On 05/17/2015 12:46 AM, Claes Redestad wrote:
On 2015-05-16 23:48, Remi Forax wrote:
On 05/16/2015 06:21 PM, Claes Redestad wrote:
Hi,
any reason not to just have Enumeration extend Iterable and
default-implement iterator()?
http://cr.openjdk.java.net/~redestad/scratch/enumerable.00/
I guess there are compatibility risks I haven't thought through
completely, but I
think concrete classes that already implement both Enumeration and
Iterable should
continue to work as expected (since the concrete class'
implementation of
iterator always takes precedence), no?
Hi Claes,
yes, but there is an issue for code that uses instanceof to do
something different if the object is an Enumeration or if the object
is an Iterable.
Hi Rémi,
I guess that's a possibility.
You can only retrofit an existing class/interface to
implements/extends an interface/class in a compatible way only if the
interface/class is newly introduced in the release by example
retrofitting Closeable to implement AutoCloseable is Ok in 1.7
because AutoCloseable was introduced in 1.7.
Probably due to introducing ambiguity in overload selection, come to
think of it.
I also realized Iterable should typically allow multiple passes over the
collection/enumeration, so this wouldn't feel right. Sorry!
So... I'm happy with Stuart's proposal.
I would also be happy (happier?) with a stream variant:
pc.elements().stream().forEach(this::doSomethingWithPermission);
We are not that far :
pc.elements().asIterator().forEachRemaining(this::doSomethingWithPermission);
and having a method stream() on an Enumeration as the very same issue as
having a method stream() on an Iterator.
A Stream need to know more than just the elements but also
characteristics like if the element can be null, are ordered, the number
of elements if known, etc.
These characteristics can be derived from List or Set but not from
Iterator/Enumeration easily.
That's why it's better to let the user to create a stream using
StreamSupport if he really want one.
and remember, prefer composition to inheritance :)
*ducks* :)
/Claes
Rémi
/Claes
Rémi
On 2015-05-16 02:37, Stuart Marks wrote:
Hi all,
Please review this small API enhancement to add a default method
"asIterator()" to Enumeration that converts it into an Iterator.
Webrev:
http://cr.openjdk.java.net/~smarks/reviews/8072726/webrev.0/
Bug:
https://bugs.openjdk.java.net/browse/JDK-8072726
Thanks,
s'marks
