fix 3.4 expressions
This commit is contained in:
@ -1,6 +1,5 @@
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> 翻译:sg552
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> 校对:numbbbbb
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> 翻译:sg552
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> 校对:numbbbbb, stanzhai
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# 表达式(Expressions)
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-----------------
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@ -19,10 +18,9 @@ Swift 中存在四种表达式: 前缀(prefix)表达式,二元(binary
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前缀表达式和二元表达式就是对某些表达式使用各种运算符(operators)。 主要表达式是最短小的表达式,它提供了获取(变量的)值的一种途径。 后缀表达式则允许你建立复杂的表达式,例如配合函数调用和成员访问。 每种表达式都在下面有详细论述~
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> 表达式的语法
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>
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> *expression* → *prefix-expression**binary-expressions(*opt)
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> *expression-list* → *expression*| *expression*,*expression-list*
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> 表达式语法
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> *表达式* → [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression) [*二元表达式列表*](..\chapter3\04_Expressions.html#binary_expressions) _可选_
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> *表达式列表* → [*表达式*](..\chapter3\04_Expressions.html#expression) | [*表达式*](..\chapter3\04_Expressions.html#expression) **,** [*表达式列表*](..\chapter3\04_Expressions.html#expression_list)
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<a name="prefix_expressions"></a>
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## 前缀表达式(Prefix Expressions)
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@ -42,18 +40,17 @@ Swift 标准库支持如下的前缀操作符:
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作为对上面标准库运算符的补充,你也可以对 某个函数的参数使用 '&'运算符。 更多信息,请参见: "In-Out parameters".
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> 前缀表达式的语法
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>
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> *prefix-expression* → *prefix-operator* (opt) *postfix-expression*
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> *prefix-expression* → *in-out-expression*
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> *in-out-expression* → &*identifier*
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> 前置表达式语法
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> *前置表达式* → [*前置运算符*](LexicalStructure.html#prefix_operator) _可选_ [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression)
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> *前置表达式* → [*写入写出(in-out)表达式*](..\chapter3\04_Expressions.html#in_out_expression)
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> *写入写出(in-out)表达式* → **&** [*标识符*](LexicalStructure.html#identifier)
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<a name="binary_expressions"></a>
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## 二元表达式(Binary Expressions)
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二元表达式由 "左边参数" + "二元运算符" + "右边参数" 组成, 它有如下的形式:
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`left-hand argument` `operator` `right-hand argument`
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> `left-hand argument` `operator` `right-hand argument`
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Swift 标准库提供了如下的二元运算符:
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@ -114,17 +111,18 @@ Swift 标准库提供了如下的二元运算符:
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关于这些运算符(operators)的更多信息,请参见:Basic Operators and Advanced Operators.
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>> 注意
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>>
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>> 在解析时, 一个二元表达式表示为一个一级数组(a flat list), 这个数组(List)根据运算符的先后顺序,被转换成了一个tree. 例如: 2 + 3 * 5 首先被认为是: 2, + , `` 3``, *, 5. 随后它被转换成 tree (2 + (3 * 5))
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> 注意
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> 在解析时, 一个二元表达式表示为一个一级数组(a flat list), 这个数组(List)根据运算符的先后顺序,被转换成了一个tree. 例如: 2 + 3 * 5 首先被认为是: 2, + , `` 3``, *, 5. 随后它被转换成 tree (2 + (3 * 5))
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<p></p>
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> 二元表达式语法
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> *二元表达式* → [*二元运算符*](LexicalStructure.html#binary_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
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> *二元表达式* → [*赋值运算符*](..\chapter3\04_Expressions.html#assignment_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
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> *二元表达式* → [*条件运算符*](..\chapter3\04_Expressions.html#conditional_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
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> *二元表达式* → [*类型转换运算符*](..\chapter3\04_Expressions.html#type_casting_operator)
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> *二元表达式列表* → [*二元表达式*](..\chapter3\04_Expressions.html#binary_expression) [*二元表达式列表*](..\chapter3\04_Expressions.html#binary_expressions) _可选_
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> 二元表达式的语法
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>
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> *binary-expression* → *binary-operator**prefix-expression*
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> *binary-expression* → *assignment-operator*prefix-expression*
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> *binary-expression* → *conditional-operator*prefix-expression*
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> *binary-expression* → *type-casting-operator*
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> *binary-expression*s → *binary-expression**binary-expressions*(opt)
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<a name="assignment_operator"></a>
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## 赋值表达式(Assignment Operator)
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@ -132,7 +130,7 @@ Swift 标准库提供了如下的二元运算符:
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The assigment operator sets a new value for a given expression. It has the following form:
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赋值表达式会对某个给定的表达式赋值。 它有如下的形式;
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`expression` = `value`
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> `expression` = `value`
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就是把右边的 *value* 赋值给左边的 *expression*. 如果左边的*expression* 需要接收多个参数(是一个tuple ),那么右边必须也是一个具有同样数量参数的tuple. (允许嵌套的tuple)
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@ -143,40 +141,36 @@ The assigment operator sets a new value for a given expression. It has the follo
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赋值运算符不返回任何值。
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> 赋值表达式的语法
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>
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> *assignment-operator* → =
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> 赋值运算符语法
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> *赋值运算符* → **=**
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<a name="ternary_conditional_operator"></a>
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## 三元条件运算符(Ternary Conditional Operator)
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三元条件运算符 是根据条件来获取值。 形式如下:
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`condition` ? `expression used if true` : `expression used if false`
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> `condition` ? `expression used if true` : `expression used if false`
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如果 `condition` 是true, 那么返回 第一个表达式的值(此时不会调用第二个表达式), 否则返回第二个表达式的值(此时不会调用第一个表达式)。
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想看三元条件运算符的例子,请参见: Ternary Conditional Operator.
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> 三元条件表达式
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>
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> `conditional-operator` → ?`expression`:
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> 三元条件运算符语法
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> *三元条件运算符* → **?** [*表达式*](..\chapter3\04_Expressions.html#expression) **:**
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<a name="type-casting_operators"></a>
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## 类型转换运算符(Type-Casting Operators)
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有两种类型转换操作符: as 和 is. 它们有如下的形式:
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`expression` as `type`
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`expression` as? `type`
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`expression` is `type`
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> `expression` as `type`
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> `expression` as? `type`
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> `expression` is `type`
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as 运算符会把`目标表达式`转换成指定的`类型`(specified type),过程如下:
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- 如果类型转换成功, 那么目标表达式就会返回指定类型的实例(instance). 例如:把子类(subclass)变成父类(superclass)时.
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- 如果转换失败,则会抛出编译错误( compile-time error)。
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- 如果上述两个情况都不是(也就是说,编译器在编译时期无法确定转换能否成功,) 那么目标表达式就会变成指定的类型的optional. (is an optional of the specified type ) 然后在运行时,如果转换成功, 目标表达式就会作为 optional的一部分来返回, 否则,目标表达式返回nil. 对应的例子是: 把一个 superclass 转换成一个 subclass.
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```swift
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@ -209,25 +203,23 @@ The check must not be known to be true or false at compile time. The following a
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关于类型转换的更多内容和例子,请参见: Type Casting.
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> 类型转换的语法
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>
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> *type-casting-operator* → is*type*| as?(opt)*type*
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> 类型转换运算符(type-casting-operator)语法
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> *类型转换运算符* → **is** [*类型*](..\chapter3\03_Types.html#type) | **as** **?** _可选_ [*类型*](..\chapter3\03_Types.html#type)
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<a name="primary_expressions"></a>
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## 主要表达式(Primary Expressions)
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## 主表达式(Primary Expressions)
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`主要表达式`是最基本的表达式。 它们可以跟 前缀表达式,二元表达式,后缀表达式以及其他主要表达式组合使用。
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`主表达式`是最基本的表达式。 它们可以跟 前缀表达式,二元表达式,后缀表达式以及其他主要表达式组合使用。
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> 主要表达式的语法
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>
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> *primary-expression* → *identifier**generic-argument-clause*(opt)
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> *primary-expression* → *literal-expression*
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> *primary-expression* → *self-expression*
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> *primary-expression* → *superclass-expression*
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> *primary-expression* → *closure-expression*
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> *primary-expression* → *parenthesized-expression*
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> *primary-expression* → *implicit-member-expression*
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> *primary-expression* → *wildcard-expression*
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> 主表达式语法
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> *主表达式* → [*标识符*](LexicalStructure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
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> *主表达式* → [*字面量表达式*](..\chapter3\04_Expressions.html#literal_expression)
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> *主表达式* → [*self表达式*](..\chapter3\04_Expressions.html#self_expression)
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> *主表达式* → [*超类表达式*](..\chapter3\04_Expressions.html#superclass_expression)
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> *主表达式* → [*闭包表达式*](..\chapter3\04_Expressions.html#closure_expression)
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> *主表达式* → [*圆括号表达式*](..\chapter3\04_Expressions.html#parenthesized_expression)
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> *主表达式* → [*隐式成员表达式*](..\chapter3\04_Expressions.html#implicit_member_expression)
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> *主表达式* → [*通配符表达式*](..\chapter3\04_Expressions.html#wildcard_expression)
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### 字符型表达式(Literal Expression)
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@ -244,37 +236,36 @@ The check must not be known to be true or false at compile time. The following a
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一个array literal,是一个有序的值的集合。 它的形式是:
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[`value 1`, `value 2`, `...`]
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> [`value 1`, `value 2`, `...`]
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数组中的最后一个表达式可以紧跟一个逗号(','). []表示空数组 。 array literal的type是 T[], 这个T就是数组中元素的type. 如果该数组中有多种type, T则是跟这些type的公共supertype最接近的type.(closest common supertype)
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一个`dictionary literal` 是一个包含无序的键值对(key-value pairs)的集合,它的形式是:
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[`key 1`: `value 1`, `key 2`: `value 2`, `...`]
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> [`key 1`: `value 1`, `key 2`: `value 2`, `...`]
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dictionary 的最后一个表达式可以是一个逗号(','). [:] 表示一个空的dictionary. 它的type是 Dictionary<KeyType, ValueType> (这里KeyType表示 key的type, ValueType表示 value的type) 如果这个dictionary 中包含多种 types, 那么KeyType, Value 则对应着它们的公共supertype最接近的type( closest common supertype).
