I agree with you about the protection. It can be a snapshot view of a particular collection that can be used forever. The looping ability is the value, not the fail-fast behaviour, in my book. My point was that I was saying it would've been nice to have the thing fail fast, but it's not as important as the looping quality, especially if it's hard to provide! I was supporting you.
Can you send me the code? I think I may've joined the list right after you posted it. You may want to provide a refresh() method that reinitializes a LoopingIterator with the contents of an array/collection (especially with a saved reference to its parent collection)-- I could see myself using it. I definitely don't think it should be an inner class of anything; I wanna be able to drop it into a project without using anything else from Collections (for instance, if I'm space-constrained on a project). I can think of plenty of uses for this thing in a wireless app, for instance. Regards, Jeff --- Jonathan Carlson <[EMAIL PROTECTED]> wrote: > This was my take on it: > > Since it uses the iterator provided by the collection, I > felt it would be wasteful to try to provide any greater > protection than that already provided by the collection's > own iterator (other than the stated benefit of allowing one > to continually loop over the collection). > > That seems so reasonable to me that I'm almost afraid I > might be missing your point. If I am, please let me know. > > Also, I can put the proper license text on it, but I didn't > do it originally because I thought it would most likely be > an inner class of IteratorUtils or CollectionUtils. > > Let me know what you want me to do. > > Thanks! > > Jonathan > > > > --- Jeff Varszegi <[EMAIL PROTECTED]> wrote: > > I don't see how to implement this without being horribly > > wasteful (checking every value in the > > collection backing the Iterator every time something is > > returned, getting a new Iterator every > > time through the loop, etc.). The thing is, you can't > > even depend on the implementation of > > hashCode() when you're dealing with generic collections, > > the use of which would be wasteful > > anyway. Jonathan, did you find a solution to this > > problem? > > > > I was going to implement a RandomIterator, but didn't > > figure a way around the concurrent-mod > > problem for an externally created Iterator. I think for > > situations like this it's acceptable to > > just notify users of the class that there are no > > guarantees in the face of concurrent > > modification. It's a shame that Sun didn't include a > > mod-check hook in the Collection interface, > > or even the chance to use Observer, at least as > > optionally supported. I mean, I can understand > > the absence of observers, because checking for them would > > slow things down a little bit, but every > > single collection I've seen that came outta Sun keeps an > > incremental count of changes to itself. > > > > Jeff > > > > --- Stephen Colebourne <[EMAIL PROTECTED]> > > wrote: > > > Jonathan, > > > I was going to include your files in the CVS. However, > > I discovered that > > > they do not cope with the situation where the > > collection being wrapped is > > > altered. ie. hasNext() always returns the initially > > cached value, even if > > > the list is clear()ed or it.remove() is called. Can you > > sort this? > > > > > > Also, if resubmitting could you place the code in the > > correct package and > > > with an Apache licence (from another collections file) > > to confirm that this > > > is an official donation of code :-) > > > > > > Thanks > > > Stephen > > > > > > ----- Original Message ----- > > > From: "Jonathan Carlson" <[EMAIL PROTECTED]> > > > > It is attached with updated unit tests. It was so > > easy > > > > that I'm surprised I didn't implement the remove() in > > the > > > > first place. > > > > > > > > Thanks! > > > > > > > > Jonathan Carlson > > > > Minneapolis, Minnesota > > > > > > > > > > > > --- Stephen Colebourne <[EMAIL PROTECTED]> > > wrote: > > > > > From: "Jonathan Carlson" <[EMAIL