It seems strange that in an effort to solve a common problem that 80% of the success stories opt to not use the automation. Perhaps, there is ground for another toolkit
Work on a compiler for a bit and I guarantee you'll get it. Parser generators pretty much always get in your way
Building an AST is an easy task once you've figured out your grammar and error recovery mechanism, but these are essentially a kind of language-specific design work that can not be automated.