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<ol class="chapter"><li class="chapter-item affix "><a href="../../about-book.html">关于本书</a></li><li class="chapter-item affix "><a href="../../into-rust.html">进入 Rust 编程世界</a></li><li class="chapter-item affix "><a href="../../first-try/sth-you-should-not-do.html">避免从入门到放弃</a></li><li class="chapter-item affix "><a href="../../community.html">社区和锈书</a></li><li class="chapter-item affix "><li class="part-title">Rust 语言基础学习</li><li class="spacer"></li><li class="chapter-item "><a href="../../first-try/intro.html"><strong aria-hidden="true">1.</strong> 寻找牛刀，以便小试</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../first-try/installation.html"><strong aria-hidden="true">1.1.</strong> 安装 Rust 环境</a></li><li class="chapter-item "><a href="../../first-try/editor.html"><strong aria-hidden="true">1.2.</strong> 墙推 VSCode!</a></li><li class="chapter-item "><a href="../../first-try/cargo.html"><strong aria-hidden="true">1.3.</strong> 认识 Cargo</a></li><li class="chapter-item "><a href="../../first-try/hello-world.html"><strong aria-hidden="true">1.4.</strong> 不仅仅是 Hello world</a></li><li class="chapter-item "><a href="../../first-try/slowly-downloading.html"><strong aria-hidden="true">1.5.</strong> 下载依赖太慢了？</a></li></ol></li><li class="chapter-item expanded "><a href="../../basic/intro.html"><strong aria-hidden="true">2.</strong> Rust 基础入门</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/variable.html"><strong aria-hidden="true">2.1.</strong> 变量绑定与解构</a></li><li class="chapter-item "><a href="../../basic/base-type/index.html"><strong aria-hidden="true">2.2.</strong> 基本类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/base-type/numbers.html"><strong aria-hidden="true">2.2.1.</strong> 数值类型</a></li><li class="chapter-item "><a href="../../basic/base-type/char-bool.html"><strong aria-hidden="true">2.2.2.</strong> 字符、布尔、单元类型</a></li><li class="chapter-item "><a href="../../basic/base-type/statement-expression.html"><strong aria-hidden="true">2.2.3.</strong> 语句与表达式</a></li><li class="chapter-item "><a href="../../basic/base-type/function.html"><strong aria-hidden="true">2.2.4.</strong> 函数</a></li></ol></li><li class="chapter-item "><a href="../../basic/ownership/index.html"><strong aria-hidden="true">2.3.</strong> 所有权和借用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/ownership/ownership.html"><strong aria-hidden="true">2.3.1.</strong> 所有权</a></li><li class="chapter-item "><a href="../../basic/ownership/borrowing.html"><strong aria-hidden="true">2.3.2.</strong> 引用与借用</a></li></ol></li><li class="chapter-item "><a href="../../basic/compound-type/intro.html"><strong aria-hidden="true">2.4.</strong> 复合类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/compound-type/string-slice.html"><strong aria-hidden="true">2.4.1.</strong> 字符串与切片</a></li><li class="chapter-item "><a href="../../basic/compound-type/tuple.html"><strong aria-hidden="true">2.4.2.</strong> 元组</a></li><li class="chapter-item "><a href="../../basic/compound-type/struct.html"><strong aria-hidden="true">2.4.3.</strong> 结构体</a></li><li class="chapter-item "><a href="../../basic/compound-type/enum.html"><strong aria-hidden="true">2.4.4.</strong> 枚举</a></li><li class="chapter-item "><a href="../../basic/compound-type/array.html"><strong aria-hidden="true">2.4.5.</strong> 数组</a></li></ol></li><li class="chapter-item "><a href="../../basic/flow-control.html"><strong aria-hidden="true">2.5.</strong> 流程控制</a></li><li class="chapter-item "><a href="../../basic/match-pattern/intro.html"><strong aria-hidden="true">2.6.</strong> 模式匹配</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/match-pattern/match-if-let.html"><strong aria-hidden="true">2.6.1.</strong> match 和 if let</a></li><li class="chapter-item "><a href="../../basic/match-pattern/option.html"><strong aria-hidden="true">2.6.2.</strong> 解构 Option</a></li><li class="chapter-item "><a href="../../basic/match-pattern/pattern-match.html"><strong aria-hidden="true">2.6.3.</strong> 模式适用场景</a></li><li class="chapter-item "><a href="../../basic/match-pattern/all-patterns.html"><strong aria-hidden="true">2.6.4.</strong> 全模式列表</a></li></ol></li><li class="chapter-item "><a href="../../basic/method.html"><strong aria-hidden="true">2.7.</strong> 方法 Method</a></li><li class="chapter-item "><a href="../../basic/trait/intro.html"><strong aria-hidden="true">2.8.</strong> 泛型和特征</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/trait/generic.html"><strong aria-hidden="true">2.8.1.</strong> 泛型 Generics</a></li><li class="chapter-item "><a href="../../basic/trait/trait.html"><strong aria-hidden="true">2.8.2.</strong> 特征 Trait</a></li><li class="chapter-item "><a href="../../basic/trait/trait-object.html"><strong aria-hidden="true">2.8.3.</strong> 特征对象</a></li><li class="chapter-item "><a href="../../basic/trait/advance-trait.html"><strong aria-hidden="true">2.8.4.</strong> 进一步深入特征</a></li></ol></li><li class="chapter-item "><a href="../../basic/collections/intro.html"><strong aria-hidden="true">2.9.</strong> 集合类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/collections/vector.html"><strong aria-hidden="true">2.9.1.</strong> 动态数组 Vector</a></li><li class="chapter-item "><a href="../../basic/collections/hashmap.html"><strong aria-hidden="true">2.9.2.</strong> KV 存储 HashMap</a></li></ol></li><li class="chapter-item "><a href="../../basic/lifetime.html"><strong aria-hidden="true">2.10.</strong> 认识生命周期</a></li><li class="chapter-item "><a href="../../basic/result-error/intro.html"><strong aria-hidden="true">2.11.</strong> 返回值和错误处理</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/result-error/panic.html"><strong aria-hidden="true">2.11.1.</strong> panic! 深入剖析</a></li><li class="chapter-item "><a href="../../basic/result-error/result.html"><strong aria-hidden="true">2.11.2.</strong> 返回值 Result 和?</a></li></ol></li><li class="chapter-item expanded "><a href="../../basic/crate-module/intro.html"><strong aria-hidden="true">2.12.</strong> 包和模块</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic/crate-module/crate.html"><strong aria-hidden="true">2.12.1.</strong> 包 Crate</a></li><li class="chapter-item expanded "><a href="../../basic/crate-module/module.html" class="active"><strong aria-hidden="true">2.12.2.</strong> 模块 Module</a></li><li class="chapter-item "><a href="../../basic/crate-module/use.html"><strong aria-hidden="true">2.12.3.</strong> 使用 use 引入模块及受限可见性</a></li></ol></li><li class="chapter-item "><a href="../../basic/comment.html"><strong aria-hidden="true">2.13.