From: Luca Bruno <[email protected]>
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 <[email protected]> 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
_______________________________________________
vala-list mailing list
[email protected]
https://mail.gnome.org/mailman/listinfo/vala-list
--
NixOS Linux
_______________________________________________
vala-list mailing list
[email protected]
https://mail.gnome.org/mailman/listinfo/vala-list
