如何处理将另一种类型封装为参数的结构片

Question

I have two structs (Dimension and Metric) and part of their attributes overlap, so I decided to go with a common struct that is then encapsulated.

type Attribute struct {
    Function *string
    Id *string
}

type Dimension struct {
    Attribute
    Class *string
}

type Metric struct {
    Alias *string
    Attribute
}

What I would like is to have a function that takes a slice of either Dimensions or a slice of Metrics and sorts it by the id field, which is common between the two.

dimensions := []Dimension{...}
metrics := []Metric{...}
sortById(dimensions)
sortById(metrics)

I could use a slice of interface types func sortItems(items []interface{}) but I would prefer to avoid this so I was wondering how I can do something like the lines below.

func sortItems(items []Attribute) {
    //Sort here
}

If I try this, I am getting cannot use metrics (type []Metric) as type []Attribute in argument to this.sortItems which is to be expected, but I am new enough to Go not to know how to approach this.

I know I could just create two functions (one for each type) but I am curious what the correct pattern is for tackling issues like these in Go.

Answer 1

Define an interface and have it be implemented by the common type Attribute.

Something like this:

type Attributer interface {
    GetId() *int
}

func (a Attribute) GetId() *int {
    return a.Id
}

func sortItems(items []Attributer) {
    //Sort here
}

By virtue of embedding the Attribute type, both Dimension and Metric can be used wherever the Attributer interface is expected.

So this will compile just fine.

items := []Attributer{Dimension{}, Metric{}}