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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="spacer"></li><li class="chapter-item affix "><a href="../some-thoughts.html">Datav: 可编程的数据可视化平台和可观测性平台</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 "><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 "><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 "><a href="../basic/crate-module/module.html"><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 expanded "><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 expanded "><a href="../basic-practice/refactoring.html" class="active"><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/production-unsafe-deque/intro.html"><strong aria-hidden="true">13.7.</strong> 生产级的双向 unsafe 队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/layout.html"><strong aria-hidden="true">13.7.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/variance-and-phantomData.html"><strong aria-hidden="true">13.7.2.</strong> 型变与子类型</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/basics.html"><strong aria-hidden="true">13.7.3.</strong> 基础结构</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/drop-and-panic-safety.html"><strong aria-hidden="true">13.7.4.</strong> 恐慌与安全</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/boring-combinatorics.html"><strong aria-hidden="true">13.7.5.</strong> 无聊的组合</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/filling-in-random-bits.html"><strong aria-hidden="true">13.7.6.</strong> 其它特征</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/testing.html"><strong aria-hidden="true">13.7.7.</strong> 测试</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/send-sync-and-compile-tests.html"><strong aria-hidden="true">13.7.8.</strong> Send,Sync和编译测试</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/implementing-cursors.html"><strong aria-hidden="true">13.7.9.</strong> 实现游标</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/testing-cursors.html"><strong aria-hidden="true">13.7.10.</strong> 测试游标</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/final-code.html"><strong aria-hidden="true">13.7.11.</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">13.8.</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/double-singly.html"><strong aria-hidden="true">13.8.1.</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">13.8.2.</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><li class="chapter-item "><a href="../appendix/rust-versions/1.70.html"><strong aria-hidden="true">16.7.13.</strong> 1.70</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.71.html"><strong aria-hidden="true">16.7.14.</strong> 1.71</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.72.html"><strong aria-hidden="true">16.7.15.</strong> 1.72</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.73.html"><strong aria-hidden="true">16.7.16.</strong> 1.73</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.74.html"><strong aria-hidden="true">16.7.17.</strong> 1.74</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.75.html"><strong aria-hidden="true">16.7.18.</strong> 1.75</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.76.html"><strong aria-hidden="true">16.7.19.</strong> 1.76</a></li></ol></li></ol></li></ol>
