Re: [aspectj-users] ITD syntax

[Simone Gianni <simoneg@xxxxxxxxxx>]

Hi Ramnivas and Dave,
yes, I also liked the proposal, in fact I also find the ITD syntax a bit
too verbose.

Ramnivas, your proposal moves from ITD to something near mixins, which I
really like :). Anyway, that class could be every class, and that bring
a number of problems, cause it could extend another class, and since
Java does not support multiple inheritance we should not give the user
the feeling that it is happening. Also, the fact that a ITD field is
private "to the aspect"is a very good feature, I already have more than
one aspect declaring a "inited" boolean field, each aspect uses it to
mark a certain instance inited regarding its own concern. I see not much
a technical problem in obtaining the same behavior with your proposal,
but again a problem from a user POV.

The direction seems correct to me, but some boundaries must be defined
to give the user the proper feeling of what they are doing.

Simone


Ramnivas Laddad wrote:
> I like this proposal.
>
> Here is an alternative syntax suggestion that
> - addresses Dave's use case
> - addresses a use case that is easy to implement in @AspectJ but not
> in code style
> - avoids new keywords
>
> public aspect ITDAspect{
>
>     /* don't have define the class here, don't need to make it private;
>         but defining it that way matches Dave's example
>    */
>     private static class ITDDefaultImpl {
>         private String string;
>
>         public String getString(){
>             return string;
>         }
>
>         public void setString(String string){
>             this.string = string;
>         }
>     }
>
>     /* declare that ITDInterface should be introduced with
>         all fields and methods in ITDDefaultImpl
>         Not sure about the choice of using "extends"
>         (trying to avoid new keyword)
>         Alternatives: declare implements? declare default?
>     */
>     declare extends: ITDInterface, ITDDefaultImpl;
> }
>
> This makes a common use case implemented by the following @AspectJ
> snippet available in the code style syntax. Essentially, I get to
> reuse the implementation available from an existing class.
>
> @DeclareParents(value="com.myco.domain.*",
>                              defaultImpl= ITDDefaultImpl.class)
> ITDInterface something;
>
> How does this sound?
>
> -Ramnivas
>
> On Wed, Dec 3, 2008 at 9:40 PM, Andy Clement <andrew.clement@xxxxxxxxx> wrote:
>   
>> I could be wrong but I think I recall someone talking about something
>> like this a while ago - possibly Ramnivas.  Although having just
>> trawled through our enhancement requests, I only found this:
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=240011 which is about
>> saving typing but isn't quite the same thing.  What you propose is
>> interesting, what do others think?
>>
>> cheers,
>> Andy.
>>
>> 2008/12/3 Dave Whittaker <dave@xxxxxxxxxx>
>>     
>>> I've been wondering recently.... is there a reason that ITDs are defined the way they are?  I don't know how others tend to use them, but for me I'm pretty likely to have an aspect that contains ITD fields and methods that apply to a single interface within a given aspect.  This makes me wonder why we have a syntax like:
>>>
>>> public aspect ITDAspect{
>>>
>>>        private String ITDInterface.string;
>>>
>>>        public String ITDInterface.getString(){
>>>                return string;
>>>        }
>>>
>>>        public void ITDInterface.setString(String string){
>>>                this.string = string;
>>>        }
>>>
>>> }
>>>
>>> Instead of:
>>>
>>> public aspect ITDAspect{
>>>
>>>        intertype(ITDInterface){
>>>
>>>
>>>                private String string;
>>>
>>>                public String getString(){
>>>                        return string;
>>>                }
>>>
>>>                public void setString(String string){
>>>                        this.string = string;
>>>                }
>>>
>>>        }
>>> }
>>>
>>> Or something similar.  Something that involved less typing, consolidated code that is defined for another type and looked more like plain java code (not to mention more like other AJ definitions in this case....).  At the very least it would allow for something that I've wanted many times: cut and paste between classes and ITDs without having to post process with some sort of wacky regex.  Am I missing a reason why it's desirable or even necessary to type out the full interface name on each line?
>>> _______________________________________________
>>> aspectj-users mailing list
>>> aspectj-users@xxxxxxxxxxx
>>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>>>       
>> _______________________________________________
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>>
>>     
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>   


-- 
Simone Gianni            CEO Semeru s.r.l.           Apache Committer
http://www.simonegianni.it/