andre/the-swift-programming-language-in-chinese
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

update anchor

Browse Source
This commit is contained in:
Jie Liang
2019-04-02 09:40:12 -05:00
parent 61e3a3243f
commit 5d3bf7bbcf
8 changed files with 714 additions and 357 deletions
Download Patch File Download Diff File Expand all files Collapse all files

183
source/chapter3/04_Expressions.md
View File

@ -6,10 +6,12 @@ Swift 中存在四种表达式：前缀表达式，二元表达式，基本表
> 表达式语法
>
###### expression {#expression}
#### expression {#expression}
> *表达式* → [*try 运算符*](#try-operator)<sub>可选</sub> [*前缀表达式*](#prefix-expression) [*二元表达式列表*](#binary-expressions)<sub>可选</sub>
>
###### expression-list {#expression-list}
#### expression-list {#expression-list}
> *表达式列表* → [*表达式*](#expression) | [*表达式*](#expression) **,** [*表达式列表*](#expression-list)
>
@ -24,12 +26,14 @@ Swift 中存在四种表达式：前缀表达式，二元表达式，基本表
> 前缀表达式语法
>
###### prefix-expression {#prefix-expression}
#### prefix-expression {#prefix-expression}
> *前缀表达式* → [*前缀运算符*](./02_Lexical_Structure.md#prefix-operator)<sub>可选</sub> [*后缀表达式*](#postfix-expression)
>
> *前缀表达式* → [*输入输出表达式*](#in-out-expression)
>
###### in-out-expression {#in-out-expression}
#### in-out-expression {#in-out-expression}
> *输入输出表达式* → **&** [*标识符*](./02_Lexical_Structure.md#identifier)
>
@ -66,7 +70,8 @@ sum = (try someThrowingFunction()) + anotherThrowingFunction() // 错误：try
关于 `try`、`try?` 和 `try!` 的更多信息，以及该如何使用的例子，请参阅 [错误处理](../chapter2/17_Error_Handling.md)。
> Try 表达式语法
>
###### try-operator {#try-operator}
#### try-operator {#try-operator}
> *try 运算符* → **try** | **try?** | **try!**
>
@ -85,7 +90,8 @@ sum = (try someThrowingFunction()) + anotherThrowingFunction() // 错误：try
> 在解析时，一个二元表达式将作为一个扁平列表表示，然后根据运算符的优先级，再进一步进行组合。例如，`2 + 3 * 5` 首先被看作具有五个元素的列表，即 `2`、`+`、`3`、`*`、`5`，随后根据运算符优先级组合为 `(2 + (3 * 5))`。
>
###### binary-expression {#binary-expression}
#### binary-expression {#binary-expression}
> 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*](#prefix-expression)
@ -96,7 +102,8 @@ sum = (try someThrowingFunction()) + anotherThrowingFunction() // 错误：try
>
> *二元表达式* → [*类型转换运算符*](#type-casting-operator)
>
###### binary-expressions {#binary-expressions}
#### binary-expressions {#binary-expressions}
> *二元表达式列表* → [*二元表达式*](#binary-expression) [*二元表达式列表*](#binary-expressions)<sub>可选</sub>
>
@ -117,7 +124,8 @@ sum = (try someThrowingFunction()) + anotherThrowingFunction() // 错误：try
> 赋值运算符语法
>
###### assignment-operator {#assignment-operator}
#### assignment-operator {#assignment-operator}
> *赋值运算符* → **=**
>
@ -133,7 +141,8 @@ sum = (try someThrowingFunction()) + anotherThrowingFunction() // 错误：try
> 三元条件运算符语法
>
###### conditional-operator {#conditional-operator}
#### conditional-operator {#conditional-operator}
> *三元条件运算符* → **?** [*表达式*](#expression) **:**
>
@ -176,7 +185,8 @@ f(x as Any)
关于类型转换的更多内容和例子，请参阅 [类型转换](../chapter2/18_Type_Casting.md)。
###### type-casting-operator {#type-casting-operator}
#### type-casting-operator {#type-casting-operator}
> 类型转换运算符语法
>
> *类型转换运算符* → **is** [*类型*](./03_Types.md#type)
@ -193,7 +203,8 @@ f(x as Any)
