RFR : JDK-8001642 : Add Optional<T>, OptionalDouble, OptionalInt, OptionalLong

[Doug Lea]

On 03/15/13 09:46, Brian Goetz wrote:
> Wouldn't the minimal change NOT have a predicate, to match the existing form of
> findFirst?
>
>    Optional<T> findFirst()
>    T findFirst(T orElse)
>

Yes and no. The only way to get non-optional-bearing
result for search would otherwise be s.filter(pred).findAny(),
which entails buffering of stuff you will throw away.

This is also the reason only adding why findAny(pred) (not findDirst)
is defensible: the alternative is of most interest to the sort of
person who want to avoid that Optional too.

-Doug



>
> On 3/15/2013 7:31 AM, Doug Lea wrote:
>> On 03/15/13 06:26, Joe Bowbeer wrote:
>>> Doug,
>>>
>>> I think your point that Optional and non-Optional forms of reduce are
>>> already
>>> provided is significant.
>>>
>>> I noticed that your proposed versions of findFirst and findAny have a
>>> Predicate
>>> argument, but the Optional forms do not:
>>>
>>> T findFirst(Predicate<? super T> predicate, T ifNone);
>>>
>>> Why is this?
>>
>>
>> It's in the spirit of proposing a minimal change. The predicate
>> form suffices for all Optional-avoiding search stuff. To reduce
>> impact by another 50%, it would suffice to ONLY include the "any" form.
>>    T findAny(Predicate<? super T> predicate, T ifNone);
>>
>> -Doug
>>
>>
>>
>>
>>
>