rect)  => rect
        } {
          case c: Circle    => Left(c)
          case r: Rectangle => Right(r)
        }
    }
  }

  Definition Classes

  algebra

• Enum
• EnumOps
• InvariantFunctorSyntax
• JsonSchema
• JsonSchemaDocumentationOps
• JsonSchemaOps
• PartialInvariantFunctorSyntax
• Record
• RecordOps
• Tagged
• TaggedOps

endpoints4s.algebra.JsonSchemas

JsonSchemaOps