[dependencies]
quick-xml = { version = "0.35", features = ["encoding"] }

<library>
  <book id="1">
    <title>Rust编程入门</title>
    <author>张三</author>
  </book>
  <book id="2">
    <title>XML精讲</title>
    <author>李四</author>
  </book>
</library>

use quick_xml::events::BytesStart;
use quick_xml::Reader;

fn main() -> Result<(), Box<std::error::Error>> {
    let xml = r#"
        <library>
          <book id="1">
            <title>Rust编程入门</title>
            <author>张三</author>
          </book>
        </library>"#;

    let mut reader = Reader::from_reader(xml.as_bytes());
    reader.trim_text(true); // 自动忽略纯空白文本节点

    let mut buf = Vec::new();
    let mut books = Vec::new();

    loop {
        match reader.read_event_into(&mut buf) {
            Ok(quick_xml::events::BytesEvent::Start(e)) => {
                if e.name().as_ref() == b"book" {
                    let id = e.attributes()
                        .find(|a| a.key.as_ref() == b"id")
                        .map(|a| std::str::from_utf8(&a.value).unwrap_or("").to_string());
                    books.push((id, String::new(), String::new()));
                }
            }
            Ok(quick_xml::events::BytesEvent::Text(e)) => {
                let text = e.unescape_and_decode(&reader)?; // 安全解码实体（& → &）
                if let Some(last) = books.last_mut() {
                    // 简单逻辑：紧接在 title/author 开始标签后的文本即为内容
                    // 实际中建议用状态机或栈记录当前路径
                }
            }
            Ok(quick_xml::events::BytesEvent::Eof) => break,
            Err(e) => return Err(e.into()),
            _ => {}
        }
        buf.clear();
    }

    Ok(())
}

use quick_xml::de::from_str;
use serde::{Deserialize, Serialize};

#[derive(Deserialize, Debug)]
struct Book {
    #[serde(rename = "@id")]
    id: String,
    title: String,
    author: String,
}

#[derive(Deserialize, Debug)]
struct Library {
    #[serde(rename = "$value")]
    books: Vec<Book>,
}

// 注意：quick-xml 的 serde 支持要求 XML 标签名与字段名匹配（或用 rename）
// 且需确保 XML 是形如 <library><book>...</book></library> 这样扁平嵌套

let data = r#"
<library>
  <book id="1">
    <title>Rust编程入门</title>
    <author>张三</author>
  </book>
</library>"#;

let library: Library = from_str(data).map_err(|e| e.to_string())?;
println!("{:#?}", library);