[Rochus]

These diagrams indeed look good. But actually I never use those for parser construction, but consider EBNF more useful, especially also when analyzing and correcting a grammar. I was surprised that there was no decent editor to develop grammars which has built-in support to find and show issues in the grammar like left recursion or ambiguities (at least I didn't find one), so I implemented my own: https://github.com/rochus-keller/ebnfstudio/. I used it in all of my programming language projects to create LL(n) versions including some pretty complicated grammars like Simula or Verilog.