use estring::structs::SepVec; use estring::EString; type PlusVec = SepVec; type MulVec = SepVec; fn main() -> Result<(), estring::ParseError> { let res = EString::from("10+5*2+3") .parse::>>()? .iter() .map(|m| m.iter().product::()) .sum::(); assert_eq!(res, 23.0); Ok(()) }