Grammar rule 'classDeclaration' error

Description

I litterally just copy pasted the 3 kotlin .g4 files and ran grun to check the generated AST using the MutableStack<E> code from the example here : https://play.kotlinlang.org/byExample/01_introduction/06_Generics And it seems like it can’t match the LCURLY bracket of the classBody rule ? Could anyone confirm please

Output + AST

[belyaev-mikhail]

Literally any feedback for the grammar is appreciated as it shows somebody is actively using it =)

[belyaev-mikhail]

The Inside_ rules are there to distinguish expressions inside parentheses from free-range ones. The Inside_WHATEVER: WHATEVER -> type(WHATEVER); boilerplate code maps them to their non-inside counterparts so they do not need to be referenced anywhere as the token stream will contain the non-Inside variant.

Why do we need to distinguish expressions inside parentheses? Because inside parentheses you can safely ignore newlines and you cannot do that on the top-level. An example of this is, for example, a * b:

a
* b // you cannot do this in Kotlin
(a
* b) // but you can do this!