Packages

  • package root
    Definition Classes
    root
  • package endpoints4s

    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

implicit final class JsonSchemaOps[A] extends JsonSchemaDocumentationOps[A]

Implicit methods for values of type JsonSchema

Source
JsonSchemas.scala
Linear Supertypes
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  2. By Inheritance
Inherited
  1. JsonSchemaOps
  2. JsonSchemaDocumentationOps
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new JsonSchemaOps(schemaA: JsonSchema[A])

Type Members

  1. type Self = JsonSchema[A]

Value Members

  1. def orFallbackTo[B](schemaB: JsonSchema[B]): JsonSchema[Either[A, B]]

    A schema that can be either schemaA or schemaB.

    A schema that can be either schemaA or schemaB.

    • Encoder interpreters forward to schemaA to encode a Left value or schemaB to encode a Right value,
    • Decoder interpreters first try to decode with schemaA, and fallback to schemaB in case of failure,
    • Documentation interpreter produce a oneOf JSON schema.

    The difference between this operation and the operation orElse on “tagged” schemas is that this operation does not rely on a discriminator field between the alternative schemas. As a consequence, decoding is slower than with “tagged” schemas and provides less precise error messages.

    schemaB

    fallback schema

    Note

    Be careful to use disjoint schemas for A and B (none must be a subtype of the other), otherwise, a value of type B might also be successfully decoded as a value of type A, and this could have surprising consequences.

  2. def withDescription(description: String): JsonSchema[A]

    Include a description of what this schema represents

    Include a description of what this schema represents

    • Encoder and decoder interpreters ignore this description,
    • Documentation interpreters can show this description.
    description

    information about the values described by the schema

    Definition Classes
    JsonSchemaOpsJsonSchemaDocumentationOps
  3. def withExample(example: A): JsonSchema[A]

    Include an example of value in this schema

    Include an example of value in this schema

    • Encoder and decoder interpreters ignore this value,
    • Documentation interpreters can show this example value.
    example

    Example value to attach to the schema

    Definition Classes
    JsonSchemaOpsJsonSchemaDocumentationOps
  4. def withTitle(title: String): JsonSchema[A]

    Include a title for the schema

    Include a title for the schema

    • Encoder and decoder interpreters ignore the title,
    • Documentation interpreters can show this title.
    title

    short title to attach to the schema

    Definition Classes
    JsonSchemaOpsJsonSchemaDocumentationOps