Interface CoProduct3<A, B, C, CP3 extends CoProduct3<A,B,C,?>>

Type Parameters:
A - the first possible type
B - the second possible type
C - the third possible type
CP3 - the recursive type of this coproduct (used for embedding)
All Known Implementing Classes:
Choice3, Choice3._A, Choice3._B, Choice3._C, ComparisonRelation, ComparisonRelation.Equal, ComparisonRelation.GreaterThan, ComparisonRelation.LessThan, These, These._A, These._B, These.Both
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface CoProduct3<A, B, C, CP3 extends CoProduct3<A,B,C,?>>
A generalization of the coproduct of three types.
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    default CoProduct2<A, B, ? extends CoProduct2<A,B,?>>
    converge(Fn1<? super C, ? extends CoProduct2<A,B,?>> convergenceFn)
    Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type.
    default <D> CoProduct4<A, B, C, D, ? extends CoProduct4<A,B,C,D,?>>
    diverge()
    Diverge this coproduct by introducing another possible type that it could represent.
    default <R> R
    embed(Fn1<? super CP3, ? extends R> aFn, Fn1<? super CP3, ? extends R> bFn, Fn1<? super CP3, ? extends R> cFn)
    Embed this coproduct inside another value; that is, given morphisms from this coproduct to R, apply the appropriate morphism to this coproduct as a whole.
    <R> R
    match(Fn1<? super A, ? extends R> aFn, Fn1<? super B, ? extends R> bFn, Fn1<? super C, ? extends R> cFn)
    Type-safe convergence requiring a match against all potential types.
    default Product3<Maybe<A>,Maybe<B>,Maybe<C>>
    project()
    Project this coproduct onto a product.
    default Maybe<A>
    projectA()
    Convenience method for projecting this coproduct onto a product and then extracting the first slot value.
    default Maybe<B>
    projectB()
    Convenience method for projecting this coproduct onto a product and then extracting the second slot value.
    default Maybe<C>
    projectC()
    Convenience method for projecting this coproduct onto a product and then extracting the third slot value.

  • Method Details

    • match

      <R> R match(Fn1<? super A, ? extends R> aFn, Fn1<? super B, ? extends R> bFn, Fn1<? super C, ? extends R> cFn)
      Type-safe convergence requiring a match against all potential types.
      Type Parameters:
      R - result type
      Parameters:
      aFn - morphism A -> R
      bFn - morphism B -> R
      cFn - morphism C -> R
      Returns:
      the result of applying the appropriate morphism to this coproduct's unwrapped value
      See Also:

    • diverge

      default <D> CoProduct4<A, B, C, D, ? extends CoProduct4<A,B,C,D,?>> diverge()
      Diverge this coproduct by introducing another possible type that it could represent.
      Type Parameters:
      D - the additional possible type of this coproduct
      Returns:
      a CoProduct4<A, B, C, D>
      See Also:

    • converge

      default CoProduct2<A, B, ? extends CoProduct2<A,B,?>> converge(Fn1<? super C, ? extends CoProduct2<A,B,?>> convergenceFn)
      Converge this coproduct down to a lower order coproduct by mapping the last possible type into an earlier possible type. This is the categorical dual of CoProduct2.diverge(), which introduces the type C and raises the order from 2 to 3.

      The following laws hold for any two coproducts of single order difference:

      • Cancellation: coProductN.diverge().converge(CoProductN::a) == coProductN
      Parameters:
      convergenceFn - function from last possible type to earlier type
      Returns:
      a CoProduct2<A, B>

    • project

      default Product3<Maybe<A>,Maybe<B>,Maybe<C>> project()
      Project this coproduct onto a product.
      Returns:
      a product of the coproduct projection
      See Also:

    • projectA

      default Maybe<A> projectA()
      Convenience method for projecting this coproduct onto a product and then extracting the first slot value.
      Returns:
      an optional value representing the projection of the "a" type index

    • projectB

      default Maybe<B> projectB()
      Convenience method for projecting this coproduct onto a product and then extracting the second slot value.
      Returns:
      an optional value representing the projection of the "b" type index

    • projectC

      default Maybe<C> projectC()
      Convenience method for projecting this coproduct onto a product and then extracting the third slot value.
      Returns:
      an optional value representing the projection of the "c" type index

    • embed

      default <R> R embed(Fn1<? super CP3, ? extends R> aFn, Fn1<? super CP3, ? extends R> bFn, Fn1<? super CP3, ? extends R> cFn)
      Embed this coproduct inside another value; that is, given morphisms from this coproduct to R, apply the appropriate morphism to this coproduct as a whole. Like match(Fn1, Fn1, Fn1), but without unwrapping the value.
      Type Parameters:
      R - result type
      Parameters:
      aFn - morphism A v B v C -> R, applied in the A case
      bFn - morphism A v B v C -> R, applied in the B case
      cFn - morphism A v B v C -> R, applied in the C case
      Returns:
      the result of applying the appropriate morphism to this coproduct