</strong> 注释和文档</a></li><li class="chapter-item "><a href="../../basic/formatted-output.html"><strong aria-hidden="true">2.14.</strong> 格式化输出</a></li></ol></li><li class="chapter-item "><a href="../../basic-practice/intro.html"><strong aria-hidden="true">3.</strong> 入门实战：文件搜索工具</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../basic-practice/base-features.html"><strong aria-hidden="true">3.1.</strong> 基本功能</a></li><li class="chapter-item "><a href="../../basic-practice/refactoring.html"><strong aria-hidden="true">3.2.</strong> 增加模块化和错误处理</a></li><li class="chapter-item "><a href="../../basic-practice/tests.html"><strong aria-hidden="true">3.3.</strong> 测试驱动开发</a></li><li class="chapter-item "><a href="../../basic-practice/envs.html"><strong aria-hidden="true">3.4.</strong> 使用环境变量</a></li><li class="chapter-item "><a href="../../basic-practice/stderr.html"><strong aria-hidden="true">3.5.</strong> 重定向错误信息的输出</a></li><li class="chapter-item "><a href="../../basic-practice/iterators.html"><strong aria-hidden="true">3.6.</strong> 使用迭代器来改进程序(可选)</a></li></ol></li><li class="chapter-item "><li class="part-title">Rust 语言进阶学习</li><li class="spacer"></li><li class="chapter-item "><a href="../../advance/intro.html"><strong aria-hidden="true">4.</strong> Rust 高级进阶</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/lifetime/intro.html"><strong aria-hidden="true">4.1.</strong> 生命周期</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/lifetime/advance.html"><strong aria-hidden="true">4.1.1.</strong> 深入生命周期</a></li><li class="chapter-item "><a href="../../advance/lifetime/static.html"><strong aria-hidden="true">4.1.2.</strong> &'static 和 T: 'static</a></li></ol></li><li class="chapter-item "><a href="../../advance/functional-programing/intro.html"><strong aria-hidden="true">4.2.</strong> 函数式编程: 闭包、迭代器</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/functional-programing/closure.html"><strong aria-hidden="true">4.2.1.</strong> 闭包 Closure</a></li><li class="chapter-item "><a href="../../advance/functional-programing/iterator.html"><strong aria-hidden="true">4.2.2.</strong> 迭代器 Iterator</a></li></ol></li><li class="chapter-item "><a href="../../advance/into-types/intro.html"><strong aria-hidden="true">4.3.</strong> 深入类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/into-types/converse.html"><strong aria-hidden="true">4.3.1.</strong> 类型转换</a></li><li class="chapter-item "><a href="../../advance/into-types/custom-type.html"><strong aria-hidden="true">4.3.2.</strong> newtype 和 类型别名</a></li><li class="chapter-item "><a href="../../advance/into-types/sized.html"><strong aria-hidden="true">4.3.3.</strong> Sized 和不定长类型 DST</a></li><li class="chapter-item "><a href="../../advance/into-types/enum-int.html"><strong aria-hidden="true">4.3.4.</strong> 枚举和整数</a></li></ol></li><li class="chapter-item "><a href="../../advance/smart-pointer/intro.html"><strong aria-hidden="true">4.4.</strong> 智能指针</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/smart-pointer/box.html"><strong aria-hidden="true">4.4.1.</strong> Box堆对象分配</a></li><li class="chapter-item "><a href="../../advance/smart-pointer/deref.html"><strong aria-hidden="true">4.4.2.</strong> Deref 解引用</a></li><li class="chapter-item "><a href="../../advance/smart-pointer/drop.html"><strong aria-hidden="true">4.4.3.</strong> Drop 释放资源</a></li><li class="chapter-item "><a href="../../advance/smart-pointer/rc-arc.html"><strong aria-hidden="true">4.4.4.</strong> Rc 与 Arc 实现 1vN 所有权机制</a></li><li class="chapter-item "><a href="../../advance/smart-pointer/cell-refcell.html"><strong aria-hidden="true">4.4.5.</strong> Cell 与 RefCell 内部可变性</a></li></ol></li><li class="chapter-item "><a href="../../advance/circle-self-ref/intro.html"><strong aria-hidden="true">4.5.</strong> 循环引用与自引用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/circle-self-ref/circle-reference.html"><strong aria-hidden="true">4.5.1.</strong> Weak 与循环引用</a></li><li class="chapter-item "><a href="../../advance/circle-self-ref/self-referential.html"><strong aria-hidden="true">4.5.2.</strong> 结构体中的自引用</a></li></ol></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/intro.html"><strong aria-hidden="true">4.6.</strong> 多线程并发编程</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/concurrency-with-threads/concurrency-parallelism.html"><strong aria-hidden="true">4.6.1.</strong> 并发和并行</a></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/thread.html"><strong aria-hidden="true">4.6.2.</strong> 使用多线程</a></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/message-passing.html"><strong aria-hidden="true">4.6.3.</strong> 线程同步：消息传递</a></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/sync1.html"><strong aria-hidden="true">4.6.4.</strong> 线程同步：锁、Condvar 和信号量</a></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/sync2.html"><strong aria-hidden="true">4.6.5.</strong> 线程同步：Atomic 原子操作与内存顺序</a></li><li class="chapter-item "><a href="../../advance/concurrency-with-threads/send-sync.html"><strong aria-hidden="true">4.6.6.</strong> 基于 Send 和 Sync 的线程安全</a></li></ol></li><li class="chapter-item "><a href="../../advance/global-variable.html"><strong aria-hidden="true">4.7.</strong> 全局变量</a></li><li class="chapter-item "><a href="../../advance/errors.html"><strong aria-hidden="true">4.8.</strong> 错误处理</a></li><li class="chapter-item "><a href="../../advance/unsafe/intro.html"><strong aria-hidden="true">4.9.</strong> Unsafe Rust</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/unsafe/superpowers.html"><strong aria-hidden="true">4.9.1.</strong> 五种兵器</a></li><li class="chapter-item "><a href="../../advance/unsafe/inline-asm.html"><strong aria-hidden="true">4.9.2.</strong> 内联汇编</a></li></ol></li><li class="chapter-item "><a href="../../advance/macro.html"><strong aria-hidden="true">4.10.</strong> Macro 宏编程</a></li><li class="chapter-item "><a href="../../advance/async/intro.html"><strong aria-hidden="true">4.11.</strong> async/await 异步编程</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance/async/getting-started.html"><strong aria-hidden="true">4.11.1.</strong> async 编程入门</a></li><li class="chapter-item "><a href="../../advance/async/future-excuting.html"><strong aria-hidden="true">4.11.2.</strong> 底层探秘: Future 执行与任务调度</a></li><li class="chapter-item "><a href="../../advance/async/pin-unpin.html"><strong aria-hidden="true">4.11.3.</strong> 定海神针 Pin 和 Unpin</a></li><li class="chapter-item "><a href="../../advance/async/async-await.html"><strong aria-hidden="true">4.11.4.