External module "sinks/reduce"

reduce

• reduce<U, T>(o: Observable<T>, f: ScanFunc<U, T>, v0: U): Promise<U>

• Accumulates value, starting with v0 and applying f to each emitted item. If no items are emitted the promise is rejected.

  Type parameters

  • U

    Type of result returned from the accumulator.

  • T

    Type of items emitted by the observable.

  Parameters

  • o: Observable<T>

    Observable to reduce.

  • f: ScanFunc<U, T>

    Reduce function called with the accumulated value so far and the current item. Should return a new accumulated value.

  • v0: U

    Initial accumulator value.

  Returns Promise<U>

  Promise that resolves with the accumulated value.