I'm not sure this should declare a dependency on parser-combinators and xml (at most, the xml dependency is only needed for scaladoc).

But in any case, the dependency, if it exists at all, should be strict. To wit:

- at the moment, scala 2.11.0-RC1 .. 2.11.0-RC5, 2.11.0 have depended on the same, untouched verison of parser-combinators : 1.0.1.
- but one can imagine some change that would require releasing a binary-incompatible 1.1.1 Or for that matter a binary-incompatible 1.0.2. (to my knowledge there's no extant agreement on semantic versioning for combinators)
- in that case, the scala compiler may want to require a very strict version of combinators/xml.