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<main>
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<h1 id="增加模块化和错误处理"><a class="header" href="#增加模块化和错误处理">增加模块化和错误处理</a></h1>
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<p>但凡稍微没那么糟糕的程序，都应该具有代码模块化和错误处理，不然连玩具都谈不上。</p>
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<p>梳理我们的代码和目标后，可以整理出大致四个改进点:</p>
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<ul>
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<li><strong>单一且庞大的函数</strong>。对于 <code>minigrep</code> 程序而言， <code>main</code> 函数当前执行两个任务：解析命令行参数和读取文件。但随着代码的增加，<code>main</code> 函数承载的功能也将快速增加。从软件工程角度来看，一个函数具有的功能越多，越是难以阅读和维护。因此最好的办法是将大的函数拆分成更小的功能单元。</li>
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<li><strong>配置变量散乱在各处</strong>。还有一点要考虑的是，当前 <code>main</code> 函数中的变量都是独立存在的，这些变量很可能被整个程序所访问，在这个背景下，独立的变量越多，越是难以维护，因此我们还可以将这些用于配置的变量整合到一个结构体中。</li>
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<li><strong>细化错误提示</strong>。 目前的实现中，我们使用 <code>expect</code> 方法来输出文件读取失败时的错误信息，这个没问题，但是无论任何情况下，都只输出 <code>Should have been able to read the file</code> 这条错误提示信息，显然是有问题的，毕竟文件不存在、无权限等等都是可能的错误，一条大一统的消息无法给予用户更多的提示。</li>
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<li><strong>使用错误而不是异常</strong>。 假如用户不给任何命令行参数，那我们的程序显然会无情崩溃，原因很简单：<code>index out of bounds</code>，一个数组访问越界的 <code>panic</code>，但问题来了，用户能看懂吗？甚至于未来接收的维护者能看懂吗？因此需要增加合适的错误处理代码，来给予使用者给详细友善的提示。还有就是需要在一个统一的位置来处理所有错误，利人利己！</li>
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</ul>
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<h2 id="分离-main-函数"><a class="header" href="#分离-main-函数">分离 main 函数</a></h2>
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<p>关于如何处理庞大的 <code>main</code> 函数，Rust 社区给出了统一的指导方案:</p>
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<ul>
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<li>将程序分割为 <code>main.rs</code> 和 <code>lib.rs</code>，并将程序的逻辑代码移动到后者内</li>
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<li>命令行解析属于非常基础的功能，严格来说不算是逻辑代码的一部分，因此还可以放在 <code>main.rs</code> 中</li>
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</ul>
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<p>按照这个方案，将我们的代码重新梳理后，可以得出 <code>main</code> 函数应该包含的功能:</p>
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<ul>
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<li>解析命令行参数</li>
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<li>初始化其它配置</li>
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<li>调用 <code>lib.rs</code> 中的 <code>run</code> 函数，以启动逻辑代码的运行</li>
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<li>如果 <code>run</code> 返回一个错误，需要对该错误进行处理</li>
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</ul>
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<p>这个方案有一个很优雅的名字: 关注点分离(Separation of Concerns)。简而言之，<code>main.rs</code> 负责启动程序，<code>lib.rs</code> 负责逻辑代码的运行。从测试的角度而言，这种分离也非常合理： <code>lib.rs</code> 中的主体逻辑代码可以得到简单且充分的测试，至于 <code>main.rs</code> ？确实没办法针对其编写额外的测试代码，但是它的代码也很少啊，很容易就能保证它的正确性。</p>
