Go高级特性探究之稳定排序详解

type Student struct {
    Id    int     sort:"id"
    Name  string  sort:"name"
    Score float64 sort:"score"
}

func SortSliceStable(slice interface{}, sortField string) {
    rv := reflect.ValueOf(slice)
    if rv.Kind() != reflect.Slice {
        panic("SortSliceStable called with non-slice type")
    }
    if rv.Len() == 0 {
        return
    }
    // 获取结构体的元素类型
    elemType := rv.Type().Elem()
    // 获取排序字段
    field, ok := elemType.FieldByName(sortField)
    if !ok {
        panic("SortSliceStable called with unknown or unexported struct field name: " + sortField)
    }
    // 获取 less 函数
    less := func(i, j int) bool {
        v1 := rv.Index(i).FieldByName(field.Name)
        v2 := rv.Index(j).FieldByName(field.Name)
        switch v1.Kind() {
        case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
            return v1.Int() < v2.Int()
        case reflect.Float32, reflect.Float64:
            return v1.Float() < v2.Float()
        case reflect.String:
            return v1.String() < v2.String()
    }
    panic("unsupported type")
}
// 使用 sort.SliceStable 进行排序
sort.SliceStable(slice, less)
}

func main() {
    students := []Student{
        {1, "zhangsan", 90.0},
        {2, "lisi", 80.0},
        {3, "wangwu", 70.0},
    }
    // 按照 Name 字段进行排序
    SortSliceStable(students, "name")
    fmt.Println(students)
}