Go 如果函数不是隐式的,那么对接口的调用如何访问函数?
下面是一个结构Go 如果函数不是隐式的,那么对接口的调用如何访问函数?,go,interface,Go,Interface,下面是一个结构Config,其中包含一个匿名函数ReturnNewAddress,该函数返回一个net.Conn接口返回新地址然后用于返回“addr” type struct Config { ReturnNewAddress func(net.Conn, error) } 下面调用了匿名函数ReturnnewAddress,请注意cfg是Config的一个实例 addr, err := cfg.ReturnNewAddress() 所以我的问题来了-考虑到接口包含许多不同的
Config
,其中包含一个匿名函数ReturnNewAddress
,该函数返回一个net.Conn
接口<代码>返回新地址然后用于返回“addr”
type struct Config {
ReturnNewAddress func(net.Conn, error)
}
下面调用了匿名函数ReturnnewAddress
,请注意cfg
是Config
的一个实例
addr, err := cfg.ReturnNewAddress()
所以我的问题来了-考虑到接口包含许多不同的功能,接口net.Conn
如何知道使用什么功能?让我感到困惑的是,LocalAddr()
或RemoteAddr()
不是隐式调用的。如何知道显式使用这些方法之一。如果我需要在RemoteAddr
上显式使用LocalAddr
,该怎么办
下面是net.Conn的go文档:
type Conn interface {
// Read reads data from the connection.
// Read can be made to time out and return an Error with Timeout() == true
// after a fixed time limit; see SetDeadline and SetReadDeadline.
Read(b []byte) (n int, err error)
// Write writes data to the connection.
// Write can be made to time out and return an Error with Timeout() == true
// after a fixed time limit; see SetDeadline and SetWriteDeadline.
Write(b []byte) (n int, err error)
// Close closes the connection.
// Any blocked Read or Write operations will be unblocked and return errors.
Close() error
// LocalAddr returns the local network address.
LocalAddr() Addr
// RemoteAddr returns the remote network address.
RemoteAddr() Addr
// SetDeadline sets the read and write deadlines associated
// with the connection. It is equivalent to calling both
// SetReadDeadline and SetWriteDeadline.
//
// A deadline is an absolute time after which I/O operations
// fail with a timeout (see type Error) instead of
// blocking. The deadline applies to all future and pending
// I/O, not just the immediately following call to Read or
// Write. After a deadline has been exceeded, the connection
// can be refreshed by setting a deadline in the future.
//
// An idle timeout can be implemented by repeatedly extending
// the deadline after successful Read or Write calls.
//
// A zero value for t means I/O operations will not time out.
SetDeadline(t time.Time) error
// SetReadDeadline sets the deadline for future Read calls
// and any currently-blocked Read call.
// A zero value for t means Read will not time out.
SetReadDeadline(t time.Time) error
// SetWriteDeadline sets the deadline for future Write calls
// and any currently-blocked Write call.
// Even if write times out, it may return n > 0, indicating that
// some of the data was successfully written.
// A zero value for t means Write will not time out.
SetWriteDeadline(t time.Time) error
}
Conn is a generic stream-oriented network connection.
这个问题还不完全清楚,但是 配置类型的代码似乎有一个输入错误
ReturnNewAddress func(net.Conn, error)
没有与后面的代码兼容的函数类型
addr, err := cfg.ReturnNewAddress()
我认为配置结构类型应该定义为
type struct Config {
ReturnNewAddress func()(net.Conn, error)
}
基于此,调用cfg.ReturnNewAddress()
返回的变量addr
的类型为net.Conn
,因此它是实现接口net.Conn
的值。因此,您可以按如下方式显式调用所需的函数:
localAddr :=addr.LocalAddr();
remoteAddr := addr.RemoteAddr();
我不确定我是否理解这个问题-它知道根据调用什么函数和底层类型使用什么函数。您的变量引用可能是接口类型,但是调用只能发生在值的具体类型上。这是函数
ReturnNewAddress
的实现,或者它出现在go src中,因为我可以看到conn
接口及其函数实现,但看不到包含匿名函数的ReturnNewAddress
,返回net.Conn接口的ReturnNewAddress
也许您的代码弄混了,但正如所写的,您的ReturnNewAddress
是一个函数字段,它接受net.Conn和一个错误,但不返回任何内容。@Kaedys这就是为什么我问OP他的实现是否实际工作的原因。