Detect linenumbers of methods in the R grammar

[austen...@googlemail.com]

Hello,

i'm a beginner in using ANTLR and would like to extend the R grammar file:

https://github.com/antlr/grammars-v4/tree/master/r

I would like to detect R methods (and maybe later R S3 and S4 classes) in R source files.

The Parser should be used in an Editor to implement code folding so i need to detect the linestart  and lineend of all available methods in a file.

In the ANTLR book i read about Actions and Listeners.

How could i implement a method detection (linestart and lineend) in the R grammar. Do i have to use Actions or listeners and where do i have to put

the detetction in the R grammar?

Any help is appreciated.