我想在gorilla/mux路由和路由器类型上添加一个方便的util方法:
package util
import(
"net/http"
"github.com/0xor1/gorillaseed/src/server/lib/mux"
)
func (r *mux.Route) Subroute(tpl string, h http.Handler) *mux.Route{
return r.PathPrefix("/" + tpl).Subrouter().PathPrefix("/").Handler(h)
}
func (r *mux.Router) Subroute(tpl string, h http.Handler) *mux.Route{
return r.PathPrefix("/" + tpl).Subrouter().PathPrefix("/").Handler(h)
}
但是编译器通知我
无法在非本地类型mux.Router上定义新方法
那我怎么做到这一点？我是否创建了一个具有匿名mux.Route和mux.Router字段的新结构类型？或者是其他东西？
我最近开始研究Go并面临下一期.我想实现Comparable接口.我有下一个代码:
type Comparable interface {
compare(Comparable) int
}
type T struct {
value int
}
func (item T) compare(other T) int {
if item.value < other.value {
return -1
} else if item.value == other.value {
return 0
}
return 1
}
func doComparison(c1, c2 Comparable) {
fmt.Println(c1.compare(c2))
}
func main() {
doComparison(T{1}, T{2})
}
所以我收到了错误
cannot use T literal (type T) as type Comparable in argument to doComparison:
T does not implement Comparable (wrong type for compare method)
have …我不明白为什么下面的代码不能编译。
我很困惑为什么 Go 说HistoryReader没有正确实现IReader。HistoryBook实现IBook. 当尝试将 a 添加到 s 的切片时，为什么Read(book Ibook)和不能同时接受？Read(book HistoryBook)HistoryReaderIReader
package main
type IReader interface {
Read(book IBook)
}
// HistoryReader implements IReader
type HistoryReader struct{}
func (r *HistoryReader) Read(book HistoryBook) {
// ...
}
type IBook interface{}
// HistoryBook implements IBook
type HistoryBook struct{}
func main() {
var readerSlice []IReader
_ = append(readerSlice, &HistoryReader{})
}
package main
type IReader interface {
Read(book IBook)
}
// …// BEGIN: external library
type realX struct {}
type realY struct {}
func (realX) Do() realY {
return realY{}
}
// END
type A struct {
a myX
}
type myY interface {}
type myX interface {
Do() myY
}
func foo (arg1 myY) {
}
func main() {
foo(realY{})
x := A{realX{}}
fmt.Println("Hello, playground")
}
我明白了:
cannot use realX literal (type realX) as type myX in field value:
realX does not implement myX (wrong type for Do method)
have …