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> 字符型表达式的语法
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>
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> *literal-expression* → *literal*
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> *literal-expression* → *array-literal*| *dictionary-literal*
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> *literal-expression* → *\__FILE__*| *\__LINE__*| *\__COLUMN__*| *\__FUNCTION__*
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> *array-literal* → [*array-literal-items*opt]
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> *array-literal-items* → *array-literal-item*,(opt) | *array-literal-item*,*array-literal-items*
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> *array-literal-item* → *expression*
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> *dictionary-literal* → [*dictionary-literal-items*] [:]
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> *dictionary-literal-items* → *dictionary-literal-item*,(opt)| *dictionary-literal-item*,*dictionary-literal-items*
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> *dictionary-literal-item* → *expression*:*expression*
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> 字面量表达式语法
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> *字面量表达式* → [*字面量*](LexicalStructure.html#literal)
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> *字面量表达式* → [*数组字面量*](..\chapter3\04_Expressions.html#array_literal) | [*字典字面量*](..\chapter3\04_Expressions.html#dictionary_literal)
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> *字面量表达式* → **__FILE__** | **__LINE__** | **__COLUMN__** | **__FUNCTION__**
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> *数组字面量* → **[** [*数组字面量项列表*](..\chapter3\04_Expressions.html#array_literal_items) _可选_ **]**
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> *数组字面量项列表* → [*数组字面量项*](..\chapter3\04_Expressions.html#array_literal_item) **,** _可选_ | [*数组字面量项*](..\chapter3\04_Expressions.html#array_literal_item) **,** [*数组字面量项列表*](..\chapter3\04_Expressions.html#array_literal_items)
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> *数组字面量项* → [*表达式*](..\chapter3\04_Expressions.html#expression)
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> *字典字面量* → **[** [*字典字面量项列表*](..\chapter3\04_Expressions.html#dictionary_literal_items) **]** | **[** **:** **]**
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> *字典字面量项列表* → [*字典字面量项*](..\chapter3\04_Expressions.html#dictionary_literal_item) **,** _可选_ | [*字典字面量项*](..\chapter3\04_Expressions.html#dictionary_literal_item) **,** [*字典字面量项列表*](..\chapter3\04_Expressions.html#dictionary_literal_items)
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> *字典字面量项* → [*表达式*](..\chapter3\04_Expressions.html#expression) **:** [*表达式*](..\chapter3\04_Expressions.html#expression)
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### self表达式(Self Expression)
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self表达式是对 当前type 或者当前instance的引用。它的形式如下:
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> self
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> self.`member name`
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> self[`subscript index`]
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> self(`initializer arguments`)
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> self.init(`initializer arguments`)
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> self
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> self.`member name`
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> self[`subscript index`]
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> self(`initializer arguments`)
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> self.init(`initializer arguments`)
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如果在 initializer, subscript, instance method中,self等同于当前type的instance. 在一个静态方法(static method), 类方法(class method)中, self等同于当前的type.
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@ -301,40 +292,38 @@ struct Point {
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}
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```
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> self表达式的语法
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>
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> *self-expression* → self
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> *self-expression* → self.*identifier*
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> *self-expression* → self[*expression*]
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> *self-expression* → self.init
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> Self 表达式语法
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> *self表达式* → **self**
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> *self表达式* → **self** **.** [*标识符*](LexicalStructure.html#identifier)
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> *self表达式* → **self** **[** [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
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> *self表达式* → **self** **.** **init**
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### 超类表达式(Superclass Expression)
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超类表达式可以使我们在某个class中访问它的超类. 它有如下形式:
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super.`member name`
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super[`subscript index`]
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super.init(`initializer arguments`)
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> super.`member name`
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> super[`subscript index`]
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> super.init(`initializer arguments`)
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形式1 用来访问超类的某个成员(member). 形式2 用来访问该超类的 subscript 实现。 形式3 用来访问该超类的 initializer.
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子类(subclass)可以通过超类(superclass)表达式在它们的 member, subscripting 和 initializers 中来利用它们超类中的某些实现(既有的方法或者逻辑)。
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> GRAMMAR OF A SUPERCLASS EXPRESSION
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> *superclass-expression* → *superclass-method-expression* | *superclass-subscript-expression*| *superclass-initializer-expression*
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> *superclass-method-expression* → super.*identifier*
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> *superclass-subscript-expression* → super[*expression*]
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> *superclass-initializer-expression* → super.init
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> 超类(superclass)表达式语法
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> *超类表达式* → [*超类方法表达式*](..\chapter3\04_Expressions.html#superclass_method_expression) | [*超类下标表达式*](..\chapter3\04_Expressions.html#超类下标表达式) | [*超类构造器表达式*](..\chapter3\04_Expressions.html#superclass_initializer_expression)
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> *超类方法表达式* → **super** **.** [*标识符*](LexicalStructure.html#identifier)
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> *超类下标表达式* → **super** **[** [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
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> *超类构造器表达式* → **super** **.** **init**
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### 闭包表达式(Closure Expression)
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闭包(closure) 表达式可以建立一个闭包(在其他语言中也叫 lambda, 或者 匿名函数(anonymous function)). 跟函数(function)的声明一样, 闭包(closure)包含了可执行的代码(跟方法主体(statement)类似) 以及接收(capture)的参数。 它的形式如下:
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```swift
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{ (parameters) -> return type in
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statements
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}
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{ (parameters) -> return type in
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statements
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}
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```
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闭包的参数声明形式跟方法中的声明一样, 请参见:Function Declaration.
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@ -384,22 +373,21 @@ myFunction { [weak parent = self.parent] in print(parent!.title) }
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关于闭包表达式的更多信息和例子,请参见: Closure Expressions.
