I'm very well aware of parse.y, if you look into the syntaqlite code, you'd find it's a critical part of how the whole "source extraction" mentioned in the article works [1]

To be clear when I say "formal specification", I'm not just talking about the formal grammar rules but also how those interpreted in practice. Something closer to the ECMAScript specification (https://ecma-international.org/publications-and-standards/st...).

[1] https://github.com/LalitMaganti/syntaqlite/blob/93638c68f9a0...