Trait/Object

shapeless

Coproduct

Related Docs: object Coproduct | package shapeless

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sealed trait Coproduct extends Product with Serializable

Encodes a coproduct type, such as a sealed family of case classes.

Each constructor from the family gets an encoding in terms of nested Inr and Inl.

Which constructor is encoded as Inl() and which as Inr(Inl()) is determined by lexical order of the subclasses. This example illustrates the encoding:

scala> sealed trait Animal
defined trait Animal

scala> case class Cat(name: String, livesLeft: Int) extends Animal
defined class Cat

scala> case class Dog(name: String, bonesBuried: Int) extends Animal
defined class Dog

scala> case class Koala(name: String, leavesEaten: Int) extends Animal
defined class Koala

scala> case class Sloth(name: String, daysToClimbDownFromCurrentTree: Int) extends Animal
defined class Sloth

scala> val garfield = Cat("Garfield", 9)
garfield: Cat = Cat(Garfield,9)

scala> val odie = Dog("Odie", 3)
odie: Dog = Dog(Odie,3)

scala> val koala = Koala("foo", 10)
koala: Koala = Koala(foo,10)

scala> val sloth = Sloth("bar", 2)
sloth: Sloth = Sloth(bar,2)

scala> val genAnimal = Generic[Animal]
genAnimal: shapeless.Generic[Animal]{type Repr = Cat :+: Dog :+: Koala :+: Sloth} = ...

scala> def showCoproduct(o: Any) : String = o match {
     | case Inl(a) => "Inl(" + showCoproduct(a) + ")"
     | case Inr(a) => "Inr(" + showCoproduct(a) + ")"
     | case a => a.toString
     | }
showCoproduct: (o: Any)String

scala> showCoproduct(genAnimal.to(garfield))
res5: String = Inl(Cat(Garfield,9))

scala> showCoproduct(genAnimal.to(odie))
res6: String = Inr(Inl(Dog(Odie,3)))

scala> showCoproduct(genAnimal.to(koala))
res7: String = Inr(Inr(Inl(Koala(foo,10))))

scala> showCoproduct(genAnimal.to(sloth))
res8: String = Inr(Inr(Inr(Inl(Sloth(bar,2)))))

scala>
Linear Supertypes
Serializable, Serializable, Product, Equals, AnyRef, Any
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Inherited
  1. Coproduct
  2. Serializable
  3. Serializable
  4. Product
  5. Equals
  6. AnyRef
  7. Any
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Abstract Value Members

  1. abstract def canEqual(that: Any): Boolean

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    Definition Classes
    Equals
  2. abstract def productArity: Int

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    Definition Classes
    Product
  3. abstract def productElement(n: Int): Any

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    Definition Classes
    Product

Concrete Value Members

  1. final def !=(arg0: Any): Boolean

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    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

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    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean

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    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0

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    Definition Classes
    Any
  5. def clone(): AnyRef

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  6. final def eq(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef
  7. def equals(arg0: Any): Boolean

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    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  9. final def getClass(): Class[_]

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    Definition Classes
    AnyRef → Any
  10. def hashCode(): Int

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    Definition Classes
    AnyRef → Any
  11. final def isInstanceOf[T0]: Boolean

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    Definition Classes
    Any
  12. final def ne(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef
  13. final def notify(): Unit

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    Definition Classes
    AnyRef
  14. final def notifyAll(): Unit

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    Definition Classes
    AnyRef
  15. def productIterator: Iterator[Any]

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    Definition Classes
    Product
  16. def productPrefix: String

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    Definition Classes
    Product
  17. final def synchronized[T0](arg0: ⇒ T0): T0

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    Definition Classes
    AnyRef
  18. def toString(): String

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    Definition Classes
    AnyRef → Any
  19. final def wait(): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  20. final def wait(arg0: Long, arg1: Int): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  21. final def wait(arg0: Long): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from Serializable

Inherited from Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

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