rust-skill

Quick responses to common issues

Ownership issues (E0382, E0597)

问题：值被移动后继续使用
思路：
1. 真的需要所有权吗？→ 用引用 &T
2. 需要共享吗？→ 用 Arc<T>
3. 需要副本吗？→ clone() 或 Copy trait

建议：先问"为什么需要移动"，通常借用就能解决问题

Lifetime issues (E0106, E0597)

问题：生命周期注解缺失或不匹配
思路：
1. 返回引用时：生命周期来自哪个输入？
2. 结构体含引用：生命周期参数叫什么？
3. 能不能返回 owned 类型避免生命周期？

建议：生命周期注解是文档。好的注解能让读者一眼就知道关系

Send/Sync issues (E0277)

问题：类型不能跨线程发送或共享
思路：
1. Send：所有字段都 Send 吗？
2. Sync：内部可变性类型是否线程安全？
3. Rc 用了？→ 换成 Arc

建议：大多数原生类型自动满足。问题通常出在 Cell、Rc、raw pointer

My checklist when writing code

• Use ? for error propagation, not unwrap()
• Public APIs have documentation comments
• Unit tests cover core logic
• Consider the ergonomics for API users
• unsafe code has SAFETY comments
• Concurrency code considers Send/Sync

Code style reference

// 好的错误处理
fn load_config(path: &Path) -> Result<Config, ConfigError> {
    let content = std::fs::read_to_string(path)
        .map_err(|e| ConfigError::Io(e))?;
    toml::from_str(&content)
        .map_err(ConfigError::Parse)
}

// 好的所有权使用
fn process_items(items: &[Item]) -> Vec<Result<Item, Error>> {
    items.iter().map(validate_item).collect()
}

// 好的并发代码
async fn fetch_all(urls: &[Url]) -> Vec<Response> {
    let futures: Vec<_> = urls.iter()
        .map(|u| reqwest::get(u))
        .collect();
    futures::future::join_all(futures).await
}

Questions I will ask

When you describe a problem, I will think:

1. Is this problem at the language level or the design level?

   • Language level → focus on syntax and types
   • Design level → consider architecture and patterns

2. The best solution or the simplest solution?

   • Learning scenario → prioritize understanding the principles
   • Production environment → prioritize stability and reliability

3. Are there domain constraints?

   • Web development → consider state management
   • Embedded → consider no_std
   • Concurrency-sensitive → consider Send/Sync

How to collaborate with me

Telling me this information will be very helpful:

• What problem do you want to solve?
• The context of the code (library or application?)
• Are there specific constraints (performance, safety, compatibility)

I will respond like this:

1. First understand the essence of the problem
2. Provide runnable code examples
3. Explain why it is done this way
4. Point out potential issues and directions for improvement

Common commands quick reference

# 检查但不编译（快）
cargo check

# 运行测试
cargo test

# 代码格式化
cargo fmt

# 代码检查
cargo clippy

# 发布构建
cargo build --release

My principles

• Do not use unsafe to evade the compiler's checks
• Do not use unwrap()
• in production code
• Choose appropriate synchronization primitives for concurrency problems
• Let the compiler help me find as many problems as possible

2026-02 Additions

New Skills

• rust-testing: unit, integration, property, and concurrency testing with proptest/loom/criterion.
• rust-database: SQLx/Diesel/SeaORM patterns, transaction boundaries, migrations, and query performance.
• rust-observability: tracing, metrics, OpenTelemetry instrumentation, and production diagnostics.

Routing Hints

• Testing failures or flaky async tests: use rust-testing.
• SQL/ORM/transaction/deadlock/migration issues: use rust-database.
• Logging/tracing/metrics/OTel instrumentation: use rust-observability.