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> 闭包表达式的语法
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>
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> *closure-expression* → {*closure-signature*opt*statements*}
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> *closure-signature* → *parameter-clause**function-result*(opt)in
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> *closure-signature* → *identifier-list**function-result*(opt)in
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> *closure-signature* → *capture-list**parameter-clause**function-result*(opt)in
|
||||
> *closure-signature* → *capture-list**identifier-list**function-result*(opt)in
|
||||
> *closure-signature* → *capture-list*in
|
||||
> *capture-list* → [*capture-specifier**expression*]
|
||||
> *capture-specifier* → weak| unowned| unowned(safe)| unowned(unsafe)
|
||||
> 闭包表达式语法
|
||||
> *闭包表达式* → **{** [*闭包签名(Signational)*](..\chapter3\04_Expressions.html#closure_signature) _可选_ [*多条语句(Statements)*](..\chapter3\10_Statements.html#statements) **}**
|
||||
> *闭包签名(Signational)* → [*参数子句*](..\chapter3\05_Declarations.html#parameter_clause) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*标识符列表*](LexicalStructure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) [*参数子句*](..\chapter3\05_Declarations.html#parameter_clause) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) [*标识符列表*](LexicalStructure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) **in**
|
||||
> *捕获(Capature)列表* → **[** [*捕获(Capature)说明符*](..\chapter3\04_Expressions.html#capture_specifier) [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
|
||||
> *捕获(Capature)说明符* → **weak** | **unowned** | **unowned(safe)** | **unowned(unsafe)**
|
||||
|
||||
### 隐式成员表达式(Implicit Member Expression)
|
||||
|
||||
在可以判断出类型(type)的上下文(context)中,隐式成员表达式是访问某个type的member( 例如 class method, enumeration case) 的简洁方法。 它的形式是:
|
||||
|
||||
.`member name`
|
||||
> .`member name`
|
||||
|
||||
例子:
|
||||
|
||||
@ -408,23 +396,21 @@ var x = MyEnumeration.SomeValue
|
||||
x = .AnotherValue
|
||||
```
|
||||
|
||||
> 隐式成员表达式的语法
|
||||
>
|
||||
> *implicit-member-expression* → .*identifier*
|
||||
> 隐式成员表达式语法
|
||||
> *隐式成员表达式* → **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
### 圆括号表达式(Parenthesized Expression)
|
||||
|
||||
圆括号表达式由多个子表达式和逗号','组成。 每个子表达式前面可以有 identifier x: 这样的可选前缀。形式如下:
|
||||
|
||||
(`identifier 1`: `expression 1`, `identifier 2`: `expression 2`, `...`)
|
||||
>(`identifier 1`: `expression 1`, `identifier 2`: `expression 2`, `...`)
|
||||
|
||||
圆括号表达式用来建立tuples , 然后把它做为参数传递给 function. 如果某个圆括号表达式中只有一个 子表达式,那么它的type就是 子表达式的type。例如: (1)的 type是Int, 而不是(Int)
|
||||
|
||||
> 圆括号表达式的语法
|
||||
>
|
||||
> *parenthesized-expression* → (*expression-element-list* (opt))
|
||||
> *expression-element-list* → *expression-element*| *expression-element*,*expression-element-list*
|
||||
> *expression-element* → *expression*| *identifier*:*expression*
|
||||
> 圆括号表达式(Parenthesized Expression)语法
|
||||
> *圆括号表达式* → **(** [*表达式元素列表*](..\chapter3\04_Expressions.html#expression_element_list) _可选_ **)**
|
||||
> *表达式元素列表* → [*表达式元素*](..\chapter3\04_Expressions.html#expression_element) | [*表达式元素*](..\chapter3\04_Expressions.html#expression_element) **,** [*表达式元素列表*](..\chapter3\04_Expressions.html#expression_element_list)
|
||||
> *表达式元素* → [*表达式*](..\chapter3\04_Expressions.html#expression) | [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) **:** [*表达式*](..\chapter3\04_Expressions.html#expression)
|
||||
|
||||
### 通配符表达式(Wildcard Expression)
|
||||
|
||||
@ -435,9 +421,8 @@ x = .AnotherValue
|
||||
// x is 10, 20 is ignored
|
||||
```
|
||||
|
||||
> 通配符表达式的语法
|
||||
>
|
||||
> *wildcard-expression* → _
|
||||
> 通配符表达式语法
|
||||
> *通配符表达式* → **_**
|
||||
|
||||
<a name="postfix_expressions"></a>
|
||||
## 后缀表达式(Postfix Expressions)
|
||||
@ -451,31 +436,30 @@ Swift 标准库提供了下列后缀表达式:
|
||||
|
||||
对于这些操作符的使用,请参见: Basic Operators and Advanced Operators
|
||||
|
||||
> 后缀表达式的语法
|
||||
>
|
||||
> *postfix-expression* → *primary-expression*
|
||||
> *postfix-expression* → *postfix-expression**postfix-operator*
|
||||
> *postfix-expression* → *function-call-expression*
|
||||
> *postfix-expression* → *initializer-expression*
|
||||
> *postfix-expression* → *explicit-member-expression*
|
||||
> *postfix-expression* → *postfix-self-expression*
|
||||
> *postfix-expression* → *dynamic-type-expression*
|
||||
> *postfix-expression* → *subscript-expression*
|
||||
> *postfix-expression* → *forced-value-expression*
|
||||
> *postfix-expression* → *optional-chaining-expression*
|
||||
> 后置表达式语法
|
||||
> *后置表达式* → [*主表达式*](..\chapter3\04_Expressions.html#primary_expression)
|
||||
> *后置表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) [*后置运算符*](..\chapter3\02_Lexical_Structure.html#postfix_operator)
|
||||
> *后置表达式* → [*函数调用表达式*](..\chapter3\04_Expressions.html#function_call_expression)
|
||||
> *后置表达式* → [*构造器表达式*](..\chapter3\04_Expressions.html#initializer_expression)
|
||||
> *后置表达式* → [*显示成员表达式*](..\chapter3\04_Expressions.html#explicit_member_expression)
|
||||
> *后置表达式* → [*后置self表达式*](..\chapter3\04_Expressions.html#postfix_self_expression)
|
||||
> *后置表达式* → [*动态类型表达式*](..\chapter3\04_Expressions.html#dynamic_type_expression)
|
||||
> *后置表达式* → [*下标表达式*](..\chapter3\04_Expressions.html#subscript_expression)
|
||||
> *后置表达式* → [*强制取值(Forced Value)表达式*](..\chapter3\04_Expressions.html#forced_value_expression)
|
||||
> *后置表达式* → [*可选链(Optional Chaining)表达式*](..\chapter3\04_Expressions.html#optional_chaining_expression)
|
||||
|
||||
### 函数调用表达式(Function Call Expression)
|
||||
|
||||
函数调用表达式由函数名和参数列表组成。它的形式如下:
|
||||
|
||||
`function name`(`argument value 1`, `argument value 2`)
|
||||
> `function name`(`argument value 1`, `argument value 2`)
|
||||
|
||||
The function name can be any expression whose value is of a function type.
|
||||
(不用翻译了, 太罗嗦)
|
||||
|
||||
如果该function 的声明中指定了参数的名字,那么在调用的时候也必须得写出来. 例如:
|
||||
|
||||
`function name`(`argument name 1`: `argument value 1`, `argument name 2`: `argument value 2`)
|
||||
> `function name`(`argument name 1`: `argument value 1`, `argument name 2`: `argument value 2`)
|
||||
|
||||
可以在 函数调用表达式的尾部(最后一个参数之后)加上 一个闭包(closure) , 该闭包会被目标函数理解并执行。它具有如下两种写法:
|
||||
|
||||
@ -493,24 +477,23 @@ myData.someMethod() {$0 == 13}
|
||||
myData.someMethod {$0 == 13}
|
||||
```
|
||||
|
||||
> GRAMMAR OF A FUNCTION CALL EXPRESSION
|
||||
>
|
||||
> *function-call-expression* → *postfix-expression**parenthesized-expression*
|
||||
> *function-call-expression* → *postfix-expression**parenthesized-expression*(opt)*trailing-closure*
|
||||
> *trailing-closure* → *closure-expression*
|
||||
> 函数调用表达式语法
|
||||
> *函数调用表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) [*圆括号表达式*](..\chapter3\04_Expressions.html#parenthesized_expression)
|
||||
> *函数调用表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) [*圆括号表达式*](..\chapter3\04_Expressions.html#parenthesized_expression) _可选_ [*后置闭包(Trailing Closure)*](..\chapter3\04_Expressions.html#trailing_closure)
|
||||
> *后置闭包(Trailing Closure)* → [*闭包表达式*](..\chapter3\04_Expressions.html#closure_expression)
|
||||
|
||||
### 初始化函数表达式(Initializer Expression)
|
||||
|
||||
Initializer表达式用来给某个Type初始化。 它的形式如下:
|
||||
|
||||
`expression`.init(`initializer arguments`)
|
||||
> `expression`.init(`initializer arguments`)
|
||||
|
||||
(Initializer表达式用来给某个Type初始化。) 跟函数(function)不同, initializer 不能返回值。
|
||||
|
||||
```swift
|
||||
var x = SomeClass.someClassFunction // ok
|
||||
var y = SomeClass.init // error
|
||||
```swift
|
||||
```
|
||||
|
||||
可以通过 initializer 表达式来委托调用(delegate to )到superclass的initializers.
|
||||
|
||||
@ -523,15 +506,14 @@ class SomeSubClass: SomeSuperClass {
|
||||
}
|
||||
```
|
||||
|
||||
> initializer表达式的语法
|
||||
>
|
||||
> *initializer-expression* → *postfix-expression*.init
|
||||
> 构造器表达式语法
|
||||
> *构造器表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** **init**
|
||||
|
||||
### 显式成员表达式(Explicit Member Expression)
|
||||
|
||||
显示成员表达式允许我们访问type, tuple, module的成员变量。它的形式如下:
|
||||
|
||||
`expression`.`member name`
|
||||
> `expression`.`member name`
|
||||
|
||||
该member 就是某个type在声明时候所定义(declaration or extension) 的变量, 例如:
|
||||
|
||||
@ -554,25 +536,23 @@ t.0 = t.1
|
||||
The members of a module access the top-level declarations of that module.
|
||||
(不确定:对于某个module的member的调用,只能调用在top-level声明中的member.)
