Re: "Hello world!" without a public class?

From:
Lew <lewbloch@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 6 Jan 2013 17:24:57 -0800 (PST)
Message-ID:
<53b5b13b-4baa-4c64-bead-404bf0073da4@googlegroups.com>
Aryeh M. Friedman wrote:

On inner classes:
...
(yes it does get compiled into something very close to inner classes [not=

 nested if I remember the jargon correctly]

Terminology: A nested type (class or interface) is a member of another typ=
e.
(JLS =A78.5)

There are two kinds of nested classes, static and inner, per the JLS.
By definition, an inner class is a nested class whose declaration does not =
include the keyword 'static'.

"The static keyword may modify the declaration of a member type C within th=
e
body of a non-inner class or interface T. Its effect is to declare that C i=
s
not an inner class."
(JLS =A78.5.1)

 but no where near as ugly):


These get compiled exactly into inner classes.

Foo.java:
 
public enum Foo
{
    ACK {


@Override

       public void doSomething(SomeClass arg)
       {
          do what ever for ACK
       }
    },
...
}


In this case the enum, itself a cover for compiler-supported boilerplate fo=
r a
class with static constant members, also covers for the boilerplate of inne=
r
class declarations in those constants.

Much as the lambdas I mentioned earlier cover for the boilerplate of inner-
class declarations of SAM interface implementations.

Neither of these work without inner classes, so your proposal to eliminate=
 
inner classes would break them.

Fred.java:
...
and voila much more readable then putting a whole rats nest of stuff in t=

he initialization of arr

Perhaps, but it doesn't prove the point, because it relies on inner classes=
..

And your claim that it's "much more readable" is not really proven.

public abstract class Bar
{
  private final String rep;
  abstract public void doSomething(Some arg);
  private Bar(String r)
  {
    this.rep = r;
  }
  public static final BAR = new Bar("BAR")
    {
      @Override
      public void doSomething(Some arg)
      {
    // do what ever for BAR
      }
    };
}

The only part of the anonymous class declaration that differs is the

new Bar("BAR")

Not even "much" different in readability, let alone "very much".

--
Lew

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