RFR 8071600: Add a flat-mapping collector

[Paul Sandoz]

On Feb 12, 2015, at 3:33 PM, Chris Hegarty <chris.hegarty at oracle.com> wrote:

> On 3 Feb 2015, at 13:48, Paul Sandoz <paul.sandoz at oracle.com> wrote:
> 
>> Hi,
>> 
>> http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8071600-Collector-flatMapping/webrev/
> 
> Looks like a useful addition.
> 

Thanks.


> Trivially, the handling of null caught my eye: "If a mapped stream is {@code null} an empty stream is used, instead.”  It looks like the result of the mapper function returning null is equivalent to it returning an empty stream, but I’m not sure that I see an empty stream being used in the implementation.

Right, and the caller cannot tell the difference, since in either case no elements will be pushed downstream.


> Is this just a convenience, for implementers of the mapping function? 
> 

Yes, the sentence makes most sense in the context of what comes before it.

Paul.