Why is this grammar not working

[mnaderhirn]

Playground
I trying to implement the simple grammar in the playground and it is giving me errors, i dont understand. Could anyone have a look at it please?

[montymxb]

Hey @mnaderhirn . There's a couple things going on here that are issues. You don't need to explicitly handle whitespace (there's hidden terminals for that case, ex hidden terminal WS:/\s+/;), and you also need a way to declare more than one statement to have something to reference, like so:

entry Reference:
    (
        references+=Refernence | // also allow declaring things you can reference, and collect them
        ('{{' Refernence '}}') |
        ('\\ref' '{' Reference '}')
    )*; // zero or more of these

For reference you can check out this modified version of your grammar. Hope that helps!