How do I embed a channel in a struct in Go?
Why the inconsistency between the map syntax:
var m map[string]int
and channel,
var m chan int
?
To clarify, in Go it is possible to embed a type in another type. The embedder type gains access to all the methods defined on the embedded type, but it is also possible to refer to the embedded type explicitly by the name of its type. Therefore, the inconsistency between the map type declaration and channel type declaration is confusing for someone who would like to refer to an embedded channel type.
The problem is that embedding allows you mainly to benefit from the methods from the embedded type (as mentioned in "Embedding instead of inheritance in Go")
And channel, like map, is an unnamed type (specified using a type literal, which composes a new type from existing types.).
It doesn't have methods of its own, or exported fields, so you wouldn't go very far by embedding a channel type within a struct {}.
You would probably have an error message similar as the one in this example:
func (x chan int) m2() {}
invalid receiver type chan int (chan int is an unnamed type)
If embedding a channel type within a struct type worked, that unnamed type would be able to act as a receiver for methods, which doesn't seem to be allowed by the language in the first place.