diff --git a/source/03_language_reference/10_Summary_of_the_Grammar.md b/source/03_language_reference/10_Summary_of_the_Grammar.md
index c4dbe9d9..5ff1351d 100755
--- a/source/03_language_reference/10_Summary_of_the_Grammar.md
+++ b/source/03_language_reference/10_Summary_of_the_Grammar.md
@@ -1,1678 +1,1678 @@
-# 语法总结（Summary of the Grammar）
-
-## 词法结构 {#lexical-structure}
-
-> 空白字符语法
->
-> *空白字符*  → [空白字符项](./02_Lexical_Structure.md#whitespace-item) [空白字符](./02-Lexical-Structure.md#whitespace)<sub>可选</sub>
->
-> *空白字符项*  → [换行符](./02_Lexical_Structure.md#line-break)
->
-> *空白字符项*   → [注释](./02_Lexical_Structure.md#comment)
->
-> *空白字符项*  → [多行注释](./02_Lexical_Structure.md#multiline-comment)
->
-> *空白字符项*  → U+0000，U+0009，U+000B，U+000C 或 U+0020
->
->
->
-> 换行符*  → U+000A
->
-> *换行符*  → U+000D
->
-> *换行符*  → U+000D 后面是 U+000A
->
->
->
-> *注释*  → **//** [单行内容注释](./02_Lexical_Structure.md#comment-text) [换行符](./02-Lexical-Structure.md#line-break)
->
-> *注释*  → **/\*** [多行内容注释](./02_Lexical_Structure.md#multiline-comment-text) **\*/**
->
->
->
-> *注释内容*  → [注释内容项](./02_Lexical_Structure.md#comment-text-item) [注释内容](./02-Lexical-Structure.md#comment-text)<sub>可选</sub>  
->
-> *注释内容项*  → 除 U+000A 或 U+000D 外的任何 Unicode 标量值
->
->
->
-> *多行注释内容*  → [多行注释内容项](./02_Lexical_Structure.md#multiline-comment-text-item) [多行注释内容](./02-Lexical-Structure.md#multiline-comment-text)<sub>可选</sub>  
->
-> *多行注释内容项*  → [多行内容](./02_Lexical_Structure.md#multiline-comment)
->
-> *多行注释内容项*  → [注释内容项](./02_Lexical_Structure.md#comment-text-item)
->
-> *多行注释内容项*  → 除 **/\*** 或 **\*/** 外的任何 Unicode 标量值
->
-
-<!-- -->
-
-> 标识符语法
->
-> *标识符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
->
-> *标识符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
->
-> *标识符* → [隐式参数名](./02_Lexical_Structure.md#implicit-parameter-name)
->
-> *标识符* → [属性包装器呈现值](./02_Lexical_Structure.md#property-wrapper-projection)
->
-> *标识符集* → [标识符](./02_Lexical_Structure.md#identifier) | [标识符](./02-Lexical-Structure.md#identifier) **,** [标识符集](./02-Lexical-Structure.md#identifier-list)
->
-> *标识符头（Head）* → 大写或者小写字母 A 到 Z
->
-> *标识符头（Head）* → _
->
-> *标识符头（Head）* → U+00A8, U+00AA, U+00AD, U+00AF, U+00B2–U+00B5, or U+00B7–U+00BA
->
-> *标识符头（Head）* → U+00BC–U+00BE, U+00C0–U+00D6, U+00D8–U+00F6, or U+00F8–U+00FF
->
-> *标识符头（Head）* → U+0100–U+02FF, U+0370–U+167F, U+1681–U+180D, or U+180F–U+1DBF
->
-> *标识符头（Head）* → U+1E00–U+1FFF
->
-> *标识符头（Head）* → U+200B–U+200D, U+202A–U+202E, U+203F–U+2040, U+2054, or U+2060–U+206F
->
-> *标识符头（Head）* → U+2070–U+20CF, U+2100–U+218F, U+2460–U+24FF, or U+2776–U+2793
->
-> *标识符头（Head）* → U+2C00–U+2DFF or U+2E80–U+2FFF
->
-> *标识符头（Head）* → U+3004–U+3007, U+3021–U+302F, U+3031–U+303F, or U+3040–U+D7FF
->
-> *标识符头（Head）* → U+F900–U+FD3D, U+FD40–U+FDCF, U+FDF0–U+FE1F, or U+FE30–U+FE44
->
-> *标识符头（Head）* → U+FE47–U+FFFD
->
-> *标识符头（Head）* → U+10000–U+1FFFD, U+20000–U+2FFFD, U+30000–U+3FFFD, or U+40000–U+4FFFD
->
-> *标识符头（Head）* → U+50000–U+5FFFD, U+60000–U+6FFFD, U+70000–U+7FFFD, or U+80000–U+8FFFD
->
-> *标识符头（Head）* → U+90000–U+9FFFD, U+A0000–U+AFFFD, U+B0000–U+BFFFD, or U+C0000–U+CFFFD
->
-> *标识符头（Head）* → U+D0000–U+DFFFD or U+E0000–U+EFFFD
->
-> *标识符字符* → 数值 0 到 9
->
-> *标识符字符* → U+0300–U+036F, U+1DC0–U+1DFF, U+20D0–U+20FF, or U+FE20–U+FE2F
->
-> *标识符字符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head)
->
-> *标识符字符集* → [标识符字符](./02_Lexical_Structure.md#identifier-character) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
->
-> *隐式参数名* → **$** [十进制数字集](./02_Lexical_Structure.md#decimal-digits)
->
-> *属性包装器呈现值* → **$**  [标识符字符集](./02-Lexical-Structure.md#identifier-characters)
->
-
-<!-- -->
-
-> 字面量语法
->
-> *字面量* → [数值型字面量](./02_Lexical_Structure.md#numeric-literal) | [字符串字面量](./02-Lexical-Structure.md#string-literal) | [布尔字面量](./02-Lexical-Structure.md#boolean-literal) | [空字面量](./02-Lexical-Structure.md#nil-literal)
->
-> *数值型字面量* → **-**<sub>可选</sub>[整形字面量](./02_Lexical_Structure.md#integer-literal) | **-**<sub>可选</sub>[浮点型字面量](./02-Lexical-Structure.md#floating-point-literal)
->
-> *布尔字面量* → **true** | **false**
->
-> *空字面量* → **nil**
->
-
-<!-- -->
-
-> 整型字面量语法
->
-> *整型字面量* → [二进制字面量](./02_Lexical_Structure.md#binary-literal)
->
-> *整型字面量* → [八进制字面量](./02_Lexical_Structure.md#octal-literal)
->
-> *整型字面量* → [十进制字面量](./02_Lexical_Structure.md#decimal-literal)
->
-> *整型字面量* → [十六进制字面量](./02_Lexical_Structure.md#hexadecimal-literal)
->
-> *二进制字面量* → **0b** [二进制数字](./02_Lexical_Structure.md#binary-digit) [二进制字面量字符集](./02-Lexical-Structure.md#binary-literal-characters)<sub>可选</sub> 
->
-> *二进制数字* → 数值 0 到 1
->
-> *二进制字面量字符* → [二进制数字](./02_Lexical_Structure.md#binary-digit) | **-**
->
-> *二进制字面量字符集* → [二进制字面量字符](./02_Lexical_Structure.md#binary-literal-character) [二进制字面量字符集](./02-Lexical-Structure.md#binary-literal-characters)<sub>可选</sub> 
->
-> *八进制字面量* → **0o** [八进制数字](./02_Lexical_Structure.md#octal-digit) [八进制字符集](./02-Lexical-Structure.md#octal-literal-characters)<sub>可选</sub> 
->
-> *八进字数字* → 数值 0 到 7
->
-> *八进制字符* → [八进制数字](./02_Lexical_Structure.md#octal-digit) | **-**
->
-> *八进制字符集* → [八进制字符](./02_Lexical_Structure.md#octal-literal-character) [八进制字符集](./02-Lexical-Structure.md#octal-literal-characters)<sub>可选</sub> 
->
-> *十进制字面量* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) [十进制字符集](./02-Lexical-Structure.md#decimal-literal-characters)<sub>可选</sub> 
->
-> *十进制数字* → 数值 0 到 9
->
-> *十进制数字集* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) [十进制数字集](./02-Lexical-Structure.md#decimal-digits)<sub>可选</sub> 
->
-> *十进制字面量字符* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) | **-**
->
-> *十进制字面量字符集* → [十进制字面量字符](./02_Lexical_Structure.md#decimal-literal-character) [十进制字面量字符集](./02-Lexical-Structure.md#decimal-literal-characters)<sub>可选</sub> 
->
-> *十六进制字面量* → **0x** [十六进制数字](./02_Lexical_Structure.md#hexadecimal-digit) [十六进制字面量字符集](./02-Lexical-Structure.md#hexadecimal-literal-characters)<sub>可选</sub> 
->
-> *十六进制数字* → 数值 0 到 9，a 到 f，或者 A 到 F
->
-> *十六进制字符* → [十六进制数字](./02_Lexical_Structure.md#hexadecimal-digit) | **-**
->
-> *十六进制字面量字符集* → [十六进制字符](./02_Lexical_Structure.md#hexadecimal-literal-character) [十六进制字面量字符集](./02-Lexical-Structure.md#hexadecimal-literal-characters)<sub>可选</sub> 
->
-
-<!-- -->
-
-> 浮点型字面量语法
->
-> *浮点数字面量* → [十进制字面量](./02_Lexical_Structure.md#decimal-literal) [十进制分数](./02-Lexical-Structure.md#decimal-fraction)<sub>可选</sub>[十进制指数](./02-Lexical-Structure.md#decimal-exponent)<sub>可选</sub> 
->
-> *浮点数字面量* → [十六进制字面量](./02_Lexical_Structure.md#hexadecimal-literal) [十六进制分数](./02-Lexical-Structure.md#hexadecimal-fraction)<sub>可选</sub>[十六进制指数](./02-Lexical-Structure.md#hexadecimal-exponent)
->
-> *十进制分数* → **.** [十进制字面量](./02_Lexical_Structure.md#decimal-literal)
->
-> *十进制指数* → [浮点数 e](./02_Lexical_Structure.md#floating-point-e) [正负号](./02-Lexical-Structure.md#sign)<sub>可选</sub>[十进制字面量](./02-Lexical-Structure.md#decimal-literal)
->
-> *十六进制分数* → **.** [十六进制数](./02_Lexical_Structure.md#hexadecimal-literal)
->
-> *十六进制指数* → [浮点数 p](./02_Lexical_Structure.md#floating-point-p) [正负号](./02-Lexical-Structure.md#sign)<sub>可选</sub>[十六进制字面量](./02-Lexical-Structure.md#hexadecimal-literal)
->
-> *浮点数 e* → **e** | **E**
->
-> *浮点数 p* → **p** | **P**
->
-> *正负号* → **+** | **-**
->
-
-<!-- -->
-
-> 字符串型字面量语法
-
-> *字符串字面量* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal) | [插值字符串字面量](./02-Lexical-Structure.md#interpolated-string-literal)
->
-> *字符串开分隔定界符* → [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter) **"**
->
-> *字符串闭分隔定界符* → **"** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)<sub>可选</sub>
->
-> *静态字符串字面量* → [字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [引用文本](./02-Lexical-Structure.md#quoted-text)<sub>可选</sub> [字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
->
-> *静态字符串字面量* → [多行字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [多行引用文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub> [多行字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
->
-> *多行字符串开分隔定界符* → [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter) **"""**
->
-> *多行字符串闭分隔定界符* → **"""** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)
->
-> *字符串扩展分隔符* → **#** [字符串扩展分隔符](./02-Lexical-Structure.md#extended-string-literal-delimiter)<sub>可选</sub>
->
-> *引用文本* → [引用文本项](./02_Lexical_Structure.md#quoted-text-item) [引用文本](#quoted-text)<sub>可选</sub>
->
-> *引用文本项* → [转义字符](./02_Lexical_Structure.md#escaped-character)
->
-> *引用文本项* → 除了 **"**、**\\\**、U+000A、U+000D 以外的所有 Unicode 字符    
->
-> *多行引用文本* → [多行引用文本项](./02_Lexical_Structure.md#multiline-quoted-text-item) [多行引用文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub>
->
-> *多行引用文本项* [转义字符](./02_Lexical_Structure.md#escaped-character)<sub>可选</sub>
->
-> *多行引用文本* → 除了 **\\** 以外的任何 Unicode 标量值
->
-> *多行引用文本* → [转义换行](./02_Lexical_Structure.md#escaped-newline)
-
-> *插值字符串字面量* → [字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub> [字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
->
-> *插值字符串字面量* → [多行字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub> [多行字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
->
-> *插值文本* → [插值文本项](./02_Lexical_Structure.md#interpolated-text-item) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub>
->
-> *插值文本项* → **\\**(**[表达式](./04_Expressions.md)**) | [引用文本项](./02_Lexical_Structure.md#quoted-text-item)
->
-> *多行插值文本* → [多行插值文本项](./02_Lexical_Structure.md#multiline-quoted-text-item) [多行插值文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub>
->
-> *多行插值文本项* → **\\(** [表达式](./04_Expressions.md) **)** | [多行引用文本项](./02_Lexical_Structure.md#multiline-quoted-text-item)
->
-> *转义序列* → **\\** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)
->
-> *转义字符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) **0** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **\\** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **t** | [转义序列](#escape-sequence) **n** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **r** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **\"** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **'**
->
-> *转义字符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) **u {** [unicode 标量数字](./02-Lexical-Structure.md#unicode-scalar-digits) **}**
->
-> *unicode 标量数字* → 一到八位的十六进制数字
->
-> *转义换行符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) [空白](./02-Lexical-Structure.md#whitespace)<sub>可选</sub> [换行符](./02-Lexical-Structure.md#line-break)
-
-
-<!-- -->
-
-> 运算符语法语法
->
-> *运算符* → [运算符头](./02_Lexical_Structure.md#operator-character) [运算符字符集](./02-Lexical-Structure.md#operator)<sub>可选</sub> 
->
-> *运算符* → [点运算符头](./02_Lexical_Structure.md#dot-operator-head) [点运算符字符集](./02-Lexical-Structure.md#dot-operator-characters)<sub>可选</sub> 
->
-> *运算符字符* → **/** | **=** | **-** | **+** | **!** | **&#42;** | **%** | **<** | **>** | **&** | **|** | **^** | **~** | **?**
->
-> *运算符头* → U+00A1–U+00A7
->
-> *运算符头* → U+00A9 or U+00AB
->
-> *运算符头* →  U+00AC or U+00AE
->
-> *运算符头* → U+00B0–U+00B1, U+00B6, U+00BB, U+00BF, U+00D7, or U+00F7
->
-> *运算符头* → U+2016–U+2017 or U+2020–U+2027
->
-> *运算符头* → U+2030–U+203E
->
-> *运算符头* → U+2041–U+2053
->
-> *运算符头* → U+2055–U+205E
->
-> *运算符头* → U+2190–U+23FF
->
-> *运算符头* → U+2500–U+2775
->
-> *运算符头* → U+2794–U+2BFF
->
-> *运算符头* → U+2E00–U+2E7F
->
-> *运算符头* → U+3001–U+3003
->
-> *运算符头* → U+3008–U+3030
->
-> *运算符字符* → [运算符头](./02_Lexical_Structure.md#operator-head)
->
-> *运算符字符* → U+0300–U+036F
->
-> *运算符字符* → U+1DC0–U+1DFF
->
-> *运算符字符* → U+20D0–U+20FF
->
-> *运算符字符* → U+FE00–U+FE0F
->
-> *运算符字符* → U+FE20–U+FE2F
->
-> *运算符字符* → U+E0100–U+E01EF
->
-> *运算符字符集* → [运算符字符](./02_Lexical_Structure.md#operator-character) [运算符字符集](./02-Lexical-Structure.md#operator-characters)<sub>可选</sub> 
->
-> *点运算符头* → **..**
->
-> *点运算符字符* → **.** | [运算符字符](./02_Lexical_Structure.md#operator-character)
->
-> *点运算符字符集* → [点运算符字符](./02_Lexical_Structure.md#dot-operator-character) [点运算符字符集](./02-Lexical-Structure.md#dot-operator-characters)<sub>可选</sub> 
->
-> *二元运算符* → [运算符](./02_Lexical_Structure.md#operator)
->
-> *前置运算符* → [运算符](./02_Lexical_Structure.md#operator)
->
-> *后置运算符* → [运算符](./02_Lexical_Structure.md#operator)
->
-
-## 类型 {#types}
-
-> 类型语法
->
-> *类型* → [数组类型](./03_Types.md#array-type)
->
-> *类型* → [字典类型](./03_Types.md#dictionary-type)
->
-> *类型* → [函数类型](./03_Types.md#function-type)
->
-> *类型* → [类型标识符](./03_Types.md#type-identifier)
->
-> *类型* → [元组类型](./03_Types.md./03_Types.md#tuple-type)
->
-> *类型* → [可选类型](./03_Types.md#optional-type)
->
-> *类型* → [隐式解析可选类型](./03_Types.md#implicitly-unwrapped-optional-type)
->
-> *类型* → [协议合成类型](./03_Types.md#protocol-composition-type)
->
-> *类型* → **Any**
->
-> *类型* → **Self**
->
-> *类型* → **（** [type](./03_Types.md#metatype-type) **）**
-
-<!-- -->
-
-> 类型注解语法
->
-> *类型注解* → **:** [属性（Attributes）集](./07_Attributes.md#attributes)<sub>可选</sub>[类型](./03-Types.md#type)
-
-<!-- -->
-
-> 类型标识语法
->
-> *类型标识* → [类型名称](./03_Types.md#type-name) [泛型参数从句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>| [类型名称](./03-Types.md#type-name) [泛型参数从句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>**.** [类型标识符](./03-Types.md#type-identifier)
->
-> *类型名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-
-> 元组类型语法
->
-> *元组类型* → **(** **)** | **(** [元组类型元素](./03_Types.md#tuple-type-element) **,** [元组类型元素列表](./03-Types.md#tuple-type-element-list) **)**
->
-> *元组类型元素列表* → [元组类型元素](./03_Types.md#tuple-type-element) | [元组类型元素](./03-Types.md#tuple-type-element) **,** [元组类型元素列表](./03-Types.md#tuple-type-element-list)
->
-> *元组类型元素* → [元素名](./03_Types.md#element-name) [类型注解](./03-Types.md#type-annotation) | [类型](./03-Types.md#type)
->
-> *元素名* → [标识符](./02_Lexical_Structure.md#identifier)
-
-<!-- -->
-
-> 函数类型语法
->
-> *函数类型* → [类型](./03_Types.md#type)  **throws**<sub>可选</sub>**->** [类型](./03-Types.md#type)
->
-> *函数类型* → [类型](./03_Types.md#)  **rethrows** **->** [类型](./03-Types.md#)
-> 
-> *函数类型子句* → **(** **)**
-> 
-> *函数类型子句* → **(** [函数类型参数列表](./03_Types.md#function-type-argument-list) *...*­<sub>可选</sub> **)**
-> 
-> *函数类型参数列表* → [函数类型参数](./03_Types.md#function-type-argument) | [函数类型参数](function-type-argument)， [函数类型参数列表](./03-Types.md#function-type-argument-list)
-> 
-> *函数类型参数* → [特性列表](./07_Attributes.md#attributes)<sub>可选</sub> **输入输出参数**<sub>可选</sub> [类型](#type) | [参数标签](#argument-label) [类型注解](#type-annotation)
-> 
-> *参数标签* → [标识符](./02_Lexical_Structure.md#identifier)
-
-<!-- -->
-
-> 数组类型语法
->
-> *数组类型* → **[** [*类型*](./03_Types.md#array-type) **]**
-
-<!-- -->
-> 字典类型语法
->
-> *字典类型* → **[** [类型 **:** 类型](./03_Types.md#type) **]**
-
-<!-- -->
-
-> 可选类型语法
->
-> *可选类型* → [类型](./03_Types.md#type) **?**
->
-
-<!-- -->
-
-> 隐式解析可选类型（Implicitly Unwrapped Optional Type）语法
->
-> *隐式解析可选类型* → [类型](./03_Types.md#type) **!**
->
-
-<!-- -->
-
-> 协议合成类型语法
->
-> *协议合成类型* → [类型标识符](./03_Types.md#type-identifier) | [协议合成延续](./03-Types.md#protocol-composition-continuation)
->
-> *协议持续延续* → [类型标识符](./03_Types.md#type-identifier) | [协议合成类型](./03-Types.md#protocol-composition-type)
-
-<!-- -->
-
-> 元（Metatype）类型语法
->
-> *元类型* → [类型](./03_Types.md#type) **.** **Type** | [类型](./03-Types.md#type) **.** **Protocol**
-
-<!-- -->
-
-> 类型继承从句语法
->
-> *类型继承从句* → **:** [类型继承集](./03_Types.md#type-inheritance-list)
