As with many rules there are cases where one may break them for other
overriding reasons. I think this is one of those cases for
ZipFile/JarFile.stream(), since for many usages the signature of the stream
will not pop out into an explicit type. I have not looked at the specific case
for streams and java.time.
Regarding the StackOverflow issue with compiler errors, i believe this is fixed
in later releases of JDK 8 (at least from 1.8.0_51) and 9-ea.
Paul.
> On 28 Jan 2016, at 05:28, Tagir F. Valeev <amae...@gmail.com> wrote:
>
> Hello!
>
> It should be noted that there's already a precedent in JDK where
> method returning stream is subclassed and returns the stream of more
> concrete objects. I'm speaking about ZipFile and JarFile:
>
> public class ZipFile {
> public Stream<? extends ZipEntry> stream() {...}
> }
>
> public class JarFile extends ZipFile {
> @Override
> public Stream<JarEntry> stream() {}
> }
>
> Such generic stream declaration adds some difficulties for ZipFile
> users. For example, consider this question:
> http://stackoverflow.com/q/31455188/4856258
> So in general I would like to avoid Stream<? extends ChronoLocalDate>.
>
> With best regards,
> Tagir Valeev.
>
> RR> Hi Stephen, Tagir,
>
> RR> On 1/27/2016 10:30 AM, Stephen Colebourne wrote:
>>> On 27 January 2016 at 15:13, Roger Riggs <roger.ri...@oracle.com> wrote:
>>>> On 1/26/2016 8:57 AM, Stephen Colebourne wrote:
>>>>> Thus, adding the ChronoLocalDate methods later will make two additional
>>>>> methods available on LocalDate (as they will not override).
>>>> Since all the calendars are built on the same 24hour days and epochDays,
>>>> the computations
>>>> result would be the same regardless of the Chronology.
>>>>
>>>> The existing LocalDate.until, compareTo, isBefore, isAfter, isEqual
>>>> methods already use the
>>>> ChronoLocalDate argument type to avoid having double the signatures.
>>>>
>>>> Modifying the type of the argument to be ChronoLocalDate would not modify
>>>> the semantics
>>>> and would make it possible to avoid extra methods in the future.
>>>>
>>>> I recommend changing the argument to ChronoLocalDate be consistent with
>>>> the existing
>>>> until method to keep the option open for a possible addition to
>>>> ChronoLocalDate
>>> The LocalDate::datesUntil(ChronoLocalDate) method internals would be
>>> unaffected as it operates off toEpochDay(). Worth noting that an
>>> abstraction on the ChronoLocalDate interface would have to return
>>> Stream<? extends ChronoLocalDate>.
> RR> Right, Interestingly, none of the tests explicitly depend on the return
> RR> type of Stream<LocalDate>
> RR> and only use methods that are in ChronoLocalDate. (Based on a quick
> RR> prototype).
>
> RR> But its enough to suggest that there should be some additional test or
> RR> use of the compile time types.
>
> RR> A Stream<ChronoLocalDate> would be inconvenient and counter intuitive.
> RR> That's enough of a reason for me to keep the current signatures.
>
> RR> Thanks for the comments, Roger
>
>
>>>
>>> A LocalDate::datesUntil(ChronoLocalDate, Period) method would however
>>> contain a mixture of Chrono and ISO specific types. Given how the
>>> internals of the method depend on access to Period specific concepts
>>> abstracting to ChronoPeriod would not be pleasant (if possible) As
>>> such, this signature seems unwise.
>>>
>>> But that gives two types of signature - an abstracted one and a specific
>>> one:
>>> LocalDate::datesUntil(ChronoLocalDate)
>>> LocalDate::datesUntil(LocalDate, Period)
>>>
>>> Again, it isn't clear that is better.
>>> Stephen
>