</strong> async/await 和 Stream 流处理</a></li><li class="chapter-item "><a href="../../advance/async/multi-futures-simultaneous.html"><strong aria-hidden="true">4.11.5.</strong> 同时运行多个 Future</a></li><li class="chapter-item "><a href="../../advance/async/pain-points-and-workarounds.html"><strong aria-hidden="true">4.11.6.</strong> 一些疑难问题的解决办法</a></li><li class="chapter-item "><a href="../../advance/async/web-server.html"><strong aria-hidden="true">4.11.7.</strong> 实践应用：Async Web 服务器</a></li></ol></li></ol></li><li class="chapter-item "><a href="../../advance-practice1/intro.html"><strong aria-hidden="true">5.</strong> 进阶实战1: 实现一个 web 服务器</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance-practice1/web-server.html"><strong aria-hidden="true">5.1.</strong> 单线程版本</a></li><li class="chapter-item "><a href="../../advance-practice1/multi-threads.html"><strong aria-hidden="true">5.2.</strong> 多线程版本</a></li><li class="chapter-item "><a href="../../advance-practice1/graceful-shutdown.html"><strong aria-hidden="true">5.3.</strong> 优雅关闭和资源清理</a></li></ol></li><li class="chapter-item "><a href="../../advance-practice/intro.html"><strong aria-hidden="true">6.</strong> 进阶实战2: 实现一个简单 Redis</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../advance-practice/overview.html"><strong aria-hidden="true">6.1.</strong> tokio 概览</a></li><li class="chapter-item "><a href="../../advance-practice/getting-startted.html"><strong aria-hidden="true">6.2.</strong> 使用初印象</a></li><li class="chapter-item "><a href="../../advance-practice/spawning.html"><strong aria-hidden="true">6.3.</strong> 创建异步任务</a></li><li class="chapter-item "><a href="../../advance-practice/shared-state.html"><strong aria-hidden="true">6.4.</strong> 共享状态</a></li><li class="chapter-item "><a href="../../advance-practice/channels.html"><strong aria-hidden="true">6.5.</strong> 消息传递</a></li><li class="chapter-item "><a href="../../advance-practice/io.html"><strong aria-hidden="true">6.6.</strong> I/O</a></li><li class="chapter-item "><a href="../../advance-practice/frame.html"><strong aria-hidden="true">6.7.</strong> 解析数据帧</a></li><li class="chapter-item "><a href="../../advance-practice/async.html"><strong aria-hidden="true">6.8.</strong> 深入 async</a></li><li class="chapter-item "><a href="../../advance-practice/select.html"><strong aria-hidden="true">6.9.</strong> select</a></li><li class="chapter-item "><a href="../../advance-practice/stream.html"><strong aria-hidden="true">6.10.</strong> 类似迭代器的 Stream</a></li><li class="chapter-item "><a href="../../advance-practice/graceful-shutdown.html"><strong aria-hidden="true">6.11.</strong> 优雅的关闭</a></li><li class="chapter-item "><a href="../../advance-practice/bridging-with-sync.html"><strong aria-hidden="true">6.12.</strong> 异步跟同步共存</a></li></ol></li><li class="chapter-item "><a href="../../difficulties/intro.html"><strong aria-hidden="true">7.</strong> Rust 难点攻关</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../difficulties/slice.html"><strong aria-hidden="true">7.1.</strong> 切片和切片引用</a></li><li class="chapter-item "><a href="../../difficulties/eq.html"><strong aria-hidden="true">7.2.</strong> Eq 和 PartialEq</a></li><li class="chapter-item "><a href="../../difficulties/string.html"><strong aria-hidden="true">7.3.</strong> String、&str 和 str TODO</a></li><li class="chapter-item "><a href="../../difficulties/lifetime.html"><strong aria-hidden="true">7.4.</strong> 作用域、生命周期和 NLL TODO</a></li><li class="chapter-item "><a href="../../difficulties/move-copy.html"><strong aria-hidden="true">7.5.</strong> move、Copy 和 Clone TODO</a></li><li class="chapter-item "><a href="../../advance/difficulties/pointer.html"><strong aria-hidden="true">7.6.</strong> 裸指针、引用和智能指针 TODO</a></li></ol></li><li class="chapter-item "><li class="part-title">常用工具链</li><li class="spacer"></li><li class="chapter-item "><a href="../../test/intro.html"><strong aria-hidden="true">8.</strong> 自动化测试</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../test/write-tests.html"><strong aria-hidden="true">8.1.</strong> 编写测试及控制执行</a></li><li class="chapter-item "><a href="../../test/unit-integration-test.html"><strong aria-hidden="true">8.2.</strong> 单元测试和集成测试</a></li><li class="chapter-item "><a href="../../test/assertion.html"><strong aria-hidden="true">8.3.</strong> 断言 assertion</a></li><li class="chapter-item "><a href="../../test/ci.html"><strong aria-hidden="true">8.4.</strong> 用 GitHub Actions 进行持续集成</a></li><li class="chapter-item "><a href="../../test/benchmark.html"><strong aria-hidden="true">8.5.</strong> 基准测试 benchmark</a></li></ol></li><li class="chapter-item "><a href="../../cargo/intro.html"><strong aria-hidden="true">9.</strong> Cargo 使用指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../cargo/getting-started.html"><strong aria-hidden="true">9.1.</strong> 上手使用</a></li><li class="chapter-item "><a href="../../cargo/guide/intro.html"><strong aria-hidden="true">9.2.</strong> 基础指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../cargo/guide/why-exist.html"><strong aria-hidden="true">9.2.1.</strong> 为何会有 Cargo</a></li><li class="chapter-item "><a href="../../cargo/guide/download-package.html"><strong aria-hidden="true">9.2.2.</strong> 下载并构建 Package</a></li><li class="chapter-item "><a href="../../cargo/guide/dependencies.html"><strong aria-hidden="true">9.2.3.</strong> 添加依赖</a></li><li class="chapter-item "><a href="../../cargo/guide/package-layout.html"><strong aria-hidden="true">9.2.4.</strong> Package 目录结构</a></li><li class="chapter-item "><a href="../../cargo/guide/cargo-toml-lock.html"><strong aria-hidden="true">9.2.5.</strong> Cargo.toml vs Cargo.lock</a></li><li class="chapter-item "><a href="../../cargo/guide/tests-ci.html"><strong aria-hidden="true">9.2.6.</strong> 测试和 CI</a></li><li class="chapter-item "><a href="../../cargo/guide/cargo-cache.html"><strong aria-hidden="true">9.2.7.</strong> Cargo 缓存</a></li><li class="chapter-item "><a href="../../cargo/guide/build-cache.html"><strong aria-hidden="true">9.2.8.</strong> Build 缓存</a></li></ol></li><li class="chapter-item "><a href="../../cargo/reference/intro.html"><strong aria-hidden="true">9.3.</strong> 进阶指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../cargo/reference/specify-deps.html"><strong aria-hidden="true">9.3.1.</strong> 指定依赖项</a></li><li class="chapter-item "><a href="../../cargo/reference/deps-overriding.html"><strong aria-hidden="true">9.3.2.</strong> 依赖覆盖</a></li><li class="chapter-item "><a href="../../cargo/reference/manifest.html"><strong aria-hidden="true">9.3.3.</strong> Cargo.toml 清单详解</a></li><li class="chapter-item "><a href="../../cargo/reference/cargo-target.html"><strong aria-hidden="true">9.3.4.