->
-> *类型继承集* → [类型标识符](./03_Types.md#type-identifier) | [类型标识符](./03-Types.md#type-identifier) **,** [类型继承集](./03-Types.md#type-inheritance-list)
->
-> *类条件* → **class**
-
-## 表达式 {#expressions}
-
-> 表达式语法
->
-> *表达式* → [try 运算符](./04_Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression) [二元表达式列表](./04-Expressions.md#binary-expressions)
->
-> *表达式列表* → [表达式](./04_Expressions.md#expression)|[表达式](./04-Expressions.md#expression), [表达式列表](./04-Expressions.md#expression-list)
->
-
-<!-- -->
-
-> 前缀表达式语法
->
-> *前缀表达式* → [前缀操作符]()<sub>可选</sub> [前缀表达式](./04_Expressions.md#prefix-expression)
->
-> *前缀表达式* → [输入输出表达式](./04_Expressions.md#in-out-expression)
->
-> *输入输出表达式* → **&** [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-
->try 表达式语法
->
-> *try 操作符* → **try** | **try ? ** | ** try ! **
->
-
-<!-- -->
-
-> 二元表达式语法
->
-> *二元表达式* → [二元运算符](./02_Lexical_Structure.md#binary-operator) [前缀表达式](./04-Expressions.md#prefix-expression)
->
-> *二元表达式* → [赋值操作符](./06_Declarations.md#class-declaration) [try 运算符](./04-Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression)
->
-> *二元表达式* → [条件运算符](./04_Expressions.md#conditional-operator) [try 运算符](./04-Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression)
->
-> *二元表达式* → [类型转换运算符](./04_Expressions.md#type-casting-operator)
->
-> *二元表达式* → [二元表达式](./04_Expressions.md#binary-expression) [二元表达式列表](./04-Expressions.md#binary-expressions)<sub>可选</sub>
->
-
-<!-- -->
-
-> 赋值操作符语法
->
-> *赋值运算符* → [=]
->
-
-<!-- -->
-
-> 条件运算符
->
-> *条件运算符* → [?] [表达式](./04_Expressions.md#expression):
-
-> 类型转换运算符语法
->
-> *类型转换运算符* → [is] [类型](./03_Types.md#type)
->
-> *类型转换运算符* → [as] [类型](./03_Types.md#type)
->
-> *类型转换运算符* → [as ?] [类型](./03_Types.md#type)
->
-> *类型转换运算符* → [as !] [类型](./03_Types.md#type)
->
-
-
-<!-- -->
-
-> 基础表达式语法
->
-> *基础表达式* → [标识符](./02_Lexical_Structure.md#identifier) [泛型实参子句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>
->
-> *基础表达式* → [字面量表达式](./04_Expressions.md#literal-expression)
->
-> *基础表达式* → [self 表达式](./04_Expressions.md#self-expression)
->
-> *基础级表达式* → [父类表达式](./04_Expressions.md#superclass-expression)
->
-> *基础表达式* → [闭包表达式](./04_Expressions.md#closure-expression)
->
-> *基础表达式* → [圆括号表达式](./04_Expressions.md#parenthesized-expression)
->
-> *基础表达式* → [元组表达式](./04_Expressions.md#Tuple-Expression)
->
-> *基础表达式* → [隐式成员表达式](./04_Expressions.md#implicit-member-expression)
->
-> *基础表达式* → [通配符表达式](./04_Expressions.md#wildcard-expression)
->
-> *基础表达式* → [key-path表达式](./04_Expressions.md#key-path-expression)
->
-> *基础表达式* → [选择器表达式](./04_Expressions.md#selector-expression)
->
-> *基础表达式* → [key-path字符串表达式](./04_Expressions.md#key-patch-string-expression)
->
-
-<!-- -->
-
-> 字面量表达式语法
->
-> *字面量表达式* → [字面量](./04_Expressions.md#literal-expression)
->
-> *字面量表达式* → [数组字面量](./04_Expressions.md#array-literal) | [字典字面量](./04-Expressions.md#dictionary-literal) | [练习场字面量](./04-Expressions.md#playground-literal)
->
-> *字面量表达式* → **#file** | **#line** | **#column** | **#function** | **dsohandle**
->
->
-> *数组字面量* → **[** [数组字面量项列表](./04_Expressions.md#array-literal-items)<sub>可选</sub> **]**
-> *数组字面量项列表* → [数组字面量项](./04_Expressions.md#array-literal-item)<sub>可选</sub> | [数组字面量项](./04-Expressions.md#array-literal-item),[数组字面量项列表](./04-Expressions.md#array-literal-items)
-> *数组字面量项* → [表达式](./04_Expressions.md#expression)
->
->
-> *字典字面量* → [[字典字面量项列表](./04_Expressions.md#dictionary-literal-items) **]** | **[** **:** **]**
-> 
-> 
-> *字典字面量项列表* → [字典字面量项](./04_Expressions.md#dictionary-literal-item) ,**<sub>可选</sub> | [字典字面量项](./04-Expressions.md#dictionary-literal-item) ,[字典字面量项列表](./04-Expressions.md#dictionary-literal-items)
->
-> *字典字面量项* → [表达式](./04_Expressions.md#expression) **:** [表达式](./04-Expressions.md#expression)
->
-> 
-> *palyground 字面量* → **#colorLiteral ( red :  [表达式](./04-Expressions.md#expression) , green :[表达式](./04-Expressions.md#expression),  blue :[表达式](./04-Expressions.md#expression) , alpha : [表达式](./04-Expressions.md#expression) )**
->
-> *playground 字面量* → **#fileLiteral ( resourceName : [表达式](#expression) )**
->
-> *playground 字面量* → **#imageLiteral ( resourceName : [表达式](#expression) )
-<!-- -->
-
-> self 表达式语法
-> 
-> *self 表达式* → **self**  | [self 方法表达式](./04_Expressions.md#self-method-expression) ｜ [self 下标表达式](./04-Expressions.md#self-subscript-expression) | [self 构造器表达式](./04-Expressions.md#self-initializer-expression)
->
->
-> *self 方法表达式* → **self** **.** [标识符](./02_Lexical_Structure.md#identifier)
->
-> *self 下标表达式* → **self** **[** [函数调用参数表](./04_Expressions.md#function-call-argument-list­) **]**
->
-> *self 构造器表达式* → **self** **.** **init**
-
-<!-- -->
-
-> 父类表达式语法
->
-> *父类表达式* → [父类方法表达式](./04_Expressions.md#superclass-method-expression) | [父类下标表达式](./04-Expressions.md#superclass-subscript-expression) | [父类构造器表达式](./04-Expressions.md#superclass-initializer-expression)
->
-> *父类方法表达式* → **super** **.** [标识符](./02_Lexical_Structure.md#identifier)
-> 
-> *父类下标表达式* → **super** [[函数调用参数表](./04_Expressions.md#function-call-argument-list­) **]**
->
-> *父类构造器表达式* → **super** **.** **init**
-> 
-
-
-<!-- -->
-
-> 闭包表达式语法
->
-> *闭包表达式* → **{** [闭包签名](./04_Expressions.md#closure-signature)<sub>可选</sub> [语句](./04-Expressions.md#statements) **}**
->
->
-> 闭包签名* → [参数子句](./04_Expressions.md#parameter-clause) [函数结果](05-Declarations.md#function-result)<sub>可选</sub> **in**
-> 
-> *闭包签名* → [标识符列表](./04_Expressions.md#identifier-list) [函数结果](05-Declarations.md#function-result)<sub>可选</sub> **in**
-> 
->
-> *闭包参数子句* **(** **)** | **(** [闭包参数列表](./04_Expressions.md#closure-parameter-list) | [标识符列表](./04-Expressions.md#identifier-list) **)**
->
-> *闭包参数列表* [闭包参数](./04_Expressions.md#implicit-member-expression) | [闭包参数](./04-Expressions.md#implicit-member-expression), [闭包参数列表](./04-Expressions.md#implicit-member-expression)
->
-> *闭包参数* [闭包参数名](./04_Expressions.md#implicit-member-expression) [类型声明](./03-Types.md#type-annotation) <sub>可选</sub>
->
-> *闭包参数* [闭包参数名](./04_Expressions.md#implicit-member-expression) [类型声明](./03-Types.md#type-annotation) **...**
->
-> *闭包参数名* [标识符](./02_Lexical_Structure.md#identifier)
-> 
->
-> *捕获列表* → [捕获列表](./04_Expressions.md#capture-list) **[** [捕获列表项列表](./04-Expressions.md#capture-list-items) **]**
->
-> *捕获列表项列表* → [捕获列表项](./04_Expressions.md#capture-list-item) | [捕获列表项](./04-Expressions.md#capture-list-item) **,** [捕获列表项列表](./04-Expressions.md#capture-list-items)
->
-> *捕获列表项* → [捕获说明符](./04_Expressions.md#capture-specifier)<sub>可选</sub> [*表达式*](./04-Expressions.md#expression)
->
-> *捕获说明符* → **weak** | **unowned** | **unowned(safe)** | **unowned(unsafe)**
-> 
-
-
-<!-- -->
-
-> 隐式成员表达式语法
->
-> *隐式成员表达式* → **.** [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-
-> 圆括号表达式语法
->
-> *圆括号表达式* → **( [表达式](./04_Expressions.md#expression) )**
-> 
-
-<!-- -->
-
-> 元组表达式语法
->
-> *元组表达式* → **( )** | **(**[元组元素](./04_Expressions.md#tuple-element)， [元组元素列表](./04-Expressions.md#tuple-element-list) **)**
-> 
-> *元组元素列表* → [元组元素](./04_Expressions.md#tuple-element) | [元组元素](./04-Expressions.md#tuple-element) **,** [元组元素列表](./04-Expressions.md#tuple-element-list)
-> *元组元素* → [表达式](./04_Expressions.md#expression) | [标识符](./04-Expressions.md#identifier) **:** [表达式](./04-Expressions.md##expression)
-> 
-
-<!-- -->
-
-> 通配符表达式语法
->
-> *通配符表达式* → **_**
->
-
-
-<!-- -->
-
-> key-path表达式语法
->
-> *key-path 表达式* → **\**  [类型](./03_Types.md#type)<sub>可选</sub>  **.**  [多个 key-path 组件]
-> *多个 key-path 组件* → [key-path 组件](./04_Expressions.md#key-path-component) | [key-path 组件](./04-Expressions.md#key-path-component) **.** [多个 key-path 组件](./04-Expressions.md#key-path-components)
-> *key-path 组件* →  [标识符](./02_Lexical_Structure.md#identifier) [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)<sub>可选<sub> | [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)
-> *多个 key-path 后缀* →  [key-path 后缀](./04_Expressions.md#key-path-postfix) [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)<sub>可选<sub> key-path-postfixes {./04-Expressions.md#key-path-postfixes}
-> 
-> *key-path 后缀* → **?** | **!** | **self** | **\[** [函数调用参数表](./04_Expressions.md#function-call-argument-list) **\]** 
-> 
-
-
-<!-- -->
-
-> 选择器表达式语法
->
-> *选择器表达式* → **#selector** **(** [*表达式*](./04-Expressions.md#expression) **)**
-> 
-> *选择器表达式* → **#selector** **(** [*getter:表达式*](./04-Expressions.md#expression) **)**
-> 
-> *选择器表达式* → **#selector** **(** [*setter:表达式*](./04-Expressions.md#expression) **)**
-> 
-
-<!-- -->
-
-> key-path 字符串表达式语法
-> *key-path 字符串表达式* → **#keyPath (** [表达式](./04-Expressions.md#expression)  **)**
-> 
-
-<!-- -->
-
-> 后缀表达式表达式语法
->
-> *后缀表达式* → [基本表达式](./04_Expressions.md#primary-expression)
-> 
-> *后缀表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [后缀运算符](02-Lexical-Structure.md#postfix-operator)
-> 
-> *后缀表达式* → [函数调用表达式](./04_Expressions.md#function-call-expression)
-> 
-> *后缀表达式* → [构造器表达式](./04_Expressions.md#initializer-expression)
-> 
-> *后缀表达式* → [显式成员表达式](./04_Expressions.md#explicit-member-expression)
-> 
-> *后缀表达式* → [后缀 self 表达式](./04_Expressions.md#postfix-self-expression)
->  
-> *后缀表达式* → [下标表达式](./04_Expressions.md#subscript-expression)
-> 
-> *后缀表达式* → [强制取值表达式](./04_Expressions.md#forced-value-expression)
-> 
-> *后缀表达式* → [可选链表达式](./04_Expressions.md#optional-chaining-expression)
-> 
-
-<!-- -->
-
-> 函数调用表达式语法
->
-> *函数调用表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [函数调用参数子句](./04-Expressions.md#function-call-argument-clause)
-> 
-> *函数调用表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [函数调用参数子句](./04-Expressions.md#function-call-argument-clause)<sub>可选</sub> [尾随闭包](./04-Expressions.md#trailing-closure)
->
-> *函数调用参数子句* → **(**  **)**  | **(** [函数调用参数表](./04_Expressions.md#function-call-argument-list) **)**
->
-> *函数调用参数表* → [函数调用参数](./04_Expressions.md#function-call-argument) | [函数调用参数](./04-Expressions.md#function-call-argument) **,** [函数调用参数表](./04-Expressions.md#function-call-argument-list)
->
-> *函数调用参数* → [表达式](./04_Expressions.md#expression) | [标识符](02-Lexical-Structure.md#identifier) **:** [表达式](./04-Expressions.md#expression)
-> 
-> *函数调用参数* → [运算符](./02_Lexical_Structure.md#operator) | [标识符](./02-Lexical-Structure.md#identifier) **:** [运算符](./02-Lexical-Structure.md#operator)
->
-> *尾随闭包* → [闭包表达式](./04_Expressions.md#closure-expression)
->
-
-<!-- -->
-
-> 初始化表达式语法
->
-> *构造器表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **init**
-> 
-> *构造器表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **init** **(** [参数名称](./04-Expressions.md#argument-names) **)**
-> 
-
-<!-- -->
-
-> 显式成员表达式语法
->
-> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [十进制数字]    (02-Lexical-Structure.md#decimal-digit)
-> 
-> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [标识符](02-Lexical-Structure.md#identifier) [泛型实参子句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub><br/>
-> 
-> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [标识符]    (02-Lexical-Structure.md#identifier) **(** [参数名称](./04-Expressions.md#argument-names) **)**
-> 
-> *参数名称* → [参数名](./04_Expressions.md#argument-name) [参数名称](./04-Expressions.md#argument-names)<sub>可选</sub><br/>
-> 
-> *参数名* → [标识符](./02_Lexical_Structure.md#identifier) **:**
->
-
-<!-- -->
-
-> 后缀 self 表达式语法
->
-> *后缀 self 表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **self**
-> 
-
-<!-- -->
-
-> 下标表达式语法
->
-> *下标表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **[** [表达式列表](./04-Expressions.md#expression-list) **]**
-> 
-
-<!-- -->
-
-> 强制取值表达式语法
-> *强制取值表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **!**
-> 
-
-
-<!-- -->
-
-> 可选链式表达式语法
-> *可选链表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **?**
-> 
-
-## 语句 {#statements}
-
-> 语句语法
->
-> *语句* → [表达式](./04_Expressions.md#expression) **;**<sub>可选</sub>
->
-> *语句* → [声明](./06_Declarations.md#declaration) **;**<sub>可选</sub>
->
-> *语句* → [循环语句](./05_Statements.md#loop-statement) **;**<sub>可选</sub>
->
-> *语句* → [分支语句](./05_Statements.md#branch-statement) **;**<sub>可选</sub>
->
-> *语句* → [标签语句](./05_Statements.md#labeled-statement) **;**<sub>可选</sub>
->
-> *语句* → [控制转移语句](./05_Statements.md#control-transfer-statement) **;**<sub>可选</sub>
->
-> *语句* → [延迟语句](./05_Statements.md#defer-statement) **;**<sub>可选</sub>
->
-> *语句* → [执行语句](./05_Statements.md#do-statement) **;**<sub>可选</sub>
->
-> *语句* → [编译控制语句](./05_Statements.md#compiler-control-statement)
->
-> *语句集* → [语句](./05_Statements.md#statement) [语句集](./05-Statements.md#statements)<sub>可选</sub>
->
-
-<!-- -->
-
-> 循环语句语法
->
-> *循环语句* → [for-in 语句](./05_Statements.md#for-in-statement)
->
-> *循环语句* → [while 语句](./05_Statements.md#wheetatype 类型 ile-statement)
->
-> *循环语句* → [repeat-while 语句](./05_Statements.md#do-while-statement)
->
-
-<!-- -->
-
-> For-In 循环语法
->
-> *for-in 语句* → **for case**<sub>可选</sub> [模式](./08_Patterns.md#pattern) **in** [表达式](./04-Expressions.md#expression) [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
->
-
-<!-- -->
-
-> While 循环语法
->
-> *while 语句* → **while** [条件集](./05_Statements.md#condition-list) [代码块](./06-Declarations.md#code-block)
->
-> *条件集* → [条件](./05_Statements.md#condition) | [条件](./05-Statements.md#condition) **,** [条件集](./05-Statements.md#condition-list)
-> *条件* → [表达式](./04_Expressions.md#expression) | [可用性条件](./05-Statements.md#availability-condition) | [case 条件](./05-Statements.md#case-condition) | [可选绑定条件](./05-Statements.md#optional-binding-condition)
->
-> *case 条件* → **case** [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)
->
-> *可选绑定条件* → **let** [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer) | **var** [模式](./08-Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)
->
-
-<!-- -->
-> Repeat-While 语句语法
->
-*repeat-while-statement* → **repeat** [代码块](./06_Declarations.md#code-block) **while** [表达式](./04-Expressions.md#expression)
-
-<!-- -->
-
-> 分支语句语法
->
-> *分支语句* → [if 语句](./05_Statements.md#if-statement)
->
-> *分支语句* → [guard 语句](./05_Statements.md#guard-statement)
->
-> *分支语句* → [switch 语句](./05_Statements.md#switch-statement)
->
-
-<!-- -->
-
-> If 语句语法
->
-> *if 语句* → **if** [条件集](./05_Statements.md#condition-list) [代码块](./06-Declarations.md#code-block) [else 子句](./05-Statements.md#else-clause)<sub>可选</sub>
->
-> *else 子句* → **else** [代码块](./06_Declarations.md#code-block) | **else** [if 语句](./05-Statements.md#if-statement)
->
-
-<!-- -->
-> Guard 语句语法
->
-> *guard 语句* → **guard** [条件集](./05_Statements.md#condition-list) **else** [代码块](./06-Declarations.md#code-block)
->
-
-
-<!-- -->
-
-> Switch 语句语法
->
-> *switch 语句* → **switch** [表达式](./04_Expressions.md#expression) **{** [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub> **}**
->
-> *switch-case集* → [switch-case](./05_Statements.md#switch-case) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
->
-> *switch-case* → [case 标签](./05_Statements.md#case-label) [语句集](./05-Statements.md#statements)
->
-> *switch-case* → [default 标签](./05_Statements.md#default-label) [语句集](./05-Statements.md#statements)
->
-> *switch-case* → [条件 switch-case](./05_Statements.md#conditional-switch-case)
->
-> *case 标签* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **case** [case 项集](./05-Statements.md#case-item-list) **:**
->