> 基本表达式语法
>
###### primary-expression {#primary-expression}
#### primary-expression {#primary-expression}
> *基本表达式* → [*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>
>
> *基本表达式* → [*字面量表达式*](#literal-expression)
@ -269,7 +280,8 @@ Xcode 使用 playground 字面量对程序编辑器中的颜色、文件或者
> 字面量表达式语法
>
>
> ###### literal-expression {#literal-expression}
>
#### literal-expression {#literal-expression}
>
> *字面量表达式* → [*字面量*](./02_Lexical_Structure.md#literal)
>
@ -279,38 +291,46 @@ Xcode 使用 playground 字面量对程序编辑器中的颜色、文件或者
>
> ###### array-literal {#array-literal}
>
#### array-literal {#array-literal}
>
> *数组字面量* → [[*数组字面量项列表*](#array-literal-items)<sub>可选</sub> **]**
>
> ###### array-literal-items {#array-literal-items}
>
#### array-literal-items {#array-literal-items}
>
> *数组字面量项列表* → [*数组字面量项*](#array-literal-item) **,**<sub>可选</sub> | [*数组字面量项*](#array-literal-item) **,** [*数组字面量项列表*](#array-literal-items)
>
> ###### array-literal-item {#array-literal-item}
>
#### array-literal-item {#array-literal-item}
>
> *数组字面量项* → [*表达式*](#expression)
>
>
> ###### dictionary-literal {#dictionary-literal}
>
#### dictionary-literal {#dictionary-literal}
>
> *字典字面量* → [[*字典字面量项列表*](#dictionary-literal-items) **]** | **[** **:** **]**
>
> ###### dictionary-literal-items {#dictionary-literal-items}
>
#### dictionary-literal-items {#dictionary-literal-items}
>
> *字典字面量项列表* → [*字典字面量项*](#dictionary-literal-item) **,**<sub>可选</sub> | [*字典字面量项*](#dictionary-literal-item) **,** [*字典字面量项列表*](#dictionary-literal-items)
>
> ###### dictionary-literal-item {#dictionary-literal-item}
>
#### dictionary-literal-item {#dictionary-literal-item}
>
> *字典字面量项* → [*表达式*](#expression) **:** [*表达式*](#expression)。
>
> ###### playground-literal {#playground-literal}
>
#### playground-literal {#playground-literal}
>
> *playground 字面量* → **#colorLiteral ( red : [*表达式*](#expression) , green :[*表达式*](#expression) [*表达式*](#e[*表达式*](#expression) xpression) , blue :[*表达式*](#expression) , alpha : [*表达式*](#expression) )**
>
> *playground 字面量* → **#fileLiteral ( resourceName : [*表达式*](#expression) )**
>
> ###### playground 字面量* → **#imageLiteral ( resourceName : [*表达式*](#expression) )**self_expression {#self_expression}
>
#### playground 字面量* → **#imageLiteral ( resourceName : [*表达式*](#expression) )**self_expression {#self_expression}
>
### Self 表达式
@ -354,17 +374,21 @@ struct Point {
> Self 表达式语法
>
###### self-expression {#self-expression}
#### self-expression {#self-expression}
> *self 表达式* → **self** | [*self 方法表达式*](#self-method-expression) ｜ [*self 下标表达式*](#self-subscript-expression) | [*self 构造器表达式*](#self-initializer-expression)
>
>
###### self-method-expression {#self-method-expression}
#### self-method-expression {#self-method-expression}
> *self 方法表达式* → **self** **.** [*标识符*](./02_Lexical_Structure.md#identifier)
>
###### self-subscript-expression {#self-subscript-expression}
#### self-subscript-expression {#self-subscript-expression}
> *self 下标表达式* → **self** **[** [*函数调用参数表*](#function-call-argument-list­) **]**
>
