在反序列化时，使用serde将外部字符串引用( in /“外键”)解析到同一文档中其他位置的结构

use serde::{Serialize, Deserialize};

#[derive(Serialize, Deserialize)]
struct Document {
    #[serde(with = "external_string")]
    reference: String,
    // other fields
}

mod external_string {
    use serde::{Serialize, Deserialize};

    pub fn serialize<S>(value: &String, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        // serialize logic
        // e.g. serializer.serialize_str(value)
        unimplemented!()
    }

    pub fn deserialize<'de, D>(deserializer: D) -> Result<String, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        // deserialize logic
        // e.g. deserializer.deserialize_str()
        unimplemented!()
    }
}

fn main() {
    let json = r#"{
        "reference": "external string"
    }"#;

    let document: Document = serde_json::from_str(json).unwrap();
    println!("{:?}", document);
}