-> *case 项集* → [模式](./08_Patterns.md#pattern) [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> | [模式](./08-Patterns.md#pattern) [where 子句](./05-Statements.md#guard-clause)<sub>可选</sub> **,** [case 项集](./05-Statements.md#case-item-list)
->
-> *default 标签* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **default** **:**
->
-> *where 子句* → **where** [where 表达式](./05_Statements.md#where-expression)
->
-> *where 表达式* → [表达式](./04_Expressions.md#expression)
->
-> *条件 switch-case* → [switch if 指令子句](./05_Statements.md#switch-if-directive-clause) [switch elseif 指令子句集](./05-Statements.md#switch-elseif-directive-clauses)<sub>可选</sub> [switch else 指令子句](./05-Statements.md#switch-else-directive-clause)<sub>可选</sub> [endif 指令](./05-Statements.md#endif-directive)
->
-> *switch if 指令子句* → [if 指令](./05_Statements.md#if-directive) [编译条件](./05-Statements.md#compilation-condition) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
->
-> *switch elseif 指令子句集* → [elseif 指令子句](./05_Statements.md#else-if-directive-clause) [switch elseif 指令子句集](./05-Statements.md#switch-elseif-directive-clauses)<sub>可选</sub>
->
-> *switch elseif 指令子句* → [elseif 指令](./05_Statements.md#elseif-directive) [编译条件](./05-Statements.md#compilation-condition) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
->
-> *switch else 指令子句* → [else 指令](./05_Statements.md#else-directive) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
->
-
-<!-- -->
-
-> 标签语句语法
->
-> *标签语句* → [语句标签](./05_Statements.md#statement-label) [循环语句](./05-Statements.md#loop-statement)
->
-> *标签语句* → [语句标签](./05_Statements.md#statement-label) [if 语句](./05-Statements.md#if-statement)
->
-> *标签语句* → [语句标签](./05_Statements.md#statement-label) [switch 语句](./05-Statements.md#switch-statement)
->
-> *标签语句* → [语句标签](./05_Statements.md#statement-label) [do 语句](./05-Statements.md#do-statement)
->
-> *语句标签* → [标签名称](./05_Statements.md#label-name) **:**
->
-> *标签名称* → [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-
-> 控制转移语句语法
->
-> *控制转移语句* → [break 语句](./05_Statements.md#break-statement)
->
-> *控制转移语句* → [continue 语句](./05_Statements.md#continue-statement)
->
-> *控制转移语句* → [fallthrough 语句](./05_Statements.md#fallthrough-statement)
->
-> *控制转移语句* → [return 语句](./05_Statements.md#return-statement)
->
-> *控制转移语句* → [throw 语句](./05_Statements.md#throw-statement)
->
-
-<!-- -->
-
-> Break 语句语法
->
-> *break 语句* → **break** [标签名称](./05_Statements.md#label-name)<sub>可选</sub>
->
-
-<!-- -->
-
-> Continue 语句语法
->
-> *continue 语句* → **continue** [标签名称](./05_Statements.md#label-name)<sub>可选</sub>
->
-
-<!-- -->
-
-> Fallthrough 语句语法
->
-> *fallthrough 语句* → **fallthrough**
->
-
-<!-- -->
-
-> Return 语句语法
->
-> *return 语句* → **return** [表达式](./04_Expressions.md#expression)<sub>可选</sub>
->
-
-<!-- -->
-
-> Throw 语句语法
->
-> *throw 语句* → **throw** [表达式](./04_Expressions.md#expression)
->
-
-<!-- -->
-
-> Defer 语句语法
->
-> *defer 语句* → **defer** [代码块](./06_Declarations.md#code-block)
->
-
-<!-- -->
-> Do 语句语法
->
-> *do 语句* → **do** [代码块](./06_Declarations.md#code-block) [catch 子句集](./05-Statements.md#catch-clauses)<sub>可选</sub>
->
-> *catch 子句集* → [catch 子句](./05_Statements.md#catch-clause) [catch 子句集](05-Statements.md#catch-clauses)<sub>可选</sub>
->
-> *catch 子句* → **catch** [模式](./08_Patterns.md#pattern)<sub>可选</sub>  [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)<sub>可选</sub>
->
-
-<!-- -->
-> 编译控制语句
->
-> *编译控制语句* → [条件编译块](./05_Statements.md#conditional-complation-block)
->
-> *编译控制语句* → [行控制语句](./05_Statements.md#line-control-statement)
->
-> *编译控制语句* → [诊断语句](./05_Statements.md#diagnostic-statement)
->
-
-<!-- -->
-> 条件编译块语法
->
-> *条件编译块* → [if 指令子句](./05_Statements.md#if-directive-clause) [elseif 指令子句集](./05-Statements.md#elseif-directive-clauses)<sub>可选</sub> [else 指令子句](./05-Statements.md#else-directive-clause)<sub>可选</sub> [endif 指令](./05-Statements.md#endif-directive)
->
-> *if 指令子句* → [if 指令](./05_Statements.md#if-directive) [编译条件](./05-Statements.md#compilation-condition) [语句集](./05-Statements.md#statements)<sub>可选</sub>
->
-> *elseif 指令子句集* → [elseif 指令子句](./05_Statements.md#else-if-directive-clause) [elseif 指令子句集](./05-Statements.md#elseif-directive-clauses)<sub>可选</sub>
->
-> *elseif 指令子句* → [elseif 指令](./05_Statements.md#elseif-directive) [编译条件](./05-Statements.md#compilation-condition) [语句集](./05-Statements.md#statements)<sub>可选</sub>
->
-> *else 指令子句* → [else 指令](./05_Statements.md#else-directive) [语句集](./05-Statements.md#statements)<sub>可选</sub>
->
-> *if 指令* → **#if**
->
-> *elseif 指令* → **#elseif**
->
-> *else 指令* → **#else**
->
-> *endif 指令* → **#endif**
->
-> *编译条件* → [平台条件](./05_Statements.md#platform-condition)
->
-> *编译条件* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *编译条件* → [布尔字面量](./02_Lexical_Structure.md#boolean-literal)
->
-> *编译条件* → **(** [编译条件](./05_Statements.md#compilation-condition) **)**
->
-> *编译条件* → **!** [编译条件](./05_Statements.md#compilation-condition)
->
-> *编译条件* → [编译条件](./05_Statements.md#compilation-condition) **&&** [编译条件](./05-Statements.md#compilation-condition)
->
-> *编译条件* → [编译条件](./05_Statements.md#compilation-condition) **||** [编译条件](./05-Statements.md#compilation-condition)
->
-> *平台条件* → **os** **(** [操作系统](./05_Statements.md#operating-system) **)**
->
-> *平台条件* → **arch** **(** [架构](./05_Statements.md#architecture) **)**
->
-> *平台条件* → **swift** **(** **>=** [swift 版本](./05_Statements.md#swift-version) **)** | **swift** **(** **<** [swift 版本](./05-Statements.md#swift-version) **)**
->
-> *平台条件* → **compiler** **(** **>=** [swift 版本](./05_Statements.md#swift-version) **)** | **compiler** **(** **<** [swift 版本](./05-Statements.md#swift-version) **)**
->
-> *平台条件* → **canImport** **(** [模块名](./05_Statements.md#module-name) **)**
->
-> *平台条件* → **targetEnvironment** **(** [环境](./05_Statements.md#environment) **)**
->
-> *操作系统* → **macOS** | **iOS** | **watchOS** | **tvOS**
->
-> *架构* → **i386** | **x86_64** | **arm** | **arm64**
->
-> *swift 版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) [swift 版本后缀](./05-Statements.md#swift-version-continuation)<sub>可选</sub>
->
-> *swift 版本后缀* → **.** [十进制数字集](./02_Lexical_Structure.md#decimal-digits) [swift 版本集](./05-Statements.md#swift-version-continuation)<sub>可选</sub>
->
-> *模块名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *环境* → **simulator**
->
-
-<!-- -->
-> 行控制语句语法
->
-> *行控制语句* → **#sourceLocation** **(** **file:** [文件名](./05-Statements.md#file-name) **,** **line:**  [行号](./05-Statements.md#line-number) **)**
->
-> *行控制语句* → **#sourceLocation** **(** **)**
->
-> *行号* → 一个大于 0 的十进制数字
->
-> *文件名* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal)
->
-
-<!-- -->
-> 编译期诊断语句语法
->
-> *诊断语句* → **#error** **(** [诊断信息](./05-Statements.md#diagnostic-message) **)**
->
-> *诊断语句* → **#warning** **(** [诊断信息](./05-Statements.md#diagnostic-message) **)**
->
-> *诊断信息* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal)
->
-
-<!-- -->
-> 可用性条件语法
->
-> *可用性条件* → **#available** **(** [可用性参数集](./05-Statements.md#availability-arguments) **)**
->
-> *可用性参数集* → [可用性参数](./05_Statements.md#availability-argument) | [可用性参数](./05-Statements.md#availability-argument) , [可用性参数集）](./05-Statements.md#availability-arguments)
->
-> *可用性参数* → [平台名](./05_Statements.md#platform-name) [平台版本](./05-Statements.md#platform-version)
->
-> *可用性参数* → **\***
->
-> *平台名* → **iOS** | **iOSApplicationExtension**
->
-> *平台名* → **macOS** | **macOSApplicationExtension**
->
-> *平台名* → **watchOS**
->
-> *平台名* → **tvOS**
->
-> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits)
->
-> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits)
->
-> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits)
->
-
-## 声明 {#declarations}
-
-> 声明语法
->
-> *声明* → [导入声明](./06_Declarations.md#import-declaration)
->
-> *声明* → [常量声明](./06_Declarations.md#constant-declaration)
->
-> *声明* → [变量声明](./06_Declarations.md#variable-declaration)
->
-> *声明* → [类型别名声明](./06_Declarations.md#typealias-declaration)
->
-> *声明* → [函数声明](./06_Declarations.md#function-declaration)
->
-> *声明* → [枚举声明](./06_Declarations.md#enum-declaration)
->
-> *声明* → [结构体声明](./06_Declarations.md#struct-declaration)
->
-> *声明* → [类声明](./06_Declarations.md#class-declaration)
->
-> *声明* → [协议声明](./06_Declarations.md#protocol-declaration)
->
-> *声明* → [构造器声明](./06_Declarations.md#initializer-declaration)
->
-> *声明* → [析构器声明](./06_Declarations.md#deinitializer-declaration)
->
-> *声明* → [扩展声明](./06_Declarations.md#extension-declaration)
->
-> *声明* → [下标声明](./06_Declarations.md#subscript-declaration)
->
-> *声明* → [运算符声明](./06_Declarations.md#operator-declaration)
->
-> *声明* → [优先级组声明](./06_Declarations.md#precedence-group-declaration)
->
-> *声明集* → [声明](./06_Declarations.md#declaration) [声明集](./06-Declarations.md#declarations)<sub>可选</sub>
->
-
-
-<!-- -->
-
-> 顶级声明语法
->
-> *顶级声明* → [多条语句](./05_Statements.md#statements)<sub>可选</sub>
->
-
-<!-- -->
-
-> 代码块语法
->
-> *代码块* → **{** [多条语句](./05_Statements.md#statements)<sub>可选</sub> **}**
->
-
-<!-- -->
-
-> 导入声明语法
->
-> *导入声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **import** [导入类型](./06-Declarations.md#import-kind)<sub>可选</sub> [导入路径](./06-Declarations.md#import-path)
->
-> *导入类型* → **typealias** | **struct** | **class** | **enum** | **protocol** | **let** | **var** | **func**
->
-> *导入路径* → [导入路径标识符](./06_Declarations.md#import-path-identifier) | [导入路径标识符](./06-Declarations.md#import-path-identifier) **.** [导入路径](./06-Declarations.md#import-path)
->
-> *导入路径标识符* → [标识符](./02_Lexical_Structure.md#identifier) | [运算符](./02-Lexical-Structure.md#operator)
->
-
-<!-- -->
-
-> 常数声明语法
->
-> *常量声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **let** [模式构造器集](./06-Declarations.md#pattern-initializer-list)
->
-> *模式构造器集* → [模式构造器](./06_Declarations.md#pattern-initializer) | [模式构造器](./06-Declarations.md#pattern-initializer)    **,** [模式构造器集](./06-Declarations.md#pattern-initializer-list)
->
-> *模式构造器* → [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)<sub>可选</sub>
->
-> *构造器* → **=** [表达式](./04_Expressions.md#expression)
->
-
-<!-- -->
-
-> 变量声明语法
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [模式构造器集](./06-Declarations.md#pattern-initializer-list)
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [代码块](./06-Declarations.md#code-block)
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 块](./06-Declarations.md#getter-setter-block)
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [构造器](./06-Declarations.md#initializer)<sub>可选</sub> [willSet-didSet 代码块](./06-Declarations.md#willSet-didSet-block)
->
-> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [构造器](./06-Declarations.md#initializer)<sub>可选</sub> [willSet-didSet 代码块](./06-Declarations.md#willSet-didSet-block)
->
-> *变量声明头* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **var**
->
-> *变量名称* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *getter-setter 块* → [代码块](./06_Declarations.md#code-block)
->
-> *getter-setter 块* → **{** [getter 子句](./06_Declarations.md#getter-keyword-clause) [setter 子句](./06-Declarations.md#setter-keyword-clause)<sub>可选</sub> **}**
->
-> *getter-setter 块* → **{** [setter 子句](./06_Declarations.md#setter-keyword-clause) [getter 子句](./06-Declarations.md#getter-keyword-clause) **}**
->
-> *getter 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub>  **get**  [代码块](./06-Declarations.md#code-block)
->
-> *setter 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **set** [setter 名称](./06-Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
->
-> *setter 名称* → **(** [标识符](./02_Lexical_Structure.md#identifier) **)**
->
-> *getter-setter 关键字（Keyword）块* → **{** [getter 关键字子句](./06_Declarations.md#getter-keyword-clause) [setter 关键字子句](./06-Declarations.md#setter-keyword-clause)<sub>可选</sub> **}**
->
-> *getter-setter 关键字（Keyword）块* → **{** [setter 关键字子句](./06_Declarations.md#setter-keyword-clause) [getter 关键字子句](./06-Declarations.md#getter-keyword-clause) **}**
->
-> *getter 关键字（Keyword）子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **get**
->
-> *setter 关键字（Keyword）子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **set**
->
-> *willSet-didSet 代码块* → **{** [willSet 子句](./06_Declarations.md#willSet-clause) [didSet 子句](./06-Declarations.md#didSet-clause)<sub>可选</sub> **}**
->
-> *willSet-didSet 代码块* → **{** [didSet 子句](./06_Declarations.md#didSet-clause) [willSet 子句](./06-Declarations.md#willSet-clause)<sub>可选</sub> **}**
->
-> *willSet 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **willSet** [setter 名称](./06-Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
->
-> *didSet 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub>
->
- **didSet** [setter 名称](./06_Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
-
-<!-- -->
-
-> 类型别名声明语法
->
-> *类型别名声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier) **typealias** [类型别名名称](./06-Declarations.md#typealias-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型别名赋值](./06-Declarations.md#typealias-assignment)
->
-> *类型别名名称* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *类型别名赋值* → **=** [类型](./03_Types.md#type)
->
-
-<!-- -->
-
-> 函数声明语法
->
-> *函数声明* → [函数头](./06_Declarations.md#function-head) [函数名](./06-Declarations.md#function-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [函数签名](./06-Declarations.md#function-signature) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [函数体](./06-Declarations.md#function-body)<sub>可选</sub>
->
-> *函数头* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明描述符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **func**
->
-> *函数名* → [标识符](./02_Lexical_Structure.md#identifier) | [运算符](./02-Lexical-Structure.md#operator)
->
-> *函数签名* → [参数子句](./06_Declarations.md#parameter-clause) **throws**<sub>可选</sub> [函数结果](./06-Declarations.md#function-result)<sub>可选</sub>
->
-
-> *函数签名* → [参数子句](./06_Declarations.md#parameter-clause) **rethrows** [函数结果](./06-Declarations.md#function-result)<sub>可选</sub>
->
-> *函数结果* → **->** [特性](./07_Attributes.md#attributes)<sub>可选</sub> [类型](./03-Types.md#type)
->
-> *函数体* → [代码块](./06_Declarations.md#code-block)
->
-> *参数子句* → **(** **)** | **(** [参数集](./06_Declarations.md#parameter-list) **)**
->
-> *参数集* → [参数](./06_Declarations.md#parameter) | [参数](./06-Declarations.md#parameter) **,** [参数集](./06-Declarations.md#parameter-list)
->
-> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation) [默认参数子句](./06-Declarations.md#default-argument-clause)<sub>可选</sub>
->
-> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation)
->
-> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation) **...**
->
-> *外部参数名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *本地参数名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *默认参数子句* → **=** [表达式](./04_Expressions.md#expression)
->
-
-<!-- -->
-
-> 枚举声明语法
->
-> *枚举声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> [联合式枚举](./06-Declarations.md#union-style-enum)
->
-> *枚举声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> [原始值式枚举](./06-Declarations.md#raw-value-style-enum)
->
-> *联合式枚举* → **indirect**<sub>可选</sub> **enum** [枚举名](./06_Declarations.md#enum-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> **{** [联合式枚举成员](./06-Declarations.md#union-style-enum-members)<sub>可选</sub> **}**
->
