golang 泛型
2021-01-17
go
背景
目前所在项目是关于资产管理，经常会有各种数据做各种操作，比如，各类数值型Join, Sort, Unique等很多操作。
由于在目前的golang 版本不支持多态， 只能人工的方式来实现。效果如下：
（图片来源）https://groups.google.com/g/golang-nuts/c/j_3n5wAZaXw/m/YkOdbCppAQAJ
泛型实现
- 多态
- 类型推导
- 操作符重载
golang 实现
golang 目前完成的主要是类型推导
如何使用golang
编译支持golang的版本
git clone https://github.com/golang/go
git checkout dev.go2go
cd src
./all.bash
go tool go2go run xx.go2
例子
(https://go2goplay.golang.org/)[官方实例]
数据类型的Join. file name: intJoin.go2
package main
import (
"fmt"
"strings"
)
func main() {
str := Join([]int64{1,2,3,4});
fmt.Println("int64", str)
str = Join([]int32{1,2,3,4});
fmt.Println("int32", str)
str = JoinNumber([]int64{1,2,3,4});
fmt.Println("int64", str)
str = JoinNumber([]int32{1,2,3,4});
fmt.Println("int32", str)
// NOTICE: ERROR. 类型不匹配时候的问题
/*
str = JoinNumber([]string{"1","2","3","4"});
fmt.Println("int32", str)
*/
}
func Join[T any](arr []T) string {
str := ""
for _, v := range arr {
str = fmt.Sprintf("%s,%v", str,v)
}
return strings.Trim(str, ",")
}
type numeric interface {
type int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64
}
func JoinNumber[T numeric](arr []T) string {
str := ""
for _, v := range arr {
str = fmt.Sprintf("%s,%v", str,v)
}
return strings.Trim(str, ",")
}
数组结构体多态实例， file: struct.go2
package main
import ("fmt")
type Pair[T1 , T2 any] struct {
ID T1
Val T2
}
type MapArr[T1, T2 any] struct {
s []Pair[T1, T2]
}
func (m * MapArr[T1,T2]) Set(k T1, v T2) {
m.s = append(m.s, Pair[T1,T2]{k,v})
}
func (m * MapArr[T1,T2]) Print() {
for _, p := range m.s {
fmt.Printf(" info:(id: %s, val:%v)", p.ID, p.Val)
}
fmt.Printf("\n")
}
func main() {
kvArr := &MapArr[string, int]{}
kvArr.s = []Pair[string, int]{}
kvArr.Set("k1", int(1))
kvArr.Set("k2", int(2))
fmt.Printf("str,int")
kvArr.Print()
kvArr1 := &MapArr[string, string]{}
kvArr1.s = []Pair[string, string]{}
kvArr1.Set("k1", "v1")
kvArr1.Set("k2", "v2")
fmt.Printf("str,str")
kvArr1.Print()
}