|
||||
|
||||
> 显示成员表达式的语法
|
||||
>
|
||||
> *explicit-member-expression* → *postfix-expression*.*decimal-digit*
|
||||
> *explicit-member-expression* → *postfix-expression*.*identifier**generic-argument-clause*(opt)
|
||||
> 显式成员表达式语法
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*十进制数字*](..\chapter3\02_Lexical_Structure.html#decimal_digit)
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
|
||||
|
||||
### 后缀self表达式(Postfix Self Expression)
|
||||
|
||||
后缀表达式由 某个表达式 + '.self' 组成. 形式如下:
|
||||
|
||||
`expression`.self
|
||||
`type`.self
|
||||
> `expression`.self
|
||||
> `type`.self
|
||||
|
||||
形式1 表示会返回 expression 的值。例如: x.self 返回 x
|
||||
|
||||
形式2:返回对应的type。我们可以用它来动态的获取某个instance的type。
|
||||
|
||||
> 后缀self表达式的语法
|
||||
>
|
||||
> *postfix-self-expression* → *postfix-expression*.self
|
||||
> 后置Self 表达式语法
|
||||
> *后置self表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** **self**
|
||||
|
||||
### dynamic表达式(Dynamic Type Expression)
|
||||
|
||||
@ -580,7 +560,7 @@ The members of a module access the top-level declarations of that module.
|
||||
|
||||
dynamicType 表达式由 某个表达式 + '.dynamicType' 组成。
|
||||
|
||||
`expression`.dynamicType
|
||||
> `expression`.dynamicType
|
||||
|
||||
上面的形式中, expression 不能是某type的名字(当然了,如果我都知道它的名字了还需要动态来获取它吗)。动态类型表达式会返回"运行时"某个instance的type, 具体请看下面的列子:
|
||||
|
||||
@ -603,41 +583,39 @@ someInstance.dynamicType.printClassName()
|
||||
// prints "SomeSubClass"
|
||||
```
|
||||
|
||||
> dynamic type 表达式
|
||||
>
|
||||
> *dynamic-type-expression* → *postfix-expression*.dynamicType
|
||||
> 动态类型表达式语法
|
||||
> *动态类型表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** **dynamicType**
|
||||
|
||||
### 下标脚本表达式(Subscript Expression)
|
||||
|
||||
下标脚本表达式提供了通过下标脚本访问getter/setter 的方法。它的形式是:
|
||||
|
||||
`expression`[`index expressions`]
|
||||
> `expression`[`index expressions`]
|
||||
|
||||
可以通过下标脚本表达式通过getter获取某个值,或者通过setter赋予某个值.
|
||||
|
||||
关于subscript的声明,请参见: Protocol Subscript Declaration.
|
||||
|
||||
> 下标脚本表达式的语法
|
||||
>
|
||||
> *subscript-expression* → *postfix-expression*[*expression-list*]
|
||||
|
||||
> 附属脚本表达式语法
|
||||
> *附属脚本表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **[** [*表达式列表*](..\chapter3\04_Expressions.html#expression_list) **]**
|
||||
|
||||
### 强制取值表达式(Forced-Value Expression)
|
||||
|
||||
强制取值表达式用来获取某个目标表达式的值(该目标表达式的值必须不是nil )。它的形式如下:
|
||||
|
||||
`expression`!
|
||||
> `expression`!
|
||||
|
||||
如果该表达式的值不是nil, 则返回对应的值。 否则,抛出运行时错误(runtime error)。
|
||||
|
||||
> 强制取值表达式的语法
|
||||
>
|
||||
> *forced-value-expression* → *postfix-expression*!
|
||||
> 强制取值(Forced Value)语法
|
||||
> *强制取值(Forced Value)表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **!**
|
||||
|
||||
### 可选链表达式(Optional-Chaining Expression)
|
||||
|
||||
可选链表达式由目标表达式 + '?' 组成,形式如下:
|
||||
|
||||
`expression`?
|
||||
> `expression`?
|
||||
|
||||
后缀'?' 返回目标表达式的值,把它做为可选的参数传递给后续的表达式
|
||||
|
||||
@ -658,6 +636,5 @@ if let unwrappedC = c {
|
||||
}
|
||||
```
|
||||
|
||||
> 可选链表达式的语法
|
||||
>
|
||||
> *optional-chaining-expression* → *postfix-expression*?
|
||||
> 可选链表达式语法
|
||||
> *可选链表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **?**
|
||||
|
||||
@ -90,7 +90,7 @@ _________________
|
||||
> 标记语句语法
|
||||
> *标记语句(Labeled Statement)* → [*语句标签*](..\chapter3\10_Statements.html#statement_label) [*循环语句*](..\chapter3\10_Statements.html#loop_statement) | [*语句标签*](..\chapter3\10_Statements.html#statement_label) [*switch语句*](..\chapter3\10_Statements.html#switch_statement)
|
||||
> *语句标签* → [*标签名称*](..\chapter3\10_Statements.html#label_name) **:**
|
||||
> *标签名称* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *标签名称* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -181,7 +181,7 @@ _________________
|
||||
> *导入声明* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **import** [*导入类型*](..\chapter3\05_Declarations.html#import_kind) _可选_ [*导入路径*](..\chapter3\05_Declarations.html#import_path)
|
||||
> *导入类型* → **typealias** | **struct** | **class** | **enum** | **protocol** | **var** | **func**
|
||||
> *导入路径* → [*导入路径标识符*](..\chapter3\05_Declarations.html#import_path_identifier) | [*导入路径标识符*](..\chapter3\05_Declarations.html#import_path_identifier) **.** [*导入路径*](..\chapter3\05_Declarations.html#import_path)
|
||||
> *导入路径标识符* → [*标识符*](LexicalStructure.html#identifier) | [*运算符*](LexicalStructure.html#operator)
|
||||
> *导入路径标识符* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) | [*运算符*](..\chapter3\02_Lexical_Structure.html#operator)
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -200,12 +200,12 @@ _________________
|
||||
> *变量声明* → [*变量声明头(Head)*](..\chapter3\05_Declarations.html#variable_declaration_head) [*变量名*](..\chapter3\05_Declarations.html#variable_name) [*类型注解*](..\chapter3\03_Types.html#type_annotation) [*getter-setter关键字(Keyword)块*](..\chapter3\05_Declarations.html#getter_setter_keyword_block)
|
||||
> *变量声明* → [*变量声明头(Head)*](..\chapter3\05_Declarations.html#variable_declaration_head) [*变量名*](..\chapter3\05_Declarations.html#variable_name) [*类型注解*](..\chapter3\03_Types.html#type_annotation) [*构造器*](..\chapter3\05_Declarations.html#initializer) _可选_ [*willSet-didSet代码块*](..\chapter3\05_Declarations.html#willSet_didSet_block)
|
||||
> *变量声明头(Head)* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ [*声明描述符(Specifiers)列表*](..\chapter3\05_Declarations.html#declaration_specifiers) _可选_ **var**
|
||||
> *变量名称* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *变量名称* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *getter-setter块* → **{** [*getter子句*](..\chapter3\05_Declarations.html#getter_clause) [*setter子句*](..\chapter3\05_Declarations.html#setter_clause) _可选_ **}**
|
||||
> *getter-setter块* → **{** [*setter子句*](..\chapter3\05_Declarations.html#setter_clause) [*getter子句*](..\chapter3\05_Declarations.html#getter_clause) **}**
|
||||
> *getter子句* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **get** [*代码块*](..\chapter3\05_Declarations.html#code_block)
|
||||
> *setter子句* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **set** [*setter名称*](..\chapter3\05_Declarations.html#setter_name) _可选_ [*代码块*](..\chapter3\05_Declarations.html#code_block)
|
||||
> *setter名称* → **(** [*标识符*](LexicalStructure.html#identifier) **)**
|
||||
> *setter名称* → **(** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) **)**
|
||||
> *getter-setter关键字(Keyword)块* → **{** [*getter关键字(Keyword)子句*](..\chapter3\05_Declarations.html#getter_keyword_clause) [*setter关键字(Keyword)子句*](..\chapter3\05_Declarations.html#setter_keyword_clause) _可选_ **}**
|
||||
> *getter-setter关键字(Keyword)块* → **{** [*setter关键字(Keyword)子句*](..\chapter3\05_Declarations.html#setter_keyword_clause) [*getter关键字(Keyword)子句*](..\chapter3\05_Declarations.html#getter_keyword_clause) **}**
|
||||
> *getter关键字(Keyword)子句* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **get**
|
||||
@ -220,7 +220,7 @@ _________________
|
||||
> 类型别名声明语法
|
||||
> *类型别名声明* → [*类型别名头(Head)*](..\chapter3\05_Declarations.html#typealias_head) [*类型别名赋值*](..\chapter3\05_Declarations.html#typealias_assignment)
|
||||
> *类型别名头(Head)* → **typealias** [*类型别名名称*](..\chapter3\05_Declarations.html#typealias_name)
|
||||
> *类型别名名称* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *类型别名名称* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *类型别名赋值* → **=** [*类型*](..\chapter3\03_Types.html#type)
