Today I’m live streaming again at the regular time, and I’ll be reviewing your Go code!. I have already received a few submissions, but there’s still time to send yours! And, of course, [join me for the live stream!](https://www.youtube.com/watch?v=pgfyrmWiUCk

The spec lays out 6 rules. We’ll start at the beginning, and discuss the first one.

Selectors

…

The following rules apply to selectors:

1. For a value x of type T or *T where T is not a pointer or interface type, x.f denotes the field or method at the shallowest depth in T where there is such an f. If there is not exactly one f with shallowest depth, the selector expression is illegal.

I promised we’d talk about depth soon. And now here we are. So what does this rule mean in practice? Let’s look at an example. (Forgive the horrible data modeling.)

type Person struct {
	Name string
	Age  int
}

type Department struct {
	Name string
}

type Manager struct {
	Department
	Person
}

type Employee struct {
	Person
	Manager
	JobTitle string
}

var e Employee
var m Manager

e.Name // References Employee.Person.Name, with depth 1
m.Name // Illegal: Both m.Department.Name and m.Person.Name have equal depth of 1

Quotes from The Go Programming Language Specification Version of August 2, 2023