go - 由于指针接收器无法实现 Go 接口(interface)

标签 go

<分区>

我的去测试无法通过。怎么了？ (Handle method has pointer receiver)是什么意思

package ipc

import (
    "testing"
)

// import (
//  "encoding/json"
//  "fmt"
// )

type Request struct {
    Method string `json/"method"`
    Params string `json/"params"`
}

type Response struct {
    Code string `json/"code"`
    Body string `json/"body"`
}

type Server interface {
    Name() string
    Handle(method, params string) *Response
}

type IpcServer struct {
    Server
}

func NewIpcServer(server Server) *IpcServer {
    return &IpcServer{server}
}

type EchoServer struct {
}

func (server *EchoServer) Name() string {
    return "EchoServer"
}

func (server *EchoServer) Handle(method, params string) *Response {
    return &Response{"OK", "Echo " + method + " " + params}
}

func TestIpc(t *testing.T) {
    server := EchoServer{}

    ipcServer := NewIpcServer(server)
}

当我运行 go test ipc_test.go

/ipc_test.go:49: cannot use server (type EchoServer) as type Server in argument to NewIpcServer:
    EchoServer does not implement Server (Handle method has pointer receiver)
FAIL    command-line-arguments [build failed]

最佳答案

1- 你可以使用

server := &EchoServer{}

代替

server := EchoServer{}

Method sets :

A type may have a method set associated with it. The method set of an interface type is its interface. The method set of any other type T consists of all methods declared with receiver type T. The method set of the corresponding pointer type *T is the set of all methods declared with receiver *T or T (that is, it also contains the method set of T). Further rules apply to structs containing anonymous fields, as described in the section on struct types. Any other type has an empty method set. In a method set, each method must have a unique non-blank method name.

并查看:Pointer receiver and Value receiver difference in implementation with Iris framework

2- 或者你可以使用

func (server EchoServer) Name() string {
    return "EchoServer"
}

func (server EchoServer) Handle(method, params string) *Response {
    return &Response{"OK", "Echo " + method + " " + params}
}

与

server := EchoServer{}

关于go - 由于指针接收器无法实现 Go 接口(interface)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39813730/

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