|
||||
|
||||
<p></p>
|
||||
@ -228,7 +228,7 @@ _________________
|
||||
> 函数声明语法
|
||||
> *函数声明* → [*函数头*](..\chapter3\05_Declarations.html#function_head) [*函数名*](..\chapter3\05_Declarations.html#function_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_parameter_clause) _可选_ [*函数签名(Signature)*](..\chapter3\05_Declarations.html#function_signature) [*函数体*](..\chapter3\05_Declarations.html#function_body)
|
||||
> *函数头* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ [*声明描述符(Specifiers)列表*](..\chapter3\05_Declarations.html#declaration_specifiers) _可选_ **func**
|
||||
> *函数名* → [*标识符*](LexicalStructure.html#identifier) | [*运算符*](LexicalStructure.html#operator)
|
||||
> *函数名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) | [*运算符*](..\chapter3\02_Lexical_Structure.html#operator)
|
||||
> *函数签名(Signature)* → [*parameter-clauses*](..\chapter3\05_Declarations.html#parameter_clauses) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_
|
||||
> *函数结果* → **->** [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ [*类型*](..\chapter3\03_Types.html#type)
|
||||
> *函数体* → [*代码块*](..\chapter3\05_Declarations.html#code_block)
|
||||
@ -238,8 +238,8 @@ _________________
|
||||
> *参数* → **inout** _可选_ **let** _可选_ **#** _可选_ [*参数名*](..\chapter3\05_Declarations.html#parameter_name) [*本地参数名*](..\chapter3\05_Declarations.html#local_parameter_name) _可选_ [*类型注解*](..\chapter3\03_Types.html#type_annotation) [*默认参数子句*](..\chapter3\05_Declarations.html#default_argument_clause) _可选_
|
||||
> *参数* → **inout** _可选_ **var** **#** _可选_ [*参数名*](..\chapter3\05_Declarations.html#parameter_name) [*本地参数名*](..\chapter3\05_Declarations.html#local_parameter_name) _可选_ [*类型注解*](..\chapter3\03_Types.html#type_annotation) [*默认参数子句*](..\chapter3\05_Declarations.html#default_argument_clause) _可选_
|
||||
> *参数* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ [*类型*](..\chapter3\03_Types.html#type)
|
||||
> *参数名* → [*标识符*](LexicalStructure.html#identifier) | **_**
|
||||
> *本地参数名* → [*标识符*](LexicalStructure.html#identifier) | **_**
|
||||
> *参数名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) | **_**
|
||||
> *本地参数名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) | **_**
|
||||
> *默认参数子句* → **=** [*表达式*](..\chapter3\04_Expressions.html#expression)
|
||||
|
||||
<p></p>
|
||||
@ -252,35 +252,35 @@ _________________
|
||||
> *联合式(Union Style)的枚举case子句* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **case** [*联合式(Union Style)的枚举case列表*](..\chapter3\05_Declarations.html#union_style_enum_case_list)
|
||||
> *联合式(Union Style)的枚举case列表* → [*联合式(Union Style)的case*](..\chapter3\05_Declarations.html#union_style_enum_case) | [*联合式(Union Style)的case*](..\chapter3\05_Declarations.html#union_style_enum_case) **,** [*联合式(Union Style)的枚举case列表*](..\chapter3\05_Declarations.html#union_style_enum_case_list)
|
||||
> *联合式(Union Style)的case* → [*枚举的case名*](..\chapter3\05_Declarations.html#enum_case_name) [*元组类型*](..\chapter3\03_Types.html#tuple_type) _可选_
|
||||
> *枚举名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *枚举的case名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *枚举名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *枚举的case名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *原始值式枚举* → [*枚举名*](..\chapter3\05_Declarations.html#enum_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_parameter_clause) _可选_ **:** [*类型标识*](..\chapter3\03_Types.html#type_identifier) **{** [*原始值式枚举成员列表*](..\chapter3\05_Declarations.html#raw_value_style_enum_members) _可选_ **}**
|
||||
> *原始值式枚举成员列表* → [*原始值式枚举成员*](..\chapter3\05_Declarations.html#raw_value_style_enum_member) [*原始值式枚举成员列表*](..\chapter3\05_Declarations.html#raw_value_style_enum_members) _可选_
|
||||
> *原始值式枚举成员* → [*声明*](..\chapter3\05_Declarations.html#declaration) | [*原始值式枚举case子句*](..\chapter3\05_Declarations.html#raw_value_style_enum_case_clause)
|
||||
> *原始值式枚举case子句* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **case** [*原始值式枚举case列表*](..\chapter3\05_Declarations.html#raw_value_style_enum_case_list)
|
||||
> *原始值式枚举case列表* → [*原始值式枚举case*](..\chapter3\05_Declarations.html#raw_value_style_enum_case) | [*原始值式枚举case*](..\chapter3\05_Declarations.html#raw_value_style_enum_case) **,** [*原始值式枚举case列表*](..\chapter3\05_Declarations.html#raw_value_style_enum_case_list)
|
||||
> *原始值式枚举case* → [*枚举的case名*](..\chapter3\05_Declarations.html#enum_case_name) [*原始值赋值*](..\chapter3\05_Declarations.html#raw_value_assignment) _可选_
|
||||
> *原始值赋值* → **=** [*字面量*](LexicalStructure.html#literal)
|
||||
> *原始值赋值* → **=** [*字面量*](..\chapter3\02_Lexical_Structure.html#literal)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 结构体声明语法
|
||||
> *结构体声明* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **struct** [*结构体名称*](..\chapter3\05_Declarations.html#struct_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_parameter_clause) _可选_ [*类型继承子句*](..\chapter3\03_Types.html#type_inheritance_clause) _可选_ [*结构体主体*](..\chapter3\05_Declarations.html#struct_body)
|
||||
> *结构体名称* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *结构体名称* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *结构体主体* → **{** [*声明(Declarations)列表*](..\chapter3\05_Declarations.html#declarations) _可选_ **}**
|
||||
|
||||
<p></p>
|
||||
|
||||
> 类声明语法
|
||||
> *类声明* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **class** [*类名*](..\chapter3\05_Declarations.html#class_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_parameter_clause) _可选_ [*类型继承子句*](..\chapter3\03_Types.html#type_inheritance_clause) _可选_ [*类主体*](..\chapter3\05_Declarations.html#class_body)
|
||||
> *类名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *类名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *类主体* → **{** [*声明(Declarations)列表*](..\chapter3\05_Declarations.html#declarations) _可选_ **}**
|
||||
|
||||
<p></p>
|
||||
|
||||
> 协议(Protocol)声明语法
|
||||
> *协议声明* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **protocol** [*协议名*](..\chapter3\05_Declarations.html#protocol_name) [*类型继承子句*](..\chapter3\03_Types.html#type_inheritance_clause) _可选_ [*协议主体*](..\chapter3\05_Declarations.html#protocol_body)
|
||||
> *协议名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *协议名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *协议主体* → **{** [*协议成员声明(Declarations)列表*](..\chapter3\05_Declarations.html#protocol_member_declarations) _可选_ **}**
|
||||
> *协议成员声明* → [*协议属性声明*](..\chapter3\05_Declarations.html#protocol_property_declaration)
|
||||
> *协议成员声明* → [*协议方法声明*](..\chapter3\05_Declarations.html#protocol_method_declaration)
|
||||
@ -345,9 +345,9 @@ _________________
|
||||
|
||||
> 运算符声明语法
|
||||
> *运算符声明* → [*前置运算符声明*](..\chapter3\05_Declarations.html#prefix_operator_declaration) | [*后置运算符声明*](..\chapter3\05_Declarations.html#postfix_operator_declaration) | [*中置运算符声明*](..\chapter3\05_Declarations.html#infix_operator_declaration)
|
||||
> *前置运算符声明* → **运算符** **prefix** [*运算符*](LexicalStructure.html#operator) **{** **}**
|
||||
> *后置运算符声明* → **运算符** **postfix** [*运算符*](LexicalStructure.html#operator) **{** **}**
|
||||
> *中置运算符声明* → **运算符** **infix** [*运算符*](LexicalStructure.html#operator) **{** [*中置运算符属性*](..\chapter3\05_Declarations.html#infix_operator_attributes) _可选_ **}**
