I don't think nextOptional will ever return null, but I think you mean empty? If so, and IIUC, what you say was exactly my objection (see discussion in the PR) but as Andy pointed out there, the Model API doesn't ever actually return an ExtendedIterator with null values, so the method turns out to be usable in the only use case we have for it.
ajs6f > On Dec 6, 2017, at 5:57 AM, Claude Warren <[email protected]> wrote: > > my reading of this is that nextOptional will return null at the end of the > iteration and that this is indistinguishable from a null in the iteration > unless hasNext() is called. but calling hasNext() after a null only tells > you if the next item is present not if the last item was present, thus a > null at the end of the iteration may be lost. It almost seems like you > need a lastRead() method to retrieve the last read object again. It seems > like this construct will only be useful when there are no nulls in the > iteration. > > Claude > > On Mon, Dec 4, 2017 at 3:59 PM, Andy Seaborne (JIRA) <[email protected]> > wrote: > >> >> [ https://issues.apache.org/jira/browse/JENA-1427?page= >> com.atlassian.jira.plugin.system.issuetabpanels:comment- >> tabpanel&focusedCommentId=16276983#comment-16276983 ] >> >> Andy Seaborne commented on JENA-1427: >> ------------------------------------- >> >> {{nextOptional}} added for release 3.6.0. >> >> Proposal: close this JIRA for now, see how {{nextOptional}} works out and >> revisit {{orElse*}} based on experience. >> >>> Add nextOrElse() method in ExtendedIterator >>> ------------------------------------------- >>> >>> Key: JENA-1427 >>> URL: https://issues.apache.org/jira/browse/JENA-1427 >>> Project: Apache Jena >>> Issue Type: Improvement >>> Components: Core >>> Affects Versions: Jena 3.5.0 >>> Reporter: Adam Jacobs >>> Priority: Trivial >>> Labels: easytask >>> >>> Allow a functional approach for returning a default value or throwing a >> custom exception from a Jena iterator. >>> The following method may be added to the ExtendedIterator interface. >>> {noformat} >>> /** >>> Answer the next object, if it exists, otherwise invoke the >> _supplier_. >>> */ >>> public default T nextOrElse( Supplier<T> supplier ) { >>> return hasNext() ? next() : supplier.get(); >>> } >>> {noformat} >> >> >> >> -- >> This message was sent by Atlassian JIRA >> (v6.4.14#64029) >> > > > > -- > I like: Like Like - The likeliest place on the web > <http://like-like.xenei.com> > LinkedIn: http://www.linkedin.com/in/claudewarren
