gentoo-utils/src/useflag/parsers.rs

use mon::{Parser, ParserIter, ascii_alphanumeric, one_of, tag};

use crate::{
    Parseable,
    useflag::{IUseFlag, UseFlag},
};

impl<'a> Parseable<'a, &'a str> for UseFlag {
    type Parser = impl Parser<&'a str, Output = Self>;

    fn parser() -> Self::Parser {
        let start = ascii_alphanumeric();
        let rest = ascii_alphanumeric()
            .or(one_of("+_@-".chars()))
            .repeated()
            .many();

        start
            .and(rest)
            .recognize()
            .map(|output: &str| UseFlag(output.to_string()))
    }
}

impl<'a> Parseable<'a, &'a str> for IUseFlag {
    type Parser = impl Parser<&'a str, Output = Self>;

    fn parser() -> Self::Parser {
        UseFlag::parser()
            .preceded_by(tag("+"))
            .map(|flag| IUseFlag {
                default: true,
                flag,
            })
            .or(UseFlag::parser().map(|flag| IUseFlag {
                default: false,
                flag,
            }))
    }
}