|
||||
> *前置运算符声明* → **运算符** **prefix** [*运算符*](..\chapter3\02_Lexical_Structure.html#operator) **{** **}**
|
||||
> *后置运算符声明* → **运算符** **postfix** [*运算符*](..\chapter3\02_Lexical_Structure.html#operator) **{** **}**
|
||||
> *中置运算符声明* → **运算符** **infix** [*运算符*](..\chapter3\02_Lexical_Structure.html#operator) **{** [*中置运算符属性*](..\chapter3\05_Declarations.html#infix_operator_attributes) _可选_ **}**
|
||||
> *中置运算符属性* → [*优先级子句*](..\chapter3\05_Declarations.html#precedence_clause) _可选_ [*结和性子句*](..\chapter3\05_Declarations.html#associativity_clause) _可选_
|
||||
> *优先级子句* → **precedence** [*优先级水平*](..\chapter3\05_Declarations.html#precedence_level)
|
||||
> *优先级水平* → 数值 0 到 255
|
||||
@ -374,7 +374,7 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 标识符模式语法
|
||||
> *标识符模式* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *标识符模式* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -410,7 +410,7 @@ _________________
|
||||
|
||||
> 特性语法
|
||||
> *特色* → **@** [*特性名*](..\chapter3\06_Attributes.html#attribute_name) [*特性参数子句*](..\chapter3\06_Attributes.html#attribute_argument_clause) _可选_
|
||||
> *特性名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *特性名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *特性参数子句* → **(** [*平衡令牌列表*](..\chapter3\06_Attributes.html#balanced_tokens) _可选_ **)**
|
||||
> *特性(Attributes)列表* → [*特色*](..\chapter3\06_Attributes.html#attribute) [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_
|
||||
> *平衡令牌列表* → [*平衡令牌*](..\chapter3\06_Attributes.html#balanced_token) [*平衡令牌列表*](..\chapter3\06_Attributes.html#balanced_tokens) _可选_
|
||||
@ -430,14 +430,14 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 前置表达式语法
|
||||
> *前置表达式* → [*前置运算符*](LexicalStructure.html#prefix_operator) _可选_ [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression)
|
||||
> *前置表达式* → [*前置运算符*](..\chapter3\02_Lexical_Structure.html#prefix_operator) _可选_ [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression)
|
||||
> *前置表达式* → [*写入写出(in-out)表达式*](..\chapter3\04_Expressions.html#in_out_expression)
|
||||
> *写入写出(in-out)表达式* → **&** [*标识符*](LexicalStructure.html#identifier)
|
||||
> *写入写出(in-out)表达式* → **&** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 二元表达式语法
|
||||
> *二元表达式* → [*二元运算符*](LexicalStructure.html#binary_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
|
||||
> *二元表达式* → [*二元运算符*](..\chapter3\02_Lexical_Structure.html#binary_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
|
||||
> *二元表达式* → [*赋值运算符*](..\chapter3\04_Expressions.html#assignment_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
|
||||
> *二元表达式* → [*条件运算符*](..\chapter3\04_Expressions.html#conditional_operator) [*前置表达式*](..\chapter3\04_Expressions.html#prefix_expression)
|
||||
> *二元表达式* → [*类型转换运算符*](..\chapter3\04_Expressions.html#type_casting_operator)
|
||||
@ -450,8 +450,8 @@ _________________
|
||||
|
||||
<p></p>
|
||||
|
||||
> 条件运算符语法
|
||||
> *条件运算符* → **?** [*表达式*](..\chapter3\04_Expressions.html#expression) **:**
|
||||
> 三元条件运算符语法
|
||||
> *三元条件运算符* → **?** [*表达式*](..\chapter3\04_Expressions.html#expression) **:**
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -461,7 +461,7 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 主表达式语法
|
||||
> *主表达式* → [*标识符*](LexicalStructure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
|
||||
> *主表达式* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
|
||||
> *主表达式* → [*字面量表达式*](..\chapter3\04_Expressions.html#literal_expression)
|
||||
> *主表达式* → [*self表达式*](..\chapter3\04_Expressions.html#self_expression)
|
||||
> *主表达式* → [*超类表达式*](..\chapter3\04_Expressions.html#superclass_expression)
|
||||
@ -473,7 +473,7 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 字面量表达式语法
|
||||
> *字面量表达式* → [*字面量*](LexicalStructure.html#literal)
|
||||
> *字面量表达式* → [*字面量*](..\chapter3\02_Lexical_Structure.html#literal)
|
||||
> *字面量表达式* → [*数组字面量*](..\chapter3\04_Expressions.html#array_literal) | [*字典字面量*](..\chapter3\04_Expressions.html#dictionary_literal)
|
||||
> *字面量表达式* → **__FILE__** | **__LINE__** | **__COLUMN__** | **__FUNCTION__**
|
||||
> *数组字面量* → **[** [*数组字面量项列表*](..\chapter3\04_Expressions.html#array_literal_items) _可选_ **]**
|
||||
@ -487,7 +487,7 @@ _________________
|
||||
|
||||
> Self 表达式语法
|
||||
> *self表达式* → **self**
|
||||
> *self表达式* → **self** **.** [*标识符*](LexicalStructure.html#identifier)
|
||||
> *self表达式* → **self** **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *self表达式* → **self** **[** [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
|
||||
> *self表达式* → **self** **.** **init**
|
||||
|
||||
@ -495,7 +495,7 @@ _________________
|
||||
|
||||
> 超类表达式语法
|
||||
> *超类表达式* → [*超类方法表达式*](..\chapter3\04_Expressions.html#superclass_method_expression) | [*超类下标表达式*](..\chapter3\04_Expressions.html#超类下标表达式) | [*超类构造器表达式*](..\chapter3\04_Expressions.html#superclass_initializer_expression)
|
||||
> *超类方法表达式* → **super** **.** [*标识符*](LexicalStructure.html#identifier)
|
||||
> *超类方法表达式* → **super** **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
> *超类下标表达式* → **super** **[** [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
|
||||
> *超类构造器表达式* → **super** **.** **init**
|
||||
|
||||
@ -504,9 +504,9 @@ _________________
|
||||
> 闭包表达式语法
|
||||
> *闭包表达式* → **{** [*闭包签名(Signational)*](..\chapter3\04_Expressions.html#closure_signature) _可选_ [*多条语句(Statements)*](..\chapter3\10_Statements.html#statements) **}**
|
||||
> *闭包签名(Signational)* → [*参数子句*](..\chapter3\05_Declarations.html#parameter_clause) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*标识符列表*](LexicalStructure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*标识符列表*](..\chapter3\02_Lexical_Structure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) [*参数子句*](..\chapter3\05_Declarations.html#parameter_clause) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) [*标识符列表*](LexicalStructure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) [*标识符列表*](..\chapter3\02_Lexical_Structure.html#identifier_list) [*函数结果*](..\chapter3\05_Declarations.html#function_result) _可选_ **in**
|
||||
> *闭包签名(Signational)* → [*捕获(Capature)列表*](..\chapter3\04_Expressions.html#capture_list) **in**
|
||||
> *捕获(Capature)列表* → **[** [*捕获(Capature)说明符*](..\chapter3\04_Expressions.html#capture_specifier) [*表达式*](..\chapter3\04_Expressions.html#expression) **]**
|
||||
> *捕获(Capature)说明符* → **weak** | **unowned** | **unowned(safe)** | **unowned(unsafe)**
|
||||
@ -514,14 +514,14 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 隐式成员表达式语法
|
||||
> *隐式成员表达式* → **.** [*标识符*](LexicalStructure.html#identifier)
|
||||
> *隐式成员表达式* → **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 圆括号表达式(Parenthesized Expression)语法
|
||||
> *圆括号表达式* → **(** [*表达式元素列表*](..\chapter3\04_Expressions.html#expression_element_list) _可选_ **)**
|
||||
> *表达式元素列表* → [*表达式元素*](..\chapter3\04_Expressions.html#expression_element) | [*表达式元素*](..\chapter3\04_Expressions.html#expression_element) **,** [*表达式元素列表*](..\chapter3\04_Expressions.html#expression_element_list)
|
||||
> *表达式元素* → [*表达式*](..\chapter3\04_Expressions.html#expression) | [*标识符*](LexicalStructure.html#identifier) **:** [*表达式*](..\chapter3\04_Expressions.html#expression)
|
||||
