RFR: CR#8004561 : Additional Functional Interfaces and Updates (original) (raw)

Brian Goetz brian.goetz at oracle.com
Sun Dec 23 18:36:41 UTC 2012

Yes, this is a deliberate u-turn that comes as a result of the unexpected interactions with the overloading resolution rules.

By having DoubleBlock extending Block, we created problems for overloading. For example, consider this expected-to-be-common overloading in Bunch:

Bunch transform(Function<T,U> transformer) IntBunch transform(IntFunction transformer)

There are some conflicting rules in overload selection:

What we'd like is to choose the former when the "natural" type of transformer is T -> Integer and the latter when the "natural" type is T -> int. But, because the more specific rule has higher priority, we would coerce a T -> Integer into a T -> int (with unboxing) all the time.

On 12/20/2012 9:07 PM, Howard Lovatt wrote:

1. DoubleBlock doesn't extend Block and doesn't have a default method, similarly int and long 2. Similarly all the rest like Function aren't extended

Is this the correct link - it seems to have gone backwards? -- Howard.

On 21 December 2012 12:41, Mike Duigou <mike.duigou at oracle.com> wrote: Hello all;

Here are some additional functional interfaces for review. The additions fill in holes for primitive types and for two operand "Bi" operations. http://cr.openjdk.java.net/~mduigou/8004561/0/webrev/ http://cr.openjdk.java.net/~mduigou/8004561/0/specdiff/java/util/function/package-summary.html Additionally, this patch contains naming updates on the existing functional interfaces following 335 EG review. It does not include the interface specializations and default methods previously proposed in CR#8004015. That proposal has been withdrawn. It turned out that user errors involving unexpected boxing were just too common for the value provided. Mike

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