struct first line is just an interface, what does it mean?

Question

I come across this code in Go:

type Mytype struct {
  Interfacename
  var1  ClientInterface1
  var2  ClientInterface2
  id    int
}

What does that first field mean?

Thanks Flimzy for the help! – Jamesszm Apr 08 '17 at 00:58 — Jamesszm, Apr 08 '17 at 00:58

alexbt · Answer 1 · 2017-04-08T11:37:19.267

2

Mostly, this is how some sort of inheritance (by composition rather than inheritance) is achieved in go. Check this out: https://golang.org/doc/effective_go.html#embedding

This will grant the Outer type (MyType) access to this inner type's Receiver methods (the assigned struct{} since this is an interface).

From Go Effective:

There's an important way in which embedding differs from subclassing. When we embed a type, the methods of that type become methods of the outer type, but when they are invoked the receiver of the method is the inner type, not the outer one

Thanks @Flimzy and @md2perpe

Also, this defines an anonymous field, for which the variable name will be the same as its type name.

edited Apr 08 '17 at 11:37

answered Apr 08 '17 at 00:56

alexbt

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oh ya, Kitchen in the example is not a type interface – Jamesszm Apr 08 '17 at 01:00
In the language of object orientation: this is how to do inheritance in Go. – md2perpe Apr 08 '17 at 06:38

struct first line is just an interface, what does it mean?

1 Answers1