> *表达式元素* → [*表达式*](..\chapter3\04_Expressions.html#expression) | [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) **:** [*表达式*](..\chapter3\04_Expressions.html#expression)
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -532,7 +532,7 @@ _________________
|
||||
|
||||
> 后置表达式语法
|
||||
> *后置表达式* → [*主表达式*](..\chapter3\04_Expressions.html#primary_expression)
|
||||
> *后置表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) [*后置运算符*](LexicalStructure.html#postfix_operator)
|
||||
> *后置表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) [*后置运算符*](..\chapter3\02_Lexical_Structure.html#postfix_operator)
|
||||
> *后置表达式* → [*函数调用表达式*](..\chapter3\04_Expressions.html#function_call_expression)
|
||||
> *后置表达式* → [*构造器表达式*](..\chapter3\04_Expressions.html#initializer_expression)
|
||||
> *后置表达式* → [*显示成员表达式*](..\chapter3\04_Expressions.html#explicit_member_expression)
|
||||
@ -557,12 +557,12 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 显式成员表达式语法
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*十进制数字*](LexicalStructure.html#decimal_digit)
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*标识符*](LexicalStructure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*十进制数字*](..\chapter3\02_Lexical_Structure.html#decimal_digit)
|
||||
> *显示成员表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_
|
||||
|
||||
<p></p>
|
||||
|
||||
> Self 表达式语法
|
||||
> 后置Self 表达式语法
|
||||
> *后置self表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **.** **self**
|
||||
|
||||
<p></p>
|
||||
@ -572,8 +572,8 @@ _________________
|
||||
|
||||
<p></p>
|
||||
|
||||
> 下标表达式语法
|
||||
> *下标表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **[** [*表达式列表*](..\chapter3\04_Expressions.html#expression_list) **]**
|
||||
> 附属脚本表达式语法
|
||||
> *附属脚本表达式* → [*后置表达式*](..\chapter3\04_Expressions.html#postfix_expression) **[** [*表达式列表*](..\chapter3\04_Expressions.html#expression_list) **]**
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -589,10 +589,10 @@ _________________
|
||||
## 词法结构
|
||||
|
||||
> 标识符语法
|
||||
> *标识符* → [*标识符头(Head)*](LexicalStructure.html#identifier_head) [*标识符字符列表*](LexicalStructure.html#identifier_characters) _可选_
|
||||
> *标识符* → **`** [*标识符头(Head)*](LexicalStructure.html#identifier_head) [*标识符字符列表*](LexicalStructure.html#identifier_characters) _可选_ **`**
|
||||
> *标识符* → [*隐式参数名*](LexicalStructure.html#implicit_parameter_name)
|
||||
> *标识符列表* → [*标识符*](LexicalStructure.html#identifier) | [*标识符*](LexicalStructure.html#identifier) **,** [*标识符列表*](LexicalStructure.html#identifier_list)
|
||||
> *标识符* → [*标识符头(Head)*](..\chapter3\02_Lexical_Structure.html#identifier_head) [*标识符字符列表*](..\chapter3\02_Lexical_Structure.html#identifier_characters) _可选_
|
||||
> *标识符* → **`** [*标识符头(Head)*](..\chapter3\02_Lexical_Structure.html#identifier_head) [*标识符字符列表*](..\chapter3\02_Lexical_Structure.html#identifier_characters) _可选_ **`**
|
||||
> *标识符* → [*隐式参数名*](..\chapter3\02_Lexical_Structure.html#implicit_parameter_name)
|
||||
> *标识符列表* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) | [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier) **,** [*标识符列表*](..\chapter3\02_Lexical_Structure.html#identifier_list)
|
||||
> *标识符头(Head)* → Upper- or lowercase letter A through Z
|
||||
> *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
|
||||
@ -610,49 +610,49 @@ _________________
|
||||
> *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)*](LexicalStructure.html#identifier_head)
|
||||
> *标识符字符列表* → [*标识符字符*](LexicalStructure.html#identifier_character) [*标识符字符列表*](LexicalStructure.html#identifier_characters) _可选_
|
||||
> *隐式参数名* → **$** [*十进制数字列表*](LexicalStructure.html#decimal_digits)
|
||||
> *标识符字符* → [*标识符头(Head)*](..\chapter3\02_Lexical_Structure.html#identifier_head)
|
||||
> *标识符字符列表* → [*标识符字符*](..\chapter3\02_Lexical_Structure.html#identifier_character) [*标识符字符列表*](..\chapter3\02_Lexical_Structure.html#identifier_characters) _可选_
|
||||
> *隐式参数名* → **$** [*十进制数字列表*](..\chapter3\02_Lexical_Structure.html#decimal_digits)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 字面量语法
|
||||
> *字面量* → [*整型字面量*](LexicalStructure.html#integer_literal) | [*浮点数字面量*](LexicalStructure.html#floating_point_literal) | [*字符串字面量*](LexicalStructure.html#string_literal)
|
||||
> *字面量* → [*整型字面量*](..\chapter3\02_Lexical_Structure.html#integer_literal) | [*浮点数字面量*](..\chapter3\02_Lexical_Structure.html#floating_point_literal) | [*字符串字面量*](..\chapter3\02_Lexical_Structure.html#string_literal)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 整型字面量语法
|
||||
> *整型字面量* → [*二进制字面量*](LexicalStructure.html#binary_literal)
|
||||
> *整型字面量* → [*八进制字面量*](LexicalStructure.html#octal_literal)
|
||||
> *整型字面量* → [*十进制字面量*](LexicalStructure.html#decimal_literal)
|
||||
> *整型字面量* → [*十六进制字面量*](LexicalStructure.html#hexadecimal_literal)
|
||||
> *二进制字面量* → **0b** [*二进制数字*](LexicalStructure.html#binary_digit) [*二进制字面量字符列表*](LexicalStructure.html#binary_literal_characters) _可选_
|
||||
> *整型字面量* → [*二进制字面量*](..\chapter3\02_Lexical_Structure.html#binary_literal)
|
||||
> *整型字面量* → [*八进制字面量*](..\chapter3\02_Lexical_Structure.html#octal_literal)
|
||||
> *整型字面量* → [*十进制字面量*](..\chapter3\02_Lexical_Structure.html#decimal_literal)
|
||||
> *整型字面量* → [*十六进制字面量*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal)
|
||||
> *二进制字面量* → **0b** [*二进制数字*](..\chapter3\02_Lexical_Structure.html#binary_digit) [*二进制字面量字符列表*](..\chapter3\02_Lexical_Structure.html#binary_literal_characters) _可选_
|
||||
> *二进制数字* → 数值 0 到 1
|
||||
> *二进制字面量字符* → [*二进制数字*](LexicalStructure.html#binary_digit) | **_**
|
||||
> *二进制字面量字符列表* → [*二进制字面量字符*](LexicalStructure.html#binary_literal_character) [*二进制字面量字符列表*](LexicalStructure.html#binary_literal_characters) _可选_
|
||||
> *八进制字面量* → **0o** [*八进字数字*](LexicalStructure.html#octal_digit) [*八进制字符列表*](LexicalStructure.html#octal_literal_characters) _可选_
|
||||
> *二进制字面量字符* → [*二进制数字*](..\chapter3\02_Lexical_Structure.html#binary_digit) | **_**
|
||||
> *二进制字面量字符列表* → [*二进制字面量字符*](..\chapter3\02_Lexical_Structure.html#binary_literal_character) [*二进制字面量字符列表*](..\chapter3\02_Lexical_Structure.html#binary_literal_characters) _可选_
|
||||
> *八进制字面量* → **0o** [*八进字数字*](..\chapter3\02_Lexical_Structure.html#octal_digit) [*八进制字符列表*](..\chapter3\02_Lexical_Structure.html#octal_literal_characters) _可选_
|
||||
> *八进字数字* → 数值 0 到 7
|
||||
> *八进制字符* → [*八进字数字*](LexicalStructure.html#octal_digit) | **_**
|
||||
> *八进制字符列表* → [*八进制字符*](LexicalStructure.html#octal_literal_character) [*八进制字符列表*](LexicalStructure.html#octal_literal_characters) _可选_
|
||||
> *十进制字面量* → [*十进制数字*](LexicalStructure.html#decimal_digit) [*十进制字符列表*](LexicalStructure.html#decimal_literal_characters) _可选_
|
||||
> *八进制字符* → [*八进字数字*](..\chapter3\02_Lexical_Structure.html#octal_digit) | **_**
|
||||
> *八进制字符列表* → [*八进制字符*](..\chapter3\02_Lexical_Structure.html#octal_literal_character) [*八进制字符列表*](..\chapter3\02_Lexical_Structure.html#octal_literal_characters) _可选_
|
||||
> *十进制字面量* → [*十进制数字*](..\chapter3\02_Lexical_Structure.html#decimal_digit) [*十进制字符列表*](..\chapter3\02_Lexical_Structure.html#decimal_literal_characters) _可选_
|
||||
> *十进制数字* → 数值 0 到 9
|
||||
> *十进制数字列表* → [*十进制数字*](LexicalStructure.html#decimal_digit) [*十进制数字列表*](LexicalStructure.html#decimal_digits) _可选_
|
||||
> *十进制字符* → [*十进制数字*](LexicalStructure.html#decimal_digit) | **_**
