Tabulators, reducers, etc

[Remi Forax]

On 12/31/2012 07:08 PM, Brian Goetz wrote:
>> One option might be: use "reduce" for the purely functional forms, use
>> accumulate/accumulateConcurrent for the others:
>>
>>      T reduce(T zero, BinaryOperator<T> reducer);
>>      Optional<T> reduce(BinaryOperator<T> reducer);
>>      <U> U reduce(U zero, BiFunction<U, T, U> accumulator,
>> BinaryOperator<U> reducer);
>>
>>      <R> R accumulate(Accumulator<T, R> reducer);
>>      <R> R accumulate(Supplier<R> seedFactory,
>>                       BiBlock<R, T> accumulator,
>>                       BiBlock<R, R> reducer);
>>
>>      <R> R accumulateConcurrent(ConcurrentAccumulator<T, R> tabulator);
>>
>>    This would let us get rid of the Tabulator abstraction (it is
>> identical to MutableReducer; both get renamed to Accumulator).
>> Separately, with a small crowbar, we could simplify
>> ConcurrentAccumulator down to fitting into existing SAMs, and the
>> top-level abstraction could go away.
>
> While the concurrent use case is clearly the odd man out here -- 
> suggesting more work is left to do on this -- the rest of it seems an 
> improvement on what we have now.  I would like to move forward with 
> this while we continue to work out the correct set of canned 
> accumulators and the correct way to surface concurrent accumulation.

while do you want to surface concurrent accumulator given that we have 
forEach ??

Rémi