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<blockquote>
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<p>关于如何在 Rust 中编写测试代码，请参见如下章节：https://course.rs/test/intro.html</p>
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</blockquote>
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<h3 id="分离命令行解析"><a class="header" href="#分离命令行解析">分离命令行解析</a></h3>
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<p>根据之前的分析，我们需要将命令行解析的代码分离到一个单独的函数，然后将该函数放置在 <code>main.rs</code> 中：</p>
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<pre><pre class="playground"><code class="language-rust edition2021">// in main.rs
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fn main() {
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let args: Vec<String> = env::args().collect();
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let (query, file_path) = parse_config(&args);
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// --省略--
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}
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fn parse_config(args: &[String]) -> (&str, &str) {
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let query = &args[1];
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let file_path = &args[2];
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|
|
|
|
|
(query, file_path)
|
|
|
}</code></pre></pre>
|
|
|
<p>经过分离后，之前的设计目标完美达成，即精简了 <code>main</code> 函数，又将配置相关的代码放在了 <code>main.rs</code> 文件里。</p>
|
|
|
<p>看起来貌似是杀鸡用了牛刀，但是重构就是这样，一步一步，踏踏实实的前行，否则未来代码多一些后，你岂不是还要再重来一次重构？因此打好项目的基础是非常重要的！</p>
|
|
|
<h3 id="聚合配置变量"><a class="header" href="#聚合配置变量">聚合配置变量</a></h3>
|
|
|
<p>前文提到，配置变量并不适合分散的到处都是，因此使用一个结构体来统一存放是非常好的选择，这样修改后，后续的使用以及未来的代码维护都将更加简单明了。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let args: Vec<String> = env::args().collect();
|
|
|
|
|
|
let config = parse_config(&args);
|
|
|
|
|
|
println!("Searching for {}", config.query);
|
|
|
println!("In file {}", config.file_path);
|
|
|
|
|
|
let contents = fs::read_to_string(config.file_path)
|
|
|
.expect("Should have been able to read the file");
|
|
|
|
|
|
// --snip--
|
|
|
}
|
|
|
|
|
|
struct Config {
|
|
|
query: String,
|
|
|
file_path: String,
|
|
|
}
|
|
|
|
|
|
fn parse_config(args: &[String]) -> Config {
|
|
|
let query = args[1].clone();
|
|
|
let file_path = args[2].clone();
|
|
|
|
|
|
Config { query, file_path }
|
|
|
}</code></pre></pre>
|
|
|
<p>值得注意的是，<code>Config</code> 中存储的并不是 <code>&str</code> 这样的引用类型，而是一个 <code>String</code> 字符串，也就是 <code>Config</code> 并没有去借用外部的字符串，而是拥有内部字符串的所有权。<code>clone</code> 方法的使用也可以佐证这一点。大家可以尝试不用 <code>clone</code> 方法，看看该如何解决相关的报错 :D</p>
|
|
|
<blockquote>
|
|
|
<p><code>clone</code> 的得与失</p>
|
|
|
<p>在上面的代码中，除了使用 <code>clone</code> ，还有其它办法来达成同样的目的，但 <code>clone</code> 无疑是最简单的方法：直接完整的复制目标数据，无需被所有权、借用等问题所困扰，但是它也有其缺点，那就是有一定的性能损耗。</p>
|
|
|
<p>因此是否使用 <code>clone</code> 更多是一种性能上的权衡，对于上面的使用而言，由于是配置的初始化，因此整个程序只需要执行一次，性能损耗几乎是可以忽略不计的。</p>
|
|
|
<p>总之，判断是否使用 <code>clone</code>:</p>
|
|
|
<ul>
|
|
|
<li>是否严肃的项目，玩具项目直接用 <code>clone</code> 就行，简单不好吗？</li>
