Extension vs defender methods

[Sam Pullara]

Would "default method" not be accurate and obvious?

Sam

On Nov 12, 2011, at 10:45 AM, Zhong Yu wrote:

> On Thu, Nov 10, 2011 at 12:44 AM, Brian Goetz <brian.goetz at oracle.com> wrote:
>> As Neal said, English is malleable.  If he wants to define "extension method" method to mean extended by a non-author, that's within the bounds of credibility.  We prefer to think of it as "extended after the fact".
> 
> But this feature is also very useful "before the fact"; an interface
> author can use this feature in version0 of his API.
> 
>> (Another way to think of it is that the "extension" refers to the notion of interface; an interface with behavior is an "extended interface".)
> 
> Is there any interesting difference between interfaces with extension
> method and interfaces without? As a programmer I don't see why I care
> to give a special name to the former type. This feature is more on the
> method level than on the interface level.
> 
> If we call it "extension method" we better have a credible explanation
> of what it is "extending" from. To the lambda team "extension" makes
> very good sense; but to programmers who see it as a general language
> feature, "extension" is very perplexing. Can't we have a better name
> to describe these "interface methods with default implementation"?
> 
> Zhong Yu
> 
>> 
>> To answer Paul's question, it is the interface that is being extended, beyond its original specification.  (Though the pedantically inclined might point out that one can add a default clause to an existing "original" method, turning it into a so-called "extension method", in a mostly binary and source compatible way.)
>> 
>> The "weaver" is just an implementation trick, one that injects bytecodes into classes that inherit behavior from extended interfaces.  We don't intend this to be the real implementation, but its a darn convenient way to experiment.
>> 
>> On Nov 10, 2011, at 12:55 AM, Paul Benedict wrote:
>> 
>>> I like this clarification but we better ask the experts who built the
>>> weaver :-) Are the concrete classes that extend List being woven or is the
>>> interface?
>>> 
>>> Paul
>>> 
>>> On Wed, Nov 9, 2011 at 3:59 PM, Patrick Wright <pdoubleya at gmail.com> wrote:
>>> 
>>>> It seems clear to me - a class implementing an interface, say
>>>> ArrayList, is automatically *extended* (via redirection to the default
>>>> implementation) to support new method(s) on List which were not part
>>>> of List's original API. Without a default method provided by the
>>>> mechanism, the class would have to be modified manually. It seems like
>>>> a useful distinction: the class's implementation is being *extended*
>>>> to include implementations it does not provide itself.
>>>> 
>>>> The type in question is ArrayList - that is the type that is being
>>>> extended - so we are adding functionality to the class not provided by
>>>> its author.
>>>> 
>>>> My interpretation, anyway.
>>>> 
>>>> 
>>>> Best,
>>>> Patrick
>>>> 
>>>> 
>>>>> The meaning of extension in the phrase extension methods is that they
>>>> allow
>>>>> functionality to be added (i.e. extend) to a type that was not provided
>>>> by
>>>>> the author of the type.  I don't know in what sense you're using the term
>>>> 
>>>> 
>>> 
>> 
>> 
>> 
>