Properly using map[string]interface{}?

I have two related questions, I did not want to open a new thread for both questions:

Given the following code:

1    type Request struct {
2       Values map[string]interface{}
3    }
4
5    func (r Request) Send() {
6       client := &http.Client{}
7       resp, _ := http.Post("http://example.com", "text/json", &r.Values)
8    }

The idea is to be able to send a block of an unknown amount key => value, key => key => value, etc. to our API endpoint.

Question 1:

How do I assign to Request.Values? An example use case we may need to employ is the following (Excuse the PHP Code, we're transitioning):

'name' => [ $first, $last ],
'address' => [ 'city' => 'city', 'state' => 'state' ],
'country' => 'US'

In this example we have key => value, key => [ values ], and key => [ key => value ]

How can I take that and assign the exact same values to Request.Values?

Question 2:

Obviously Values is of type map[string]interface{} , how can I convert that to type io.Reader so I can send the values to the server?

Any guidance is greatly appreciated on both questions.

Question 1

You can assign values to Request.Values just like with any other value.

Example (on play):

x := map[string]interface{}{
	"foo": []string{"a","b"},
	"bar": "foo",
	"baz": 10.4,
}

Question 2

You are in need of an intermediate format, for example JSON.

With this package you can marshal your Request struct to a JSON string, transfer
said string and parse it on the other (PHP?) side.