Hmm this article really misses out on what makes the recursive decent parser special by not diving deep into the "recursive" part. An example grammar one level more complex would have been great.
The post shows how parsing functions call each other so it isn't really so far off:
fn parse_money(&mut self) -> ParseResult {
let currency = self.parse_currency_symbol()?;
let amount = self.parse_amount()?;
return Ok(MoneyNode {
currency,
amount
});
}That code could be copied directly from some real-world examples - sqlparser-rs code looks pretty much exactly the same.