-> *联合式枚举成员集* → [联合式枚举成员](./06_Declarations.md#union-style-enum-member) [联合样式枚举成员集](./06-Declarations.md#union-style-enum-members)<sub>可选</sub>
->
-> *联合样式枚举成员* → [声明](./06_Declarations.md#declaration) | [联合式枚举 case 子句](./06-Declarations.md#union-style-enum-case-clause) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-> *联合式枚举 case 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **indirect**<sub>可选</sub> **case** [联合式枚举 case 集](./06-Declarations.md#union-style-enum-case-list)
->
-> *联合式枚举 case 集* → [联合式枚举 case](./06_Declarations.md#union-style-enum-case) | [联合式枚举 case](./06-Declarations.md#union-style-enum-case) **,** [联合式枚举 case 集](./06-Declarations.md#union-style-enum-case-list)
->
-> *联合式枚举 case* → [枚举的 case 名](./06_Declarations.md#enum-case-name) [元组类型](./03-Types.md#tuple-type)<sub>可选</sub>
->
-> *枚举名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *枚举的 case 名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *原始值式枚举* → **enum** [枚举名](./06_Declarations.md#enum-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> **{** [原始值式枚举成员集](./06-Declarations.md#raw-value-style-enum-members) **}**
->
-> *原始值式枚举成员集* → [原始值式枚举成员](./06_Declarations.md#raw-value-style-enum-member) [原始值式枚举成员集](./06-Declarations.md#raw-value-style-enum-members)<sub>可选</sub>
->
-> *原始值式枚举成员* → [声明](./06_Declarations.md#declaration) | [原始值式枚举 case 子句](./06-Declarations.md#raw-value-style-enum-case-clause) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-> *原始值式枚举 case 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **case** [原始值式枚举 case 集](./06-Declarations.md#raw-value-style-enum-case-list)
->
-> *原始值式枚举 case 集* → [原始值式枚举 case](./06_Declarations.md#raw-value-style-enum-case) | [原始值式枚举 case](./06-Declarations.md#raw-value-style-enum-case) **,** [原始值式枚举 case 集](./06-Declarations.md#raw-value-style-enum-case-list)
->
-> *原始值式枚举 case* → [枚举的 case 名](./06_Declarations.md#enum-case-name) [原始值赋值](./06-Declarations.md#raw-value-assignment)<sub>可选</sub>
->
-> *原始值赋值* → **=** [原始值字面量](./02_Lexical_Structure.md#literal)
->
-> *原始值字面量（raw-value-literal）* → [数值字面量](./02_Lexical_Structure.md#literal) | [静态字符串字面量](./02-Lexical-Structure.md#literal) | [布尔字面量](./02-Lexical-Structure.md#literal)
->
-
-<!-- -->
-
-> 结构体声明语法
->
-> *结构体声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **struct** [结构体名称](./06-Declarations.md#struct-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [结构体主体](./06-Declarations.md#struct-body)
->
-> *结构体名称* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *结构体主体* → **{** [结构体成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
->
-> *结构体成员集* → [结构体成员](./06_Declarations.md#declarations) [结构体成员集](./06-Declarations.md#declarations)<sub>可选</sub>
->
-> *结构体成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-
-<!-- -->
-
-> 类声明语法
->
-> *类声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **final**<sub>可选</sub> **class** [类名](./06-Declarations.md#class-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [类主体](./06-Declarations.md#class-body)
->
-> *类声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **final** [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **class** [类名](./06-Declarations.md#class-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [类主体](./06-Declarations.md#class-body)
->
-> *类名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *类主体* → **{** [类成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
->
-> *类成员集* → [类成员](./06_Declarations.md#declarations) [类成员集](./06-Declarations.md#declarations)<sub>可选</sub>
->
-> *类成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-
-<!-- -->
-
-> 协议声明语法
->
-> *协议声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub>  **protocol** [协议名](./06-Declarations.md#protocol-name) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [协议主体](./06-Declarations.md#protocol-body)
->
-> *协议名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *协议主体* → **{** [协议成员集](./06_Declarations.md#protocol-member-declarations)<sub>可选</sub> **}**
->
-> *协议成员集* → [协议成员](./06_Declarations.md#declarations) [协议成员集](./06-Declarations.md#declarations)<sub>可选</sub>
->
-> *协议成员* → [协议成员声明](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-> *协议成员声明* → [协议属性声明](./06_Declarations.md#protocol-property-declaration)
->
-> *协议成员声明* → [协议方法声明](./06_Declarations.md#protocol-method-declaration)
->
-> *协议成员声明* → [协议构造器声明](./06_Declarations.md#protocol-initializer-declaration)
->
-> *协议成员声明* → [协议下标声明](./06_Declarations.md#protocol-subscript-declaration)
->
-> *协议成员声明* → [协议关联类型声明](./06_Declarations.md#protocol-associated-type-declaration)
->
-> *协议成员声明* → [类型别名声明](./06_Declarations.md#typealias-declaration)
->
-
-<!-- -->
-
-> 协议属性声明语法
->
-> *协议属性声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
->
-
-<!-- -->
-
-> 协议方法声明语法
->
-> *协议方法声明* → [函数头](./06_Declarations.md#function-head) [函数名](./06-Declarations.md#function-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [函数签名](./06-Declarations.md#function-signature) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
->
-
-<!-- -->
-
-> 协议构造器声明语法
->
-> *协议构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **throws**<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
->
-> *协议构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **rethrows** [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
->
-
-<!-- -->
-
-> 协议下标声明语法
->
-> *协议下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
->
-
-<!-- -->
-
-> 协议关联类型声明语法
->
-> *协议关联类型声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **associatedtype** [类型别名](./06-Declarations.md#typealias-name) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [类型别名赋值](./06-Declarations.md#typealias-assignment)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
->
-
-<!-- -->
-
-> 构造器声明语法
->
-> *构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **throws**<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [构造器主体](./06-Declarations.md#initializer-body)
->
-> *构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **rethrows** [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [构造器主体](./06-Declarations.md#initializer-body)
->
-> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init**
->
-> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init ?**
->
-> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init !**
->
-> *构造器主体* → [代码块](./06_Declarations.md#code-block)
->
-
-<!-- -->
-
-> 析构器声明语法
->
-> *析构器声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **deinit** [代码块](./06-Declarations.md#code-block)
->
-
-<!-- -->
-
-> 扩展声明语法
->
-> *扩展声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **extension** [类型标识](./03-Types.md#type-identifier) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [扩展主体](./06-Declarations.md#extension-body)
->
-> *扩展主体* → **{** [扩展成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
->
-> *扩展成员集* → [扩展成员](./06_Declarations.md#declarations) [扩展成员集](./06-Declarations.md#declarations)<sub>可选</sub>
->
-> *扩展成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
->
-
-<!-- -->
-
-> 下标声明语法
->
-> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
->
-> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 块](./06-Declarations.md#getter-setter-block)
->
-> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
->
-> *下标头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub> **subscript** [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause)
->
-> *下标结果（Result）* → **->** [特性](./07_Attributes.md#attributes)<sub>可选</sub> [类型](./03-Types.md#type)
->
-
-<!-- -->
-
-> 运算符声明语法
->
-> *运算符声明* → [前置运算符声明](./06_Declarations.md#prefix-operator-declaration) | [后置运算符声明](./06-Declarations.md#postfix-operator-declaration) | [中置运算符声明](./06-Declarations.md#infix-operator-declaration)
->
-> *前置运算符声明* → **prefix** **operator**  [运算符](./02_Lexical_Structure.md#operator)
->
-> *后置运算符声明* → **postfix** **operator**  [运算符](./02_Lexical_Structure.md#operator)
->
-> *中置运算符声明* → **infix** **operator**  [运算符](./02_Lexical_Structure.md#operator) [中置运算符特性](./06-Declarations.md#infix-operator-attributes)<sub>可选</sub>
->
-> *中置运算符特性* → [优先级组名](./06_Declarations.md#precedence-group-name)
->
-
-> 优先级组声明语法
->
-> *优先级组声明* → **precedencegroup** [优先级组名](./06_Declarations.md#precedence-group-name) **{** [优先级组特性](./06-Declarations.md#precedence-group-attributes)<sub>可选</sub> **}**
->
-> *优先级组特性* → [优先级组属性](./06_Declarations.md#declarations) [优先级组特性](./06-Declarations.md#declarations)<sub>可选</sub>
->
-> *优先级组属性* → [优先级组关系](./06_Declarations.md#declarations)
->
-> *优先级组属性* → [优先级组赋值](./06_Declarations.md#declarations)
->
-> *优先级组属性* → [优先级组结合](./06_Declarations.md#declarations)
->
-> *优先级组关系* → **higherThan :** [优先级组名集](./06_Declarations.md#declarations)
->
-> *优先级组关系* → **lowerThan :** [优先级组名集](./06_Declarations.md#declarations)
->
-> *优先级组赋值* → **assignment :** [布尔字面量](./02_Lexical_Structure.md#string-literal)
->
-> *优先级组结合* → **associativity : left**
->
-> *优先级组结合* → **associativity : right**
->
-> *优先级组结合* → **associativity : none**
->
-> *优先级组名集* → [优先级组名](./06_Declarations.md#declarations) | [优先级组名](./06-Declarations.md#declarations) **,** [优先级组名集](./06-Declarations.md#declarations)
->
-> *优先级组名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-> 声明修饰符语法
->
-> *声明修饰符* → **class** | **convenience** | **dynamic** | **final** | **infix** | **lazy** | **optional** | **override** | **postfix** | **prefix** | **required** | **static** | **unowned** | **unowned(safe)** | **unowned(unsafe)** | **weak**
->
-> *声明修饰符* → [访问级别修饰符](./07_Attributes.md#access-level-modifier)
->
-> *声明修饰符* → [可变性修饰符](./07_Attributes.md#mutation-modifier)
->
-> *声明修饰符集* → [声明修饰符](./06_Declarations.md#declaration-modifier) [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>
->
-> *访问级别修饰符* → **private** | **private(set)**
->
-> *访问级别修饰符* → **fileprivate** | **fileprivate(set)**
->
-> *访问级别修饰符* → **internal** | **internal(set)**
->
-> *访问级别修饰符* → **public** | **public(set)**
->
-> *访问级别修饰符* → **open** | **open(set)**
->
-> *可变性修饰符* → **mutating** | **nonmutating**
->  
-
-## 属性 {#attributes}
-
-> 属性语法
->
-> *属性* → **@** [属性名](./07_Attributes.md#attribute-name) [属性参数子句](./07-Attributes.md#attribute-argument-clause)<sub>可选</sub>
->
-> *属性名* → [标识符](./02_Lexical_Structure.md#identifier)
->
-> *属性参数子句* → **{** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub>  **}**
->
-> *属性（Attributes）集* → [属性](./07_Attributes.md#attribute) [特性](./07-Attributes.md#attributes)<sub>可选</sub>
->
-> *平衡令牌集* → [平衡令牌](./07_Attributes.md#balanced-token) [平衡令牌集](./07-Attributes.md#balanced-tokens)<sub>可选</sub>
->
-> *平衡令牌* → **(** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **)**
->
-> *平衡令牌* → **[** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **]**
->
-> *平衡令牌* → **{** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **}**
->
-> *平衡令牌* → 任意标识符、关键字、字面量或运算符
->
-> *平衡令牌* → 除 **(** 、**)**、**[**、**]**、**{**、**}** 外的任意标点符号
->
->
-
-## 模式 {#patterns}
-
-> 模式语法
->
-> *模式* → [通配符模式](./08_Patterns.md#wildcard-pattern) [类型注解](./03-Types.md#type-annotation)<sub>可选</sub>
->
-> *模式* → [标识符模式](./08_Patterns.md#identifier-pattern) [类型注解](./03-Types.md#type-annotati Value Bindingon )<sub>可选</sub>
->
-> *模式* → [值绑定模式](./08_Patterns.md#value-binding-pattern)
->
-> *模式* → [元组模式](./08_Patterns.md#tuple-pattern) [类型注解](./03-Types.md#type-annotation)<sub>可选</sub>
->
-> *模式* → [枚举 case 模式](./08_Patterns.md#enum-case-pattern)
->
-> *模式* → [可选模式](./08_Patterns.md#optional-pattern)
->
-> *模式* → [类型转换模式](./08_Patterns.md#type-casting-pattern)
->
-> *模式* → [表达式模式](./08_Patterns.md#expression-pattern)
->
-
-<!-- -->
-
-> 通配符模式语法
->
-> *通配符模式* → **_**
->
-
-<!-- -->
-
-> 标识符模式语法
->
-> *标识符模式* → [标识符](./02_Lexical_Structure.md#identifier)
->
-
-<!-- -->
-
-> 值绑定模式语法
->
-> *值绑定模式* → **var** [模式](./08_Patterns.md#pattern) | **let** [模式](./08-Patterns.md#pattern)
->
-
-<!-- -->
-
-> 元组模式语法
->
-> *元组模式* → **(** [元组模式元素集](./08_Patterns.md#tuple-pattern-element-list)<sub>可选</sub> **)**
->
-> *元组模式元素集* → [元组模式元素](./08_Patterns.md#tuple-pattern-element) | [元组模式元素](./08-Patterns.md#tuple-pattern-element) **,** [元组模式元素集](./08-Patterns.md#tuple-pattern-element-list)
->
-> *元组模式元素* → [模式](./08_Patterns.md#pattern) | [标识符](./02-Lexical-Structure.md#identifier) **:** [模式](./08-Patterns.md#pattern)
->
-
-<!-- -->
-
-> 枚举 case 模式语法
->
-> *enum-case-pattern* → [类型标识](./03_Types.md#type-identifier)<sub>可选</sub> **.** [枚举 case 名](./06-Declarations.md#enum-case-name) [元组模式](./08-Patterns.md#tuple-pattern)<sub>可选</sub>
->
-
-<!-- -->
-> 可选模式语法
->
-> *可选模式* → [标识符模式](./02_Lexical_Structure.md#identifier) **?**
->
-
-<!-- -->
-
-> 类型转换模式语法
->
-> *类型转换模式* → [is 模式](./08_Patterns.md#is-pattern) | [as 模式](./08-Patterns.md#as-pattern)
->
-> *is 模式* → **is** [类型](./03_Types.md#type)
->
-> *as 模式* → [模式](./08_Patterns.md#pattern) **as** [类型](./03-Types.md#type)
->
-
-<!-- -->
-
-> 表达式模式语法
->
-> *表达式模式* → [表达式](./04_Expressions.md#expression)
->
-
-## 泛型参数 {#generic-parameters-and-arguments}
-
-> 泛型形参子句语法
->
->
-> *泛型参数子句* → **<** [泛型参数集](./09_Generic_Parameters_and_Arguments.md#generic-parameter-list) **>**
->
-> *泛型参数集* → [泛型参数](./09_Generic_Parameters_and_Arguments.md#generic-parameter) | [泛形参数](./09-Generic-Parameters-and-Arguments.md#generic-parameter) **,** [泛型参数集](./09-Generic-Parameters-and-Arguments.md#generic-parameter-list)
->
-> *泛形参数* → [类型名称](./03_Types.md#type-name)
->
-> *泛形参数* → [类型名称](./03_Types.md#type-name) **:** [类型标识](./03-Types.md#type-identifier)
->
-> *泛形参数* → [类型名称](./03_Types.md#type-name) **:** [协议合成类型](./03-Types.md#protocol-composition-type)
->
-> *泛型 where 子句* → **where** [约束集](./09_Generic_Parameters_and_Arguments.md#requirement-list)
->
-> *约束集* → [约束](./09_Generic_Parameters_and_Arguments.md#requirement) | [约束](./09-Generic-Parameters-and-Arguments.md#requirement) **,** [约束集](./09-Generic-Parameters-and-Arguments.md#requirement-list)
->
-> *约束* → [一致性约束](./09_Generic_Parameters_and_Arguments.md#conformance-requirement) | [同类型约束](./09-Generic-Parameters-and-Arguments.md#same-type-requirement)
->
-> *一致性约束* → [类型标识](./03_Types.md#type-identifier) **:** [类型标识](./03-Types.md#type-identifier)
->
-> *一致性约束* → [类型标识](./03_Types.md#type-identifier) **:** [协议合成类型](./03-Types.md#protocol-composition-type)
->
-> *同类型约束* → [类型标识](./03_Types.md#type-identifier) **==** [类型](./03-Types.md#type-identifier)
->
-
-<!-- -->
-
-> 泛型实参子句语法
->
-> *泛型实参子句* → **<** [泛型实参集](./09_Generic_Parameters_and_Arguments.md#generic-argument-list) **>**
->
-> *泛型实参集* → [泛型实参](./09_Generic_Parameters_and_Arguments.md#generic-argument) | [泛形实参](./09-Generic-Parameters-and-Arguments.md#generic-argument) **,** [泛型实参集](./09-Generic-Parameters-and-Arguments.md#generic-argument-list)
->
+# 语法总结（Summary of the Grammar）
+
+## 词法结构 {#lexical-structure}
+
+> 空白字符语法
+>
+> *空白字符*  → [空白字符项](./02_Lexical_Structure.md#whitespace-item) [空白字符](./02-Lexical-Structure.md#whitespace)<sub>可选</sub>
+>
+> *空白字符项*  → [换行符](./02_Lexical_Structure.md#line-break)
+>
+> *空白字符项*   → [注释](./02_Lexical_Structure.md#comment)
+>
+> *空白字符项*  → [多行注释](./02_Lexical_Structure.md#multiline-comment)
+>
+> *空白字符项*  → U+0000，U+0009，U+000B，U+000C 或 U+0020
+>
+>
+>
+> 换行符*  → U+000A
+>
+> *换行符*  → U+000D
+>
+> *换行符*  → U+000D 后面是 U+000A
+>
+>
+>
+> *注释*  → **//** [单行内容注释](./02_Lexical_Structure.md#comment-text) [换行符](./02-Lexical-Structure.md#line-break)
