A way to just obtain a route's URL without invoking it

[kevinresol]

Given:

interface Images {
  @:get('/$filename')
  function ofFilename(filename:String):RealSource;
}

For example, on client side we may want to do something like this:

<img src=${remote.images.ofFilename('foo.jpg').asUrl()}/>

in that case we just want the URL but not actually fetch it (because the img tag will).

or on server side we may want to perform redirection:

interface Redirected {
  @:get('/$filename')
  function ofFilename(filename:String):Url {
    return new Image().ofFilename(filename).asUrl(BASE_URL);
  }
}