Serialization 使用serde对yaml或json进行反序列化时，如何分解枚举？

我有一段

serde

代码，它能满足我的需要，但我不喜欢它的工作方式。我正在寻求帮助，以找出如何改进它

应解析为

struct Connector

我想我可以使用枚举表示来处理这个问题，但是，它会产生不希望的副作用-默认情况下，遵循yaml：

- id: Foo
  source: Bar
  type: Connector
- id: Foo
  source: Bar
  type: Generator

将被解析为：

[Connector(Connector{...}), Generator(Generator{...})]

因此，我的结构被包装在枚举变量中。为了“展开它”，我想我可以从迭代器实现

#[serde（from=“FromType”）]
-我认为它的工作方式是强制将枚举变量直接转换为所需的结构，无需额外迭代和代码重复。然而，我没有实现它-

当我试图从

属性添加

时

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
enum AllModels {
  Gene(Generator),
  Connector(Connector),
}

编译器会对我大喊大叫

 ❯ cargo r
   Compiling serdeissue v0.1.0 (/sandbox/serdeissue)
error[E0277]: the trait bound `Box<dyn Model>: From<AllModels>` is not satisfied
  --> src/main.rs:21:24
   |
21 | #[derive(Debug, Clone, Serialize, Deserialize)]
   |                        ^^^^^^^^^ the trait `From<AllModels>` is not implemented for `Box<dyn Model>`
   |
   = help: the following implementations were found:
             <Box<(dyn StdError + 'a)> as From<E>>
             <Box<(dyn StdError + 'static)> as From<&str>>
             <Box<(dyn StdError + 'static)> as From<Cow<'a, str>>>
             <Box<(dyn StdError + 'static)> as From<std::string::String>>
           and 22 others
   = note: required because of the requirements on the impl of `Into<Box<dyn Model>>` for `AllModels`
   = note: required by `into`
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `dyn Model: Serialize` is not satisfied
   --> src/main.rs:21:24
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                        ^^^^^^^^^ the trait `Serialize` is not implemented for `dyn Model`
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/ser/mod.rs:247:18
    |
247 |     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    |                  - required by this bound in `serialize`
    |
    = note: required because of the requirements on the impl of `Serialize` for `Box<dyn Model>`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `dyn Model: Deserialize<'_>` is not satisfied
   --> src/main.rs:21:35
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                                   ^^^^^^^^^^^ the trait `Deserialize<'_>` is not implemented for `dyn Model`
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/de/mod.rs:539:12
    |
539 |         D: Deserializer<'de>;
    |            ----------------- required by this bound in `_::_serde::Deserialize::deserialize`
    |
    = note: required because of the requirements on the impl of `Deserialize<'_>` for `Box<dyn Model>`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `AllModels: From<Box<dyn Model>>` is not satisfied
   --> src/main.rs:21:35
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                                   ^^^^^^^^^^^ the trait `From<Box<dyn Model>>` is not implemented for `AllModels`
    |
   ::: /home/marcin/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:372:1
    |
372 | pub trait From<T>: Sized {
    | ------------------------ required by this bound in `From`
    |
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

我正在寻找的功能似乎正等待在此处实现：

还有一个问题建议手动反序列化器实现。游乐场代码表明，这可能有助于解决我的问题#2“额外迭代”，但代码实现中仍有一些重复，因此我仍在寻找更好的答案


编辑：我也在考虑，不知道什么是评估我是否需要其中一个的正确方法。
我找到了一个让我满意的解决方案：


光滑的
没有代码重复
没有动态调度，没有额外的迭代
使用
enum
和
serde（tag=“…”）

type
字段在json/yaml中可能会出现顺序错误（不必是第一个）
类型
字段在序列化回json/yaml时包含在内



诀窍是使用

使用serde:：{序列化，反序列化}；
使用enum_dispatch:：enum_dispatch；
#[派生（调试、克隆、序列化、反序列化）]
结构生成器{
source_id:String，
id:String，
}
#[派生（调试、克隆、序列化、反序列化）]
结构门{
source_id:String，
id:String，
}
#[枚举调度]
性状模型{fn时间推进（self，a:i32，b:i32）->i32；}
发电机{fn时间推进（self，a:i32，b:i32）->i32{a+b}的impl模型
门{fn时间推进（self，a:i32，b:i32）->i32{a+b}的impl模型
#[枚举调度（模型）]
#[派生（调试、克隆、序列化、反序列化）]
#[serde（tag=“type”）]
枚举模型类型{
发电机（发电机），
门(门),，
}
fn main（）{
设s=r#”
-来源_id:“发电机-01”
id:“连接器-01”
类型：“发电机”
-来源编号：“geneiator-01”
类型：“浇口”
id:“连接器-01”
"#;
让数据：Vec=serde_yaml:：from_str（s）.unwrap（）；
println！（“{：？}”，serde_yaml:：to_string（&data））；
对于数据中的d{
println！（“{：？}”，d.time_-advance（4,2））；
}
}

