Trying to parse a function

[TeaDrinkingProgrammer]

hey y'all, I have been building a parser using winnow for my regex-like language, and I have been very pleased with the library. I have been able to build a lot of parts of my parser, but I am stuck on this problem. I want to parse a function, where I parse the identifier first and then parse the arguments. I have come up with this, but the problem with it is that it obviously doesn't use the combinators:

Input identifier(param1,param2)
Output (OK variant of result):

Function {
  identifier: "identifier"
  params: ["param1", "param2"]
}

   // I don't use unwrap normally, I just wanted to show what I want the result to be of the 'OK' variant.
    let identifier: String =  repeat(1.., parse_alpha_numerical).parse_next(input).unwrap();
    let params = delimited('(', separated(1.., parse_param, ','), ')').parse_next(input).unwrap();

    return Function {
        identifier: identifier,
        params: params
    }

What would be a more ergonomic way of doing this? flat_map and and_then seem to come close, but only allow one value to be returned, when I was looking for a similar function that allows you to return tuples. If there is some obvious different solution I am missing here, I would love to hear that too.

[epage]

In being fully declarative, I would write:

let identifier = repeat(1.., parse_alpha_numerical);
let params = delimited('(', separated(1.., parse_param, ','), ')');
seq!{Function {
    identifier,
    params,
}).parse_next(input)

alternatively, you could do:

(
    repeat(1.., parse_alpha_numerical),
    delimited('(', separated(1.., parse_param, ','), ')')
)
    .map(|(identifier, params)| Function { identifier, params })
    .parse_next(input)

However, do not feel obligated to force everything into being declarative. Imperative parsing has its place.

btw I'd recommend take_while over repeat for identifier. You'd need to add a .map(|s| s.to_owned()) to it.