Go语言中利用接口实现结构体切片的通用迭代与数据提取

type Foo struct {
    Id int
    Name string
}

type Bar struct {
    Id int
    Value float64
}

func getIdsFoo(foos []Foo) []int {
    ids := make([]int, 0, len(foos))
    for _, f := range foos {
        ids = append(ids, f.Id)
    }
    return ids
}

func getIdsBar(bars []Bar) []int {
    ids := make([]int, 0, len(bars))
    for _, b := range bars {
        ids = append(ids, b.Id)
    }
    return ids
}

type Identifiable interface {
    GetId() int
}

type Foo struct {
    Id int
    Name string
}

// Foo 类型实现了 Identifiable 接口
func (f Foo) GetId() int {
    return f.Id
}

type Bar struct {
    Id int
    Value float64
}

// Bar 类型也实现了 Identifiable 接口
func (b Bar) GetId() int {
    return b.Id
}

func GatherIds(items []Identifiable) []int {
    ids := make([]int, 0, len(items)) // 预分配容量，提高效率
    for _, item := range items {
        ids = append(ids, item.GetId()) // 调用接口方法获取ID
    }
    return ids
}

package main

import "fmt"

// 定义 Identifiable 接口
type Identifiable interface {
    GetId() int
}

// Foo 结构体及其 GetId 方法
type Foo struct {
    Id   int
    Name string
}

func (f Foo) GetId() int {
    return f.Id
}

// Bar 结构体及其 GetId 方法
type Bar struct {
    Id    int
    Value float64
}

func (b Bar) GetId() int {
    return b.Id
}

// 通用函数：从 Identifiable 切片中收集所有 ID
func GatherIds(items []Identifiable) []int {
    ids := make([]int, 0, len(items))
    for _, item := range items {
        ids = append(ids, item.GetId())
    }
    return ids
}

func main() {
    // 创建 Foo 结构体切片
    foos := []Foo{
        {Id: 101, Name: "Alpha"},
        {Id: 102, Name: "Beta"},
        {Id: 103, Name: "Gamma"},
    }

    // 将 []Foo 转换为 []Identifiable
    // 注意：Go不支持直接将 []Foo 赋值给 []Identifiable
    // 需要逐个元素进行转换或通过辅助函数
    identifiableFoos := make([]Identifiable, len(foos))
    for i, f := range foos {
        identifiableFoos[i] = f
    }

    // 使用通用函数处理 Foo 切片
    fooIds := GatherIds(identifiableFoos)
    fmt.Printf("Foo IDs: %v\n", fooIds) // 输出: Foo IDs: [101 102 103]

    // 创建 Bar 结构体切片
    bars := []Bar{
        {Id: 201, Value: 1.1},
        {Id: 202, Value: 2.2},
    }

    // 将 []Bar 转换为 []Identifiable
    identifiableBars := make([]Identifiable, len(bars))
    for i, b := range bars {
        identifiableBars[i] = b
    }

    // 使用通用函数处理 Bar 切片
    barIds := GatherIds(identifiableBars)
    fmt.Printf("Bar IDs: %v\n", barIds) // 输出: Bar IDs: [201 202]

    // 也可以直接创建 Identifiable 类型的切片
    mixedItems := []Identifiable{
        Foo{Id: 301, Name: "Delta"},
        Bar{Id: 302, Value: 3.3},
        Foo{Id: 303, Name: "Epsilon"},
    }
    mixedIds := GatherIds(mixedItems)
    fmt.Printf("Mixed IDs: %v\n", mixedIds) // 输出: Mixed IDs: [301 302 303]
}