[news.eclipse.modeling.tmf] Re: How to return a list of objects?

[Sebastian Zarnekow <Sebastian.Zarnekow@xxxxxxxxx>]

Hi Michael,

it's the case that we don't have enough ideas - actually we have a 
concept on how to solve this one - it has just not yet been implemented :-)

You may want to subscribe to 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=263773

Regards,
Sebastian
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Michael Scharf schrieb:
> > it is currently not possible to return a list of objects from a parser 
> > rule. You'll have to copy the annotation snippet to every location.
>
> I have been thinking of different solutions:
>
> 1. have something like macro-rules: they look like rules
>    but in realty, they are copied into each location
>    (the solution you suggested but automated)
> 2. allow to inherit a rule (run it in the context of the
>    "parent" rule). In that case it would act as
>    "extension" (not much different form solution 1)
> 3. rules with no assignment could return a list
>    that can be assigned to a list variable:
>      ListRule returns list: list+=Element (',' List+=Element);
> 4. rules could have attributes
>      Parent: list=ListRule.list;
>      ListRule: list+=Element (',' List+=Element);
> 5. Allow expression to build up the object:
>      Parent: ListRule as X {list=X.list; foo=X.foo};
>      ListRule: (foo?='foo')? list+=Element (',' List+=Element);
> ....
>
> Michael