Re: [Vala] enum access modifiers

[Luca Bruno <lethalman88 gmail com>]

Good point, in general private inside nested classes or namespaces is a
no-op in the same project.
The only thing that makes a difference is the internal modifier (which is
also the behavior of private) when creating libraries: the resulting vapi
and header files will not have that symbol.

On Sat, Dec 6, 2014 at 3:51 PM, Al Thomas <astavale yahoo co uk> wrote:

>   ------------------------------
>  *From:* Luca Bruno <lethalman88 gmail com>
> *Sent:* Saturday, 6 December 2014, 14:27
> *Subject:* Re: [Vala] enum access modifiers
>
> Nested classes or whatelse type is always "static" from a Java view point.
> So you access those enum values with test.a.TEST. There's no way those
> types can be tied to a particular instance of the parent class.
>
>
> Thanks for the reply. It was more the use of the 'private' keyword and by
> extension the 'protected' keyword that I was trying to understand. For
> example:
>
> void main(){
>         //var aa = new test();
>         print( test.a.TEST.to_string ());
>         }
>
> class test: Object {
>         private enum a {
>                 TEST
>                 }
>         }
> will compile and run without any errors. But Vala allows an access
> modifier for the enum, so should the use of 'private' above, instead
> produce a compile time error such as "Access to private member `test.a'
> denied"?
>
>
>
>
> I could not understand the rest of the mail, sorry.
>
>
>
> On Sat, Dec 6, 2014 at 3:21 PM, Al Thomas <astavale yahoo co uk> wrote:
>
> The Vala manual states that an enum takes an access modifier, from
> https://wiki.gnome.org/Projects/Vala/Manual/Enumerated%20types%20%28Enums%29
> :"enum-declaration:
>  [ access-modifier ] enum qualified-enum-name { [ enum-members ] }"
> The following compiles and runs with Vala 0.26.0.33:
>
> void main(){
>         var aa = new test();
>         print( aa.a.TEST.to_string ());
>         }
>
> class test: Object {
>         private enum a {
>                 TEST
>                 }
>         }
>
> and only gives a compilation warning about static
> members:"private_enum.vala:3.9-3.12: warning: Access to static member
> `test.a' with an instance reference
>     print( aa.a.TEST.to_string ());"
> So it would appear the current implementation for enums is that they are
> public and static. So is this an implementation bug because the access
> modifier is ignored or a documentation bug because access modifiers for
> enums aren't that useful?
> What has brought this on is a patch adding the 'protected' access modifier
> to the Genie parser - https://bugzilla.gnome.org/show_bug.cgi?id=690848
> Generally I would say the 'public', 'private' and 'protected' access
> modifiers allow a public interface for using and extending a class to be
> defined a bit more clearly. So implementation details can be hidden with
> 'private', but also allowed to be extended with 'protected'. While 'public'
> provides the accessible API. In that sense enum, as well as struct and
> delegate, can be implementation details where access can be restricted.
> Enum, struct and delegate are all type definitions so probably should not
> be modifiable by a class sub-type, but readable so they can be accessed for
> creating a variable of the right type. The patch has also highlighted that
> 'interface' has an access modifier. Surely an interface should always be
> public? Although a method within an interface could possibly be protected
> as a mixin for implementation only?
> Any thoughts?
> Al Thomas
>
>
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>
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