RFR(m): 8139233 add initial compact immutable collection implementations

[Alan Bateman]

On 04/05/2016 05:55, Stuart Marks wrote:
> Hi all,
>
> This is a reimplementation of collections created by the JEP 269 
> convenience factory methods. These implementations are overall quite a 
> bit smaller than their conventional collections counterparts, 
> particularly at small sizes. Lookup performance for the hash-based 
> structures (Set and Map) is not particularly fast, though in most 
> cases it's comparable to TreeSet/TreeMap. Further improvements are 
> likely possible.
>
> There are no API changes in this changeset.
>
> Please review:
>
>     http://cr.openjdk.java.net/~smarks/reviews/8139233/webrev.0/
This looks very good, but I just wonder about the iteration order 
varying from run to run in the Set/Map implementations. I recall the 
section added to the javadoc where it made it very clear that the 
iteration order is unspecified and subject to change and no issue with 
that. I'm just thinking about troubleshooting scenarios where it could 
make some issue harder to diagnose.

-Alan