first(Iterator/Iterable) is shorthand for get(Iterator/Iterable, 0), so the Javadocs is much like get().
My current use case is to replace: aSet.iterator().next() with: first(aSet) Gary On Fri, Jan 12, 2018 at 12:43 AM, Claude Warren <cla...@xenei.com> wrote: > actually last() would probably be more useful. I still don't see the need > for first() when next() will suffice, unless first() is changing the return > value when there is no first(). > > As clarification what happens if I call: > > Iterator<String> iterator = Arrays.asList( "a","b" ).iterator(); > x = IteratorUtil.first( iterator ); > y = IteratorUtil.first( iterator ); > > Is the value of y intended to be "a" or "b"? I assume "b" > > how does this differ from: > > Iterator<String> iterator = Arrays.asList( "a","b" ).iterator(); > x = iterator.next(); > y = iterator.next(); > > If I add another call so I have: > > Iterator<String> iterator = Arrays.asList( "a","b" ).iterator(); > x = IteratorUtil.first( iterator ); > y = IteratorUtil.first( iterator ); > z = IteratorUtil.first( iterator ); > > what happens on the 3rd call? > > I know I get an exception in the standard case. > > Claude > > On Fri, Jan 12, 2018 at 1:21 AM, sebb <seb...@gmail.com> wrote: > > > On 12 January 2018 at 00:51, Gary Gregory <garydgreg...@gmail.com> > wrote: > > > On Thu, Jan 11, 2018 at 5:23 PM, sebb <seb...@gmail.com> wrote: > > > > > >> On 11 January 2018 at 15:22, Gary Gregory <garydgreg...@gmail.com> > > wrote: > > >> > Hi, > > >> > > > >> > Some APIs, either due to age or design, deal out an Iterator and > > nothing > > >> > else. And sometimes, all I care about (in tests, for example, or if > > the > > >> > list is a set of aliases) is the first object. > > >> > > > >> > The method IteratorUtils.first(Iterator) is a shorthand for > > >> > IteratorUtils.get(Iterator, 0). > > >> > > >> The code method is only shorter by one character and that is a space. > > >> > > >> This will just add unnecessary code and maintenance costs. > > >> > > > > > > I do not look at it that way. I see it at providing an abstraction that > > > says "give me the first element" instead of "give me the 0th element". > > Code > > > reads better that way. IMO. > > > > So add a comment. > > Or write your own wrapper. > > > > > What maintenance costs are referring to here? > > > > All code needs updating from time to time. > > > > Remember JUnit3? Javadoc pre-8? > > > > Are you sure that the initial commit will be perfect? > > Or will the Javadoc need adjusting? > > > > Will there be questions asking whether first includes null or not? > > Such queries may occur even if the Javadoc is perfect. > > > > And of course it takes a tiny bit longer to run the tests, and the > > test logs are bigger. > > > > And it's a bit harder to navigate the source. > > > > etc. > > > > > > > > > Gary > > > > > > > > > > > >> > > >> > I do not plan to add last(), the obvious sibling to such a method, > > YAGNI > > >> > for now. > > >> > > > >> > Gary > > >> > > > >> > > > >> > On Thu, Jan 11, 2018 at 2:52 AM, sebb <seb...@gmail.com> wrote: > > >> > > > >> >> Also, what is the use case for such methods? > > >> >> How many will there be - i.e. do you plan to add .last, .second, > > >> .random? > > >> >> > > >> >> I'm not keen on methods that save a few lines of code unless > there's > > a > > >> >> common use case and the behaviour is obvious/unambiguous from the > > >> >> name. > > >> >> > > >> >> On 11 January 2018 at 07:45, Claude Warren <cla...@xenei.com> > wrote: > > >> >> > does first return the first object or the first non-null object? > > >> >> > > > >> >> > If the first object how do you distinguish between first() > > returning a > > >> >> null > > >> >> > object and there being an empty container? > > >> >> > If the first non-null object how do you determine that nulls were > > >> >> skipped? > > >> >> > > > >> >> > Keep in mind that the Optional implementation in Java8 will throw > > an > > >> >> > exception if it is constructed with a null object. > > >> >> > > > >> >> > On Wed, Jan 10, 2018 at 4:45 PM, Gary Gregory < > > garydgreg...@gmail.com > > >> > > > >> >> > wrote: > > >> >> > > > >> >> >> Hi All, > > >> >> >> > > >> >> >> I plan on adding methods like: > > >> >> >> - IteratorUtils.first(Iterator) > > >> >> >> - IterableUtils.first(Iterable) > > >> >> >> > > >> >> >> Gary > > >> >> >> > > >> >> > > > >> >> > > > >> >> > > > >> >> > -- > > >> >> > I like: Like Like - The likeliest place on the web > > >> >> > <http://like-like.xenei.com> > > >> >> > LinkedIn: http://www.linkedin.com/in/claudewarren > > >> >> > > >> >> ------------------------------------------------------------ > > --------- > > >> >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > >> >> For additional commands, e-mail: dev-h...@commons.apache.org > > >> >> > > >> >> > > >> > > >> --------------------------------------------------------------------- > > >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > >> For additional commands, e-mail: dev-h...@commons.apache.org > > >> > > >> > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > -- > I like: Like Like - The likeliest place on the web > <http://like-like.xenei.com> > LinkedIn: http://www.linkedin.com/in/claudewarren >
