# Uses of Interface
org.apache.storm.streams.operations.BiFunction

Packages that use BiFunction
Package
Description
org.apache.storm.streams
org.apache.storm.streams.operations

- ## Uses of BiFunction in org.apache.storm.streams

  Methods in org.apache.storm.streams with parameters of type BiFunction
  Modifier and Type
  Method
  Description
  `<R> Stream<R>`
  Stream.`aggregate(R initialValue, BiFunction<? super R,? super T,? extends R> accumulator, BiFunction<? super R,? super R,? extends R> combiner)`
  Aggregates the values in this stream using the given initial value, accumulator and combiner.
  `<R> PairStream<K,R>`
  PairStream.`aggregateByKey(R initialValue, BiFunction<? super R,? super V,? extends R> accumulator, BiFunction<? super R,? super R,? extends R> combiner)`
  Aggregates the values for each key of this stream using the given initial value, accumulator and combiner.
  `<R> StreamState<K,R>`
  PairStream.`updateStateByKey(R initialValue, BiFunction<? super R,? super V,? extends R> stateUpdateFn)`
  Update the state by applying the given state update function to the previous state of the key and the new value for the key.

- ## Uses of BiFunction in org.apache.storm.streams.operations

  Subinterfaces of BiFunction in org.apache.storm.streams.operations
  Modifier and Type
  Interface
  Description
  `interface`
  `Reducer<T>`
  The `Reducer` performs an operation on two values of the same type producing a result of the same type.
  Methods in org.apache.storm.streams.operations with parameters of type BiFunction
  Modifier and Type
  Method
  Description
  `static <T, R> CombinerAggregator<T,R,R>`
  CombinerAggregator.`of(R initialValue, BiFunction<? super R,? super T,? extends R> accumulator, BiFunction<? super R,? super R,? extends R> combiner)`
  A static factory to create a `CombinerAggregator` based on initial value, accumulator and combiner.
  `static <T, S> StateUpdater<T,S>`
  StateUpdater.`of(S initialValue, BiFunction<? super S,? super T,? extends S> stateUpdateFn)`
  A static factory to create a `StateUpdater` based on an initial value of the state and a state update function.