|
||||
> *十进制字符列表* → [*十进制字符*](LexicalStructure.html#decimal_literal_character) [*十进制字符列表*](LexicalStructure.html#decimal_literal_characters) _可选_
|
||||
> *十六进制字面量* → **0x** [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制字面量字符列表*](LexicalStructure.html#hexadecimal_literal_characters) _可选_
|
||||
> *十进制数字列表* → [*十进制数字*](..\chapter3\02_Lexical_Structure.html#decimal_digit) [*十进制数字列表*](..\chapter3\02_Lexical_Structure.html#decimal_digits) _可选_
|
||||
> *十进制字符* → [*十进制数字*](..\chapter3\02_Lexical_Structure.html#decimal_digit) | **_**
|
||||
> *十进制字符列表* → [*十进制字符*](..\chapter3\02_Lexical_Structure.html#decimal_literal_character) [*十进制字符列表*](..\chapter3\02_Lexical_Structure.html#decimal_literal_characters) _可选_
|
||||
> *十六进制字面量* → **0x** [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制字面量字符列表*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal_characters) _可选_
|
||||
> *十六进制数字* → 数值 0 到 9, a through f, or A through F
|
||||
> *十六进制字符* → [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) | **_**
|
||||
> *十六进制字面量字符列表* → [*十六进制字符*](LexicalStructure.html#hexadecimal_literal_character) [*十六进制字面量字符列表*](LexicalStructure.html#hexadecimal_literal_characters) _可选_
|
||||
> *十六进制字符* → [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) | **_**
|
||||
> *十六进制字面量字符列表* → [*十六进制字符*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal_character) [*十六进制字面量字符列表*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal_characters) _可选_
|
||||
|
||||
<p></p>
|
||||
|
||||
> 浮点型字面量语法
|
||||
> *浮点数字面量* → [*十进制字面量*](LexicalStructure.html#decimal_literal) [*十进制分数*](LexicalStructure.html#decimal_fraction) _可选_ [*十进制指数*](LexicalStructure.html#decimal_exponent) _可选_
|
||||
> *浮点数字面量* → [*十六进制字面量*](LexicalStructure.html#hexadecimal_literal) [*十六进制分数*](LexicalStructure.html#hexadecimal_fraction) _可选_ [*十六进制指数*](LexicalStructure.html#hexadecimal_exponent)
|
||||
> *十进制分数* → **.** [*十进制字面量*](LexicalStructure.html#decimal_literal)
|
||||
> *十进制指数* → [*浮点数e*](LexicalStructure.html#floating_point_e) [*正负号*](LexicalStructure.html#sign) _可选_ [*十进制字面量*](LexicalStructure.html#decimal_literal)
|
||||
> *十六进制分数* → **.** [*十六进制字面量*](LexicalStructure.html#hexadecimal_literal) _可选_
|
||||
> *十六进制指数* → [*浮点数p*](LexicalStructure.html#floating_point_p) [*正负号*](LexicalStructure.html#sign) _可选_ [*十六进制字面量*](LexicalStructure.html#hexadecimal_literal)
|
||||
> *浮点数字面量* → [*十进制字面量*](..\chapter3\02_Lexical_Structure.html#decimal_literal) [*十进制分数*](..\chapter3\02_Lexical_Structure.html#decimal_fraction) _可选_ [*十进制指数*](..\chapter3\02_Lexical_Structure.html#decimal_exponent) _可选_
|
||||
> *浮点数字面量* → [*十六进制字面量*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal) [*十六进制分数*](..\chapter3\02_Lexical_Structure.html#hexadecimal_fraction) _可选_ [*十六进制指数*](..\chapter3\02_Lexical_Structure.html#hexadecimal_exponent)
|
||||
> *十进制分数* → **.** [*十进制字面量*](..\chapter3\02_Lexical_Structure.html#decimal_literal)
|
||||
> *十进制指数* → [*浮点数e*](..\chapter3\02_Lexical_Structure.html#floating_point_e) [*正负号*](..\chapter3\02_Lexical_Structure.html#sign) _可选_ [*十进制字面量*](..\chapter3\02_Lexical_Structure.html#decimal_literal)
|
||||
> *十六进制分数* → **.** [*十六进制字面量*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal) _可选_
|
||||
> *十六进制指数* → [*浮点数p*](..\chapter3\02_Lexical_Structure.html#floating_point_p) [*正负号*](..\chapter3\02_Lexical_Structure.html#sign) _可选_ [*十六进制字面量*](..\chapter3\02_Lexical_Structure.html#hexadecimal_literal)
|
||||
> *浮点数e* → **e** | **E**
|
||||
> *浮点数p* → **p** | **P**
|
||||
> *正负号* → **+** | **-**
|
||||
@ -660,24 +660,24 @@ _________________
|
||||
<p></p>
|
||||
|
||||
> 字符型字面量语法
|
||||
> *字符串字面量* → **"** [*引用文本*](LexicalStructure.html#quoted_text) **"**
|
||||
> *引用文本* → [*引用文本条目*](LexicalStructure.html#quoted_text_item) [*引用文本*](LexicalStructure.html#quoted_text) _可选_
|
||||
> *引用文本条目* → [*转义字符*](LexicalStructure.html#escaped_character)
|
||||
> *字符串字面量* → **"** [*引用文本*](..\chapter3\02_Lexical_Structure.html#quoted_text) **"**
|
||||
> *引用文本* → [*引用文本条目*](..\chapter3\02_Lexical_Structure.html#quoted_text_item) [*引用文本*](..\chapter3\02_Lexical_Structure.html#quoted_text) _可选_
|
||||
> *引用文本条目* → [*转义字符*](..\chapter3\02_Lexical_Structure.html#escaped_character)
|
||||
> *引用文本条目* → **\(** [*表达式*](..\chapter3\04_Expressions.html#expression) **)**
|
||||
> *引用文本条目* → 除了", \, U+000A, or U+000D的所有Unicode的字符
|
||||
> *转义字符* → **\0** | **\\** | **\t** | **\n** | **\r** | **\"** | **\'**
|
||||
> *转义字符* → **\x** [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit)
|
||||
> *转义字符* → **\u** [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit)
|
||||
> *转义字符* → **\U** [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit) [*十六进制数字*](LexicalStructure.html#hexadecimal_digit)
|
||||
> *转义字符* → **\x** [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit)
|
||||
> *转义字符* → **\u** [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit)
|
||||
> *转义字符* → **\U** [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit) [*十六进制数字*](..\chapter3\02_Lexical_Structure.html#hexadecimal_digit)
|
||||
|
||||
<p></p>
|
||||
|
||||
> 运算符语法语法
|
||||
> *运算符* → [*运算符字符*](LexicalStructure.html#operator_character) [*运算符*](LexicalStructure.html#operator) _可选_
|
||||
> *运算符* → [*运算符字符*](..\chapter3\02_Lexical_Structure.html#operator_character) [*运算符*](..\chapter3\02_Lexical_Structure.html#operator) _可选_
|
||||
> *运算符字符* → **/** | **=** | **-** | **+** | **!** | ***** | **%** | **<** | **>** | **&** | **|** | **^** | **~** | **.**
|
||||
> *二元运算符* → [*运算符*](LexicalStructure.html#operator)
|
||||
> *前置运算符* → [*运算符*](LexicalStructure.html#operator)
|
||||
> *后置运算符* → [*运算符*](LexicalStructure.html#operator)
|
||||
> *二元运算符* → [*运算符*](..\chapter3\02_Lexical_Structure.html#operator)
|
||||
> *前置运算符* → [*运算符*](..\chapter3\02_Lexical_Structure.html#operator)
|
||||
> *后置运算符* → [*运算符*](..\chapter3\02_Lexical_Structure.html#operator)
|
||||
|
||||
<a name="types"></a>
|
||||
## 类型
|
||||
@ -694,7 +694,7 @@ _________________
|
||||
|
||||
> 类型标识语法
|
||||
> *类型标识* → [*类型名称*](..\chapter3\03_Types.html#type_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_ | [*类型名称*](..\chapter3\03_Types.html#type_name) [*泛型参数子句*](GenericParametersAndArguments.html#generic_argument_clause) _可选_ **.** [*类型标识*](..\chapter3\03_Types.html#type_identifier)
|
||||
> *类名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *类名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
@ -703,7 +703,7 @@ _________________
|
||||
> *元组类型主体* → [*元组类型的元素列表*](..\chapter3\03_Types.html#tuple_type_element_list) **...** _可选_
|
||||
> *元组类型的元素列表* → [*元组类型的元素*](..\chapter3\03_Types.html#tuple_type_element) | [*元组类型的元素*](..\chapter3\03_Types.html#tuple_type_element) **,** [*元组类型的元素列表*](..\chapter3\03_Types.html#tuple_type_element_list)
|
||||
> *元组类型的元素* → [*特性(Attributes)列表*](..\chapter3\06_Attributes.html#attributes) _可选_ **inout** _可选_ [*类型*](..\chapter3\03_Types.html#type) | **inout** _可选_ [*元素名*](..\chapter3\03_Types.html#element_name) [*类型注解*](..\chapter3\03_Types.html#type_annotation)
|
||||
> *元素名* → [*标识符*](LexicalStructure.html#identifier)
|
||||
> *元素名* → [*标识符*](..\chapter3\02_Lexical_Structure.html#identifier)
|
||||
|
||||
<p></p>
|
||||
|
||||
|
||||
Reference in New Issue
Block a user