Should we have an Unimplemented Attribute?

[Jacob Carlborg]

On 2011-02-03 00:38, Piotr Szturmaj wrote:
> Andrej Mitrovic wrote:
>> We know what a Deprecated Attribute is for:
>> http://www.digitalmars.com/d/2.0/attribute.html#deprecated.
>>
>> You can use a compiler switch to enable using these:
>> -d
>> allow deprecated features
>>
>> But what about structs/classes/functions/etc which are partially
>> implemented, but still unusable? Marking them with deprecated doesn't
>> make sense, as this will likely confuse both the user and the library
>> writers. Would it be overkill to introduce a new attribute?
>>
>> The idea came after I've spent some good time trying to get druntime's
>> getMembers function to work in my code, only to find out from this NG
>> that it's not properly implemented.
>>
>> Discuss?
>
> In C# there is NotImplementedException for that.
>
> public class A
> {
> public int foo()
> {
> throw new NotImplementedException();
> }
> }
>
> I see people ask for new attributes. Why not add user defined attributes
> into language? C# has custom attributes and Java has custom annotations.
>
> Custom attributes could be just classes (as in C#):
>
> class GuidAttribute : Attribute
> {
> string guid;
>
> this(string guid)
> {
> this.guid = guid;
> }
> }
>
> used like this (COM interfaces):
>
> @Guid("48eecd81-35d7-4d4e-9ab8-479a38713053")
> interface MyInterface
> {
> byte foo();
> ulong bar();
> }
>
> or used for ORM:
>
> @DBTable("users")
> struct UserRow
> {
> @NotNull string username;
> @NotNull string password
> ubyte age;
> }
>
> There would be also need for some method to enumerate those attributes
> at compile time/run time. We already have that possibility for
> predefined attributes.

I would love to have user defined attributes/annotations.

-- 
/Jacob Carlborg