14.3.2. 反序列化 TOML 配置文件

将一些 TOML 配置项解析为一个通用的值 toml::Value，该值能够表示任何有效的 TOML 数据。

use toml::{Value, de::Error};

fn main() -> Result<(), Error> {
    let toml_content = r#"
          [package]
          name = "your_package"
          version = "0.1.0"
          authors = ["You! <you@example.org>"]

          [dependencies]
          serde = "1.0"
          "#;

    let package_info: Value = toml::from_str(toml_content)?;

    assert_eq!(package_info["dependencies"]["serde"].as_str(), Some("1.0"));
    assert_eq!(package_info["package"]["name"].as_str(),
               Some("your_package"));

    Ok(())
}

使用 Serde crate 将 TOML 解析为自定义的结构体。

use serde::Deserialize;

use toml::de::Error;
use std::collections::HashMap;

#[derive(Deserialize)]
struct Config {
    package: Package,
    dependencies: HashMap<String, String>,
}

#[derive(Deserialize)]
struct Package {
    name: String,
    version: String,
    authors: Vec<String>,
}

fn main() -> Result<(), Error> {
    let toml_content = r#"
          [package]
          name = "your_package"
          version = "0.1.0"
          authors = ["You! <you@example.org>"]

          [dependencies]
          serde = "1.0"
          "#;

    let package_info: Config = toml::from_str(toml_content)?;

    assert_eq!(package_info.package.name, "your_package");
    assert_eq!(package_info.package.version, "0.1.0");
    assert_eq!(package_info.package.authors, vec!["You! <you@example.org>"]);
    assert_eq!(package_info.dependencies["serde"], "1.0");

    Ok(())
}