|
|
|
<li>要看所在的代码路径是否是热点路径(hot path)，例如执行次数较多的显然就是热点路径，热点路径就值得去使用性能更好的实现方式</li>
|
|
|
</ul>
|
|
|
</blockquote>
|
|
|
<p>好了，言归正传，从 <code>C</code> 语言过来的同学可能会觉得上面的代码已经很棒了，但是从 OO 语言角度来说，还差了那么一点意思。</p>
|
|
|
<p>下面我们试着来优化下，通过构造函数来初始化一个 <code>Config</code> 实例，而不是直接通过函数返回实例，典型的，标准库中的 <code>String::new</code> 函数就是一个范例。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let args: Vec<String> = env::args().collect();
|
|
|
|
|
|
let config = Config::new(&args);
|
|
|
|
|
|
// --snip--
|
|
|
}
|
|
|
|
|
|
// --snip--
|
|
|
|
|
|
impl Config {
|
|
|
fn new(args: &[String]) -> Config {
|
|
|
let query = args[1].clone();
|
|
|
let file_path = args[2].clone();
|
|
|
|
|
|
Config { query, file_path }
|
|
|
}
|
|
|
}</code></pre></pre>
|
|
|
<p>修改后，类似 <code>String::new</code> 的调用，我们可以通过 <code>Config::new</code> 来创建一个实例，看起来代码是不是更有那味儿了 ：）</p>
|
|
|
<h2 id="错误处理"><a class="header" href="#错误处理">错误处理</a></h2>
|
|
|
<p>回顾一下，如果用户不输入任何命令行参数，我们的程序会怎么样？</p>
|
|
|
<pre><code class="language-shell">$ cargo run
|
|
|
Compiling minigrep v0.1.0 (file:///projects/minigrep)
|
|
|
Finished dev [unoptimized + debuginfo] target(s) in 0.0s
|
|
|
Running `target/debug/minigrep`
|
|
|
thread 'main' panicked at 'index out of bounds: the len is 1 but the index is 1', src/main.rs:27:21
|
|
|
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
|
|
|
</code></pre>
|
|
|
<p>结果喜闻乐见，由于 <code>args</code> 数组没有任何元素，因此通过索引访问时，会直接报出数组访问越界的 <code>panic</code>。</p>
|
|
|
<p>报错信息对于开发者会很明确，但是对于使用者而言，就相当难理解了，下面一起来解决它。</p>
|
|
|
<h3 id="改进报错信息"><a class="header" href="#改进报错信息">改进报错信息</a></h3>
|
|
|
<p>还记得在错误处理章节，我们提到过 <code>panic</code> 的两种用法: 被动触发和主动调用嘛？上面代码的出现方式很明显是被动触发，这种报错信息是不可控的，下面我们先改成主动调用的方式:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>// in main.rs
|
|
|
// --snip--
|
|
|
fn new(args: &[String]) -> Config {
|
|
|
if args.len() < 3 {
|
|
|
panic!("not enough arguments");
|
|
|
}
|
|
|
// --snip--
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>目的很明确，一旦传入的参数数组长度小于 3，则报错并让程序崩溃推出，这样后续的数组访问就不会再越界了。</p>
|
|
|
<pre><code class="language-shell">$ cargo run
|
|
|
Compiling minigrep v0.1.0 (file:///projects/minigrep)
|
|
|
Finished dev [unoptimized + debuginfo] target(s) in 0.0s
|
|
|
Running `target/debug/minigrep`
|
|
|
thread 'main' panicked at 'not enough arguments', src/main.rs:26:13
|
|
|
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
|
|
|
</code></pre>
|
|
|
<p>不错，用户看到了更为明确的提示，但是还是有一大堆 <code>debug</code> 输出，这些我们其实是不想让用户看到的。这么看来，想要输出对用户友好的信息, <code>panic</code> 是不太适合的，它更适合告知开发者，哪里出现了问题。</p>
|
|
|
<h3 id="返回-result-来替代直接-panic"><a class="header" href="#返回-result-来替代直接-panic">返回 Result 来替代直接 panic</a></h3>
|
|
|
<p>那只能祭出之前学过的错误处理大法了，也就是返回一个 <code>Result</code>：成功时包含 <code>Config</code> 实例，失败时包含一条错误信息。</p>
|
|
|
<p>有一点需要额外注意下，从代码惯例的角度出发，<code>new</code> 往往不会失败，毕竟新建一个实例没道理失败，对不？因此修改为 <code>build</code> 会更加合适。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>impl Config {
|
|
|
fn build(args: &[String]) -> Result<Config, &'static str> {
|
|
|
if args.len() < 3 {
|
|
|
return Err("not enough arguments");
|
|
|
}
|
|
|
|
|
|
let query = args[1].clone();
|
|
|
let file_path = args[2].clone();