###### self-initializer-expression {#self-initializer-expression}
#### self-initializer-expression {#self-initializer-expression}
> *self 构造器表达式* → **self** **.** **init**
>
@ -384,16 +408,20 @@ struct Point {
> 父类表达式语法
>
###### superclass-expression {#superclass-expression}
#### superclass-expression {#superclass-expression}
> *父类表达式* → [*父类方法表达式*](#superclass-method-expression) | [*父类下标表达式*](#superclass-subscript-expression) | [*父类构造器表达式*](#superclass-initializer-expression)
>
###### superclass-method-expression {#superclass-method-expression}
#### superclass-method-expression {#superclass-method-expression}
> *父类方法表达式* → **super** **.** [*标识符*](./02_Lexical_Structure.md#identifier)
>
###### superclass-subscript-expression {#superclass-subscript-expression}
#### superclass-subscript-expression {#superclass-subscript-expression}
> *父类下标表达式* → **super** [[*函数调用参数表*](#function-call-argument-list­) **]**
>
###### superclass-initializer-expression {#superclass-initializer-expression}
#### superclass-initializer-expression {#superclass-initializer-expression}
> *父类构造器表达式* → **super** **.** **init**
>
@ -501,12 +529,14 @@ myFunction { [weak parent = self.parent] in print(parent!.title) }
> 闭包表达式语法
>
>
> ###### closure-expression {#closure-expression}
>
#### closure-expression {#closure-expression}
>
> *闭包表达式* → **{** [*闭包签名*](#closure-signature)<sub>可选</sub> [*语句*](#statements) **}**
>
>
> ###### closure-signature {#closure-signature}
>
#### closure-signature {#closure-signature}
>
>
> 闭包签名* → [*参数子句*](#parameter-clause) [*函数结果*](05_Declarations.md#function-result)<sub>可选</sub> **in**
@ -520,20 +550,24 @@ myFunction { [weak parent = self.parent] in print(parent!.title) }
> *闭包签名* → [*捕获列表*](#capture-list) **in**
>
>
> ###### capture-list {#capture-list}
>
#### capture-list {#capture-list}
>
>
> 捕获列表* → [ [*捕获列表项列表*](#capture-list-items) **]**
>
> ###### capture-list-items {#capture-list-items}
>
#### capture-list-items {#capture-list-items}
>
> *捕获列表项列表* → [*捕获列表项*](#capture-list-item) | [*捕获列表项*](#capture-list-item) **,** [*捕获列表项列表*](#capture-list-items)
>
> ###### capture-list-item {#capture-list-item}
>
#### capture-list-item {#capture-list-item}
>
> *捕获列表项* → [*捕获说明符*](#capture-specifier)<sub>可选</sub> [*表达式*](#expression)
>
> ###### capture-specifier {#capture-specifier}
>
#### capture-specifier {#capture-specifier}
>
> *捕获说明符* → **weak** | **unowned** | **unowned(safe)** | **unowned(unsafe)**
>
@ -553,7 +587,8 @@ x = .AnotherValue
> 隐式成员表达式语法
>
###### implicit-member-expression {#implicit-member-expression}
#### implicit-member-expression {#implicit-member-expression}
> *隐式成员表达式* → **.** [*标识符*](./02_Lexical_Structure.md#identifier)
>
@ -562,7 +597,8 @@ x = .AnotherValue
> 圆括号表达式语法
>
###### parenthesized-expression {#parenthesized-expression}
#### parenthesized-expression {#parenthesized-expression}
> *圆括号表达式* → **( [*表达式*](#expression) )**
>
@ -583,13 +619,16 @@ x = .AnotherValue
> 元组表达式语法
>
###### tuple-expression {#tuple-expression}
#### tuple-expression {#tuple-expression}
> *元组表达式* → **( )** | **(**[*元组元素*](#tuple-element)， [*元组元素列表*](#tuple-element-list) **)**
>
