Updated State of the Specialization

Ali Ebrahimi ali.ebrahimi1781 at gmail.com
Sat Dec 20 18:36:37 UTC 2014


what is your translation scheme for specialization? is that Brian's Or ...
I'm confused, from your response T instantiated as “valuable” int not int?
I'm correct?

On Sat, Dec 20, 2014 at 9:41 PM, Timo Kinnunen <timo.kinnunen at gmail.com>
wrote:

>  It is int, so you end up with two methods in the API which both take the
> same type and a need to distinguish between them somehow.
>
> This is analogous to the BigList<BigInteger> example from the previous
> email. There the problem was about choosing between one method taking a
> normal BigInteger and another taking an “erasable” BigInteger.
>
> Here the problem is about choosing between one method taking a plain int
> and another method taking a “valuable” int.
>
>
>
>
> --
> Have a nice day,
> Timo.
>
> Sent from Windows Mail
>
> *From:* Ali Ebrahimi <ali.ebrahimi1781 at gmail.com>
> *Sent:* ‎Saturday‎, ‎December‎ ‎20‎, ‎2014 ‎19‎:‎04
> *To:* Timo Kinnunen <timo.kinnunen at gmail.com>
> *Cc:* valhalla-dev at openjdk.java.net
>
> What is instantiated type var for T in List<int>? Integer or int
>
> On Sat, Dec 20, 2014 at 3:54 PM, Timo Kinnunen <timo.kinnunen at gmail.com>
> wrote:
>
>>  Here an anyfied List version and a demo:
>>
>> interface List<any T> {
>> public void remove(int position);
>> public void remove(T element);
>>
>> static void test(List<int> list) {
>>
>> // calls remove(int position);
>> list.remove((int) 3);
>>
>> // calls remove(T element);
>> list.remove(3);
>> }
>> }
>>
>> The choice of which method to prefer with the plain, cast-less version is
>> somewhat arbitrary. My rationale for preferring it like this rather than
>> the other way around is that the specialized type is more interesting. Thus
>> the compiler should make calling methods taking one as easy as possible.
>>
>> --
>> Have a nice day,
>> Timo.
>>
>> Sent from Windows Mail
>>
>> *From:* Ali Ebrahimi <ali.ebrahimi1781 at gmail.com>
>> *Sent:* ‎Saturday‎, ‎December‎ ‎20‎, ‎2014 ‎0‎:‎53
>> *To:* Timo Kinnunen <timo.kinnunen at gmail.com>
>> *Cc:* Brian Goetz <brian.goetz at oracle.com>, valhalla-dev at openjdk.java.net
>>
>> As long as I know, we currently have List<E> and We try to specialize (or
>> any-fy) that.
>> How your solution handle List<int> case?
>>
>>
>> On Sat, Dec 20, 2014 at 2:15 AM, Timo Kinnunen <timo.kinnunen at gmail.com>
>> wrote:
>>>
>>> Hi,
>>>
>>>
>>> I’m not sure Peeling is necessary. The reason is that the problem it’s
>>> trying to solve already exists in the current Java and it has workarounds
>>> too. Here’s a demonstration with three ListLike<T> adaptations and the
>>> workarounds:
>>>
>>>
>>> interface SmallList<T> {
>>>
>>> public void remove(short position);
>>>
>>> public void remove(T element);
>>>
>>> }
>>>
>>> interface MediumList<T> {
>>>
>>> public void remove(int position);
>>>
>>> public void remove(T element);
>>>
>>> }
>>>
>>> interface BigList<T> {
>>>
>>> public void remove(BigInteger position);
>>>
>>> public void remove(T element);
>>>
>>> }
>>>
>>>
>>> public class Workaround {
>>>
>>> @SuppressWarnings({ "rawtypes", "unchecked" })
>>>
>>> static void method(SmallList<Short> smallList, MediumList<Integer>
>>> mediumList, BigList<BigInteger> bigList) {
>>>
>>>
>>> smallList.remove((short) 3);
>>>
>>> smallList.remove((Short) (short) 3);
>>>
>>>
>>> mediumList.remove(3);
>>>
>>> mediumList.remove((Integer) 3);
>>>
>>>
>>> ((BigList<?>) bigList).remove(BigInteger.valueOf(3));
>>>
>>> ((BigList) bigList).remove((Object) BigInteger.valueOf(3));
>>>
>>> }
>>>
>>> }
>>>
>>>
>>> For the record, none of the workarounds feel “correct” to me, although
>>> the int/Integer pair gets close.
>>>
>>>
>>> Rather than Peeling, what I think is needed is to streamline overload
>>> selection so that the specialized methods are selected whenever possible
>>> and the non-specialized methods can be manually selected with extra casts,
>>> like this:
>>>
>>>
>>>
>>> smallList.remove((short) 3);
>>>
>>> smallList.remove(3);
>>>
>>>
>>>
>>>
>>> mediumList.remove((int) 3);
>>>
>>> mediumList.remove(3);
>>>
>>>
>>>
>>>
>>> bigList.remove((BigInteger) BigInteger.valueOf(3));
>>>
>>> bigList.remove(BigInteger.valueOf(3));
>>>
>>>
>>>
>>>
>>> --
>>> Have a nice day,
>>> Timo.
>>>
>>> Sent from Windows Mail
>>>
>>>
>>>
>>>
>>>
>>> From: Brian Goetz
>>> Sent: ‎Friday‎, ‎December‎ ‎19‎, ‎2014 ‎22‎:‎31
>>> To: valhalla-dev at openjdk.java.net
>>>
>>>
>>>
>>>
>>>
>>> I've updated the State of the Specialization here:
>>>    http://cr.openjdk.java.net/~briangoetz/valhalla/specialization.html
>>>
>>> The old version is here:
>>>    http://cr.openjdk.java.net/~briangoetz/valhalla/specialization-1.html
>>>
>>
>


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