</strong> Cargo Target</a></li><li class="chapter-item "><a href="../../cargo/reference/workspaces.html"><strong aria-hidden="true">9.3.5.</strong> 工作空间 Workspace</a></li><li class="chapter-item "><a href="../../cargo/reference/features/intro.html"><strong aria-hidden="true">9.3.6.</strong> 条件编译 Features</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../cargo/reference/features/examples.html"><strong aria-hidden="true">9.3.6.1.</strong> Features 示例</a></li></ol></li><li class="chapter-item "><a href="../../cargo/reference/profiles.html"><strong aria-hidden="true">9.3.7.</strong> 发布配置 Profile</a></li><li class="chapter-item "><a href="../../cargo/reference/configuration.html"><strong aria-hidden="true">9.3.8.</strong> 通过 config.toml 对 Cargo 进行配置</a></li><li class="chapter-item "><a href="../../cargo/reference/publishing-on-crates.io.html"><strong aria-hidden="true">9.3.9.</strong> 发布到 crates.io</a></li><li class="chapter-item "><a href="../../cargo/reference/build-script/intro.html"><strong aria-hidden="true">9.3.10.</strong> 构建脚本 build.rs</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../cargo/reference/build-script/examples.html"><strong aria-hidden="true">9.3.10.1.</strong> 构建脚本示例</a></li></ol></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">开发实践</li><li class="spacer"></li><li class="chapter-item "><a href="../../usecases/intro.html"><strong aria-hidden="true">10.</strong> 企业落地实践</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../usecases/aws-rust.html"><strong aria-hidden="true">10.1.</strong> AWS 为何这么喜欢 Rust?</a></li></ol></li><li class="chapter-item "><a href="../../logs/intro.html"><strong aria-hidden="true">11.</strong> 日志和监控</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../logs/about-log.html"><strong aria-hidden="true">11.1.</strong> 日志详解</a></li><li class="chapter-item "><a href="../../logs/log.html"><strong aria-hidden="true">11.2.</strong> 日志门面 log</a></li><li class="chapter-item "><a href="../../logs/tracing.html"><strong aria-hidden="true">11.3.</strong> 使用 tracing 记录日志</a></li><li class="chapter-item "><a href="../../logs/tracing-logger.html"><strong aria-hidden="true">11.4.</strong> 自定义 tracing 的输出格式</a></li><li class="chapter-item "><a href="../../logs/observe/intro.html"><strong aria-hidden="true">11.5.</strong> 监控</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../logs/observe/about-observe.html"><strong aria-hidden="true">11.5.1.</strong> 可观测性</a></li><li class="chapter-item "><a href="../../logs/observe/trace.html"><strong aria-hidden="true">11.5.2.</strong> 分布式追踪</a></li></ol></li></ol></li><li class="chapter-item "><a href="../../practice/intro.html"><strong aria-hidden="true">12.</strong> Rust 最佳实践</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../practice/third-party-libs.html"><strong aria-hidden="true">12.1.</strong> 日常开发三方库精选</a></li><li class="chapter-item "><a href="../../practice/naming.html"><strong aria-hidden="true">12.2.</strong> 命名规范</a></li><li class="chapter-item "><a href="../../practice/interview.html"><strong aria-hidden="true">12.3.</strong> 面试经验</a></li><li class="chapter-item "><a href="../../practice/best-pratice.html"><strong aria-hidden="true">12.4.</strong> 代码开发实践 todo</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/intro.html"><strong aria-hidden="true">13.</strong> 手把手带你实现链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/do-we-need-it.html"><strong aria-hidden="true">13.1.</strong> 我们到底需不需要链表</a></li><li class="chapter-item "><a href="../../too-many-lists/bad-stack/intro.html"><strong aria-hidden="true">13.2.</strong> 不太优秀的单向链表：栈</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/bad-stack/layout.html"><strong aria-hidden="true">13.2.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../../too-many-lists/bad-stack/basic-operations.html"><strong aria-hidden="true">13.2.2.</strong> 基本操作</a></li><li class="chapter-item "><a href="../../too-many-lists/bad-stack/final-code.html"><strong aria-hidden="true">13.2.3.</strong> 最后实现</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/ok-stack/intro.html"><strong aria-hidden="true">13.3.</strong> 还可以的单向链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/ok-stack/type-optimizing.html"><strong aria-hidden="true">13.3.1.</strong> 优化类型定义</a></li><li class="chapter-item "><a href="../../too-many-lists/ok-stack/peek.html"><strong aria-hidden="true">13.3.2.</strong> 定义 Peek 函数</a></li><li class="chapter-item "><a href="../../too-many-lists/ok-stack/iter.html"><strong aria-hidden="true">13.3.3.</strong> IntoIter 和 Iter</a></li><li class="chapter-item "><a href="../../too-many-lists/ok-stack/itermut.html"><strong aria-hidden="true">13.3.4.</strong> IterMut 以及完整代码</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/persistent-stack/intro.html"><strong aria-hidden="true">13.4.</strong> 持久化单向链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/persistent-stack/layout.html"><strong aria-hidden="true">13.4.1.</strong> 数据布局和基本操作</a></li><li class="chapter-item "><a href="../../too-many-lists/persistent-stack/drop-arc.html"><strong aria-hidden="true">13.4.2.</strong> Drop、Arc 及完整代码</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/deque/intro.html"><strong aria-hidden="true">13.5.</strong> 不咋样的双端队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/deque/layout.html"><strong aria-hidden="true">13.5.1.</strong> 数据布局和基本操作</a></li><li class="chapter-item "><a href="../../too-many-lists/deque/peek.html"><strong aria-hidden="true">13.5.2.</strong> Peek</a></li><li class="chapter-item "><a href="../../too-many-lists/deque/symmetric.html"><strong aria-hidden="true">13.5.3.</strong> 基本操作的对称镜像</a></li><li class="chapter-item "><a href="../../too-many-lists/deque/iterator.html"><strong aria-hidden="true">13.5.4.</strong> 迭代器</a></li><li class="chapter-item "><a href="../../too-many-lists/deque/final-code.html"><strong aria-hidden="true">13.5.5.</strong> 最终代码</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/intro.html"><strong aria-hidden="true">13.6.</strong> 不错的 unsafe 队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/layout.html"><strong aria-hidden="true">13.6.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/basics.html"><strong aria-hidden="true">13.6.2.</strong> 基本操作</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/miri.html"><strong aria-hidden="true">13.6.3.</strong> Miri</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/stacked-borrow.html"><strong aria-hidden="true">13.6.4.