Method constructor

packages/db-ivm/src/operators/count.ts:11–25

(
    id: number,
    inputA: DifferenceStreamReader<[K, V]>,
    output: DifferenceStreamWriter<[K, number]>,
  )

 */
export class CountOperator<K, V> extends ReduceOperator<K, V, number> {
  constructor(
    id: number,
    inputA: DifferenceStreamReader<[K, V]>,
    output: DifferenceStreamWriter<[K, number]>,
  ) {
    const countInner = (vals: Array<[V, number]>): Array<[number, number]> => {
      let totalCount = 0
      for (const [_, diff] of vals) {
        totalCount += diff
      }
      return [[totalCount, 1]]
    }

    super(id, inputA, output, countInner)
  }
}

/**