title: private/public fields in structs.. acting differently
body: <p>Why can I do this</p>
  
  <pre><code>package main
  
  import "fmt"
  
  func main() {
      c := Circle{x: 0, y: 0, r: 5}
      fmt.Println(c.r)
  }
  
  type Circle struct {
      x float64
      y float64
      r float64
  }
  </code></pre>
  
  <p><a href="http://play.golang.org/p/0ypcekVDV9" rel="nofollow">http://play.golang.org/p/0ypcekVDV9</a></p>
  
  <p>When I can't do the same with a struct in a package?</p>
  
  <p>If I would try to access a struct with a field with lowercase a compiler error is returned..</p>