Biggest use case is definitely when creating different histograms from the same dataset. Our friends in sci-py land spend A LOT of time doing this. Our R friends also use this frequently.
I can imagine this bag implementation would not just be good for Collections, but would play well with the Collectors framework, as well as Gatherers. On Sat, Apr 20, 2024 at 5:57 PM Holo The Sage Wolf <holo3...@gmail.com> wrote: > By "ordered collection" you mean "unordered collection"? > > How common is it to actually use a multiset in general? Of course there > are use cases, and there are areas in which it is used a lot, but I don't > believe it is common enough to be part of the std with the one exception of > concurrent bag. > > On Sat, 20 Apr 2024, 23:25 ІП-24 Олександр Ротань, < > rotan.olexa...@gmail.com> wrote: > >> In this letter I would like to express some of my thoughts regarding the >> potential Multiset interface. >> >> I, personally, have encountered a few situations where such an interface >> could come in handy, mostly when I needed an ordered collection that >> permits duplicates. That time I used guava`s TreeMultiset, but I think Java >> itself should have such a collection in its std library. While it is not a >> very common problem, there are still a bunch of use cases where such things >> could come in handy. >> >> I am willing to take on development of such thing, but there are a few >> concerns about Multiset: >> >> 1. Is there any other use for this besides ordered collection that >> permits duplicates? I can't remember anything else from the top of my head. >> >> 2. Guava's TreeMultiset class hierarchy pretty much imitates TreeSet >> class hierarchy, while not being directly connected. I think introducing >> any other ordered collection will require some refactoring of existing >> collection interfaces (for example extract SortedCollection from SortedSet, >> Navigable Collection from NavigableSet etc.). From the perspective of clean >> code, this would be the right decision, but I feel like this will be a very >> complex task to accomplish. >> >> 3. Maybe there should be few versions of Tree collection (for example, >> for regular tasks red-black tree and B-Tree for large amounts of data). I >> have some expirience implementing both, but is it really needed in standard >> library? >> >