输出：

>货物运输
编译enum_unpack v0.1.0（…/enum_unpack）
在0.66秒内完成开发[未优化+调试信息]目标
正在运行“目标/调试/枚举”解包`
正常（“--\n-类型：生成器\n源\u id:生成器-01\n id:连接器-01\n-类型：门\n源\u id:生成器-01\n id:连接器-01\n”）
6.
6.

[Connector{...}, Generator{...}]

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
enum AllModels {
  Gene(Generator),
  Connector(Connector),
}

 ❯ cargo r
   Compiling serdeissue v0.1.0 (/sandbox/serdeissue)
error[E0277]: the trait bound `Box<dyn Model>: From<AllModels>` is not satisfied
  --> src/main.rs:21:24
   |
21 | #[derive(Debug, Clone, Serialize, Deserialize)]
   |                        ^^^^^^^^^ the trait `From<AllModels>` is not implemented for `Box<dyn Model>`
   |
   = help: the following implementations were found:
             <Box<(dyn StdError + 'a)> as From<E>>
             <Box<(dyn StdError + 'static)> as From<&str>>
             <Box<(dyn StdError + 'static)> as From<Cow<'a, str>>>
             <Box<(dyn StdError + 'static)> as From<std::string::String>>
           and 22 others
   = note: required because of the requirements on the impl of `Into<Box<dyn Model>>` for `AllModels`
   = note: required by `into`
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `dyn Model: Serialize` is not satisfied
   --> src/main.rs:21:24
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                        ^^^^^^^^^ the trait `Serialize` is not implemented for `dyn Model`
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/ser/mod.rs:247:18
    |
247 |     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    |                  - required by this bound in `serialize`
    |
    = note: required because of the requirements on the impl of `Serialize` for `Box<dyn Model>`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `dyn Model: Deserialize<'_>` is not satisfied
   --> src/main.rs:21:35
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                                   ^^^^^^^^^^^ the trait `Deserialize<'_>` is not implemented for `dyn Model`
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/de/mod.rs:539:12
    |
539 |         D: Deserializer<'de>;
    |            ----------------- required by this bound in `_::_serde::Deserialize::deserialize`
    |
    = note: required because of the requirements on the impl of `Deserialize<'_>` for `Box<dyn Model>`
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `AllModels: From<Box<dyn Model>>` is not satisfied
   --> src/main.rs:21:35
    |
21  | #[derive(Debug, Clone, Serialize, Deserialize)]
    |                                   ^^^^^^^^^^^ the trait `From<Box<dyn Model>>` is not implemented for `AllModels`
    |
   ::: /home/marcin/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:372:1
    |
372 | pub trait From<T>: Sized {
    | ------------------------ required by this bound in `From`
    |
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

impl From<AllModels> for Box<dyn Model> {
    fn from(am: AllModels) -> Self {
        Box::new(Generator{id:String::from("arst"),source_id:String::from("arst")})
    }
}
impl Serialize for dyn Model {
    fn serialize(&self) -> Self {
        Box::new(Generator{id:String::from("arst"),source_id:String::from("arst")})
    }
}

impl Deserialize<'_> for dyn Model {}
impl From<Box<dyn Model>> for AllModels {
    fn from(dm: Box<dyn Model>) -> Self {
        AllModels::Gene(Generator{id:String::from("arst"),source_id:String::from("arst")})
    }
}

 ❯ cargo r
   Compiling serdeissue v0.1.0 (/sandbox/serdeissue)
error[E0277]: the size for values of type `(dyn Model + 'static)` cannot be known at compilation time
   --> src/main.rs:75:6
    |
75  | impl Deserialize<'_> for dyn Model {}
    |      ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/de/mod.rs:530:29
    |
530 | pub trait Deserialize<'de>: Sized {
    |                             ----- required by this bound in `Deserialize`
    |
    = help: the trait `Sized` is not implemented for `(dyn Model + 'static)`

use erased_serde::{Deserializer,  Serializer, serialize_trait_object};
use serde::{Serialize, Deserialize};


