Design for collections upgrades

[Craig P. Motlin]

In the Scalable implementation, both println statements print the same
thing. Yes that's confusing, but its very similar to mutating a collection
while working with lazy evaluation.
On Mar 14, 2011 10:39 AM, "Rémi Forax" <forax at univ-mlv.fr> wrote:
> On 03/14/2011 02:30 PM, Craig P. Motlin wrote:
>> There are two forms of lazy evaluation and I see people using the same
term
>> (Stream) to refer to both. In Scala they are called view and stream and I
>> was confused about the difference so I asked on Stack Overflow. Basically
>> the difference is:
>> In a view elements are recomputed each time they are accessed. In a
stream
>> elements are retained as they are evaluated.
>>
>> I think that Java collections ought to support both, which is another
reason
>> I think that eager ought to be the default. See the full explanation
here:
>>
http://stackoverflow.com/questions/2282754/what-is-the-difference-between-a-view-and-a-stream
>
> Interresting.
> But memoization is hard to provide when your original collection is
mutable:
>
> What does this code print ?
>
> LinkedList<Integer> list = new LinkedList<>();
> Collections.addAll(list, 1, 2, 3, 4, 5);
> List<Integer> list2 = list.asScalaStreamPlease();
> System.out.println(list2.join(" ")); // the whole list is now memoized
>
> list.remove(0); // wink wink
> System.out.println(list2.join(" "));
>
> Rémi
>
>