This repo is for rebuild of Irony. For now, we open it for experiments. Read the introductory materials in repo's Wiki (https://github.com/IronyProject/Irony3/wiki) IronyExperiments is the project for experiments and exploring the ideas of new Irony. If you want to contribute, create a subfolder in the project named as your user name, and put your code there. This is exploration phase, we are trying to figure out APIs and interfaces, not implementations. For example, your suggestion of new NonTerminal class. Or Scanner interface. The code does not need to be runnable, just make it compilable. We do not create branches, just folders, to easily browse and compare different suggestions.
I think that's the easiest way for now.
If, in addition to stuff in Wiki, you come up with your own ideas and suggestions about features and capabilities for new version - we welcome it, share this in a post, let's discuss it.