</strong> 栈借用</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/testing-stacked-borrow.html"><strong aria-hidden="true">13.6.5.</strong> 测试栈借用</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/layout2.html"><strong aria-hidden="true">13.6.6.</strong> 数据布局 2</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/extra-junk.html"><strong aria-hidden="true">13.6.7.</strong> 额外的操作</a></li><li class="chapter-item "><a href="../../too-many-lists/unsafe-queue/final-code.html"><strong aria-hidden="true">13.6.8.</strong> 最终代码</a></li></ol></li><li class="chapter-item "><a href="../../too-many-lists/advanced-lists/intro.html"><strong aria-hidden="true">13.7.</strong> 使用高级技巧实现链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../too-many-lists/advanced-lists/unsafe-deque.html"><strong aria-hidden="true">13.7.1.</strong> 生产级可用的双向链表</a></li><li class="chapter-item "><a href="../../too-many-lists/advanced-lists/double-singly.html"><strong aria-hidden="true">13.7.2.</strong> 双单向链表</a></li><li class="chapter-item "><a href="../../too-many-lists/advanced-lists/stack-allocated.html"><strong aria-hidden="true">13.7.3.</strong> 栈上的链表</a></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">攻克编译错误</li><li class="spacer"></li><li class="chapter-item "><a href="../../compiler/intro.html"><strong aria-hidden="true">14.</strong> 征服编译错误</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../compiler/fight-with-compiler/intro.html"><strong aria-hidden="true">14.1.</strong> 对抗编译检查</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../compiler/fight-with-compiler/lifetime/intro.html"><strong aria-hidden="true">14.1.1.</strong> 生命周期</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../compiler/fight-with-compiler/lifetime/too-long1.html"><strong aria-hidden="true">14.1.1.1.</strong> 生命周期过大-01</a></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/lifetime/too-long2.html"><strong aria-hidden="true">14.1.1.2.</strong> 生命周期过大-02</a></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/lifetime/loop.html"><strong aria-hidden="true">14.1.1.3.</strong> 循环中的生命周期</a></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/lifetime/closure-with-static.html"><strong aria-hidden="true">14.1.1.4.</strong> 闭包碰到特征对象-01</a></li></ol></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/borrowing/intro.html"><strong aria-hidden="true">14.1.2.</strong> 重复借用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../compiler/fight-with-compiler/borrowing/ref-exist-in-out-fn.html"><strong aria-hidden="true">14.1.2.1.</strong> 同时在函数内外使用引用</a></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/borrowing/borrow-distinct-fields-of-struct.html"><strong aria-hidden="true">14.1.2.2.</strong> 智能指针引起的重复借用错误</a></li></ol></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/unconstrained.html"><strong aria-hidden="true">14.1.3.</strong> 类型未限制(todo)</a></li><li class="chapter-item "><a href="../../compiler/fight-with-compiler/phantom-data.html"><strong aria-hidden="true">14.1.4.</strong> 幽灵数据(todo)</a></li></ol></li><li class="chapter-item "><a href="../../compiler/pitfalls/index.html"><strong aria-hidden="true">14.2.</strong> Rust 常见陷阱</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../compiler/pitfalls/use-vec-in-for.html"><strong aria-hidden="true">14.2.1.</strong> for 循环中使用外部数组</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/stack-overflow.html"><strong aria-hidden="true">14.2.2.</strong> 线程类型导致的栈溢出</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/arithmetic-overflow.html"><strong aria-hidden="true">14.2.3.</strong> 算术溢出导致的 panic</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/closure-with-lifetime.html"><strong aria-hidden="true">14.2.4.</strong> 闭包中奇怪的生命周期</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/the-disabled-mutability.html"><strong aria-hidden="true">14.2.5.</strong> 可变变量不可变？</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/multiple-mutable-references.html"><strong aria-hidden="true">14.2.6.</strong> 可变借用失败引发的深入思考</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/lazy-iterators.html"><strong aria-hidden="true">14.2.7.</strong> 不太勤快的迭代器</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/weird-ranges.html"><strong aria-hidden="true">14.2.8.</strong> 奇怪的序列 x..y</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/iterator-everywhere.html"><strong aria-hidden="true">14.2.9.</strong> 无处不在的迭代器</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/main-with-channel-blocked.html"><strong aria-hidden="true">14.2.10.</strong> 线程间传递消息导致主线程无法结束</a></li><li class="chapter-item "><a href="../../compiler/pitfalls/utf8-performance.html"><strong aria-hidden="true">14.2.11.</strong> 警惕 UTF-8 引发的性能隐患</a></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">性能优化</li><li class="spacer"></li><li class="chapter-item "><a href="../../profiling/intro.html"><strong aria-hidden="true">15.</strong> Rust 性能优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../profiling/memory/intro.html"><strong aria-hidden="true">15.1.</strong> 深入内存 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../profiling/memory/pointer-ref.html"><strong aria-hidden="true">15.1.1.</strong> 指针和引用 todo</a></li><li class="chapter-item "><a href="../../profiling/memory/uninit.html"><strong aria-hidden="true">15.1.2.</strong> 未初始化内存 todo</a></li><li class="chapter-item "><a href="../../profiling/memory/allocation.html"><strong aria-hidden="true">15.1.3.</strong> 内存分配 todo</a></li><li class="chapter-item "><a href="../../profiling/memory/layout.html"><strong aria-hidden="true">15.1.4.</strong> 内存布局 todo</a></li><li class="chapter-item "><a href="../../profiling/memory/virtual.html"><strong aria-hidden="true">15.1.5.</strong> 虚拟内存 todo</a></li></ol></li><li class="chapter-item "><a href="../../profiling/performance/intro.html"><strong aria-hidden="true">15.2.</strong> 性能调优 doing</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../profiling/performance/string.html"><strong aria-hidden="true">15.2.1.</strong> 字符串操作性能</a></li><li class="chapter-item "><a href="../../profiling/performance/deep-into-move.html"><strong aria-hidden="true">15.2.2.</strong> 深入理解 move</a></li><li class="chapter-item "><a href="../../profiling/performance/early-optimise.html"><strong aria-hidden="true">15.2.3.</strong> 糟糕的提前优化 todo</a></li><li class="chapter-item "><a href="../../profiling/performance/clone-copy.html"><strong aria-hidden="true">15.2.4.</strong> Clone 和 Copy todo</a></li><li class="chapter-item "><a href="../../profiling/performance/runtime-check.html"><strong aria-hidden="true">15.2.5.