+>
+> *注释*  → **/\*** [多行内容注释](./02_Lexical_Structure.md#multiline-comment-text) **\*/**
+>
+>
+>
+> *注释内容*  → [注释内容项](./02_Lexical_Structure.md#comment-text-item) [注释内容](./02-Lexical-Structure.md#comment-text)<sub>可选</sub>  
+>
+> *注释内容项*  → 除 U+000A 或 U+000D 外的任何 Unicode 标量值
+>
+>
+>
+> *多行注释内容*  → [多行注释内容项](./02_Lexical_Structure.md#multiline-comment-text-item) [多行注释内容](./02-Lexical-Structure.md#multiline-comment-text)<sub>可选</sub>  
+>
+> *多行注释内容项*  → [多行内容](./02_Lexical_Structure.md#multiline-comment)
+>
+> *多行注释内容项*  → [注释内容项](./02_Lexical_Structure.md#comment-text-item)
+>
+> *多行注释内容项*  → 除 **/\*** 或 **\*/** 外的任何 Unicode 标量值
+>
+
+<!-- -->
+
+> 标识符语法
+>
+> *标识符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
+>
+> *标识符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
+>
+> *标识符* → [隐式参数名](./02_Lexical_Structure.md#implicit-parameter-name)
+>
+> *标识符* → [属性包装器呈现值](./02_Lexical_Structure.md#property-wrapper-projection)
+>
+> *标识符集* → [标识符](./02_Lexical_Structure.md#identifier) | [标识符](./02-Lexical-Structure.md#identifier) **,** [标识符集](./02-Lexical-Structure.md#identifier-list)
+>
+> *标识符头（Head）* → 大写或者小写字母 A 到 Z
+>
+> *标识符头（Head）* → _
+>
+> *标识符头（Head）* → U+00A8, U+00AA, U+00AD, U+00AF, U+00B2–U+00B5, or U+00B7–U+00BA
+>
+> *标识符头（Head）* → U+00BC–U+00BE, U+00C0–U+00D6, U+00D8–U+00F6, or U+00F8–U+00FF
+>
+> *标识符头（Head）* → U+0100–U+02FF, U+0370–U+167F, U+1681–U+180D, or U+180F–U+1DBF
+>
+> *标识符头（Head）* → U+1E00–U+1FFF
+>
+> *标识符头（Head）* → U+200B–U+200D, U+202A–U+202E, U+203F–U+2040, U+2054, or U+2060–U+206F
+>
+> *标识符头（Head）* → U+2070–U+20CF, U+2100–U+218F, U+2460–U+24FF, or U+2776–U+2793
+>
+> *标识符头（Head）* → U+2C00–U+2DFF or U+2E80–U+2FFF
+>
+> *标识符头（Head）* → U+3004–U+3007, U+3021–U+302F, U+3031–U+303F, or U+3040–U+D7FF
+>
+> *标识符头（Head）* → U+F900–U+FD3D, U+FD40–U+FDCF, U+FDF0–U+FE1F, or U+FE30–U+FE44
+>
+> *标识符头（Head）* → U+FE47–U+FFFD
+>
+> *标识符头（Head）* → U+10000–U+1FFFD, U+20000–U+2FFFD, U+30000–U+3FFFD, or U+40000–U+4FFFD
+>
+> *标识符头（Head）* → U+50000–U+5FFFD, U+60000–U+6FFFD, U+70000–U+7FFFD, or U+80000–U+8FFFD
+>
+> *标识符头（Head）* → U+90000–U+9FFFD, U+A0000–U+AFFFD, U+B0000–U+BFFFD, or U+C0000–U+CFFFD
+>
+> *标识符头（Head）* → U+D0000–U+DFFFD or U+E0000–U+EFFFD
+>
+> *标识符字符* → 数值 0 到 9
+>
+> *标识符字符* → U+0300–U+036F, U+1DC0–U+1DFF, U+20D0–U+20FF, or U+FE20–U+FE2F
+>
+> *标识符字符* → [标识符头（Head）](./02_Lexical_Structure.md#identifier-head)
+>
+> *标识符字符集* → [标识符字符](./02_Lexical_Structure.md#identifier-character) [标识符字符集](./02-Lexical-Structure.md#identifier-characters)<sub>可选</sub> 
+>
+> *隐式参数名* → **$** [十进制数字集](./02_Lexical_Structure.md#decimal-digits)
+>
+> *属性包装器呈现值* → **$**  [标识符字符集](./02-Lexical-Structure.md#identifier-characters)
+>
+
+<!-- -->
+
+> 字面量语法
+>
+> *字面量* → [数值型字面量](./02_Lexical_Structure.md#numeric-literal) | [字符串字面量](./02-Lexical-Structure.md#string-literal) | [布尔字面量](./02-Lexical-Structure.md#boolean-literal) | [空字面量](./02-Lexical-Structure.md#nil-literal)
+>
+> *数值型字面量* → **-**<sub>可选</sub>[整形字面量](./02_Lexical_Structure.md#integer-literal) | **-**<sub>可选</sub>[浮点型字面量](./02-Lexical-Structure.md#floating-point-literal)
+>
+> *布尔字面量* → **true** | **false**
+>
+> *空字面量* → **nil**
+>
+
+<!-- -->
+
+> 整型字面量语法
+>
+> *整型字面量* → [二进制字面量](./02_Lexical_Structure.md#binary-literal)
+>
+> *整型字面量* → [八进制字面量](./02_Lexical_Structure.md#octal-literal)
+>
+> *整型字面量* → [十进制字面量](./02_Lexical_Structure.md#decimal-literal)
+>
+> *整型字面量* → [十六进制字面量](./02_Lexical_Structure.md#hexadecimal-literal)
+>
+> *二进制字面量* → **0b** [二进制数字](./02_Lexical_Structure.md#binary-digit) [二进制字面量字符集](./02-Lexical-Structure.md#binary-literal-characters)<sub>可选</sub> 
+>
+> *二进制数字* → 数值 0 到 1
+>
+> *二进制字面量字符* → [二进制数字](./02_Lexical_Structure.md#binary-digit) | **-**
+>
+> *二进制字面量字符集* → [二进制字面量字符](./02_Lexical_Structure.md#binary-literal-character) [二进制字面量字符集](./02-Lexical-Structure.md#binary-literal-characters)<sub>可选</sub> 
+>
+> *八进制字面量* → **0o** [八进制数字](./02_Lexical_Structure.md#octal-digit) [八进制字符集](./02-Lexical-Structure.md#octal-literal-characters)<sub>可选</sub> 
+>
+> *八进字数字* → 数值 0 到 7
+>
+> *八进制字符* → [八进制数字](./02_Lexical_Structure.md#octal-digit) | **-**
+>
+> *八进制字符集* → [八进制字符](./02_Lexical_Structure.md#octal-literal-character) [八进制字符集](./02-Lexical-Structure.md#octal-literal-characters)<sub>可选</sub> 
+>
+> *十进制字面量* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) [十进制字符集](./02-Lexical-Structure.md#decimal-literal-characters)<sub>可选</sub> 
+>
+> *十进制数字* → 数值 0 到 9
+>
+> *十进制数字集* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) [十进制数字集](./02-Lexical-Structure.md#decimal-digits)<sub>可选</sub> 
+>
+> *十进制字面量字符* → [十进制数字](./02_Lexical_Structure.md#decimal-digit) | **-**
+>
+> *十进制字面量字符集* → [十进制字面量字符](./02_Lexical_Structure.md#decimal-literal-character) [十进制字面量字符集](./02-Lexical-Structure.md#decimal-literal-characters)<sub>可选</sub> 
+>
+> *十六进制字面量* → **0x** [十六进制数字](./02_Lexical_Structure.md#hexadecimal-digit) [十六进制字面量字符集](./02-Lexical-Structure.md#hexadecimal-literal-characters)<sub>可选</sub> 
+>
+> *十六进制数字* → 数值 0 到 9，a 到 f，或者 A 到 F
+>
+> *十六进制字符* → [十六进制数字](./02_Lexical_Structure.md#hexadecimal-digit) | **-**
+>
+> *十六进制字面量字符集* → [十六进制字符](./02_Lexical_Structure.md#hexadecimal-literal-character) [十六进制字面量字符集](./02-Lexical-Structure.md#hexadecimal-literal-characters)<sub>可选</sub> 
+>
+
+<!-- -->
+
+> 浮点型字面量语法
+>
+> *浮点数字面量* → [十进制字面量](./02_Lexical_Structure.md#decimal-literal) [十进制分数](./02-Lexical-Structure.md#decimal-fraction)<sub>可选</sub>[十进制指数](./02-Lexical-Structure.md#decimal-exponent)<sub>可选</sub> 
+>
+> *浮点数字面量* → [十六进制字面量](./02_Lexical_Structure.md#hexadecimal-literal) [十六进制分数](./02-Lexical-Structure.md#hexadecimal-fraction)<sub>可选</sub>[十六进制指数](./02-Lexical-Structure.md#hexadecimal-exponent)
+>
+> *十进制分数* → **.** [十进制字面量](./02_Lexical_Structure.md#decimal-literal)
+>
+> *十进制指数* → [浮点数 e](./02_Lexical_Structure.md#floating-point-e) [正负号](./02-Lexical-Structure.md#sign)<sub>可选</sub>[十进制字面量](./02-Lexical-Structure.md#decimal-literal)
+>
+> *十六进制分数* → **.** [十六进制数](./02_Lexical_Structure.md#hexadecimal-literal)
+>
+> *十六进制指数* → [浮点数 p](./02_Lexical_Structure.md#floating-point-p) [正负号](./02-Lexical-Structure.md#sign)<sub>可选</sub>[十六进制字面量](./02-Lexical-Structure.md#hexadecimal-literal)
+>
+> *浮点数 e* → **e** | **E**
+>
+> *浮点数 p* → **p** | **P**
+>
+> *正负号* → **+** | **-**
+>
+
+<!-- -->
+
+> 字符串型字面量语法
+
+> *字符串字面量* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal) | [插值字符串字面量](./02-Lexical-Structure.md#interpolated-string-literal)
+>
+> *字符串开分隔定界符* → [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter) **"**
+>
+> *字符串闭分隔定界符* → **"** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)<sub>可选</sub>
+>
+> *静态字符串字面量* → [字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [引用文本](./02-Lexical-Structure.md#quoted-text)<sub>可选</sub> [字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
+>
+> *静态字符串字面量* → [多行字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [多行引用文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub> [多行字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
+>
+> *多行字符串开分隔定界符* → [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter) **"""**
+>
+> *多行字符串闭分隔定界符* → **"""** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)
+>
+> *字符串扩展分隔符* → **#** [字符串扩展分隔符](./02-Lexical-Structure.md#extended-string-literal-delimiter)<sub>可选</sub>
+>
+> *引用文本* → [引用文本项](./02_Lexical_Structure.md#quoted-text-item) [引用文本](#quoted-text)<sub>可选</sub>
+>
+> *引用文本项* → [转义字符](./02_Lexical_Structure.md#escaped-character)
+>
+> *引用文本项* → 除了 **"**、**\\\**、U+000A、U+000D 以外的所有 Unicode 字符    
+>
+> *多行引用文本* → [多行引用文本项](./02_Lexical_Structure.md#multiline-quoted-text-item) [多行引用文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub>
+>
+> *多行引用文本项* [转义字符](./02_Lexical_Structure.md#escaped-character)<sub>可选</sub>
+>
+> *多行引用文本* → 除了 **\\** 以外的任何 Unicode 标量值
+>
+> *多行引用文本* → [转义换行](./02_Lexical_Structure.md#escaped-newline)
+
+> *插值字符串字面量* → [字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub> [字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
+>
+> *插值字符串字面量* → [多行字符串开分隔定界符](./02_Lexical_Structure.md#extended-string-literal-delimiter) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub> [多行字符串闭分隔定界符](./02-Lexical-Structure.md#extended-string-literal-delimiter)
+>
+> *插值文本* → [插值文本项](./02_Lexical_Structure.md#interpolated-text-item) [插值文本](./02-Lexical-Structure.md#interpolated-text)<sub>可选</sub>
+>
+> *插值文本项* → **\\**(**[表达式](./04_Expressions.md)**) | [引用文本项](./02_Lexical_Structure.md#quoted-text-item)
+>
+> *多行插值文本* → [多行插值文本项](./02_Lexical_Structure.md#multiline-quoted-text-item) [多行插值文本](./02-Lexical-Structure.md#multiline-quoted-text)<sub>可选</sub>
+>
+> *多行插值文本项* → **\\(** [表达式](./04_Expressions.md) **)** | [多行引用文本项](./02_Lexical_Structure.md#multiline-quoted-text-item)
+>
+> *转义序列* → **\\** [字符串扩展分隔符](./02_Lexical_Structure.md#extended-string-literal-delimiter)
+>
+> *转义字符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) **0** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **\\** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **t** | [转义序列](#escape-sequence) **n** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **r** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **\"** | [转义序列](./02-Lexical-Structure.md#escape-sequence) **'**
+>
+> *转义字符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) **u {** [unicode 标量数字](./02-Lexical-Structure.md#unicode-scalar-digits) **}**
+>
+> *unicode 标量数字* → 一到八位的十六进制数字
+>
+> *转义换行符* → [转义序列](./02_Lexical_Structure.md#escape-sequence) [空白](./02-Lexical-Structure.md#whitespace)<sub>可选</sub> [换行符](./02-Lexical-Structure.md#line-break)
+
+
+<!-- -->
+
+> 运算符语法语法
+>
+> *运算符* → [运算符头](./02_Lexical_Structure.md#operator-character) [运算符字符集](./02-Lexical-Structure.md#operator)<sub>可选</sub> 
+>
+> *运算符* → [点运算符头](./02_Lexical_Structure.md#dot-operator-head) [点运算符字符集](./02-Lexical-Structure.md#dot-operator-characters)<sub>可选</sub> 
+>
+> *运算符字符* → **/** | **=** | **-** | **+** | **!** | **&#42;** | **%** | **<** | **>** | **&** | **|** | **^** | **~** | **?**
+>
+> *运算符头* → U+00A1–U+00A7
+>
+> *运算符头* → U+00A9 or U+00AB
+>
+> *运算符头* →  U+00AC or U+00AE
+>
+> *运算符头* → U+00B0–U+00B1, U+00B6, U+00BB, U+00BF, U+00D7, or U+00F7
+>
+> *运算符头* → U+2016–U+2017 or U+2020–U+2027
+>
+> *运算符头* → U+2030–U+203E
+>
+> *运算符头* → U+2041–U+2053
+>
+> *运算符头* → U+2055–U+205E
+>
+> *运算符头* → U+2190–U+23FF
+>
+> *运算符头* → U+2500–U+2775
+>
+> *运算符头* → U+2794–U+2BFF
+>
+> *运算符头* → U+2E00–U+2E7F
+>
+> *运算符头* → U+3001–U+3003
+>
+> *运算符头* → U+3008–U+3030
+>
+> *运算符字符* → [运算符头](./02_Lexical_Structure.md#operator-head)
+>
+> *运算符字符* → U+0300–U+036F
+>
+> *运算符字符* → U+1DC0–U+1DFF
+>
+> *运算符字符* → U+20D0–U+20FF
+>
+> *运算符字符* → U+FE00–U+FE0F
+>
+> *运算符字符* → U+FE20–U+FE2F
+>
+> *运算符字符* → U+E0100–U+E01EF
+>
+> *运算符字符集* → [运算符字符](./02_Lexical_Structure.md#operator-character) [运算符字符集](./02-Lexical-Structure.md#operator-characters)<sub>可选</sub> 
+>
+> *点运算符头* → **..**
+>
+> *点运算符字符* → **.** | [运算符字符](./02_Lexical_Structure.md#operator-character)
+>
+> *点运算符字符集* → [点运算符字符](./02_Lexical_Structure.md#dot-operator-character) [点运算符字符集](./02-Lexical-Structure.md#dot-operator-characters)<sub>可选</sub> 
+>
+> *二元运算符* → [运算符](./02_Lexical_Structure.md#operator)
+>
+> *前置运算符* → [运算符](./02_Lexical_Structure.md#operator)
+>
+> *后置运算符* → [运算符](./02_Lexical_Structure.md#operator)
+>
+
+## 类型 {#types}
+
+> 类型语法
+>
+> *类型* → [数组类型](./03_Types.md#array-type)
+>
+> *类型* → [字典类型](./03_Types.md#dictionary-type)
+>
+> *类型* → [函数类型](./03_Types.md#function-type)
+>
+> *类型* → [类型标识符](./03_Types.md#type-identifier)
+>
+> *类型* → [元组类型](./03_Types.md./03_Types.md#tuple-type)
+>
+> *类型* → [可选类型](./03_Types.md#optional-type)
+>
+> *类型* → [隐式解析可选类型](./03_Types.md#implicitly-unwrapped-optional-type)
+>
+> *类型* → [协议合成类型](./03_Types.md#protocol-composition-type)
+>
+> *类型* → **Any**
+>
+> *类型* → **Self**
+>
+> *类型* → **（** [type](./03_Types.md#metatype-type) **）**
+
+<!-- -->
+
+> 类型注解语法
+>
+> *类型注解* → **:** [属性（Attributes）集](./07_Attributes.md#attributes)<sub>可选</sub>[类型](./03-Types.md#type)
+
+<!-- -->
+
+> 类型标识语法
+>
+> *类型标识* → [类型名称](./03_Types.md#type-name) [泛型参数从句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>| [类型名称](./03-Types.md#type-name) [泛型参数从句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>**.** [类型标识符](./03-Types.md#type-identifier)
+>
+> *类型名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+
+> 元组类型语法
+>
+> *元组类型* → **(** **)** | **(** [元组类型元素](./03_Types.md#tuple-type-element) **,** [元组类型元素列表](./03-Types.md#tuple-type-element-list) **)**
+>
+> *元组类型元素列表* → [元组类型元素](./03_Types.md#tuple-type-element) | [元组类型元素](./03-Types.md#tuple-type-element) **,** [元组类型元素列表](./03-Types.md#tuple-type-element-list)
+>
+> *元组类型元素* → [元素名](./03_Types.md#element-name) [类型注解](./03-Types.md#type-annotation) | [类型](./03-Types.md#type)
+>
+> *元素名* → [标识符](./02_Lexical_Structure.md#identifier)
+
+<!-- -->
+
+> 函数类型语法
+>
+> *函数类型* → [类型](./03_Types.md#type)  **throws**<sub>可选</sub>**->** [类型](./03-Types.md#type)
+>
+> *函数类型* → [类型](./03_Types.md#)  **rethrows** **->** [类型](./03-Types.md#)
+> 
+> *函数类型子句* → **(** **)**
+> 
+> *函数类型子句* → **(** [函数类型参数列表](./03_Types.md#function-type-argument-list) *...*­<sub>可选</sub> **)**
+> 
+> *函数类型参数列表* → [函数类型参数](./03_Types.md#function-type-argument) | [函数类型参数](function-type-argument)， [函数类型参数列表](./03-Types.md#function-type-argument-list)
+> 
+> *函数类型参数* → [特性列表](./07_Attributes.md#attributes)<sub>可选</sub> **输入输出参数**<sub>可选</sub> [类型](#type) | [参数标签](#argument-label) [类型注解](#type-annotation)
+> 
+> *参数标签* → [标识符](./02_Lexical_Structure.md#identifier)
+
+<!-- -->
+
+> 数组类型语法
+>
+> *数组类型* → **[** [*类型*](./03_Types.md#array-type) **]**
+
+<!-- -->
+> 字典类型语法
+>
+> *字典类型* → **[** [类型 **:** 类型](./03_Types.md#type) **]**
+
+<!-- -->
+
+> 可选类型语法
+>
+> *可选类型* → [类型](./03_Types.md#type) **?**
+>
+
+<!-- -->
+
+> 隐式解析可选类型（Implicitly Unwrapped Optional Type）语法
+>
+> *隐式解析可选类型* → [类型](./03_Types.md#type) **!**
+>
+
+<!-- -->
+
+> 协议合成类型语法
+>
+> *协议合成类型* → [类型标识符](./03_Types.md#type-identifier) | [协议合成延续](./03-Types.md#protocol-composition-continuation)
+>
+> *协议持续延续* → [类型标识符](./03_Types.md#type-identifier) | [协议合成类型](./03-Types.md#protocol-composition-type)
+
+<!-- -->
+
+> 元（Metatype）类型语法
+>
+> *元类型* → [类型](./03_Types.md#type) **.** **Type** | [类型](./03-Types.md#type) **.** **Protocol**
+
+<!-- -->
+
+> 类型继承从句语法
+>
+> *类型继承从句* → **:** [类型继承集](./03_Types.md#type-inheritance-list)
+>
+> *类型继承集* → [类型标识符](./03_Types.md#type-identifier) | [类型标识符](./03-Types.md#type-identifier) **,** [类型继承集](./03-Types.md#type-inheritance-list)
+>
+> *类条件* → **class**
+
+## 表达式 {#expressions}
+
+> 表达式语法
+>
+> *表达式* → [try 运算符](./04_Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression) [二元表达式列表](./04-Expressions.md#binary-expressions)
+>
+> *表达式列表* → [表达式](./04_Expressions.md#expression)|[表达式](./04-Expressions.md#expression), [表达式列表](./04-Expressions.md#expression-list)
+>
+
+<!-- -->
+
+> 前缀表达式语法
+>
+> *前缀表达式* → [前缀操作符]()<sub>可选</sub> [前缀表达式](./04_Expressions.md#prefix-expression)
+>
+> *前缀表达式* → [输入输出表达式](./04_Expressions.md#in-out-expression)
+>
+> *输入输出表达式* → **&** [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+
+>try 表达式语法
+>
+> *try 操作符* → **try** | **try ? ** | ** try ! **
+>
