Go语言语法混乱

So I'm brand new to Go, I am moving over from python b/c of concurrecny. Anyways I was looking at the net/http package documentation and stumbled upon this:

client := &http.Client{
    CheckRedirect: redirectPolicyFunc
}

So I see we are creating a client variable by referencing the original Client structure (I think that is how you would word that) but I am totally lost at the

CheckRedirect: redirectPolicyFunc

What the heck does the ":" mean and what are we doing with it? Also what are the things before and after it? I read the struct documentation and did the introduction to go tutorial but I didn't see anything, I may not of been looking hard enough. No doubt its simple I just have no idea where to start looking for answers.

Thanks for the answers everyone! This makes much more sense now!

This is called a composite literal.

You're just creating an instance of the http.Client type and setting the CheckRedirect property, then taking a pointer of it.