> break it down into the much simpler problem of reading tokens, then write simple "combinators" (and, or, one_or_many, etc etc) to combine these simple parsers into larger more complex parsers.

The popular `pyparsing` library for Python (https://pypi.org/project/pyparsing/) expresses these concepts, just written more in traditional OO style rather than functional style (i.e. there are classes like OneOrMany that you instantiate, rather than binding a single-token-matcher argument to lambda or whatever).