RFR(s): 8060192: Add default method Collection.toArray(generator)

[John Rose]

On Dec 11, 2017, at 6:00 PM, John Rose <john.r.rose at oracle.com> wrote:
> 
> class Arrays {
>  // people who want x.toArray can also use x.copy(Arrays::make):
>  static <T> T[] make(SequenceContent<T,T[]> content) { … }

Correction; that one needs an array type to know what to make:

static <T> T[] make(SequenceContent<T,T[]> content,
   Class<? extends T[]> arrayClass) { … }


> // ArrayList.copy uses this one internally as "myContent":
>  static <T> SequenceContent<T> slice(T[] a, int start, int end) { … }
> }
> class List<T> {
>  // people who want x.asUnmodifiableList can also use x.copy(List::make):
>  default SequenceCopier<T,List<T>> make(SequenceContent<T,T[]> content) { … }
> 
>  // external access to a sized snapshot of a list:
>  default SequenceContent<T> sizedContent() { … }
> }

Also, sizedContent is there for completeness but doesn't carry
as much weight as the other three.  It might be derived from
Collection::copy applied to the identity function, unless there
are scoping rules on the operand to Collection::copy.