+
+<!-- -->
+
+> 二元表达式语法
+>
+> *二元表达式* → [二元运算符](./02_Lexical_Structure.md#binary-operator) [前缀表达式](./04-Expressions.md#prefix-expression)
+>
+> *二元表达式* → [赋值操作符](./06_Declarations.md#class-declaration) [try 运算符](./04-Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression)
+>
+> *二元表达式* → [条件运算符](./04_Expressions.md#conditional-operator) [try 运算符](./04-Expressions.md#try-operator)<sub>可选</sub> [前缀表达式](./04-Expressions.md#prefix-expression)
+>
+> *二元表达式* → [类型转换运算符](./04_Expressions.md#type-casting-operator)
+>
+> *二元表达式* → [二元表达式](./04_Expressions.md#binary-expression) [二元表达式列表](./04-Expressions.md#binary-expressions)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 赋值操作符语法
+>
+> *赋值运算符* → [=]
+>
+
+<!-- -->
+
+> 条件运算符
+>
+> *条件运算符* → [?] [表达式](./04_Expressions.md#expression):
+
+> 类型转换运算符语法
+>
+> *类型转换运算符* → [is] [类型](./03_Types.md#type)
+>
+> *类型转换运算符* → [as] [类型](./03_Types.md#type)
+>
+> *类型转换运算符* → [as ?] [类型](./03_Types.md#type)
+>
+> *类型转换运算符* → [as !] [类型](./03_Types.md#type)
+>
+
+
+<!-- -->
+
+> 基础表达式语法
+>
+> *基础表达式* → [标识符](./02_Lexical_Structure.md#identifier) [泛型实参子句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub>
+>
+> *基础表达式* → [字面量表达式](./04_Expressions.md#literal-expression)
+>
+> *基础表达式* → [self 表达式](./04_Expressions.md#self-expression)
+>
+> *基础级表达式* → [父类表达式](./04_Expressions.md#superclass-expression)
+>
+> *基础表达式* → [闭包表达式](./04_Expressions.md#closure-expression)
+>
+> *基础表达式* → [圆括号表达式](./04_Expressions.md#parenthesized-expression)
+>
+> *基础表达式* → [元组表达式](./04_Expressions.md#Tuple-Expression)
+>
+> *基础表达式* → [隐式成员表达式](./04_Expressions.md#implicit-member-expression)
+>
+> *基础表达式* → [通配符表达式](./04_Expressions.md#wildcard-expression)
+>
+> *基础表达式* → [key-path表达式](./04_Expressions.md#key-path-expression)
+>
+> *基础表达式* → [选择器表达式](./04_Expressions.md#selector-expression)
+>
+> *基础表达式* → [key-path字符串表达式](./04_Expressions.md#key-patch-string-expression)
+>
+
+<!-- -->
+
+> 字面量表达式语法
+>
+> *字面量表达式* → [字面量](./04_Expressions.md#literal-expression)
+>
+> *字面量表达式* → [数组字面量](./04_Expressions.md#array-literal) | [字典字面量](./04-Expressions.md#dictionary-literal) | [练习场字面量](./04-Expressions.md#playground-literal)
+>
+> *字面量表达式* → **#file** | **#line** | **#column** | **#function** | **dsohandle**
+>
+>
+> *数组字面量* → **[** [数组字面量项列表](./04_Expressions.md#array-literal-items)<sub>可选</sub> **]**
+> *数组字面量项列表* → [数组字面量项](./04_Expressions.md#array-literal-item)<sub>可选</sub> | [数组字面量项](./04-Expressions.md#array-literal-item),[数组字面量项列表](./04-Expressions.md#array-literal-items)
+> *数组字面量项* → [表达式](./04_Expressions.md#expression)
+>
+>
+> *字典字面量* → [[字典字面量项列表](./04_Expressions.md#dictionary-literal-items) **]** | **[** **:** **]**
+> 
+> 
+> *字典字面量项列表* → [字典字面量项](./04_Expressions.md#dictionary-literal-item) ,**<sub>可选</sub> | [字典字面量项](./04-Expressions.md#dictionary-literal-item) ,[字典字面量项列表](./04-Expressions.md#dictionary-literal-items)
+>
+> *字典字面量项* → [表达式](./04_Expressions.md#expression) **:** [表达式](./04-Expressions.md#expression)
+>
+> 
+> *palyground 字面量* → **#colorLiteral ( red :  [表达式](./04-Expressions.md#expression) , green :[表达式](./04-Expressions.md#expression),  blue :[表达式](./04-Expressions.md#expression) , alpha : [表达式](./04-Expressions.md#expression) )**
+>
+> *playground 字面量* → **#fileLiteral ( resourceName : [表达式](#expression) )**
+>
+> *playground 字面量* → **#imageLiteral ( resourceName : [表达式](#expression) )
+<!-- -->
+
+> self 表达式语法
+> 
+> *self 表达式* → **self**  | [self 方法表达式](./04_Expressions.md#self-method-expression) ｜ [self 下标表达式](./04-Expressions.md#self-subscript-expression) | [self 构造器表达式](./04-Expressions.md#self-initializer-expression)
+>
+>
+> *self 方法表达式* → **self** **.** [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *self 下标表达式* → **self** **[** [函数调用参数表](./04_Expressions.md#function-call-argument-list­) **]**
+>
+> *self 构造器表达式* → **self** **.** **init**
+
+<!-- -->
+
+> 父类表达式语法
+>
+> *父类表达式* → [父类方法表达式](./04_Expressions.md#superclass-method-expression) | [父类下标表达式](./04-Expressions.md#superclass-subscript-expression) | [父类构造器表达式](./04-Expressions.md#superclass-initializer-expression)
+>
+> *父类方法表达式* → **super** **.** [标识符](./02_Lexical_Structure.md#identifier)
+> 
+> *父类下标表达式* → **super** [[函数调用参数表](./04_Expressions.md#function-call-argument-list­) **]**
+>
+> *父类构造器表达式* → **super** **.** **init**
+> 
+
+
+<!-- -->
+
+> 闭包表达式语法
+>
+> *闭包表达式* → **{** [闭包签名](./04_Expressions.md#closure-signature)<sub>可选</sub> [语句](./04-Expressions.md#statements) **}**
+>
+>
+> 闭包签名* → [参数子句](./04_Expressions.md#parameter-clause) [函数结果](05-Declarations.md#function-result)<sub>可选</sub> **in**
+> 
+> *闭包签名* → [标识符列表](./04_Expressions.md#identifier-list) [函数结果](05-Declarations.md#function-result)<sub>可选</sub> **in**
+> 
+>
+> *闭包参数子句* **(** **)** | **(** [闭包参数列表](./04_Expressions.md#closure-parameter-list) | [标识符列表](./04-Expressions.md#identifier-list) **)**
+>
+> *闭包参数列表* [闭包参数](./04_Expressions.md#implicit-member-expression) | [闭包参数](./04-Expressions.md#implicit-member-expression), [闭包参数列表](./04-Expressions.md#implicit-member-expression)
+>
+> *闭包参数* [闭包参数名](./04_Expressions.md#implicit-member-expression) [类型声明](./03-Types.md#type-annotation) <sub>可选</sub>
+>
+> *闭包参数* [闭包参数名](./04_Expressions.md#implicit-member-expression) [类型声明](./03-Types.md#type-annotation) **...**
+>
+> *闭包参数名* [标识符](./02_Lexical_Structure.md#identifier)
+> 
+>
+> *捕获列表* → [捕获列表](./04_Expressions.md#capture-list) **[** [捕获列表项列表](./04-Expressions.md#capture-list-items) **]**
+>
+> *捕获列表项列表* → [捕获列表项](./04_Expressions.md#capture-list-item) | [捕获列表项](./04-Expressions.md#capture-list-item) **,** [捕获列表项列表](./04-Expressions.md#capture-list-items)
+>
+> *捕获列表项* → [捕获说明符](./04_Expressions.md#capture-specifier)<sub>可选</sub> [*表达式*](./04-Expressions.md#expression)
+>
+> *捕获说明符* → **weak** | **unowned** | **unowned(safe)** | **unowned(unsafe)**
+> 
+
+
+<!-- -->
+
+> 隐式成员表达式语法
+>
+> *隐式成员表达式* → **.** [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+
+> 圆括号表达式语法
+>
+> *圆括号表达式* → **( [表达式](./04_Expressions.md#expression) )**
+> 
+
+<!-- -->
+
+> 元组表达式语法
+>
+> *元组表达式* → **( )** | **(**[元组元素](./04_Expressions.md#tuple-element)， [元组元素列表](./04-Expressions.md#tuple-element-list) **)**
+> 
+> *元组元素列表* → [元组元素](./04_Expressions.md#tuple-element) | [元组元素](./04-Expressions.md#tuple-element) **,** [元组元素列表](./04-Expressions.md#tuple-element-list)
+> *元组元素* → [表达式](./04_Expressions.md#expression) | [标识符](./04-Expressions.md#identifier) **:** [表达式](./04-Expressions.md##expression)
+> 
+
+<!-- -->
+
+> 通配符表达式语法
+>
+> *通配符表达式* → **_**
+>
+
+
+<!-- -->
+
+> key-path表达式语法
+>
+> *key-path 表达式* → **\**  [类型](./03_Types.md#type)<sub>可选</sub>  **.**  [多个 key-path 组件]
+> *多个 key-path 组件* → [key-path 组件](./04_Expressions.md#key-path-component) | [key-path 组件](./04-Expressions.md#key-path-component) **.** [多个 key-path 组件](./04-Expressions.md#key-path-components)
+> *key-path 组件* →  [标识符](./02_Lexical_Structure.md#identifier) [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)<sub>可选<sub> | [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)
+> *多个 key-path 后缀* →  [key-path 后缀](./04_Expressions.md#key-path-postfix) [多个 key-path 后缀](./04-Expressions.md#key-path-postfixes)<sub>可选<sub> key-path-postfixes {./04-Expressions.md#key-path-postfixes}
+> 
+> *key-path 后缀* → **?** | **!** | **self** | **\[** [函数调用参数表](./04_Expressions.md#function-call-argument-list) **\]** 
+> 
+
+
+<!-- -->
+
+> 选择器表达式语法
+>
+> *选择器表达式* → **#selector** **(** [*表达式*](./04-Expressions.md#expression) **)**
+> 
+> *选择器表达式* → **#selector** **(** [*getter:表达式*](./04-Expressions.md#expression) **)**
+> 
+> *选择器表达式* → **#selector** **(** [*setter:表达式*](./04-Expressions.md#expression) **)**
+> 
+
+<!-- -->
+
+> key-path 字符串表达式语法
+> *key-path 字符串表达式* → **#keyPath (** [表达式](./04-Expressions.md#expression)  **)**
+> 
+
+<!-- -->
+
+> 后缀表达式表达式语法
+>
+> *后缀表达式* → [基本表达式](./04_Expressions.md#primary-expression)
+> 
+> *后缀表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [后缀运算符](02-Lexical-Structure.md#postfix-operator)
+> 
+> *后缀表达式* → [函数调用表达式](./04_Expressions.md#function-call-expression)
+> 
+> *后缀表达式* → [构造器表达式](./04_Expressions.md#initializer-expression)
+> 
+> *后缀表达式* → [显式成员表达式](./04_Expressions.md#explicit-member-expression)
+> 
+> *后缀表达式* → [后缀 self 表达式](./04_Expressions.md#postfix-self-expression)
+>  
+> *后缀表达式* → [下标表达式](./04_Expressions.md#subscript-expression)
+> 
+> *后缀表达式* → [强制取值表达式](./04_Expressions.md#forced-value-expression)
+> 
+> *后缀表达式* → [可选链表达式](./04_Expressions.md#optional-chaining-expression)
+> 
+
+<!-- -->
+
+> 函数调用表达式语法
+>
+> *函数调用表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [函数调用参数子句](./04-Expressions.md#function-call-argument-clause)
+> 
+> *函数调用表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) [函数调用参数子句](./04-Expressions.md#function-call-argument-clause)<sub>可选</sub> [尾随闭包](./04-Expressions.md#trailing-closure)
+>
+> *函数调用参数子句* → **(**  **)**  | **(** [函数调用参数表](./04_Expressions.md#function-call-argument-list) **)**
+>
+> *函数调用参数表* → [函数调用参数](./04_Expressions.md#function-call-argument) | [函数调用参数](./04-Expressions.md#function-call-argument) **,** [函数调用参数表](./04-Expressions.md#function-call-argument-list)
+>
+> *函数调用参数* → [表达式](./04_Expressions.md#expression) | [标识符](02-Lexical-Structure.md#identifier) **:** [表达式](./04-Expressions.md#expression)
+> 
+> *函数调用参数* → [运算符](./02_Lexical_Structure.md#operator) | [标识符](./02-Lexical-Structure.md#identifier) **:** [运算符](./02-Lexical-Structure.md#operator)
+>
+> *尾随闭包* → [闭包表达式](./04_Expressions.md#closure-expression)
+>
+
+<!-- -->
+
+> 初始化表达式语法
+>
+> *构造器表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **init**
+> 
+> *构造器表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **init** **(** [参数名称](./04-Expressions.md#argument-names) **)**
+> 
+
+<!-- -->
+
+> 显式成员表达式语法
+>
+> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [十进制数字]    (02-Lexical-Structure.md#decimal-digit)
+> 
+> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [标识符](02-Lexical-Structure.md#identifier) [泛型实参子句](./09-Generic-Parameters-and-Arguments.md#generic-argument-clause)<sub>可选</sub><br/>
+> 
+> *显式成员表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** [标识符]    (02-Lexical-Structure.md#identifier) **(** [参数名称](./04-Expressions.md#argument-names) **)**
+> 
+> *参数名称* → [参数名](./04_Expressions.md#argument-name) [参数名称](./04-Expressions.md#argument-names)<sub>可选</sub><br/>
+> 
+> *参数名* → [标识符](./02_Lexical_Structure.md#identifier) **:**
+>
+
+<!-- -->
+
+> 后缀 self 表达式语法
+>
+> *后缀 self 表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **.** **self**
+> 
+
+<!-- -->
+
+> 下标表达式语法
+>
+> *下标表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **[** [表达式列表](./04-Expressions.md#expression-list) **]**
+> 
+
+<!-- -->
+
+> 强制取值表达式语法
+> *强制取值表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **!**
+> 
+
+
+<!-- -->
+
+> 可选链式表达式语法
+> *可选链表达式* → [后缀表达式](./04_Expressions.md#postfix-expression) **?**
+> 
+
+## 语句 {#statements}
+
+> 语句语法
+>
+> *语句* → [表达式](./04_Expressions.md#expression) **;**<sub>可选</sub>
+>
+> *语句* → [声明](./06_Declarations.md#declaration) **;**<sub>可选</sub>
+>
+> *语句* → [循环语句](./05_Statements.md#loop-statement) **;**<sub>可选</sub>
+>
+> *语句* → [分支语句](./05_Statements.md#branch-statement) **;**<sub>可选</sub>
+>
+> *语句* → [标签语句](./05_Statements.md#labeled-statement) **;**<sub>可选</sub>
+>
+> *语句* → [控制转移语句](./05_Statements.md#control-transfer-statement) **;**<sub>可选</sub>
+>
+> *语句* → [延迟语句](./05_Statements.md#defer-statement) **;**<sub>可选</sub>
+>
+> *语句* → [执行语句](./05_Statements.md#do-statement) **;**<sub>可选</sub>
+>
+> *语句* → [编译控制语句](./05_Statements.md#compiler-control-statement)
+>
+> *语句集* → [语句](./05_Statements.md#statement) [语句集](./05-Statements.md#statements)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 循环语句语法
+>
+> *循环语句* → [for-in 语句](./05_Statements.md#for-in-statement)
+>
+> *循环语句* → [while 语句](./05_Statements.md#wheetatype 类型 ile-statement)
+>
+> *循环语句* → [repeat-while 语句](./05_Statements.md#do-while-statement)
+>
+
+<!-- -->
+
+> For-In 循环语法
+>
+> *for-in 语句* → **for case**<sub>可选</sub> [模式](./08_Patterns.md#pattern) **in** [表达式](./04-Expressions.md#expression) [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
+>
+
+<!-- -->
+
+> While 循环语法
+>
+> *while 语句* → **while** [条件集](./05_Statements.md#condition-list) [代码块](./06-Declarations.md#code-block)
+>
+> *条件集* → [条件](./05_Statements.md#condition) | [条件](./05-Statements.md#condition) **,** [条件集](./05-Statements.md#condition-list)
+> *条件* → [表达式](./04_Expressions.md#expression) | [可用性条件](./05-Statements.md#availability-condition) | [case 条件](./05-Statements.md#case-condition) | [可选绑定条件](./05-Statements.md#optional-binding-condition)
+>
+> *case 条件* → **case** [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)
+>
+> *可选绑定条件* → **let** [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer) | **var** [模式](./08-Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)
+>
+
+<!-- -->
+> Repeat-While 语句语法
+>
+*repeat-while-statement* → **repeat** [代码块](./06_Declarations.md#code-block) **while** [表达式](./04-Expressions.md#expression)
+
+<!-- -->
+
+> 分支语句语法
+>
+> *分支语句* → [if 语句](./05_Statements.md#if-statement)
+>
+> *分支语句* → [guard 语句](./05_Statements.md#guard-statement)
+>
+> *分支语句* → [switch 语句](./05_Statements.md#switch-statement)
+>
+
+<!-- -->
+
+> If 语句语法
+>
+> *if 语句* → **if** [条件集](./05_Statements.md#condition-list) [代码块](./06-Declarations.md#code-block) [else 子句](./05-Statements.md#else-clause)<sub>可选</sub>
+>
+> *else 子句* → **else** [代码块](./06_Declarations.md#code-block) | **else** [if 语句](./05-Statements.md#if-statement)
+>
+
+<!-- -->
+> Guard 语句语法
+>
+> *guard 语句* → **guard** [条件集](./05_Statements.md#condition-list) **else** [代码块](./06-Declarations.md#code-block)
+>
+
+
+<!-- -->
+
+> Switch 语句语法
+>
+> *switch 语句* → **switch** [表达式](./04_Expressions.md#expression) **{** [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub> **}**
+>
+> *switch-case集* → [switch-case](./05_Statements.md#switch-case) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
+>
+> *switch-case* → [case 标签](./05_Statements.md#case-label) [语句集](./05-Statements.md#statements)
+>
+> *switch-case* → [default 标签](./05_Statements.md#default-label) [语句集](./05-Statements.md#statements)
+>
+> *switch-case* → [条件 switch-case](./05_Statements.md#conditional-switch-case)
+>
+> *case 标签* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **case** [case 项集](./05-Statements.md#case-item-list) **:**
+>
+> *case 项集* → [模式](./08_Patterns.md#pattern) [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> | [模式](./08-Patterns.md#pattern) [where 子句](./05-Statements.md#guard-clause)<sub>可选</sub> **,** [case 项集](./05-Statements.md#case-item-list)
+>
+> *default 标签* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **default** **:**
+>
+> *where 子句* → **where** [where 表达式](./05_Statements.md#where-expression)
+>
+> *where 表达式* → [表达式](./04_Expressions.md#expression)
+>
+> *条件 switch-case* → [switch if 指令子句](./05_Statements.md#switch-if-directive-clause) [switch elseif 指令子句集](./05-Statements.md#switch-elseif-directive-clauses)<sub>可选</sub> [switch else 指令子句](./05-Statements.md#switch-else-directive-clause)<sub>可选</sub> [endif 指令](./05-Statements.md#endif-directive)