|
|
|
|
|
|
Ok(Config { query, file_path })
|
|
|
}
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>这里的 <code>Result</code> 可能包含一个 <code>Config</code> 实例，也可能包含一条错误信息 <code>&static str</code>，不熟悉这种字符串类型的同学可以回头看看字符串章节，代码中的字符串字面量都是该类型，且拥有 <code>'static</code> 生命周期。</p>
|
|
|
<h3 id="处理返回的-result"><a class="header" href="#处理返回的-result">处理返回的 Result</a></h3>
|
|
|
<p>接下来就是在调用 <code>build</code> 函数时，对返回的 <code>Result</code> 进行处理了，目的就是给出准确且友好的报错提示, 为了让大家更好的回顾我们修改过的内容，这里给出整体代码:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::env;
|
|
|
use std::fs;
|
|
|
use std::process;
|
|
|
|
|
|
fn main() {
|
|
|
let args: Vec<String> = env::args().collect();
|
|
|
|
|
|
// 对 build 返回的 `Result` 进行处理
|
|
|
let config = Config::build(&args).unwrap_or_else(|err| {
|
|
|
println!("Problem parsing arguments: {err}");
|
|
|
process::exit(1);
|
|
|
});
|
|
|
|
|
|
|
|
|
println!("Searching for {}", config.query);
|
|
|
println!("In file {}", config.file_path);
|
|
|
|
|
|
let contents = fs::read_to_string(config.file_path)
|
|
|
.expect("Should have been able to read the file");
|
|
|
|
|
|
println!("With text:\n{contents}");
|
|
|
}
|
|
|
|
|
|
struct Config {
|
|
|
query: String,
|
|
|
file_path: String,
|
|
|
}
|
|
|
|
|
|
impl Config {
|
|
|
fn build(args: &[String]) -> Result<Config, &'static str> {
|
|
|
if args.len() < 3 {
|
|
|
return Err("not enough arguments");
|
|
|
}
|
|
|
|
|
|
let query = args[1].clone();
|
|
|
let file_path = args[2].clone();
|
|
|
|
|
|
Ok(Config { query, file_path })
|
|
|
}
|
|
|
}</code></pre></pre>
|
|
|
<p>上面代码有几点值得注意:</p>
|
|
|
<ul>
|
|
|
<li>当 <code>Result</code> 包含错误时，我们不再调用 <code>panic</code> 让程序崩溃，而是通过 <code>process::exit(1)</code> 来终结进程，其中 <code>1</code> 是一个信号值(事实上非 0 值都可以)，通知调用我们程序的进程，程序是因为错误而退出的。</li>
|
|
|
<li><code>unwrap_or_else</code> 是定义在 <code>Result<T,E></code> 上的常用方法，如果 <code>Result</code> 是 <code>Ok</code>，那该方法就类似 <code>unwrap</code>：返回 <code>Ok</code> 内部的值；如果是 <code>Err</code>，就调用<a href="https://course.rs/advance/functional-programing/closure.html">闭包</a>中的自定义代码对错误进行进一步处理</li>
|
|
|
</ul>
|
|
|
<p>综上可知，<code>config</code> 变量的值是一个 <code>Config</code> 实例，而 <code>unwrap_or_else</code> 闭包中的 <code>err</code> 参数，它的类型是 <code>'static str</code>，值是 "not enough arguments" 那个字符串字面量。</p>
|
|
|
<p>运行后，可以看到以下输出：</p>
|
|
|
<pre><code class="language-shell">$ cargo run
|
|
|
Compiling minigrep v0.1.0 (file:///projects/minigrep)
|
|
|
Finished dev [unoptimized + debuginfo] target(s) in 0.48s
|
|
|
Running `target/debug/minigrep`
|
|
|
Problem parsing arguments: not enough arguments
|
|
|
</code></pre>
|
|
|
<p>终于，我们得到了自己想要的输出：既告知了用户为何报错，又消除了多余的 debug 信息，非常棒。可能有用户疑惑，<code>cargo run</code> 底下还有一大堆 <code>debug</code> 信息呢，实际上，这是 <code>cargo run</code> 自带的，大家可以试试编译成二进制可执行文件后再调用，会是什么效果。</p>
|
|
|
<h2 id="分离主体逻辑"><a class="header" href="#分离主体逻辑">分离主体逻辑</a></h2>
|
|
|
<p>接下来可以继续精简 <code>main</code> 函数，那就是将主体逻辑( 例如业务逻辑 )从 <code>main</code> 中分离出去，这样 <code>main</code> 函数就保留主流程调用，非常简洁。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">// in main.rs
|
|
|
fn main() {
|
|
|
let args: Vec<String> = env::args().collect();
|
