distinctBy but with last element

[ckosmowski]

I am currently evaluating vavr as a replacement for Java 8 Streams. While processing batches of events we always want to keep the last value unique by some key. The semantics would be the same as

.reverse()
.dicstinctBy(e -> e.getSomeKey())
.reverse()

i think.

But i do think that this comes with performance hits. To achieve this we are using a LinkedHashMap where we put elements one after the other with their generated keys and afterwards get the .values() again from that map which will now contain only the last elements of each key.

Would you consider adding "distinctByLast" or as we call it "keepLast" ?

[pivovarit]

That sounds like a good idea :) I'd lean towards a new distinctByKeepLast method for the sake of backward compatibility. We could target 0.11 and 1.0