Returning lazy sequences-CodePudding

I have a lazy sequence I do some operations on and want to return from a function

func getSeq() -> ??? {
  let a = array.lazy
      ./* ... operations like map, filter, etc */
}

The final type of a is:

LazyMapSequence<FlattenSequence<LazyMapSequence<LazyFilterSequence<LazySequence<[[ComponentId] : ArchetypeId]>.Elements>.Elements, Zip2Sequence<Zip2Sequence<[C1], [C2]>, [C3]>>>, (C1, C2, C3)>

now how do I return a without having to specify the return type as that long type?

CodePudding user response：

Opaque result types exist for exactly this purpose. You can use them in conjunction with primary associated types.

You would say your function returns some Sequence<Element>