|
|
|
|
|
let config = Config::build(&args).unwrap_or_else(|err| {
|
|
|
println!("Problem parsing arguments: {err}");
|
|
|
process::exit(1);
|
|
|
});
|
|
|
|
|
|
println!("Searching for {}", config.query);
|
|
|
println!("In file {}", config.file_path);
|
|
|
|
|
|
run(config);
|
|
|
}
|
|
|
|
|
|
fn run(config: Config) {
|
|
|
let contents = fs::read_to_string(config.file_path)
|
|
|
.expect("Should have been able to read the file");
|
|
|
|
|
|
println!("With text:\n{contents}");
|
|
|
}
|
|
|
|
|
|
// --snip--</code></pre></pre>
|
|
|
<p>如上所示，<code>main</code> 函数仅保留主流程各个环节的调用，一眼看过去非常简洁清晰。</p>
|
|
|
<p>继续之前，先请大家仔细看看 <code>run</code> 函数，你们觉得还缺少什么？提示：参考 <code>build</code> 函数的改进过程。</p>
|
|
|
<h3 id="使用--和特征对象来返回错误"><a class="header" href="#使用--和特征对象来返回错误">使用 ? 和特征对象来返回错误</a></h3>
|
|
|
<p>答案就是 <code>run</code> 函数没有错误处理，因为在文章开头我们提到过，错误处理最好统一在一个地方完成，这样极其有利于后续的代码维护。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>//in main.rs
|
|
|
use std::error::Error;
|
|
|
|
|
|
// --snip--
|
|
|
|
|
|
fn run(config: Config) -> Result<(), Box<dyn Error>> {
|
|
|
let contents = fs::read_to_string(config.file_path)?;
|
|
|
|
|
|
println!("With text:\n{contents}");
|
|
|
|
|
|
Ok(())
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>值得注意的是这里的 <code>Result<(), Box<dyn Error>></code> 返回类型，首先我们的程序无需返回任何值，但是为了满足 <code>Result<T,E></code> 的要求，因此使用了 <code>Ok(())</code> 返回一个单元类型 <code>()</code>。</p>
|
|
|
<p>最重要的是 <code>Box<dyn Error></code>， 如果按照顺序学到这里，大家应该知道这是一个<code>Error</code> 的特征对象(为了使用 <code>Error</code>，我们通过 <code>use std::error::Error;</code> 进行了引入)，它表示函数返回一个类型，该类型实现了 <code>Error</code> 特征，这样我们就无需指定具体的错误类型，否则你还需要查看 <code>fs::read_to_string</code> 返回的错误类型，然后复制到我们的 <code>run</code> 函数返回中，这么做一个是麻烦，最主要的是，一旦这么做，意味着我们无法在上层调用时统一处理错误，但是 <code>Box<dyn Error></code> 不同，其它函数也可以返回这个特征对象，然后调用者就可以使用统一的方式来处理不同函数返回的 <code>Box<dyn Error></code>。</p>
|
|
|
<p>明白了 <code>Box<dyn Error></code> 的重要战略地位，接下来大家分析下，<code>fs::read_to_string</code> 返回的具体错误类型是怎么被转化为 <code>Box<dyn Error></code> 的？其实原因在之前章节都有讲过，这里就不直接给出答案了，参见 <a href="https://course.rs/basic/result-error/result.html#%E4%BC%A0%E6%92%AD%E7%95%8C%E7%9A%84%E5%A4%A7%E6%98%8E%E6%98%9F-">?-传播界的大明星</a>。</p>
|
|
|
<p>运行代码看看效果： </p>
|
|
|
<pre><code class="language-shell">$ cargo run the poem.txt
|
|
|
Compiling minigrep v0.1.0 (file:///projects/minigrep)
|
|
|
warning: unused `Result` that must be used
|
|
|
--> src/main.rs:19:5
|
|
|
|
|
|
|
19 | run(config);
|
|
|
| ^^^^^^^^^^^^
|
|
|
|
|
|
|
= note: `#[warn(unused_must_use)]` on by default
|
|
|
= note: this `Result` may be an `Err` variant, which should be handled
|
|
|
|
|
|
warning: `minigrep` (bin "minigrep") generated 1 warning
|
|
|
Finished dev [unoptimized + debuginfo] target(s) in 0.71s
|
|
|
Running `target/debug/minigrep the poem.txt`
|
|
|
Searching for the
|
|
|
In file poem.txt
|
|
|
With text:
|
|
|
I'm nobody! Who are you?
|
|
|
Are you nobody, too?
|
|
|
Then there's a pair of us - don't tell!
|
|
|
They'd banish us, you know.
|
|
|
|
|
|
How dreary to be somebody!
|
|
|
How public, like a frog
|
|
|
To tell your name the livelong day
|
|
|
To an admiring bog!
