序列化未实现序列化的外部机箱枚举的vec

Question

我使用外部crate与枚举，它没有实现序列化，我想在struct中使用它，它将包含此枚举的Vec of，并有可能对此结构进行反/序列化。基于我创建的serde documentation，下面的代码

use serde::{Serialize, Deserialize};

#[derive(Debug, PartialEq, Eq)]
enum ExternalCrateColor {
    Red,
    Green,
    Blue
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(remote = "ExternalCrateColor")]
enum LocalColor {
    Red,
    Green,
    Blue
}

#[derive(Debug, Serialize, Deserialize)]
struct Hue {
    #[serde(with = "LocalColor")]
    color: ExternalCrateColor
}

fn main() {
    let tones = Hue { color: ExternalCrateColor::Blue };
    let serialized = serde_json::to_string(&tones).unwrap();
    println!("serialized = {}", serialized);
    let deserialized: Hue = serde_json::from_str(&serialized).unwrap();
    if deserialized.color == ExternalCrateColor::Blue {
      println!("Blue tones");
    }
}

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但我想要的是让色调结构包含ExternalCrateColor的Vec：

struct Hue {
    #[serde(with = "LocalColor")]
    colors: Vec<ExternalCrateColor>
}

而且它不起作用，因为在这种情况下，反/序列化需要单个ExternalCrateColor。如何让它工作？

Answer 1

我不认为您可以使用serde的远程类型特性来实现这一点，但是您可以通过首先定义一个转换来实现：

fn to_local(color: &ExternalCrateColor) -> LocalColor {
    match color {
        ExternalCrateColor::Red => LocalColor::Red,
        ExternalCrateColor::Green => LocalColor::Green,
        ExternalCrateColor::Blue => LocalColor::Blue,
    }
}
fn to_external(color: &LocalColor) -> ExternalCrateColor {
    match color {
        LocalColor::Red => ExternalCrateColor::Red,
        LocalColor::Green => ExternalCrateColor::Green,
        LocalColor::Blue => ExternalCrateColor::Blue,
    }
}

使用这些转换，您可以像这样实现它：

fn color_vec_ser<S: Serializer>(
    vec: &Vec<ExternalCrateColor>,
    serializer: S
) -> Result<S::Ok, S::Error> {
    // First convert the vector into a Vec<LocalColor>.
    let vec2: Vec<LocalColor> = vec.iter().map(to_local).collect();

    // Instead of serializing Vec<ExternalCrateColor>, we serialize Vec<LocalColor>.
    vec2.serialize(serializer)
}
fn color_vec_deser<'de, D: Deserializer<'de>>(
    deserializer: D
) -> Result<Vec<ExternalCrateColor>, D::Error> {
    // Deserialize as if it was a Vec<LocalColor>.
    let vec: Vec<LocalColor> = Deserialize::deserialize(deserializer)?;

    // Convert it into an Vec<ExternalCrateColor>
    Ok(vec.iter().map(to_external).collect())
}

#[derive(Debug, Serialize, Deserialize)]
struct Hue {
    #[serde(serialize_with = "color_vec_ser")]
    #[serde(deserialize_with = "color_vec_deser")]
    colors: Vec<ExternalCrateColor>
}

Answer 2

我将需要检查serde的代码库，但我能够使它与黑客的工作。

use serde::{Serialize, Deserialize};

#[derive(Debug, PartialEq, Eq,)]
enum ExternalCrateColor {
    Red,
    Green,
    Blue
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(remote = "ExternalCrateColor")]
enum LocalColor {
    Red,
    Green,
    Blue
}

#[derive(Debug, Serialize, Deserialize)]
struct Adapter {
    #[serde(with = "LocalColor")]
    color: ExternalCrateColor
}

#[derive(Debug, Serialize, Deserialize)]
struct Hue {
    colors: Vec<Adapter>
}

fn main() {
        let adapters = vec![Adapter {  color: ExternalCrateColor::Blue }, Adapter {color: ExternalCrateColor::Green}];
        let hue = Hue {colors: adapters};
//     let tones = Hue { color: ExternalCrateColor::Blue };
//     let serialized = serde_json::to_string(&tones).unwrap();
//     println!("serialized = {}", serialized);
//     let deserialized: Hue = serde_json::from_str(&serialized).unwrap();
//     if deserialized.color == ExternalCrateColor::Blue {
//       println!("Blue tones");
//     }
}

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