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Re: pushing the JLS envelope... (6.4.2. Obscuring)

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Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> wrote:
> On 2013-10-19 01:48, Andreas Leitgeb allegedly wrote:
>> Ok, I know that this breaks conventions and common sense, but
>> just for the sake of understanding the JLS...
>> --- snip  foo/Foo.java ---
>> package foo;
>> public class Foo {
>>    public static String bad_name = "boo!"; // bad name for a field
>>    public static class  bad_name { // even worse, because lower case
>>       public static void foo() { }
>>    }
>>    static {
>>       bad_name.foo(); // doesn't work, because field obscures type - Ok.
>>       foo.Foo.bad_name.foo(); // fqn doesn't work, either, but shouldn't it?
>>    }
>> }
>> --- end snip ---
>> JLS (6.4.2. Obscuring) has to say about this case:
>>  - If a field name obscures a type name, then a
>>     fully qualified name for the type can be used
>>     unless the type name denotes a local class (§14.3). 
>> ("bad_name" isn't a local class, so the "unless"-part doesn't apply.)

My fault for stopping reading at (6.4.2) in the JLS...

It seems that "Obscuring" is really only meant between some 
visible field and some visible type which however stem from
different qualifying paths (or local versus qualifyable).

> The FQN is ambiguous. According to [6.5.2. Reclassification of
> Contextually Ambiguous Names]:

Thanks for pointing that out (although I had to read all the
6.5 and 6.5.1 to make any sense of the quoted part of 6.5.2 :-) !

After having determined "foo.Foo" as a Type and considering
Identifier "bad_name":

>     If the Identifier is the name of a method or field of the type
> denoted by TypeName, this AmbiguousName is reclassified as an
> ExpressionName.
>
>     *Otherwise*, if the Identifier is the name of a member type of the
> type denoted by TypeName, this AmbiguousName is reclassified as a TypeName.

So, this is, where field "bad_name" wins over type "bad_name" and
that is regardless that the next identifier is not a member of that
field's type.

Now, I'm going to be (unsolicitedly) sadistic, maybe causing some cringe...
In my example, if I rewrote the static initializer block as follows:
   static { bad_name bad_name = null; bad_name.foo(); }
then it becomes "correct" w.r.t. the JLS, because the name now first
appears in a context that infers a type name, then as a local variable
that beats the field ;-)

Thanks, Daniele, for pointing out, that "Obscuring" wasn't the case.

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pushing the JLS envelope... (6.4.2. Obscuring) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-10-18 23:48 +0000
  Re: pushing the JLS envelope... (6.4.2. Obscuring) Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-10-19 02:49 +0200
    Re: pushing the JLS envelope... (6.4.2. Obscuring) Lew <lewbloch@gmail.com> - 2013-10-19 14:41 -0700
    Re: pushing the JLS envelope... (6.4.2. Obscuring) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-10-20 21:33 +0000
      Re: pushing the JLS envelope... (6.4.2. Obscuring) Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-10-22 12:27 +0200

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