How to override a rule from an imported grammar

[ydaveluy]

Hi,

I have a core Grammar with lots of predefined rules (expressions, annotations) including a QualifiedName and ValidId rule.
This core grammar is used by 6 others grammars. I would like to override in some way the ValidID rule to add some specific keywords for each grammar.
If I can avoid to put all of these keywords in the ValidId rules defined in the core grammar it would be great.

In Xtext it was possibleto override a rule imported from an other grammar but Langium does not seems to support this feature.

Is there an other approach or is it planned to add such mechanism in Langium ?

[msujew]

Hey @ydaveluy,

No other approach possible, please create a feature request. We didn't implement it so far due to:

1. complexity
2. no one asked for it

We already talked about this internally, we are fine with having an override keyword that allows to override rules similar to Xtext.