sum_double
Description:
Returns a collector that produces the sum of the given function applied to the elements. If there are no elements, the result is 0.
The result can vary because of accumulated rounding error.
The mapper function must not return null.
Parameters:
| mapper |
a mapping function |
Returns:
|
the collector implementation |
Namespace: Gpseq.Collectors
Package: gpseq-1.0