groupingByConcurrent javadoc shows an example use that does not require a map factory

[Brian Goetz]

Ah, OK.  It should be ConcurrentSkipListMap (the concurrent Map impl 
with sorted keys.)

On 6/17/2013 8:11 PM, Arul Dhesiaseelan wrote:
> Ok, this example fails to compile in build 94 with incompatible types
> error, since TreeMap is not a ConcurrentMap, so this example still needs
> correction, no?
>
> java: incompatible types: Cannot instantiate inference variables T
> because of an inference loop
>
>
> On Mon, Jun 17, 2013 at 1:21 PM, Brian Goetz <brian.goetz at oracle.com
> <mailto:brian.goetz at oracle.com>> wrote:
>
>     No, the default factory is HashMap::new.  This asks for a TreeMap,
>     which has the additional property of having a sorted encounter order
>     for keys.
>
>
>     On 6/17/2013 7:13 PM, Arul Dhesiaseelan wrote:
>
>         Looks like this example in Collectors javadoc needs to be
>         corrected for
>         groupingByConcurrent that does not take a map factory?
>
>                     ConcurrentMap<City, Set<String>> namesByCity
>                         =
>         people.stream().collect(__groupingByConcurrent(Person::__getCity, TreeMap::new,
>
>            mapping(Person::getLastName, toSet())));
>
>         map factory should not be included in this example, as it uses
>         the default
>         factory.
>
>         - Arul
>
>