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

Stuart Marks stuart.marks at oracle.com
Tue Dec 5 19:19:07 UTC 2017

On 12/5/17 10:47 AM, Paul Sandoz wrote:
>   345      * <p>Suppose {@code x} is a collection known to contain only strings.
>   346      * The following code can be used to dump the collection into a newly
>   347      * allocated array of {@code String}:
> Make it an API note? (same for toArray(T[])

Will do.

>   352      * @implSpec
>   353      * The default implementation calls the generator function with zero
>   354      * and then passes the resulting array to {@link #toArray(T[])}.
> That’s reasonable. I pondered about being vague and specifying a value in the range if [0, size()), to allow wiggle room for using 0 or size().

No, I really think it has to be exactly zero. If the default were to choose some 
value K < size(), the collection size could change to be smaller than K after 
allocation but before the call to toArray(T[]), resulting in an array that is 
unexpectedly large.

>   360      * @throws ArrayStoreException if the runtime type of any element in this
>   361      *         collection is not assignable to the {@linkplain Class#getComponentType
>   362      *         runtime component type} of array returned by the generator function
> s/of array returned by the generator function/of the generated array/ ?

Will do.


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