Question

Anyone know if Guava has an equivalent version to Functionaljava’s HashMap?

Answer 1

As far as I know, no.

But you can wrap all your keys in Equivalence.Wrapper instances using the Equivalence strategy you need:

Equivalence<K> equiv = ...
Map<Equivalence.Wrapper<K>, V> map = ...

map.put(equiv.wrap(key), value);

Of course this means you need an additional object for every entry in your map. Thus I think a map implementation like you suggest would be nice to have.