Initialize embedded struct in Go

Question

I have the following struct which contains a net/http.Request :

type MyRequest struct {
    http.Request
    PathParams map[string]string
}

Now I want to initialize the anonymous inner struct http.Request in the following function:

func New(origRequest *http.Request, pathParams map[string]string) *MyRequest {
    req := new(MyRequest)
    req.PathParams = pathParams
    return req
}

How can I initialize the inner struct with the parameter origRequest ?

Answer 1

req := new(MyRequest)
req.PathParams = pathParams
req.Request = origRequest

or...

req := &MyRequest{
  PathParams: pathParams
  Request: origRequest
}

See: http://golang.org/ref/spec#Struct_types for more about embedding and how the fields get named.

Answer 2

What about:

func New(origRequest *http.Request, pathParams map[string]string) *MyRequest {
        return &MyRequest{*origRequest, pathParams}
}

It shows that instead of

New(foo, bar)

you might prefer just

&MyRequest{*foo, bar}

directly.

Answer 3

As Jeremy shows above, the "name" of an anonymous field is the same as the type of the field. So if the value of x were a struct containing an anonymous int, then x.int would refer to that field.