Primitive streams and optional

[Tim Peierls]

On Sun, Nov 25, 2012 at 10:42 AM, Remi Forax <forax at univ-mlv.fr> wrote:

> On 11/25/2012 02:14 PM, Doug Lea wrote:
>
>> On 11/21/12 12:59, Brian Goetz wrote:
>>
>>> OK, I think we have all the options and combinations of options on the
>>> table.
>>>
>>> A: OptionalInt min()
>>> B: int min(int defaultValue)
>>> C: int min() throws NSEE
>>>
>>
>> I vote for renaming to make clearer that this is a reduction with
>> a basis, and then providing two forms:
>>
>>  int least(int ceiling); // return least value < ceiling, or ceiling if
>> none
>>  int least(); // default ceiling == Integer.MAX_VALUE
>>
>
> I prefer :
>   int least(IntSupplier supplier); // return least value < ceiling, or
> suplier.supply() if none
>   int least(); // default supplier == () -> Integer.MAX_VALUE
>
> it's not rare to have a default value that also requires computation and I
> don't want
> to compute it if I don't need it.


This would be more appealing with OptionalXxx, moving the Supplier argument
away from the stream and onto the Optional object itself:

    return s.least().or(() -> computeDefaultValue());

--tim