</strong> 减少 Runtime check(todo)</a></li><li class="chapter-item "><a href="../../profiling/performance/cpu-cache.html"><strong aria-hidden="true">15.2.6.</strong> CPU 缓存性能优化 todo</a></li><li class="chapter-item "><a href="../../profiling/performance/calculate.html"><strong aria-hidden="true">15.2.7.</strong> 计算性能优化 todo</a></li><li class="chapter-item "><a href="../../profiling/performance/heap-stack.html"><strong aria-hidden="true">15.2.8.</strong> 堆和栈 todo</a></li><li class="chapter-item "><a href="../../profiling/performance/allocator.html"><strong aria-hidden="true">15.2.9.</strong> 内存 allocator todo</a></li><li class="chapter-item "><a href="../../profiling/performance/tools.html"><strong aria-hidden="true">15.2.10.</strong> 常用性能测试工具 todo</a></li><li class="chapter-item "><a href="../../profiling/performance/enum.html"><strong aria-hidden="true">15.2.11.</strong> Enum 内存优化 todo</a></li></ol></li><li class="chapter-item "><a href="../../profiling/compiler/intro.html"><strong aria-hidden="true">15.3.</strong> 编译优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../profiling/compiler/llvm.html"><strong aria-hidden="true">15.3.1.</strong> LLVM todo</a></li><li class="chapter-item "><a href="../../profiling/compiler/attributes.html"><strong aria-hidden="true">15.3.2.</strong> 常见属性标记 todo</a></li><li class="chapter-item "><a href="../../profiling/compiler/speed-up.html"><strong aria-hidden="true">15.3.3.</strong> 提升编译速度 todo</a></li><li class="chapter-item "><a href="../../profiling/compiler/optimization/intro.html"><strong aria-hidden="true">15.3.4.</strong> 编译器优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../profiling/compiler/optimization/option.html"><strong aria-hidden="true">15.3.4.1.</strong> Option 枚举 todo</a></li></ol></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">附录</li><li class="spacer"></li><li class="chapter-item "><div><strong aria-hidden="true">16.</strong> Appendix</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../appendix/keywords.html"><strong aria-hidden="true">16.1.</strong> 关键字</a></li><li class="chapter-item "><a href="../../appendix/operators.html"><strong aria-hidden="true">16.2.</strong> 运算符与符号</a></li><li class="chapter-item "><a href="../../appendix/expressions.html"><strong aria-hidden="true">16.3.</strong> 表达式</a></li><li class="chapter-item "><a href="../../appendix/derive.html"><strong aria-hidden="true">16.4.</strong> 派生特征 trait</a></li><li class="chapter-item "><a href="../../appendix/prelude.html"><strong aria-hidden="true">16.5.</strong> prelude 模块 todo</a></li><li class="chapter-item "><a href="../../appendix/rust-version.html"><strong aria-hidden="true">16.6.</strong> Rust 版本说明</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/intro.html"><strong aria-hidden="true">16.7.</strong> Rust 历次版本更新解读</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../../appendix/rust-versions/1.58.html"><strong aria-hidden="true">16.7.1.</strong> 1.58</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.59.html"><strong aria-hidden="true">16.7.2.</strong> 1.59</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.60.html"><strong aria-hidden="true">16.7.3.</strong> 1.60</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.61.html"><strong aria-hidden="true">16.7.4.</strong> 1.61</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.62.html"><strong aria-hidden="true">16.7.5.</strong> 1.62</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.63.html"><strong aria-hidden="true">16.7.6.</strong> 1.63</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.64.html"><strong aria-hidden="true">16.7.7.</strong> 1.64</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.65.html"><strong aria-hidden="true">16.7.8.</strong> 1.65</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.66.html"><strong aria-hidden="true">16.7.9.</strong> 1.66</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.67.html"><strong aria-hidden="true">16.7.10.</strong> 1.67</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.68.html"><strong aria-hidden="true">16.7.11.</strong> 1.68</a></li><li class="chapter-item "><a href="../../appendix/rust-versions/1.69.html"><strong aria-hidden="true">16.7.12.</strong> 1.69</a></li></ol></li></ol></li></ol>
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<!-- Page table of contents -->
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<div class="sidetoc"><nav class="pagetoc"></nav></div>
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<main>
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<h1 id="模块-module"><a class="header" href="#模块-module">模块 Module</a></h1>
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<p>在本章节，我们将深入讲讲 Rust 的代码构成单元：模块。使用模块可以将包中的代码按照功能性进行重组，最终实现更好的可读性及易用性。同时，我们还能非常灵活地去控制代码的可见性，进一步强化 Rust 的安全性。</p>
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<h2 id="创建嵌套模块"><a class="header" href="#创建嵌套模块">创建嵌套模块</a></h2>
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<p>小旅馆，sorry，是小餐馆，相信大家都挺熟悉的，学校外的估计也没少去，那么咱就用小餐馆为例，来看看 Rust 的模块该如何使用。</p>
|
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<p>使用 <code>cargo new --lib restaurant</code> 创建一个小餐馆，注意，这里创建的是一个库类型的 <code>Package</code>，然后将以下代码放入 <code>src/lib.rs</code> 中：</p>
|
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<pre><pre class="playground"><code class="language-rust edition2021">
|
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|
<span class="boring">#![allow(unused)]
|
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</span><span class="boring">fn main() {
|
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</span>// 餐厅前厅，用于吃饭
|
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mod front_of_house {
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mod hosting {
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fn add_to_waitlist() {}
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|
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fn seat_at_table() {}
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}
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mod serving {
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fn take_order() {}
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fn serve_order() {}
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fn take_payment() {}
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}
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}
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<span class="boring">}
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</span></code></pre></pre>