#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Generator {
  id: String,
  source: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Connector {
  id: String,
  source: String,
}

trait Model: std::fmt::Debug + erased_serde::Serialize {}
erased_serde::serialize_trait_object!(Model);
impl Model for Generator {}
impl Model for Connector {}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type", into = "Box<dyn Model>", from = "Box<dyn Model>")]
enum AllModels {
  Generator(Generator),
  Connector(Connector),
}

fn main() {
  let data = r#"
- source: "generator-01"
  id: "g-01"
  type: "Generator"
- source: "connector-01"
  type: "Connector"
  id: "c-01"
"#;
  let p: Vec<Box<dyn Model>> = serde_yaml::from_str(&data).unwrap();
  println!("{:?}", p);
}


impl From<AllModels> for Box<dyn Model> {
    fn from(am: AllModels) -> Self {
        Box::new(Generator{id:String::from("arst"),source_id:String::from("arst")})
    }
}
// impl Serialize for dyn Model {
//     fn serialize(&self) -> Self {
//         Box::new(Generator{id:String::from("arst"),source_id:String::from("arst")})
//     }
// }
impl Deserialize<'_> for dyn Model {}
impl From<Box<dyn Model>> for AllModels {
    fn from(dm: Box<dyn Model>) -> Self {
        AllModels::Generator(Generator{id:String::from("arst"),source_id:String::from("arst")})
    }
}

// impl std::convert::From<AllModels> for Box<dyn Model> {
//     fn from(m: AllModels) -> Self {
//        Box::new(Generator {source_id: String::from("i"), id: String::from("r")})
//     }
//     }


 ❯ cargo r
   Compiling serdeissue v0.1.0 (/sandbox/serdeissue)
warning: unused imports: `Deserializer`, `Serializer`, `serialize_trait_object`
 --> src/main.rs:1:20
  |
1 | use erased_serde::{Deserializer,  Serializer, serialize_trait_object};
  |                    ^^^^^^^^^^^^   ^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

error[E0277]: the size for values of type `(dyn Model + 'static)` cannot be known at compilation time
   --> src/main.rs:76:6
    |
76  | impl Deserialize<'_> for dyn Model {}
    |      ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
   ::: /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/de/mod.rs:530:29
    |
530 | pub trait Deserialize<'de>: Sized {
    |                             ----- required by this bound in `Deserialize`
    |
    = help: the trait `Sized` is not implemented for `(dyn Model + 'static)`

❯ cargo r
   Compiling serdeissue v0.1.0 (/sandbox/serdeissue)
error[E0603]: module `export` is private
   --> src/main.rs:168:10
    |
168 | #[derive(Serialize)]
    |          ^^^^^^^^^ private module
    |
note: the module `export` is defined here
   --> /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/lib.rs:275:5
    |
275 | use self::__private as export;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0603]: module `export` is private
   --> src/main.rs:173:10
    |
173 | #[derive(Serialize)]
    |          ^^^^^^^^^ private module
    |
note: the module `export` is defined here
   --> /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/lib.rs:275:5
    |
275 | use self::__private as export;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0603]: module `export` is private
   --> src/main.rs:179:10
    |
179 | #[derive(Serialize)]
    |          ^^^^^^^^^ private module
    |
note: the module `export` is defined here
   --> /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/lib.rs:275:5
    |
275 | use self::__private as export;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0603]: module `export` is private
   --> src/main.rs:184:10
    |
184 | #[derive(Serialize)]
    |          ^^^^^^^^^ private module
    |
note: the module `export` is defined here
   --> /home/marcin/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.123/src/lib.rs:275:5
    |
275 | use self::__private as export;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^

warning: trait objects without an explicit `dyn` are deprecated
   --> src/main.rs:176:22
    |
176 |     widgets: Vec<Box<WidgetTrait>>,
    |                      ^^^^^^^^^^^ help: use `dyn`: `dyn WidgetTrait`
    |
    = note: `#[warn(bare_trait_objects)]` on by default

[package]
name = "enum_unpack"
version = "0.1.0"
authors = ["---"]
edition = "2018"

[dependencies]
serde = { version = "1.0.124", features = ["derive"] }
serde_yaml = "0.8.1"
enum_dispatch = "0.3.5"