Add additional data to the accumulator value.
Add additional data to the accumulator value. Is allowed to modify and return r
for efficiency (to avoid allocating objects).
the current value of the accumulator
the data to be added to the accumulator
the new value of the accumulator
Merge two accumulated values together.
Merge two accumulated values together. Is allowed to modify and return the first value for efficiency (to avoid allocating objects).
one set of accumulated data
another set of accumulated data
both data sets merged together
Return the "zero" (identity) value for an accumulator type, given its initial value.
Return the "zero" (identity) value for an accumulator type, given its initial value. For example, if R was a vector of N dimensions, this would return a vector of N zeroes.
Helper object defining how to accumulate values of a particular type. An implicit AccumulableParam needs to be available when you create Accumulables of a specific type.
the full accumulated data (result type)
partial data that can be added in