import { scan as higherOrderScan } from '../operators/scan';
/* tslint:enable:max-line-length */
/**
* Applies an accumulator function over the source Observable, and returns each
* intermediate result, with an optional seed value.
*
* It's like {@link reduce}, but emits the current
* accumulation whenever the source emits a value.
*
*
*
* Combines together all values emitted on the source, using an accumulator
* function that knows how to join a new source value into the accumulation from
* the past. Is similar to {@link reduce}, but emits the intermediate
* accumulations.
*
* Returns an Observable that applies a specified `accumulator` function to each
* item emitted by the source Observable. If a `seed` value is specified, then
* that value will be used as the initial value for the accumulator. If no seed
* value is specified, the first item of the source is used as the seed.
*
* @example