> So, one of the key things that I see is that the constructed abstract syntax tree must have the raw tokens within it so all other layers have full awareness.

> So, one of the key things that I see is that the constructed abstract syntax tree must have the raw tokens within it so all other layers have full awareness. I don't see why you say that, parser combinators are just a structured way to compose recursive descent parsers, you can do everything with them that you can with any other hand-rolled parser. You don't even need to construct an AST at all, a mathematical expression "parser combinator" could just return a single number, the result of evaluating the expression.