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https://issues.apache.org/jira/browse/GROOVY-7772?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15180590#comment-15180590
]
UEHARA Junji commented on GROOVY-7772:
--------------------------------------
I mean y as String.
In Java8, Class::instanceMethod is not mean the instance method is actually
method of the Class.
{code}
class P {
public String method(){return "P.method";}
}
class C extends P {
@Override
public String method(){return "C.method";}
}
:
public static String test5(Function<? super C,String> func, C c) {
return func.apply(c); // c.method()
}
:
System.out.println(test5(P::method, new C())); // => "C.method".
{code}
So whet we need for y is only name of the method, not method object.
> Class.&instanceMethod had better to have same meaning of
> Class::instanceMethod of Java8
> ---------------------------------------------------------------------------------------
>
> Key: GROOVY-7772
> URL: https://issues.apache.org/jira/browse/GROOVY-7772
> Project: Groovy
> Issue Type: Improvement
> Components: groovy-runtime
> Affects Versions: 2.4.6
> Reporter: UEHARA Junji
> Assignee: Jochen Theodorou
> Priority: Minor
>
> Groovy's operator .& for method is similar functionality to Java8's method
> reference operator ::.
> ||No.||lhs||rhs||meaing of Groovy's .& (Closure) ||meaning of java8's ::
> (FunctionalInterface)||
> |1|instance|instanceMethod| { ..args -> instance.instanceMethod(args) | same
> as groovy |
> |2|Class|staticMethod| { ..args -> Class.staticMethod(args) | same as groovy |
> |3|instance|staticMethod| ERROR groovy.lang.MissingMethodException: | Error
> same as groovy (compile error) |
> |4|Class|instanceMethod|error| Function<RetType,Class,Args..>, where method
> instance method of Class which is declared as ```RetType
> instanceMethod(Args..) {...}```. In other words it is interpreted as a
> function which takes LHS Class as the first parameter which additionally
> inserted to the method.)|
> IMHO, i'd like to propose to change the No 4 pattern semantics of groovy
> same as Java 8 's. Because:
> * You can write:
> {code}
> ["a,b,c"].collect ( String.&toUpperCase )
> {code}
> instaed of
> {code}
> ["a,b,c"].collect { it.toUpperCase() }
> {code}
> * Can have correspond operator to java8's ::. which is understandablea and
> needed for Java programmers.
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