Generating documentation for all projects

gistfile1.txt

sbt
> project docs
Set current project to docs 1.0
> docs
[info] == docs ==
[info] Generating API documentation ...

MyParentProject.scala

class MyParentProject(info: ProjectInfo) extends ParentProject(info) {

  lazy val core = project("core", "mpp-core", new Core(_))
  // ... more sub projects
  
  lazy val docs = project("docs", "docs", new Docs(_), core /*, ... */)

  def concatPaths[T](s: Seq[T])(f: PartialFunction[T, PathFinder]): PathFinder = {
    def finder: T => PathFinder = f orElse { case _ => Path.emptyPathFinder }
    (Path.emptyPathFinder /: s)(_ +++ finder(_))
  }

  def deepSources = concatPaths(topologicalSort) { case p: ScalaPaths => p.mainSources }
  def deepDocClasspath = (Path.emptyPathFinder /: dependencies.map {
    case p: DefaultProject => p.compileClasspath })(_ +++ _)

  class Docs(info: ProjectInfo) extends DefaultProject(info) {
    lazy val docs = scaladocTask("MyParentProject", deepSources, docPath, deepDocClasspath, documentOptions)
  }
}