Consider making datatype rules explicit about langium

[msujew]

The value keyword doesn't convey a lot of meaning to me (unlike terminal or enum) because it is quite generic. I'd use a keyword like datatype. WDYT, @spoenemann?

Also, the we commonly use assignments with a value feature. Declaring value as a keyword, would force the user to escape it everytime.

[spoenemann]

Right, we should be careful introducing new keywords because of name clashes with user-defined properties (I prefer the term "property" over "feature"; the latter is quite EMF-specific).

I though about value because of the ValueConverter service. IMO the term "datatype" is not fully clear as well. Is primitive more descriptive?

[msujew]

I like primitive. Is the corresponding rule type PrimitiveRule as well?

[spoenemann]

👍

Should it be PrimitiveConverter then to make clear that it applies to terminal rules as well as primitive rules?

[msujew]

Sure, since it basically only converts string (and maybe number) values right? A ValueConverter in my eyes could be used to transform the whole AST.

[spoenemann]

In Xtext you can define value converters that create complex types like LocalDate. I'm not sure whether we want to support that.