I'm trying to append a specific class to an element depending on the outcome of a switch-statement. Code below is just for clarification.

```
mixin changeColor(color)
  case color
    when 1
       .blue
    when 2
       .green
    default
       .red

div.foo +changeColor(1)
    p Bar

```

Should result in

```
<div class="foo blue">
    <p>Bar</p>
</div>

```

The foo element may contain multiple child elements, not just the `p` tag.