静态匿名函数Static anonymous functions

总结Summary

允许对 lambda 和匿名方法使用 "static" 修饰符，这不允许从包含范围捕获局部变量或实例状态。Allow a 'static' modifier on lambdas and anonymous methods, which disallows capture of locals or instance state from containing scopes.

动机Motivation

避免意外捕获来自封闭上下文的状态，这可能导致捕获对象的意外保留或意外的额外分配。Avoid unintentionally capturing state from the enclosing context, which can result in unexpected retention of captured objects or unexpected additional allocations.

详细设计Detailed design

Lambda 或匿名方法可能具有 static 修饰符。A lambda or anonymous method may have a static modifier. static修饰符指示 lambda 或匿名方法为 静态匿名函数。The static modifier indicates that the lambda or anonymous method is a static anonymous function.

静态匿名函数 无法从封闭范围中捕获状态。A static anonymous function cannot capture state from the enclosing scope. 因此， this 不能在 静态匿名函数 内使用封闭范围中的局部变量、参数和。As a result, locals, parameters, and this from the enclosing scope are not available within a static anonymous function.

静态匿名函数 不能通过隐式或显式或引用来引用实例成员 this base 。A static anonymous function cannot reference instance members from an implicit or explicit this or base reference.

静态匿名函数 可以引用 static 封闭范围内的成员。A static anonymous function may reference static members from the enclosing scope.

静态匿名函数 可以引用 constant 来自封闭范围的定义。A static anonymous function may reference constant definitions from the enclosing scope.

nameof() 在 静态匿名函数 中，可以引用局部变量、参数或 this 或 base 从封闭范围引用。nameof() in a static anonymous function may reference locals, parameters, or this or base from the enclosing scope.

封闭范围中的成员的可访问性规则与 private static 非 static 匿名函数相同。Accessibility rules for private members in the enclosing scope are the same for static and non-static anonymous functions.

不保证 静态匿名函数 定义是否作为 static 元数据中的方法发出。No guarantee is made as to whether a static anonymous function definition is emitted as a static method in metadata. 这留给了编译器实现进行优化。This is left up to the compiler implementation to optimize.

非 static 本地函数或匿名函数可以从封闭 静态匿名函数 捕获状态，但不能在封闭 静态匿名函数 之外捕获状态。A non-static local function or anonymous function can capture state from an enclosing static anonymous function but cannot capture state outside the enclosing static anonymous function.

static从有效程序中的匿名函数删除修饰符不会更改程序的含义。Removing the static modifier from an anonymous function in a valid program does not change the meaning of the program.