|
|
|
</code></pre>
|
|
|
<p>没任何问题，不过 Rust 编译器也给出了善意的提示，那就是 <code>Result</code> 并没有被使用，这可能意味着存在错误的潜在可能性。</p>
|
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<h3 id="处理返回的错误"><a class="header" href="#处理返回的错误">处理返回的错误</a></h3>
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<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
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// --snip--
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|
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println!("Searching for {}", config.query);
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println!("In file {}", config.file_path);
|
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|
|
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if let Err(e) = run(config) {
|
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println!("Application error: {e}");
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process::exit(1);
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}
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}</code></pre></pre>
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<p>先回忆下在 <code>build</code> 函数调用时，我们怎么处理错误的？然后与这里的方式做一下对比，是不是发现了一些区别？</p>
|
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<p>没错 <code>if let</code> 的使用让代码变得更简洁，可读性也更加好，原因是，我们并不关注 <code>run</code> 返回的 <code>Ok</code> 值，因此只需要用 <code>if let</code> 去匹配是否存在错误即可。</p>
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<p>好了，截止目前，代码看起来越来越美好了，距离我们的目标也只差一个：将主体逻辑代码分离到一个独立的文件 <code>lib.rs</code> 中。</p>
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<h2 id="分离逻辑代码到库包中"><a class="header" href="#分离逻辑代码到库包中">分离逻辑代码到库包中</a></h2>
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<blockquote>
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<p>对于 Rust 的代码组织( 包和模块 )还不熟悉的同学，强烈建议回头温习下<a href="https://course.rs/basic/crate-module/intro.html">这一章</a>。</p>
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</blockquote>
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<p>首先，创建一个 <code>src/lib.rs</code> 文件，然后将所有的非 <code>main</code> 函数都移动到其中。代码大概类似：</p>
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<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
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</span><span class="boring">fn main() {
|
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</span>use std::error::Error;
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use std::fs;
|
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|
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pub struct Config {
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|
pub query: String,
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|
pub file_path: String,
|
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|
}
|
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|
|
|
impl Config {
|
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pub fn build(args: &[String]) -> Result<Config, &'static str> {
|
|
|
// --snip--
|
|
|
}
|
|
|
}
|
|
|
|
|
|
pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
|
|
|
// --snip--
|
|
|
}
|
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<span class="boring">}</span></code></pre></pre>
|
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<p>为了内容的简洁性，这里忽略了具体的实现，下一步就是在 <code>main.rs</code> 中引入 <code>lib.rs</code> 中定义的 <code>Config</code> 类型。</p>
|
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<pre><pre class="playground"><code class="language-rust edition2021">use std::env;
|
|
|
use std::process;
|
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|
|
|
|
use minigrep::Config;
|
|
|
|
|
|
fn main() {
|
|
|
// --snip--
|
|
|
let args: Vec<String> = env::args().collect();
|
|
|
|
|
|
let config = Config::build(&args).unwrap_or_else(|err| {
|
|
|
println!("Problem parsing arguments: {err}");
|
|
|
process::exit(1);
|
|
|
});
|
|
|
|
|
|
println!("Searching for {}", config.query);
|
|
|
println!("In file {}", config.file_path);
|
|
|
|
|
|
if let Err(e) = minigrep::run(config) {
|
|
|
// --snip--
|
|
|
println!("Application error: {e}");
|
|
|
process::exit(1);
|
|
|
}
|
|
|
}</code></pre></pre>
|
|
|
<p>很明显，这里的 <code>mingrep::run</code> 的调用，以及 <code>Config</code> 的引入，跟使用其它第三方包已经没有任何区别，也意味着我们成功的将逻辑代码放置到一个独立的库包中，其它包只要引入和调用就行。</p>
|
|
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<p>呼，一顿书写猛如虎，回头一看。。。这么长的篇幅就写了这么点简单的代码？？只能说，我也希望像很多国内的大学教材一样，只要列出定理和解题方法，然后留下足够的习题，就万事大吉了，但是咱们不行。</p>
|
|
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<p>接下来，到了最喜(令)闻(人)乐(讨)见(厌)的环节：写测试代码，一起来开心吧。</p>
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