+>
+> *switch if 指令子句* → [if 指令](./05_Statements.md#if-directive) [编译条件](./05-Statements.md#compilation-condition) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
+>
+> *switch elseif 指令子句集* → [elseif 指令子句](./05_Statements.md#else-if-directive-clause) [switch elseif 指令子句集](./05-Statements.md#switch-elseif-directive-clauses)<sub>可选</sub>
+>
+> *switch elseif 指令子句* → [elseif 指令](./05_Statements.md#elseif-directive) [编译条件](./05-Statements.md#compilation-condition) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
+>
+> *switch else 指令子句* → [else 指令](./05_Statements.md#else-directive) [switch-case集](./05-Statements.md#switch-cases)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 标签语句语法
+>
+> *标签语句* → [语句标签](./05_Statements.md#statement-label) [循环语句](./05-Statements.md#loop-statement)
+>
+> *标签语句* → [语句标签](./05_Statements.md#statement-label) [if 语句](./05-Statements.md#if-statement)
+>
+> *标签语句* → [语句标签](./05_Statements.md#statement-label) [switch 语句](./05-Statements.md#switch-statement)
+>
+> *标签语句* → [语句标签](./05_Statements.md#statement-label) [do 语句](./05-Statements.md#do-statement)
+>
+> *语句标签* → [标签名称](./05_Statements.md#label-name) **:**
+>
+> *标签名称* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+
+> 控制转移语句语法
+>
+> *控制转移语句* → [break 语句](./05_Statements.md#break-statement)
+>
+> *控制转移语句* → [continue 语句](./05_Statements.md#continue-statement)
+>
+> *控制转移语句* → [fallthrough 语句](./05_Statements.md#fallthrough-statement)
+>
+> *控制转移语句* → [return 语句](./05_Statements.md#return-statement)
+>
+> *控制转移语句* → [throw 语句](./05_Statements.md#throw-statement)
+>
+
+<!-- -->
+
+> Break 语句语法
+>
+> *break 语句* → **break** [标签名称](./05_Statements.md#label-name)<sub>可选</sub>
+>
+
+<!-- -->
+
+> Continue 语句语法
+>
+> *continue 语句* → **continue** [标签名称](./05_Statements.md#label-name)<sub>可选</sub>
+>
+
+<!-- -->
+
+> Fallthrough 语句语法
+>
+> *fallthrough 语句* → **fallthrough**
+>
+
+<!-- -->
+
+> Return 语句语法
+>
+> *return 语句* → **return** [表达式](./04_Expressions.md#expression)<sub>可选</sub>
+>
+
+<!-- -->
+
+> Throw 语句语法
+>
+> *throw 语句* → **throw** [表达式](./04_Expressions.md#expression)
+>
+
+<!-- -->
+
+> Defer 语句语法
+>
+> *defer 语句* → **defer** [代码块](./06_Declarations.md#code-block)
+>
+
+<!-- -->
+> Do 语句语法
+>
+> *do 语句* → **do** [代码块](./06_Declarations.md#code-block) [catch 子句集](./05-Statements.md#catch-clauses)<sub>可选</sub>
+>
+> *catch 子句集* → [catch 子句](./05_Statements.md#catch-clause) [catch 子句集](05-Statements.md#catch-clauses)<sub>可选</sub>
+>
+> *catch 子句* → **catch** [模式](./08_Patterns.md#pattern)<sub>可选</sub>  [where 子句](./05-Statements.md#where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)<sub>可选</sub>
+>
+
+<!-- -->
+> 编译控制语句
+>
+> *编译控制语句* → [条件编译块](./05_Statements.md#conditional-complation-block)
+>
+> *编译控制语句* → [行控制语句](./05_Statements.md#line-control-statement)
+>
+> *编译控制语句* → [诊断语句](./05_Statements.md#diagnostic-statement)
+>
+
+<!-- -->
+> 条件编译块语法
+>
+> *条件编译块* → [if 指令子句](./05_Statements.md#if-directive-clause) [elseif 指令子句集](./05-Statements.md#elseif-directive-clauses)<sub>可选</sub> [else 指令子句](./05-Statements.md#else-directive-clause)<sub>可选</sub> [endif 指令](./05-Statements.md#endif-directive)
+>
+> *if 指令子句* → [if 指令](./05_Statements.md#if-directive) [编译条件](./05-Statements.md#compilation-condition) [语句集](./05-Statements.md#statements)<sub>可选</sub>
+>
+> *elseif 指令子句集* → [elseif 指令子句](./05_Statements.md#else-if-directive-clause) [elseif 指令子句集](./05-Statements.md#elseif-directive-clauses)<sub>可选</sub>
+>
+> *elseif 指令子句* → [elseif 指令](./05_Statements.md#elseif-directive) [编译条件](./05-Statements.md#compilation-condition) [语句集](./05-Statements.md#statements)<sub>可选</sub>
+>
+> *else 指令子句* → [else 指令](./05_Statements.md#else-directive) [语句集](./05-Statements.md#statements)<sub>可选</sub>
+>
+> *if 指令* → **#if**
+>
+> *elseif 指令* → **#elseif**
+>
+> *else 指令* → **#else**
+>
+> *endif 指令* → **#endif**
+>
+> *编译条件* → [平台条件](./05_Statements.md#platform-condition)
+>
+> *编译条件* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *编译条件* → [布尔字面量](./02_Lexical_Structure.md#boolean-literal)
+>
+> *编译条件* → **(** [编译条件](./05_Statements.md#compilation-condition) **)**
+>
+> *编译条件* → **!** [编译条件](./05_Statements.md#compilation-condition)
+>
+> *编译条件* → [编译条件](./05_Statements.md#compilation-condition) **&&** [编译条件](./05-Statements.md#compilation-condition)
+>
+> *编译条件* → [编译条件](./05_Statements.md#compilation-condition) **||** [编译条件](./05-Statements.md#compilation-condition)
+>
+> *平台条件* → **os** **(** [操作系统](./05_Statements.md#operating-system) **)**
+>
+> *平台条件* → **arch** **(** [架构](./05_Statements.md#architecture) **)**
+>
+> *平台条件* → **swift** **(** **>=** [swift 版本](./05_Statements.md#swift-version) **)** | **swift** **(** **<** [swift 版本](./05-Statements.md#swift-version) **)**
+>
+> *平台条件* → **compiler** **(** **>=** [swift 版本](./05_Statements.md#swift-version) **)** | **compiler** **(** **<** [swift 版本](./05-Statements.md#swift-version) **)**
+>
+> *平台条件* → **canImport** **(** [模块名](./05_Statements.md#module-name) **)**
+>
+> *平台条件* → **targetEnvironment** **(** [环境](./05_Statements.md#environment) **)**
+>
+> *操作系统* → **macOS** | **iOS** | **watchOS** | **tvOS**
+>
+> *架构* → **i386** | **x86_64** | **arm** | **arm64**
+>
+> *swift 版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) [swift 版本后缀](./05-Statements.md#swift-version-continuation)<sub>可选</sub>
+>
+> *swift 版本后缀* → **.** [十进制数字集](./02_Lexical_Structure.md#decimal-digits) [swift 版本集](./05-Statements.md#swift-version-continuation)<sub>可选</sub>
+>
+> *模块名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *环境* → **模拟器** ｜ **macCatalyst**
+
+<!-- -->
+
+> 行控制语句语法
+>
+> *行控制语句* → **#sourceLocation** **(** **file:** [文件名](./05-Statements.md#file-name) **,** **line:**  [行号](./05-Statements.md#line-number) **)**
+>
+> *行控制语句* → **#sourceLocation** **(** **)**
+>
+> *行号* → 一个大于 0 的十进制数字
+>
+> *文件名* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal)
+>
+
+<!-- -->
+> 编译期诊断语句语法
+>
+> *诊断语句* → **#error** **(** [诊断信息](./05-Statements.md#diagnostic-message) **)**
+>
+> *诊断语句* → **#warning** **(** [诊断信息](./05-Statements.md#diagnostic-message) **)**
+>
+> *诊断信息* → [静态字符串字面量](./02_Lexical_Structure.md#static-string-literal)
+>
+
+<!-- -->
+> 可用性条件语法
+>
+> *可用性条件* → **#available** **(** [可用性参数集](./05-Statements.md#availability-arguments) **)**
+>
+> *可用性参数集* → [可用性参数](./05_Statements.md#availability-argument) | [可用性参数](./05-Statements.md#availability-argument) , [可用性参数集）](./05-Statements.md#availability-arguments)
+>
+> *可用性参数* → [平台名](./05_Statements.md#platform-name) [平台版本](./05-Statements.md#platform-version)
+>
+> *可用性参数* → **\***
+>
+> *平台名* → **iOS** | **iOSApplicationExtension**
+>
+> *平台名* → **macOS** | **macOSApplicationExtension**
+>
+> *平台名* → **watchOS**
+>
+> *平台名* → **tvOS**
+>
+> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits)
+>
+> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits)
+>
+> *平台版本* → [十进制数字集](./02_Lexical_Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits) **.** [十进制数字集](./02-Lexical-Structure.md#decimal-digits)
+>
+
+## 声明 {#declarations}
+
+> 声明语法
+>
+> *声明* → [导入声明](./06_Declarations.md#import-declaration)
+>
+> *声明* → [常量声明](./06_Declarations.md#constant-declaration)
+>
+> *声明* → [变量声明](./06_Declarations.md#variable-declaration)
+>
+> *声明* → [类型别名声明](./06_Declarations.md#typealias-declaration)
+>
+> *声明* → [函数声明](./06_Declarations.md#function-declaration)
+>
+> *声明* → [枚举声明](./06_Declarations.md#enum-declaration)
+>
+> *声明* → [结构体声明](./06_Declarations.md#struct-declaration)
+>
+> *声明* → [类声明](./06_Declarations.md#class-declaration)
+>
+> *声明* → [协议声明](./06_Declarations.md#protocol-declaration)
+>
+> *声明* → [构造器声明](./06_Declarations.md#initializer-declaration)
+>
+> *声明* → [析构器声明](./06_Declarations.md#deinitializer-declaration)
+>
+> *声明* → [扩展声明](./06_Declarations.md#extension-declaration)
+>
+> *声明* → [下标声明](./06_Declarations.md#subscript-declaration)
+>
+> *声明* → [运算符声明](./06_Declarations.md#operator-declaration)
+>
+> *声明* → [优先级组声明](./06_Declarations.md#precedence-group-declaration)
+>
+> *声明集* → [声明](./06_Declarations.md#declaration) [声明集](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+
+
+<!-- -->
+
+> 顶级声明语法
+>
+> *顶级声明* → [多条语句](./05_Statements.md#statements)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 代码块语法
+>
+> *代码块* → **{** [多条语句](./05_Statements.md#statements)<sub>可选</sub> **}**
+>
+
+<!-- -->
+
+> 导入声明语法
+>
+> *导入声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **import** [导入类型](./06-Declarations.md#import-kind)<sub>可选</sub> [导入路径](./06-Declarations.md#import-path)
+>
+> *导入类型* → **typealias** | **struct** | **class** | **enum** | **protocol** | **let** | **var** | **func**
+>
+> *导入路径* → [导入路径标识符](./06_Declarations.md#import-path-identifier) | [导入路径标识符](./06-Declarations.md#import-path-identifier) **.** [导入路径](./06-Declarations.md#import-path)
+>
+> *导入路径标识符* → [标识符](./02_Lexical_Structure.md#identifier) | [运算符](./02-Lexical-Structure.md#operator)
+>
+
+<!-- -->
+
+> 常数声明语法
+>
+> *常量声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **let** [模式构造器集](./06-Declarations.md#pattern-initializer-list)
+>
+> *模式构造器集* → [模式构造器](./06_Declarations.md#pattern-initializer) | [模式构造器](./06-Declarations.md#pattern-initializer)    **,** [模式构造器集](./06-Declarations.md#pattern-initializer-list)
+>
+> *模式构造器* → [模式](./08_Patterns.md#pattern) [构造器](./06-Declarations.md#initializer)<sub>可选</sub>
+>
+> *构造器* → **=** [表达式](./04_Expressions.md#expression)
+>
+
+<!-- -->
+
+> 变量声明语法
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [模式构造器集](./06-Declarations.md#pattern-initializer-list)
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [代码块](./06-Declarations.md#code-block)
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 块](./06-Declarations.md#getter-setter-block)
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [构造器](./06-Declarations.md#initializer)<sub>可选</sub> [willSet-didSet 代码块](./06-Declarations.md#willSet-didSet-block)
+>
+> *变量声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [构造器](./06-Declarations.md#initializer)<sub>可选</sub> [willSet-didSet 代码块](./06-Declarations.md#willSet-didSet-block)
+>
+> *变量声明头* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **var**
+>
+> *变量名称* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *getter-setter 块* → [代码块](./06_Declarations.md#code-block)
+>
+> *getter-setter 块* → **{** [getter 子句](./06_Declarations.md#getter-keyword-clause) [setter 子句](./06-Declarations.md#setter-keyword-clause)<sub>可选</sub> **}**
+>
+> *getter-setter 块* → **{** [setter 子句](./06_Declarations.md#setter-keyword-clause) [getter 子句](./06-Declarations.md#getter-keyword-clause) **}**
+>
+> *getter 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub>  **get**  [代码块](./06-Declarations.md#code-block)
+>
+> *setter 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **set** [setter 名称](./06-Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
+>
+> *setter 名称* → **(** [标识符](./02_Lexical_Structure.md#identifier) **)**
+>
+> *getter-setter 关键字（Keyword）块* → **{** [getter 关键字子句](./06_Declarations.md#getter-keyword-clause) [setter 关键字子句](./06-Declarations.md#setter-keyword-clause)<sub>可选</sub> **}**
+>
+> *getter-setter 关键字（Keyword）块* → **{** [setter 关键字子句](./06_Declarations.md#setter-keyword-clause) [getter 关键字子句](./06-Declarations.md#getter-keyword-clause) **}**
+>
+> *getter 关键字（Keyword）子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **get**
+>
+> *setter 关键字（Keyword）子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [可变性修饰符](./06-Declarations.md#mutation-modifier)<sub>可选</sub> **set**
+>
+> *willSet-didSet 代码块* → **{** [willSet 子句](./06_Declarations.md#willSet-clause) [didSet 子句](./06-Declarations.md#didSet-clause)<sub>可选</sub> **}**
+>
+> *willSet-didSet 代码块* → **{** [didSet 子句](./06_Declarations.md#didSet-clause) [willSet 子句](./06-Declarations.md#willSet-clause)<sub>可选</sub> **}**
+>
+> *willSet 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **willSet** [setter 名称](./06-Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
+>
+> *didSet 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub>
+>
+ **didSet** [setter 名称](./06_Declarations.md#setter-name)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
+
+<!-- -->
+
+> 类型别名声明语法
+>
+> *类型别名声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier) **typealias** [类型别名名称](./06-Declarations.md#typealias-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型别名赋值](./06-Declarations.md#typealias-assignment)
+>
+> *类型别名名称* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *类型别名赋值* → **=** [类型](./03_Types.md#type)
+>
+
+<!-- -->
+
+> 函数声明语法
+>
+> *函数声明* → [函数头](./06_Declarations.md#function-head) [函数名](./06-Declarations.md#function-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [函数签名](./06-Declarations.md#function-signature) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [函数体](./06-Declarations.md#function-body)<sub>可选</sub>
+>
+> *函数头* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明描述符集](./06-Declarations.md#declaration-specifiers)<sub>可选</sub> **func**
+>
+> *函数名* → [标识符](./02_Lexical_Structure.md#identifier) | [运算符](./02-Lexical-Structure.md#operator)
+>
+> *函数签名* → [参数子句](./06_Declarations.md#parameter-clause) **throws**<sub>可选</sub> [函数结果](./06-Declarations.md#function-result)<sub>可选</sub>
+>
+
+> *函数签名* → [参数子句](./06_Declarations.md#parameter-clause) **rethrows** [函数结果](./06-Declarations.md#function-result)<sub>可选</sub>
+>
+> *函数结果* → **->** [特性](./07_Attributes.md#attributes)<sub>可选</sub> [类型](./03-Types.md#type)
+>
+> *函数体* → [代码块](./06_Declarations.md#code-block)
+>
+> *参数子句* → **(** **)** | **(** [参数集](./06_Declarations.md#parameter-list) **)**
+>
+> *参数集* → [参数](./06_Declarations.md#parameter) | [参数](./06-Declarations.md#parameter) **,** [参数集](./06-Declarations.md#parameter-list)
+>
+> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation) [默认参数子句](./06-Declarations.md#default-argument-clause)<sub>可选</sub>
+>
+> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation)
+>
+> *参数* → [外部参数名](./06_Declarations.md#parameter-name)<sub>可选</sub> [本地参数名](./06-Declarations.md#local-parameter-name) [类型注解](./03-Types.md#type-annotation) **...**
+>
+> *外部参数名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *本地参数名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *默认参数子句* → **=** [表达式](./04_Expressions.md#expression)
+>
+
+<!-- -->
+
+> 枚举声明语法
+>
+> *枚举声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> [联合式枚举](./06-Declarations.md#union-style-enum)
+>
+> *枚举声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> [原始值式枚举](./06-Declarations.md#raw-value-style-enum)
+>
+> *联合式枚举* → **indirect**<sub>可选</sub> **enum** [枚举名](./06_Declarations.md#enum-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> **{** [联合式枚举成员](./06-Declarations.md#union-style-enum-members)<sub>可选</sub> **}**
+>
+> *联合式枚举成员集* → [联合式枚举成员](./06_Declarations.md#union-style-enum-member) [联合样式枚举成员集](./06-Declarations.md#union-style-enum-members)<sub>可选</sub>
+>
+> *联合样式枚举成员* → [声明](./06_Declarations.md#declaration) | [联合式枚举 case 子句](./06-Declarations.md#union-style-enum-case-clause) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+> *联合式枚举 case 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **indirect**<sub>可选</sub> **case** [联合式枚举 case 集](./06-Declarations.md#union-style-enum-case-list)