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<p>以上的代码创建了三个模块，有几点需要注意的：</p>
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<ul>
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|
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<li>使用 <code>mod</code> 关键字来创建新模块，后面紧跟着模块名称</li>
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<li>模块可以嵌套，这里嵌套的原因是招待客人和服务都发生在前厅，因此我们的代码模拟了真实场景</li>
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<li>模块中可以定义各种 Rust 类型，例如函数、结构体、枚举、特征等</li>
|
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<li>所有模块均定义在同一个文件中</li>
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</ul>
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<p>类似上述代码中所做的，使用模块，我们就能将功能相关的代码组织到一起，然后通过一个模块名称来说明这些代码为何被组织在一起。这样其它程序员在使用你的模块时，就可以更快地理解和上手。</p>
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<h2 id="模块树"><a class="header" href="#模块树">模块树</a></h2>
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<p>在<a href="https://course.rs/basic/crate-module/crate.html">上一节</a>中，我们提到过 <code>src/main.rs</code> 和 <code>src/lib.rs</code> 被称为包根(crate root)，这个奇葩名称的来源(我不想承认是自己翻译水平太烂-,-)是由于这两个文件的内容形成了一个模块 <code>crate</code>，该模块位于包的树形结构(由模块组成的树形结构)的根部：</p>
|
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|
<pre><code class="language-console">crate
|
|
|
└── front_of_house
|
|
|
├── hosting
|
|
|
│ ├── add_to_waitlist
|
|
|
│ └── seat_at_table
|
|
|
└── serving
|
|
|
├── take_order
|
|
|
├── serve_order
|
|
|
└── take_payment
|
|
|
</code></pre>
|
|
|
<p>这颗树展示了模块之间<strong>彼此的嵌套</strong>关系，因此被称为<strong>模块树</strong>。其中 <code>crate</code> 包根是 <code>src/lib.rs</code> 文件，包根文件中的三个模块分别形成了模块树的剩余部分。</p>
|
|
|
<h4 id="父子模块"><a class="header" href="#父子模块">父子模块</a></h4>
|
|
|
<p>如果模块 <code>A</code> 包含模块 <code>B</code>，那么 <code>A</code> 是 <code>B</code> 的父模块，<code>B</code> 是 <code>A</code> 的子模块。在上例中，<code>front_of_house</code> 是 <code>hosting</code> 和 <code>serving</code> 的父模块，反之，后两者是前者的子模块。</p>
|
|
|
<p>聪明的读者，应该能联想到，模块树跟计算机上文件系统目录树的相似之处。不仅仅是组织结构上的相似，就连使用方式都很相似：每个文件都有自己的路径，用户可以通过这些路径使用它们，在 Rust 中，我们也通过路径的方式来引用模块。</p>
|
|
|
<h2 id="用路径引用模块"><a class="header" href="#用路径引用模块">用路径引用模块</a></h2>
|
|
|
<p>想要调用一个函数，就需要知道它的路径，在 Rust 中，这种路径有两种形式：</p>
|
|
|
<ul>
|
|
|
<li><strong>绝对路径</strong>，从包根开始，路径名以包名或者 <code>crate</code> 作为开头</li>
|
|
|
<li><strong>相对路径</strong>，从当前模块开始，以 <code>self</code>，<code>super</code> 或当前模块的标识符作为开头</li>
|
|
|
</ul>
|
|
|
<p>让我们继续经营那个惨淡的小餐馆，这次为它实现一个小功能：
|
|
|
<span class="filename">文件名：src/lib.rs</span></p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
mod hosting {
|
|
|
fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
// 绝对路径
|
|
|
crate::front_of_house::hosting::add_to_waitlist();
|
|
|
|
|
|
// 相对路径
|
|
|
front_of_house::hosting::add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>上面的代码为了简化实现，省去了其余模块和函数，这样可以把关注点放在函数调用上。<code>eat_at_restaurant</code> 是一个定义在包根中的函数，在该函数中使用了两种方式对 <code>add_to_waitlist</code> 进行调用。</p>
|
|
|
<h4 id="绝对路径引用"><a class="header" href="#绝对路径引用">绝对路径引用</a></h4>
|
|
|
<p>因为 <code>eat_at_restaurant</code> 和 <code>add_to_waitlist</code> 都定义在一个包中，因此在绝对路径引用时，可以直接以 <code>crate</code> 开头，然后逐层引用，每一层之间使用 <code>::</code> 分隔：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>crate::front_of_house::hosting::add_to_waitlist();
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>对比下之前的模块树：</p>
|
|
|
<pre><code class="language-console">crate
|
|
|
└── eat_at_restaurant
|
|
|
└── front_of_house
|
|
|
├── hosting
|
|
|
│ ├── add_to_waitlist
|
|
|
│ └── seat_at_table
|
|
|
└── serving
|
|
|
├── take_order
|
|
|
├── serve_order
|
|
|
└── take_payment
|
|
|
</code></pre>
|
|
|
<p>可以看出，绝对路径的调用，完全符合了模块树的层级递进，非常符合直觉，如果类比文件系统，就跟使用绝对路径调用可执行程序差不多：<code>/front_of_house/hosting/add_to_waitlist</code>，使用 <code>crate</code> 作为开始就和使用 <code>/</code> 作为开始一样。</p>
|
|
|
<h4 id="相对路径引用"><a class="header" href="#相对路径引用">相对路径引用</a></h4>
|
|
|
<p>再回到模块树中，因为 <code>eat_at_restaurant</code> 和 <code>front_of_house</code> 都处于包根 <code>crate</code> 中，因此相对路径可以使用 <code>front_of_house</code> 作为开头：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>front_of_house::hosting::add_to_waitlist();
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>如果类比文件系统，那么它类似于调用同一个目录下的程序，你可以这么做：<code>front_of_house/hosting/add_to_waitlist</code>，嗯也很符合直觉。</p>
|
|
|
<h4 id="绝对还是相对"><a class="header" href="#绝对还是相对">绝对还是相对？</a></h4>
|
|
|
<p>如果只是为了引用到指定模块中的对象，那么两种都可以，但是在实际使用时，需要遵循一个原则：<strong>当代码被挪动位置时，尽量减少引用路径的修改</strong>，相信大家都遇到过，修改了某处代码，导致所有路径都要挨个替换，这显然不是好的路径选择。</p>
|
|
|
<p>回到之前的例子，如果我们把 <code>front_of_house</code> 模块和 <code>eat_at_restaurant</code> 移动到一个模块中 <code>customer_experience</code>，那么绝对路径的引用方式就必须进行修改：<code>crate::customer_experience::front_of_house ...</code>，但是假设我们使用的相对路径，那么该路径就无需修改，因为它们两个的相对位置其实没有变：</p>
|
|
|
<pre><code class="language-console">crate
|
|
|
└── customer_experience
|
|
|
└── eat_at_restaurant
|
|
|
└── front_of_house
|
|
|
├── hosting
|
|
|
│ ├── add_to_waitlist
|
|
|
│ └── seat_at_table
|
|
|
</code></pre>
|
|
|
<p>从新的模块树中可以很清晰的看出这一点。</p>
|
|
|
<p>再比如，其它的都不动，把 <code>eat_at_restaurant</code> 移动到模块 <code>dining</code> 中，如果使用相对路径，你需要修改该路径，但如果使用的是绝对路径，就无需修改：</p>
|
|
|
<pre><code class="language-console">crate
|
|
|
└── dining
|
|
|
└── eat_at_restaurant
|
|
|
└── front_of_house
|
|
|
├── hosting
|
|
|
│ ├── add_to_waitlist
|
|
|
</code></pre>
|
|
|
<p>不过，如果不确定哪个好，你可以考虑优先使用绝对路径，因为调用的地方和定义的地方往往是分离的，而定义的地方较少会变动。</p>
|
|
|
<h2 id="代码可见性"><a class="header" href="#代码可见性">代码可见性</a></h2>
|
|
|
<p>让我们运行下面(之前)的代码：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
mod hosting {
|
|
|
fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
// 绝对路径
|
|
|
crate::front_of_house::hosting::add_to_waitlist();
|
|
|
|
|
|
// 相对路径
|
|
|
front_of_house::hosting::add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>意料之外的报错了，毕竟看上去确实很简单且没有任何问题：</p>
|
|
|
<pre><code class="language-console">error[E0603]: module `hosting` is private
|
|
|
--> src/lib.rs:9:28
|
|
|
|
|
|
|
9 | crate::front_of_house::hosting::add_to_waitlist();
|
|
|
| ^^^^^^^ private module
|
|
|
</code></pre>
|
|
|
<p>错误信息很清晰：<code>hosting</code> 模块是私有的，无法在包根进行访问，那么为何 <code>front_of_house</code> 模块就可以访问？因为它和 <code>eat_at_restaurant</code> 同属于一个包根作用域内，同一个模块内的代码自然不存在私有化问题(所以我们之前章节的代码都没有报过这个错误！)。</p>
|
|
|
<p>模块不仅仅对于组织代码很有用，它还能定义代码的私有化边界：在这个边界内，什么内容能让外界看到，什么内容不能，都有很明确的定义。因此，如果希望让函数或者结构体等类型变成私有化的，可以使用模块。</p>
|
|
|
<p>Rust 出于安全的考虑，默认情况下，所有的类型都是私有化的，包括函数、方法、结构体、枚举、常量，是的，就连模块本身也是私有化的。在中国，父亲往往不希望孩子拥有小秘密，但是在 Rust 中，<strong>父模块完全无法访问子模块中的私有项，但是子模块却可以访问父模块、父父..模块的私有项</strong>。</p>
|
|
|
<h4 id="pub-关键字"><a class="header" href="#pub-关键字">pub 关键字</a></h4>
