GoLang约定-从切片创建自定义类型

Question

Is it a good idea to create own type from a slice in Golang?

Example:

type Trip struct {
    From   string
    To     string
    Length int
}

type Trips []Trip // <-- is this a good idea?

func (trips *Trips) TotalLength() int {
    ret := 0
    for _, i := range *trips {
        ret += i.Length
    }

    return ret
}

Is it somehow a convention in Golang to create types like Trips in my example? Or it is better to use []Trip in the whole project? Any pros and cons?

Answer 1

There's no convention, as far as I am aware of. It's OK to create a slice type if you really need it. In fact, if you ever want to sort your data, this is pretty much the only way: create a type and define the sort.Interface methods on it.

Also, in your example there is no need to take the address of Trips since slice is already a "fat pointer" of a kind. So you can simplify your method to:

func (trips Trips) TotalLength() (tl int) {
    for _, l := range trips {
        tl += l.Length
    }
    return tl
}