+>
+> *联合式枚举 case 集* → [联合式枚举 case](./06_Declarations.md#union-style-enum-case) | [联合式枚举 case](./06-Declarations.md#union-style-enum-case) **,** [联合式枚举 case 集](./06-Declarations.md#union-style-enum-case-list)
+>
+> *联合式枚举 case* → [枚举的 case 名](./06_Declarations.md#enum-case-name) [元组类型](./03-Types.md#tuple-type)<sub>可选</sub>
+>
+> *枚举名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *枚举的 case 名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *原始值式枚举* → **enum** [枚举名](./06_Declarations.md#enum-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> **{** [原始值式枚举成员集](./06-Declarations.md#raw-value-style-enum-members) **}**
+>
+> *原始值式枚举成员集* → [原始值式枚举成员](./06_Declarations.md#raw-value-style-enum-member) [原始值式枚举成员集](./06-Declarations.md#raw-value-style-enum-members)<sub>可选</sub>
+>
+> *原始值式枚举成员* → [声明](./06_Declarations.md#declaration) | [原始值式枚举 case 子句](./06-Declarations.md#raw-value-style-enum-case-clause) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+> *原始值式枚举 case 子句* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **case** [原始值式枚举 case 集](./06-Declarations.md#raw-value-style-enum-case-list)
+>
+> *原始值式枚举 case 集* → [原始值式枚举 case](./06_Declarations.md#raw-value-style-enum-case) | [原始值式枚举 case](./06-Declarations.md#raw-value-style-enum-case) **,** [原始值式枚举 case 集](./06-Declarations.md#raw-value-style-enum-case-list)
+>
+> *原始值式枚举 case* → [枚举的 case 名](./06_Declarations.md#enum-case-name) [原始值赋值](./06-Declarations.md#raw-value-assignment)<sub>可选</sub>
+>
+> *原始值赋值* → **=** [原始值字面量](./02_Lexical_Structure.md#literal)
+>
+> *原始值字面量（raw-value-literal）* → [数值字面量](./02_Lexical_Structure.md#literal) | [静态字符串字面量](./02-Lexical-Structure.md#literal) | [布尔字面量](./02-Lexical-Structure.md#literal)
+>
+
+<!-- -->
+
+> 结构体声明语法
+>
+> *结构体声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **struct** [结构体名称](./06-Declarations.md#struct-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [结构体主体](./06-Declarations.md#struct-body)
+>
+> *结构体名称* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *结构体主体* → **{** [结构体成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
+>
+> *结构体成员集* → [结构体成员](./06_Declarations.md#declarations) [结构体成员集](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+> *结构体成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+
+<!-- -->
+
+> 类声明语法
+>
+> *类声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **final**<sub>可选</sub> **class** [类名](./06-Declarations.md#class-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [类主体](./06-Declarations.md#class-body)
+>
+> *类声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **final** [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **class** [类名](./06-Declarations.md#class-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [类型继承子句](./03-Types.md#type-inheritance-clause) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [类主体](./06-Declarations.md#class-body)
+>
+> *类名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *类主体* → **{** [类成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
+>
+> *类成员集* → [类成员](./06_Declarations.md#declarations) [类成员集](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+> *类成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+
+<!-- -->
+
+> 协议声明语法
+>
+> *协议声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub>  **protocol** [协议名](./06-Declarations.md#protocol-name) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [协议主体](./06-Declarations.md#protocol-body)
+>
+> *协议名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *协议主体* → **{** [协议成员集](./06_Declarations.md#protocol-member-declarations)<sub>可选</sub> **}**
+>
+> *协议成员集* → [协议成员](./06_Declarations.md#declarations) [协议成员集](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+> *协议成员* → [协议成员声明](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+> *协议成员声明* → [协议属性声明](./06_Declarations.md#protocol-property-declaration)
+>
+> *协议成员声明* → [协议方法声明](./06_Declarations.md#protocol-method-declaration)
+>
+> *协议成员声明* → [协议构造器声明](./06_Declarations.md#protocol-initializer-declaration)
+>
+> *协议成员声明* → [协议下标声明](./06_Declarations.md#protocol-subscript-declaration)
+>
+> *协议成员声明* → [协议关联类型声明](./06_Declarations.md#protocol-associated-type-declaration)
+>
+> *协议成员声明* → [类型别名声明](./06_Declarations.md#typealias-declaration)
+>
+
+<!-- -->
+
+> 协议属性声明语法
+>
+> *协议属性声明* → [变量声明头](./06_Declarations.md#variable-declaration-head) [变量名](./06-Declarations.md#variable-name) [类型注解](./03-Types.md#type-annotation) [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
+>
+
+<!-- -->
+
+> 协议方法声明语法
+>
+> *协议方法声明* → [函数头](./06_Declarations.md#function-head) [函数名](./06-Declarations.md#function-name) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [函数签名](./06-Declarations.md#function-signature) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 协议构造器声明语法
+>
+> *协议构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **throws**<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
+>
+> *协议构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **rethrows** [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 协议下标声明语法
+>
+> *协议下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
+>
+
+<!-- -->
+
+> 协议关联类型声明语法
+>
+> *协议关联类型声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **associatedtype** [类型别名](./06-Declarations.md#typealias-name) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [类型别名赋值](./06-Declarations.md#typealias-assignment)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub>
+>
+
+<!-- -->
+
+> 构造器声明语法
+>
+> *构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **throws**<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [构造器主体](./06-Declarations.md#initializer-body)
+>
+> *构造器声明* → [构造器头](./06_Declarations.md#initializer-head) [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause) **rethrows** [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [构造器主体](./06-Declarations.md#initializer-body)
+>
+> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init**
+>
+> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init ?**
+>
+> *构造器头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>  **init !**
+>
+> *构造器主体* → [代码块](./06_Declarations.md#code-block)
+>
+
+<!-- -->
+
+> 析构器声明语法
+>
+> *析构器声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> **deinit** [代码块](./06-Declarations.md#code-block)
+>
+
+<!-- -->
+
+> 扩展声明语法
+>
+> *扩展声明* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [访问级别修饰符](./07-Attributes.md#access-level-modifier)<sub>可选</sub> **extension** [类型标识](./03-Types.md#type-identifier) [类型继承子句](./03-Types.md#type-inheritance-clause)<sub>可选</sub> [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [扩展主体](./06-Declarations.md#extension-body)
+>
+> *扩展主体* → **{** [扩展成员集](./06_Declarations.md#declarations)<sub>可选</sub> **}**
+>
+> *扩展成员集* → [扩展成员](./06_Declarations.md#declarations) [扩展成员集](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+> *扩展成员* → [声明集](./06_Declarations.md#declarations) | [编译控制语句](./05-Statements.md#compiler-control-statement)
+>
+
+<!-- -->
+
+> 下标声明语法
+>
+> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [代码块](./06-Declarations.md#code-block)
+>
+> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 块](./06-Declarations.md#getter-setter-block)
+>
+> *下标声明* → [下标头](./06_Declarations.md#subscript-head) [下标结果](./06-Declarations.md#subscript-result) [泛型 where 子句](./09-Generic-Parameters-and-Arguments.md#generic-where-clause)<sub>可选</sub> [getter-setter 关键字块](./06-Declarations.md#getter-setter-keyword-block)
+>
+> *下标头（Head）* → [特性](./07_Attributes.md#attributes)<sub>可选</sub> [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub> **subscript** [泛型参数子句](./09-Generic-Parameters-and-Arguments.md#generic-parameter-clause)<sub>可选</sub> [参数子句](./06-Declarations.md#parameter-clause)
+>
+> *下标结果（Result）* → **->** [特性](./07_Attributes.md#attributes)<sub>可选</sub> [类型](./03-Types.md#type)
+>
+
+<!-- -->
+
+> 运算符声明语法
+>
+> *运算符声明* → [前置运算符声明](./06_Declarations.md#prefix-operator-declaration) | [后置运算符声明](./06-Declarations.md#postfix-operator-declaration) | [中置运算符声明](./06-Declarations.md#infix-operator-declaration)
+>
+> *前置运算符声明* → **prefix** **operator**  [运算符](./02_Lexical_Structure.md#operator)
+>
+> *后置运算符声明* → **postfix** **operator**  [运算符](./02_Lexical_Structure.md#operator)
+>
+> *中置运算符声明* → **infix** **operator**  [运算符](./02_Lexical_Structure.md#operator) [中置运算符特性](./06-Declarations.md#infix-operator-attributes)<sub>可选</sub>
+>
+> *中置运算符特性* → [优先级组名](./06_Declarations.md#precedence-group-name)
+>
+
+> 优先级组声明语法
+>
+> *优先级组声明* → **precedencegroup** [优先级组名](./06_Declarations.md#precedence-group-name) **{** [优先级组特性](./06-Declarations.md#precedence-group-attributes)<sub>可选</sub> **}**
+>
+> *优先级组特性* → [优先级组属性](./06_Declarations.md#declarations) [优先级组特性](./06-Declarations.md#declarations)<sub>可选</sub>
+>
+> *优先级组属性* → [优先级组关系](./06_Declarations.md#declarations)
+>
+> *优先级组属性* → [优先级组赋值](./06_Declarations.md#declarations)
+>
+> *优先级组属性* → [优先级组结合](./06_Declarations.md#declarations)
+>
+> *优先级组关系* → **higherThan :** [优先级组名集](./06_Declarations.md#declarations)
+>
+> *优先级组关系* → **lowerThan :** [优先级组名集](./06_Declarations.md#declarations)
+>
+> *优先级组赋值* → **assignment :** [布尔字面量](./02_Lexical_Structure.md#string-literal)
+>
+> *优先级组结合* → **associativity : left**
+>
+> *优先级组结合* → **associativity : right**
+>
+> *优先级组结合* → **associativity : none**
+>
+> *优先级组名集* → [优先级组名](./06_Declarations.md#declarations) | [优先级组名](./06-Declarations.md#declarations) **,** [优先级组名集](./06-Declarations.md#declarations)
+>
+> *优先级组名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+> 声明修饰符语法
+>
+> *声明修饰符* → **class** | **convenience** | **dynamic** | **final** | **infix** | **lazy** | **optional** | **override** | **postfix** | **prefix** | **required** | **static** | **unowned** | **unowned(safe)** | **unowned(unsafe)** | **weak**
+>
+> *声明修饰符* → [访问级别修饰符](./07_Attributes.md#access-level-modifier)
+>
+> *声明修饰符* → [可变性修饰符](./07_Attributes.md#mutation-modifier)
+>
+> *声明修饰符集* → [声明修饰符](./06_Declarations.md#declaration-modifier) [声明修饰符集](./06-Declarations.md#declaration-modifiers)<sub>可选</sub>
+>
+> *访问级别修饰符* → **private** | **private(set)**
+>
+> *访问级别修饰符* → **fileprivate** | **fileprivate(set)**
+>
+> *访问级别修饰符* → **internal** | **internal(set)**
+>
+> *访问级别修饰符* → **public** | **public(set)**
+>
+> *访问级别修饰符* → **open** | **open(set)**
+>
+> *可变性修饰符* → **mutating** | **nonmutating**
+>  
+
+## 属性 {#attributes}
+
+> 属性语法
+>
+> *属性* → **@** [属性名](./07_Attributes.md#attribute-name) [属性参数子句](./07-Attributes.md#attribute-argument-clause)<sub>可选</sub>
+>
+> *属性名* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+> *属性参数子句* → **{** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub>  **}**
+>
+> *属性（Attributes）集* → [属性](./07_Attributes.md#attribute) [特性](./07-Attributes.md#attributes)<sub>可选</sub>
+>
+> *平衡令牌集* → [平衡令牌](./07_Attributes.md#balanced-token) [平衡令牌集](./07-Attributes.md#balanced-tokens)<sub>可选</sub>
+>
+> *平衡令牌* → **(** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **)**
+>
+> *平衡令牌* → **[** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **]**
+>
+> *平衡令牌* → **{** [平衡令牌集](./07_Attributes.md#balanced-tokens)<sub>可选</sub> **}**
+>
+> *平衡令牌* → 任意标识符、关键字、字面量或运算符
+>
+> *平衡令牌* → 除 **(** 、**)**、**[**、**]**、**{**、**}** 外的任意标点符号
+>
+>
+
+## 模式 {#patterns}
+
+> 模式语法
+>
+> *模式* → [通配符模式](./08_Patterns.md#wildcard-pattern) [类型注解](./03-Types.md#type-annotation)<sub>可选</sub>
+>
+> *模式* → [标识符模式](./08_Patterns.md#identifier-pattern) [类型注解](./03-Types.md#type-annotati Value Bindingon )<sub>可选</sub>
+>
+> *模式* → [值绑定模式](./08_Patterns.md#value-binding-pattern)
+>
+> *模式* → [元组模式](./08_Patterns.md#tuple-pattern) [类型注解](./03-Types.md#type-annotation)<sub>可选</sub>
+>
+> *模式* → [枚举 case 模式](./08_Patterns.md#enum-case-pattern)
+>
+> *模式* → [可选模式](./08_Patterns.md#optional-pattern)
+>
+> *模式* → [类型转换模式](./08_Patterns.md#type-casting-pattern)
+>
+> *模式* → [表达式模式](./08_Patterns.md#expression-pattern)
+>
+
+<!-- -->
+
+> 通配符模式语法
+>
+> *通配符模式* → **_**
+>
+
+<!-- -->
+
+> 标识符模式语法
+>
+> *标识符模式* → [标识符](./02_Lexical_Structure.md#identifier)
+>
+
+<!-- -->
+
+> 值绑定模式语法
+>
+> *值绑定模式* → **var** [模式](./08_Patterns.md#pattern) | **let** [模式](./08-Patterns.md#pattern)
+>
+
+<!-- -->
+
+> 元组模式语法
+>
+> *元组模式* → **(** [元组模式元素集](./08_Patterns.md#tuple-pattern-element-list)<sub>可选</sub> **)**
+>
+> *元组模式元素集* → [元组模式元素](./08_Patterns.md#tuple-pattern-element) | [元组模式元素](./08-Patterns.md#tuple-pattern-element) **,** [元组模式元素集](./08-Patterns.md#tuple-pattern-element-list)
+>
+> *元组模式元素* → [模式](./08_Patterns.md#pattern) | [标识符](./02-Lexical-Structure.md#identifier) **:** [模式](./08-Patterns.md#pattern)
+>
+
+<!-- -->
+
+> 枚举 case 模式语法
+>
+> *enum-case-pattern* → [类型标识](./03_Types.md#type-identifier)<sub>可选</sub> **.** [枚举 case 名](./06-Declarations.md#enum-case-name) [元组模式](./08-Patterns.md#tuple-pattern)<sub>可选</sub>
+>
+
+<!-- -->
+> 可选模式语法
+>
+> *可选模式* → [标识符模式](./02_Lexical_Structure.md#identifier) **?**
+>
+
+<!-- -->
+
+> 类型转换模式语法
+>
+> *类型转换模式* → [is 模式](./08_Patterns.md#is-pattern) | [as 模式](./08-Patterns.md#as-pattern)
+>
+> *is 模式* → **is** [类型](./03_Types.md#type)
+>
+> *as 模式* → [模式](./08_Patterns.md#pattern) **as** [类型](./03-Types.md#type)
+>
+
+<!-- -->
+
+> 表达式模式语法
+>
+> *表达式模式* → [表达式](./04_Expressions.md#expression)
+>
+
+## 泛型参数 {#generic-parameters-and-arguments}
+
+> 泛型形参子句语法
+>
+>
+> *泛型参数子句* → **<** [泛型参数集](./09_Generic_Parameters_and_Arguments.md#generic-parameter-list) **>**
+>
+> *泛型参数集* → [泛型参数](./09_Generic_Parameters_and_Arguments.md#generic-parameter) | [泛形参数](./09-Generic-Parameters-and-Arguments.md#generic-parameter) **,** [泛型参数集](./09-Generic-Parameters-and-Arguments.md#generic-parameter-list)
+>
+> *泛形参数* → [类型名称](./03_Types.md#type-name)
+>
+> *泛形参数* → [类型名称](./03_Types.md#type-name) **:** [类型标识](./03-Types.md#type-identifier)
+>
+> *泛形参数* → [类型名称](./03_Types.md#type-name) **:** [协议合成类型](./03-Types.md#protocol-composition-type)
+>
+> *泛型 where 子句* → **where** [约束集](./09_Generic_Parameters_and_Arguments.md#requirement-list)
+>
+> *约束集* → [约束](./09_Generic_Parameters_and_Arguments.md#requirement) | [约束](./09-Generic-Parameters-and-Arguments.md#requirement) **,** [约束集](./09-Generic-Parameters-and-Arguments.md#requirement-list)
+>
+> *约束* → [一致性约束](./09_Generic_Parameters_and_Arguments.md#conformance-requirement) | [同类型约束](./09-Generic-Parameters-and-Arguments.md#same-type-requirement)
+>
+> *一致性约束* → [类型标识](./03_Types.md#type-identifier) **:** [类型标识](./03-Types.md#type-identifier)
+>
+> *一致性约束* → [类型标识](./03_Types.md#type-identifier) **:** [协议合成类型](./03-Types.md#protocol-composition-type)
+>
+> *同类型约束* → [类型标识](./03_Types.md#type-identifier) **==** [类型](./03-Types.md#type-identifier)
+>
+
+<!-- -->
+
+> 泛型实参子句语法
+>
+> *泛型实参子句* → **<** [泛型实参集](./09_Generic_Parameters_and_Arguments.md#generic-argument-list) **>**
+>
+> *泛型实参集* → [泛型实参](./09_Generic_Parameters_and_Arguments.md#generic-argument) | [泛形实参](./09-Generic-Parameters-and-Arguments.md#generic-argument) **,** [泛型实参集](./09-Generic-Parameters-and-Arguments.md#generic-argument-list)
+>
 > *泛形实参* → [类型](./03_Types.md#type)
\ No newline at end of file