reserve records when fun(T) == true
reserve records when fun(T) == true
the filter
a new stream after filter
convert a value[T] to a list of value[R]
convert a value[T] to a list of value[R]
function
the description message for this operation
a new stream with type [R]
Group by fun(T)
Group by fun(T)
For example, we have T type, People(name: String, gender: String, age: Int) groupBy[People](_.gender) will group the people by gender.
You can append other combinators after groupBy
For example,
Stream[People].groupBy(_.gender).flatmap(..).filter.(..).reduce(..)
group by function
parallelism level
the description
the grouped stream
Log to task log file
convert value[T] to value[R]
convert value[T] to value[R]
function
a new stream with type [R]
Merge data from two stream into one
Merge data from two stream into one
the other stream
the merged stream
connect with a low level Processor(TaskDescription)
connect with a low level Processor(TaskDescription)
a user defined processor
parallelism level
new stream after processing with type [R]
Reduce opeartion
Reduce opeartion
reduction function
description message for this operator
a new stream after reduction