|
|
|
<p>类似其它语言的 <code>public</code> 或者 Go 语言中的首字母大写，Rust 提供了 <code>pub</code> 关键字，通过它你可以控制模块和模块中指定项的可见性。</p>
|
|
|
<p>由于之前的解释，我们知道了只需要将 <code>hosting</code> 模块标记为对外可见即可：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
pub mod hosting {
|
|
|
fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/*--- snip ----*/
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>但是不幸的是，又报错了：</p>
|
|
|
<pre><code class="language-console">error[E0603]: function `add_to_waitlist` is private
|
|
|
--> src/lib.rs:12:30
|
|
|
|
|
|
|
12 | front_of_house::hosting::add_to_waitlist();
|
|
|
| ^^^^^^^^^^^^^^^ private function
|
|
|
</code></pre>
|
|
|
<p>哦？难道模块可见还不够，还需要将函数 <code>add_to_waitlist</code> 标记为可见的吗？ 是的，没错，模块可见性不代表模块内部项的可见性，模块的可见性仅仅是允许其它模块去引用它，但是想要引用它内部的项，还得继续将对应的项标记为 <code>pub</code>。</p>
|
|
|
<p>在实际项目中，一个模块需要对外暴露的数据和 API 往往就寥寥数个，如果将模块标记为可见代表着内部项也全部对外可见，那你是不是还得把那些不可见的，一个一个标记为 <code>private</code>？反而是更麻烦的多。</p>
|
|
|
<p>既然知道了如何解决，那么我们为函数也标记上 <code>pub</code>：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
pub mod hosting {
|
|
|
pub fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/*--- snip ----*/
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>Bang，顺利通过编译，感觉自己又变强了。</p>
|
|
|
<h2 id="使用-super-引用模块"><a class="header" href="#使用-super-引用模块">使用 <code>super</code> 引用模块</a></h2>
|
|
|
<p>在<a href="#%E7%94%A8%E8%B7%AF%E5%BE%84%E5%BC%95%E7%94%A8%E6%A8%A1%E5%9D%97">用路径引用模块</a>中，我们提到了相对路径有三种方式开始：<code>self</code>、<code>super</code>和 <code>crate</code> 或者模块名，其中第三种在前面已经讲到过，现在来看看通过 <code>super</code> 的方式引用模块项。</p>
|
|
|
<p><code>super</code> 代表的是父模块为开始的引用方式，非常类似于文件系统中的 <code>..</code> 语法：<code>../a/b</code>
|
|
|
<span class="filename">文件名：src/lib.rs</span></p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>fn serve_order() {}
|
|
|
|
|
|
// 厨房模块
|
|
|
mod back_of_house {
|
|
|
fn fix_incorrect_order() {
|
|
|
cook_order();
|
|
|
super::serve_order();
|
|
|
}
|
|
|
|
|
|
fn cook_order() {}
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>嗯，我们的小餐馆又完善了，终于有厨房了！看来第一个客人也快可以有了。。。在厨房模块中，使用 <code>super::serve_order</code> 语法，调用了父模块(包根)中的 <code>serve_order</code> 函数。</p>
|
|
|
<p>那么你可能会问，为何不使用 <code>crate::serve_order</code> 的方式？额，其实也可以，不过如果你确定未来这种层级关系不会改变，那么 <code>super::serve_order</code> 的方式会更稳定，未来就算它们都不在包根了，依然无需修改引用路径。所以路径的选用，往往还是取决于场景，以及未来代码的可能走向。</p>
|
|
|
<h2 id="使用-self-引用模块"><a class="header" href="#使用-self-引用模块">使用 <code>self</code> 引用模块</a></h2>
|
|
|
<p><code>self</code> 其实就是引用自身模块中的项，也就是说和我们之前章节的代码类似，都调用同一模块中的内容，区别在于之前章节中直接通过名称调用即可，而 <code>self</code>，你得多此一举：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>fn serve_order() {
|
|
|
self::back_of_house::cook_order()
|
|
|
}
|
|
|
|
|
|
mod back_of_house {
|
|
|
fn fix_incorrect_order() {
|
|
|
cook_order();
|
|
|
crate::serve_order();
|
|
|
}
|
|
|
|
|
|
pub fn cook_order() {}
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>是的，多此一举，因为完全可以直接调用 <code>back_of_house</code>，但是 <code>self</code> 还有一个大用处，在下一节中我们会讲。</p>
|
|
|
<h2 id="结构体和枚举的可见性"><a class="header" href="#结构体和枚举的可见性">结构体和枚举的可见性</a></h2>
|
|
|
<p>为何要把结构体和枚举的可见性单独拎出来讲呢？因为这两个家伙的成员字段拥有完全不同的可见性：</p>
|
|
|
<ul>
|
|
|
<li>将结构体设置为 <code>pub</code>，但它的所有字段依然是私有的</li>
|
|
|
<li>将枚举设置为 <code>pub</code>，它的所有字段也将对外可见</li>
|
|
|
</ul>
|
|
|
<p>原因在于，枚举和结构体的使用方式不一样。如果枚举的成员对外不可见，那该枚举将一点用都没有，因此枚举成员的可见性自动跟枚举可见性保持一致，这样可以简化用户的使用。</p>
|
|
|
<p>而结构体的应用场景比较复杂，其中的字段也往往部分在 A 处被使用，部分在 B 处被使用，因此无法确定成员的可见性，那索性就设置为全部不可见，将选择权交给程序员。</p>
|
|
|
<h2 id="模块与文件分离"><a class="header" href="#模块与文件分离">模块与文件分离</a></h2>
|
|
|
<p>在之前的例子中，我们所有的模块都定义在 <code>src/lib.rs</code> 中，但是当模块变多或者变大时，需要将模块放入一个单独的文件中，让代码更好维护。</p>
|
|
|
<p>现在，把 <code>front_of_house</code> 前厅分离出来，放入一个单独的文件中 <code>src/front_of_house.rs</code>：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub mod hosting {
|
|
|
pub fn add_to_waitlist() {}
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>然后，将以下代码留在 <code>src/lib.rs</code> 中：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house;
|
|
|
|
|
|
pub use crate::front_of_house::hosting;
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>so easy！其实跟之前在同一个文件中也没有太大的不同，但是有几点值得注意：</p>
|
|
|
<ul>
|
|
|
<li><code>mod front_of_house;</code> 告诉 Rust 从另一个和模块 <code>front_of_house</code> 同名的文件中加载该模块的内容</li>
|
|
|
<li>使用绝对路径的方式来引用 <code>hosting</code> 模块：<code>crate::front_of_house::hosting;</code></li>
|
|
|
</ul>
|
|
|
<p>需要注意的是，和之前代码中 <code>mod front_of_house{..}</code> 的完整模块不同，现在的代码中，模块的声明和实现是分离的，实现是在单独的 <code>front_of_house.rs</code> 文件中，然后通过 <code>mod front_of_house;</code> 这条声明语句从该文件中把模块内容加载进来。因此我们可以认为，模块 <code>front_of_house</code> 的定义还是在 <code>src/lib.rs</code> 中，只不过模块的具体内容被移动到了 <code>src/front_of_house.rs</code> 文件中。</p>
|
|
|
<p>在这里出现了一个新的关键字 <code>use</code>，联想到其它章节我们见过的标准库引入 <code>use std::fmt;</code>，可以大致猜测，该关键字用来将外部模块中的项引入到当前作用域中来，这样无需冗长的父模块前缀即可调用：<code>hosting::add_to_waitlist();</code>，在下节中，我们将对 <code>use</code> 进行详细的讲解。</p>
|
|
|
<p>当一个模块有许多子模块时，我们也可以通过文件夹的方式来组织这些子模块。</p>
|
|
|
<p>在上述例子中，我们可以创建一个目录 <code>front_of_house</code>，然后在文件夹里创建一个 <code>hosting.rs</code> 文件，<code>hosting.rs</code> 文件现在就剩下：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub fn add_to_waitlist() {}
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<p>现在，我们尝试编译程序，很遗憾，编译器报错：</p>
|
|
|
<pre><code>error[E0583]: file not found for module `front_of_house`
|
|
|
--> src/lib.rs:3:1
|
|
|
|
|
|
|
1 | mod front_of_house;
|
|
|
| ^^^^^^^^^^^^^^^^^^
|
|
|
|
|
|
|
= help: to create the module `front_of_house`, create file "src/front_of_house.rs" or "src/front_of_house/mod.rs"
|
|
|
</code></pre>
|
|
|
<p>是的，如果需要将文件夹作为一个模块，我们需要进行显示指定暴露哪些子模块。按照上述的报错信息，我们有两种方法：</p>
|
|
|
<ul>
|
|
|
<li>在 <code>front_of_house</code> 目录里创建一个 <code>mod.rs</code>，如果你使用的 <code>rustc</code> 版本 <code>1.30</code> 之前，这是唯一的方法。</li>
|
|
|
<li>在 <code>front_of_house</code> 同级目录里创建一个与模块（目录）同名的 rs 文件 <code>front_of_house.rs</code>，在新版本里，更建议使用这样的命名方式来避免项目中存在大量同名的 <code>mod.rs</code> 文件（ Python 点了个 <code>踩</code>）。</li>
|
|
|
</ul>
|
|
|
<p>而无论是上述哪个方式创建的文件，其内容都是一样的，你需要定义你的子模块（子模块名与文件名相同）：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">
|
|
|
<span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub mod hosting;
|
|
|
// pub mod serving;
|
|
|
<span class="boring">}
|
|
|
</span></code></pre></pre>
|
|
|
<h2 id="课后练习"><a class="header" href="#课后练习">课后练习</a></h2>
|
|
|
<blockquote>
|
|
|
<p><a href="https://zh.practice.rs/crate-module/module.html">Rust By Practice</a>，支持代码在线编辑和运行，并提供详细的<a href="https://github.com/sunface/rust-by-practice/blob/master/solutions/crate-module/module.md">习题解答</a>。</p>
|
|
|
</blockquote>
|
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