PCollections sound like a good candidate, as you're its maintainer ;-) (so it's easy to fix bugs, make updates, etc), it's lightweight / standalone (not bringing odd dependencies).
On Wed, Oct 14, 2015 at 10:55 AM, Jochen Theodorou <blackd...@gmx.org> wrote: > Hi all, > > I was thinking of adding persistent collections to Groovy for quite a > while now. but I am wondering what library we should depend on here and > wanted to ask what you people generally use. Like pcollections, Guava, > functional Java, maybe stuff from Clojure or Scala? > > Background: > > persistent collection are collections (may or may not implement the > Collection interface) which cannot be modified later on. they have nothing > to do with persisting data in a database or on hard disc. They are just > more functional structures. Even though you cannot modify them, you can > combine the structure with new elements and get a new structure. So a > list+element will create a new list consisting of the old list and the new > element. But they will not just copy over data, they will reuse the > internal structure of the old list. A very simple form is that of a filo > stack. It can be a simple linked list of elements and we add the new > element in front, letting us to reuse the old list to almost 100% and to > create only a very small amount of new objects. There are of course lists, > sets and maps. > > So why use them? Unlike unmodifiable made collections in Java, these > persistent collections are relatively safe to share between threads with > minimal synchronizations. Also, if you are working with functional idioms > they are more fitting the implicit assumptions of the data not being > modifiable. > > Java collections are in general a bad fit here, since Collections are more > or less assumed to be modifiable. pcollections for example tries to bridge > that. In a Java8 world there is of course streams, which are a much better > fit in that. > > bye blackdrag > -- Guillaume Laforge Apache Groovy committer & PMC member Product Ninja & Advocate at Restlet <http://restlet.com> Blog: http://glaforge.appspot.com/ Social: @glaforge <http://twitter.com/glaforge> / Google+ <https://plus.google.com/u/0/114130972232398734985/posts>
