map and null values

[Jed Wesley-Smith]

It should fairly clear by now that the decision to allow a null key
and null values in the Map interface was a mistake and should not be
continued. Null-intolerance – particularly now there is an Optional
class that solves partiality properly – is not only ok but should be
the default, promoted position.

Concurrency simply makes the overloading of null to mean something and
nothing more obviously absurd.

If we can agree that nulls should essentially be deprecated as a legal
value or key then we avoid all the complicated gymnastics this thread
shows are necessary to support them.

cheers,
jed.