Q: Why lambda struct needed?

A: With the structure like:

type person struct {
	name string
	age  int
}

type student struct {
	young person
	class  string
}

s := student{
    young: person{
        name: "hxia",
        age:  21,
    },
    class: "三年二班",
}

fmt.Printf("%p, %p, %p, %p, %p\n", &s, &s.young, &s.young.name, &s.young.age, &s.class)

output:

0xc0000a0150, 0xc0000a0150, 0xc0000a0150, 0xc0000a0160, 0xc0000a0168

With the named struct, the student access to the filed of name/age, it should access to the identifier young first.

With the lambda structure nesting like:

type empolyee struct {
	person
	company string
}

e := empolyee{
    person:  s.young,
    company: "Nokia",
}

fmt.Printf("%p, %p, %p, %p, %p\n", &e, &e.person, &e.person.name, &e.person.age, &e.company)
fmt.Println(e.name, e.age)

output:

0xc000074150, 0xc000074150, 0xc000074150, 0xc000074160, 0xc000074168
hxia 21

The memory allocated is same as specific struct nesting, but can directly access to the filed of name/age by object e.
It can implement the effect of inherit, which to make a relationship with A has B, like e