Loose end: concat

[Brian Goetz]

Seems we've seen no objections on the existence of these methods.  So 
the remaining issue is where they live.

Candidates:

   Streams.concat(a, b) x 4
   Stream.concat(a, b), IntStream.concat(a, b), etc.

Over time, we've been moving away from "overloaded" stream methods 
towards more explicitly typed methods, which is a point against the 
first candidate.

I initially preferred the first version, but am more on the fence now. 
Sam prefers the second.  Other opinions?


On 5/23/2013 2:06 PM, Brian Goetz wrote:
> I cleaned up concat() and wrote Int/Long/Double versions.  (Fortunately,
> with the recent addition of Spliterator.OfPrimitive, the duplication
> quotient was much lower.)
>
> Currently these still live in Streams.  Is that still the right place?
> The stream classes (Stream, IntStream, etc) seem a little wrong for
> them, but I can't quite put my finger on why.
>
> Specs:
>
>      /**
>       * Creates a lazy concatenated {@code Stream} whose elements are
> all the
>       * elements of a first {@code Stream} succeeded by all the elements
> of the
>       * second {@code Stream}. The resulting stream is ordered if both
>       * of the input streams are ordered, and parallel if either of the
> input
>       * streams is parallel.
>       *
>       * @param <T> The type of stream elements
>       * @param a the first stream
>       * @param b the second stream to concatenate on to end of the first
>       *        stream
>       * @return the concatenation of the two input streams
>       */
>      public static <T> Stream<T> concat(Stream<? extends T> a, Stream<?
> extends T> b) {
>
>
>      /**
>       * Creates a lazy concatenated {@code IntStream} whose elements are
> all the
>       * elements of a first {@code IntStream} succeeded by all the
> elements of the
>       * second {@code IntStream}. The resulting stream is ordered if both
>       * of the input streams are ordered, and parallel if either of the
> input
>       * streams is parallel.
>       *
>       * @param a the first stream
>       * @param b the second stream to concatenate on to end of the first
> stream
>       * @return the concatenation of the two streams
>       */
>      public static IntStream concat(IntStream a, IntStream b) {
>
>
> (and similar for Long and Double).
>