###### tuple-element-list {#tuple-element-list}
#### tuple-element-list {#tuple-element-list}
> *元组元素列表* → [*元组元素*](#tuple-element) | [*元组元素*](#tuple-element) **,** [*元组元素列表*](#tuple-element-list)
>
###### tuple-element {#tuple-element}
#### tuple-element {#tuple-element}
> *元组元素* → [*表达式*](#expression) | [*标识符*](identifier) **:** [*表达式*](#expression)
>
@ -603,7 +642,8 @@ x = .AnotherValue
> 通配符表达式语法
>
###### wildcard-expression {#wildcard-expression}
#### wildcard-expression {#wildcard-expression}
> *通配符表达式* → **_**
>
@ -740,21 +780,26 @@ print(interestingNumbers[keyPath: \[String: [Int]].["hexagonal"]!.count.bitWidth
> key-path 表达式语法
>
>
> ###### key-path-expression {#key-path-expression}
>
#### key-path-expression {#key-path-expression}
>
> *key-path 表达式* → **\\** [类型](./03_Types.md#type)<sub>可选</sub> **.** [多个 key-path 组件](#key-path-components)
>
> ###### key-path-components {#key-path-components}
>
#### key-path-components {#key-path-components}
>
> *多个 key-path 组件* → [key-path 组件](#key-path-component) | [key-path 组件](#key-path-component) **.** [多个 key-path 组件](#key-path-components)
>
> ###### key-path-component {#key-path-component}
>
#### key-path-component {#key-path-component}
>
> *key-path 组件* → [标识符](./02_Lexical_Structure.md#identifier) [多个 key-path 后缀](#key-path-postfixes)<sub>可选<sub> | [多个 key-path 后缀](#key-path-postfixes)
>
> ###### key-path-postfixes {#key-path-postfixes}
>
> ###### *多个 key-path 后缀* → [key-path 后缀](#key-path-postfix) [多个 key-path 后缀](#key-path-postfixes)<sub>可选<sub> key-path-postfixes {#key-path-postfixes}
#### key-path-postfixes {#key-path-postfixes}
>
>
#### *多个 key-path 后缀* → [key-path 后缀](#key-path-postfix) [多个 key-path 后缀](#key-path-postfixes)<sub>可选<sub> key-path-postfixes {#key-path-postfixes}
>
> *key-path 后缀* → **?** | **!** | **self** | **\[** [函数调用参数表](#function-call-argument-list) **\]**
>
@ -809,7 +854,8 @@ let anotherSelector = #selector(SomeClass.doSomething(_:) as (SomeClass) -> (Str
> 选择器表达式语法
>
###### selector-expression {#selector-expression}
#### selector-expression {#selector-expression}
> *选择器表达式* → __#selector__ **(** [*表达式*](#expression) **)**
>
> *选择器表达式* → __#selector__ **(** [*getter:表达式*](#expression) **)**
@ -867,7 +913,8 @@ print(keyPath == c.getSomeKeyPath())
> key-path 字符串表达式语法
>
> ###### key-path-string-expression {#key-path-string-expression}
>
#### key-path-string-expression {#key-path-string-expression}
>
> *key-path 字符串表达式* → **#keyPath (** [表达式](#expression) **)**
>
@ -881,7 +928,8 @@ print(keyPath == c.getSomeKeyPath())
> 后缀表达式语法
>
###### postfix-expression {#postfix-expression}
#### postfix-expression {#postfix-expression}
> *后缀表达式* → [*基本表达式*](#primary-expression)
>
> *后缀表达式* → [*后缀表达式*](#postfix-expression) [*后缀运算符*](02_Lexical_Structure.md#postfix-operator)
@ -934,29 +982,34 @@ myData.someMethod {$0 == 13}
> 函数调用表达式语法
>
> ###### function-call-expression {#function-call-expression}
>
#### function-call-expression {#function-call-expression}
>
> *函数调用表达式* → [*后缀表达式*](#postfix-expression) [*函数调用参数子句*](#function-call-argument-clause)
>
