Stream generators

[Joe Bowbeer]

I mean a more general merge which may emit an element from either stream,
depending, and may drop some elements from one or both streams.
On Nov 30, 2012 9:51 AM, "Brian Goetz" <brian.goetz at oracle.com> wrote:

> I think it would be beneficial for comparison to show a bit of their
>> implementations.
>>
>
> Here's iterate(seed, UnaryOperator):
>
>     public static<T> Stream<T> iterate(final T seed, final
> UnaryOperator<T> f) {
>         Objects.requireNonNull(f);
>         final InfiniteIterator<T> iterator = new InfiniteIterator<T>() {
>             T t = null;
>
>             @Override
>             public T next() {
>                 return t = (t == null) ? seed : f.operate(t);
>             }
>         };
>         return stream(new StreamSource.ForIterator<>(**iterator),
> StreamOpFlag.IS_ORDERED);
>     }
>
> Not too difficult.  But, the idea is to make things that are easy in the
> header of a for-loop to be easy as the source of a stream.
>
>  repeat(n) in Scheme is about 10 characters.
>>
>
> Yeah, well this is Java...
>
>  How difficult is it to implement a merge, as might be needed to generate
>> Hamming numbers? (One of my favorite test cases.)
>>
>
> You mean, interleave two streams?  That's on our list to implement as
> Streams.interleave(a, b).
>
>  Is there a method to limit a stream to a length?  If so then one of your
>> methods may be extra baggage.
>>
>
> Yes: stream.limit(n).
>
>