PROTECTED]> > > > > > > I can add a remove method and test cases unless > > it's > > > > > easier > > > > > > for you to just add it. I think it would just > > use the > > > > > > remove method on the Collection. If the iterator > > > > > returned > > > > > > by the Collection implementer doesn't support it > > then > > > > > this > > > > > > won't either. > > > > > > > > > > If you could submit the revised code and test case, > > I > > > > > think that I'm willing > > > > > to commit it to collections. > > > > > > > > > > Stephen > > > > > > > > > > > > > > > > As for a use-case, I am using it for a displaying > > a > > > > > number > > > > > > of our banner ads on our e-commerce site. The > > > > > round-robin > > > > > > task dispatcher mentioned earlier is another one. > > > > > > > > > > > > Jonathan Carlson > > > > > > > > > > > > > > > > > > > > > > > > --- Stephen Colebourne <[EMAIL PROTECTED]> > > wrote: > > > > > > > [Jonathan, I have sent back to commons-dev > > mailing > > > > > list > > > > > > > which is the > > > > > > > appropriate place for design/code discussions.] > > > > > > > > > > > > > > I took a quick look, and I believe that the > > code in > > > > > the > > > > > > > zip will work. > > > > > > > However, my main concern is why this would be > > needed. > > > > > Is > > > > > > > there a use case > > > > > > > for an iterator that never ends? > > > > > > > > > > > > > > I would also like to see the remove method > > > > > implemented. > > > > > > > It should be > > > > > > > possible. > > > > > > > > > > > > > > Stephen > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > > From: "Jonathan Carlson" <[EMAIL PROTECTED]> > > > > > > > To: <[EMAIL PROTECTED]> > > > > > > > Sent: Friday, October 18, 2002 3:53 PM > > > > > > > Subject: LoopingIterator > > > > > > > > > > > > > > > > > > > > > > Hi Stephen, > > > > > > > > > > > > > > > > Thanks for your work on the IteratorUtils. I > > > > > thought > > > > > > > this > > > > > > > > might be a good addition if it hasn't been > > added > > > > > > > already. > > > > > > > > It's an iterator that loops continually. > > > > > > > Unfortunately, it > > > > > > > > can't just decorate another iterator but has > > to > > > > > wrap a > > > > > > > > collection due to the fact that iterators > > cannot be > > > > > > > reset > > > > > > > > to the beginning of the collection. > > > > > > > > > > > > > > > > Included is a jUnit test case that shows it > > works > > > > > "as > > > > > > > > advertised". Hope this helps. > > > > > > > > > > > > > > > > Jonathan Carlson > > > > > > > > Minneapolis, Minnesota > > > > > > > > > > > > > > > > > > > > > > > > ===== > > > > > > > > Jonathan Carlson > > > > > > > > [EMAIL PROTECTED] > > > > > > > > Minneapolis, Minnesota > > > > > > > > > > > > > > > > > > __________________________________________________ > > > > > > > > Do you Yahoo!? > > > > > > > > Faith Hill - Exclusive Performances, Videos & > > More > > > > > > > > http://faith.yahoo.com > > > > > > > > > > > > > > > > > > > > ATTACHMENT part 2 application/x-zip-compressed > > > > > > name=LoopingIterator.zip > > > > > > > > > > > > > > > > > > > > > > > > ===== > > > > > > Jonathan Carlson > > > > > > [EMAIL PROTECTED] > > > > > > Minneapolis, Minnesota > > > > > > > > > > > > > > __________________________________________________ > > > > > > Do you Yahoo!? > > > > > > HotJobs - Search new jobs daily now > > > > > > http://hotjobs.yahoo.com/ > > > > > > > > > > > > -- > > > > > > To unsubscribe, e-mail: > > > > > <mailto:[EMAIL PROTECTED]> > > > > > > For additional commands, e-mail: > > > > > <mailto:[EMAIL PROTECTED]> > > > > > > > > > > > > > > > > > > > > > > > > > > > ===== > > > > Jonathan Carlson > > > > [EMAIL PROTECTED] > > > > Minneapolis, Minnesota > > > > > > > > __________________________________________________ > > > === message truncated === > > > ===== > Jonathan Carlson > [EMAIL PROTECTED] > Minneapolis, Minnesota > > __________________________________________________ > Do you Yahoo!? > Yahoo! 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