> *函数调用表达式* → [*后缀表达式*](#postfix-expression) [*函数调用参数子句*](#function-call-argument-clause)<sub>可选</sub> [*尾随闭包*](#trailing-closure)
>
>
> ###### function-call-argument-clause {#function-call-argument-clause}
>
#### function-call-argument-clause {#function-call-argument-clause}
>
> *函数调用参数子句* → **(** **)** | **(** [*函数调用参数表*](#function-call-argument-list) **)**
>
> ###### function-call-argument-list {#function-call-argument-list}
>
#### function-call-argument-list {#function-call-argument-list}
>
> *函数调用参数表* → [函数调用参数](#function-call-argument) | [函数调用参数](#function-call-argument) **,** [*函数调用参数表*](#function-call-argument-list)
>
> ###### function-call-argument {#function-call-argument}
>
#### function-call-argument {#function-call-argument}
>
> *函数调用参数* → [表达式](#expression) | [标识符](02_Lexical_Structure.md#identifier) **:** [*表达式*](#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)
>
>
> ###### trailing-closure {#trailing-closure}
>
#### trailing-closure {#trailing-closure}
>
> *尾随闭包* → [*闭包表达式*](#closure-expression)
>
@ -1001,7 +1054,8 @@ let s3 = someValue.dynamicType.init(data: 7) // 有效
> 构造器表达式语法
>
###### initializer-expression {#initializer-expression}
#### initializer-expression {#initializer-expression}
> *构造器表达式* → [*后缀表达式*](#postfix-expression) **.** **init**
>
> *构造器表达式* → [*后缀表达式*](#postfix-expression) **.** **init** **(** [*参数名称*](#argument-names) **)**
@ -1067,17 +1121,20 @@ let x = [10, 3, 20, 15, 4]
> 显式成员表达式语法
>
###### explicit-member-expression {#explicit-member-expression}
#### explicit-member-expression {#explicit-member-expression}
> *显式成员表达式* → [*后缀表达式*](#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*](#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*](#postfix-expression) **.** [*标识符*] (02_Lexical_Structure.md#identifier) **(** [*参数名称*](#argument-names) **)**
>
###### argument-names {#argument-names}
#### argument-names {#argument-names}
> *参数名称* → [*参数名*](#argument-name) [*参数名称*](#argument-names)<sub>可选</sub><br/>
>
###### argument-name {#argument-name}
#### argument-name {#argument-name}
> *参数名* → [*标识符*](./02_Lexical_Structure.md#identifier) **:**
>
@ -1095,7 +1152,8 @@ let x = [10, 3, 20, 15, 4]
> 后缀 self 表达式语法
>
###### postfix-self-expression {#postfix-self-expression}
#### postfix-self-expression {#postfix-self-expression}
> *后缀 self 表达式* → [*后缀表达式*](#postfix-expression) **.** **self**
>
@ -1112,7 +1170,8 @@ let x = [10, 3, 20, 15, 4]
> 下标表达式语法
>
###### subscript-expression {#subscript-expression}
#### subscript-expression {#subscript-expression}
> *下标表达式* → [*后缀表达式*](#postfix-expression) **[** [*表达式列表*](#expression-list) **]**
>
@ -1138,7 +1197,8 @@ someDictionary["a"]![0] = 100
> 强制取值语法
>
###### forced-value-expression {#forced-value-expression}
#### forced-value-expression {#forced-value-expression}
> *强制取值表达式* → [*后缀表达式*](#postfix-expression) **!**
>
@ -1190,6 +1250,7 @@ someDictionary["a"]?[0] = someFunctionWithSideEffects()
> 可选链表达式语法
>
###### optional-chaining-expression {#optional-chaining-expression}
#### optional-chaining-expression {#optional-chaining-expression}
> *可选链表达式* → [*后缀表达式*](#postfix-expression) **?**
>