[news.eclipse.technology.ldt] Re: Beyond textual represenations...

["Ted Carroll" <tcarroll@xxxxxxx>]

I agree that a typical AST parsed from source would underutilize the 
capabilities of EMF.  From my use of EMF I see the major benefits as being:

1) Model Specification
2) Persistence/Interchange
3) Notification
4) Undo/Redo
5) Rich Metadata API

What aspects of these (or other things that I've missed) do you see as 
particularly useful in the mainline case of the JDT/CDT/WTP supported 
languages?

And, what languages and/or features do you think would be easier to support 
using EMF?

Ted Carroll
BEA Systems, Inc.

"Constantie Plotnikov" <constantine.plotnikov@xxxxxxxxx> wrote in message 
news:d1psm5$hln$1@xxxxxxxxxxxxxxxxxxx
> Mike Kaufman wrote:
>> Yes, I think this is a good compromise.  I think that part of the LDT's 
>> intial effort is going to be define APIs for a generic AST. 
>> Consequently, tools can be written to the API to operate on a 
>> language-neutral AST.
>>
>> Persisting this AST is orthogonal to these APIs though, and I'm not at 
>> all aware how the plugin you describe would be written.  And, it feels 
>> like a pretty large effort to build a plugin to have eclipse persist ASTs 
>> instead of text files.  I do think though, that such a plugin would be a 
>> client of the LDT APIs though, and not part of the LDT itself.
>>
> 1. JDT DOM API is too Java dependent now. Changing it to make it more 
> generic would break clients anyway. So it might make sense not become too 
> fixed on JDT. A new API that is JDT other might be used.
>
> 2. EMF project (http://www.eclipse.org/emf) already provides a generic 
> model API. Usual AST there is result of parsing some document would 
> usually underuse EMF features. This API natively supports persisting as 
> XML. As I understand there is a work underway to support persisting to the 
> database. It also natively supports event notifcations and with some 
> efforts undo/redo through commands.
>
> I cannot say that EMF is perfect. But a lot of efforts is invested in it 
> and new AST API would just duplicate these efforts.
>
> 3. The competing to eclipse.org project named Netbeans have a competing to 
> EMF framework named MDR (http://mdr.netbeans.org). As I heard, this 
> framework is used to implement part similar to JDT AST in netbeans 4.0 
> (see http://mdr.netbeans.org/javamdr/).
>
> Constantine