I make a quick attempt, but there is no way to write:

```scala
case DRef.IsKeyword(KW(":foo/bar")) => …
```

?

I get:

```
[error] DatomicDataSpec.scala:34:
macro method KW is not a case class constructor, nor does it have an unapply/unapplySeq method
[error]         case DRef.IsKeyword(KW(":foo/bar"))  => success
```