add 'project /' and 'project ..' commands

main/Command.scala

@@ -79,9 +79,18 @@ trait Named
 {
 	def name: String
 }
+
+trait Navigation[Project]
+{
+	def parentProject: Option[Project]
+	def self: Project
+	def initialProject(s: State): Project
+	def projectClosure(s: State): Seq[Project]
+	def rootProject: Project
+}
 trait Member[Node <: Member[Node]]
-{ self: Node =>
-	def projectClosure(state: State): Seq[Node]
+{
+	def navigation: Navigation[Node]
 }
 trait Tasked
 {

main/CommandSupport.scala

@@ -53,6 +53,14 @@ ProjectCommand +
 """ + ProjectCommand + """ name
 	Changes to the project with the provided name.
 	This command fails if there is no project with the given name.
+""" + ProjectCommand + """ /
+	Changes to the initial project.
+""" + ProjectCommand + """ ..
+	Changes to the parent project of the current project.
+	If there is no parent project, the current project is unchanged.
+
+	Use n+1 dots to change to the nth parent.
+	For example, 'project ....' is equivalent to three consecutive 'project ..' commands.
 """
 
 	def projectsBrief = (ProjectsCommand, projectsDetailed)

main/Main.scala

@@ -199,7 +199,7 @@ object Commands
 	def projects = Command { case s @ State(d: Member[_]) =>
 		Apply.simple(ProjectsCommand, projectsBrief, projectsDetailed ) { (in,s) =>
 			val log = logger(s)
-			d.projectClosure(s).foreach { case n: Named => listProject(n, d eq n, log); case _ => () }
+			d.navigation.projectClosure(s).foreach { case n: Named => listProject(n, d eq n, log); case _ => () }
 			s
 		}(s)
 	}
@@ -212,17 +212,34 @@ object Commands
 				logger(s).info(d.name)
 				s
 			}
+			else if(to == "/")
+				setProject(d.navigation.initialProject(s), s)
+			else if(to.forall(_ == '.'))
+				if(to.length > 1) gotoParent(to.length - 1, d, s) else s
 			else
 			{
-				d.projectClosure(s).find { case n: Named => n.name == to; case _ => false } match
+				d.navigation.projectClosure(s).find { case n: Named => n.name == to; case _ => false } match
 				{
-					case Some(np) => logger(s).info("Set current project to " + to); s.copy(np)()
+					case Some(np) => setProject(np, s)
 					case None => logger(s).error("Invalid project name '" + to + "' (type 'projects' to list available projects)."); s.fail
 				}
 			}
 		}(s)
 	}
-	
+	@tailrec def gotoParent[Node <: Member[Node]](n: Int, base: Member[Node], s: State): State =
+		base.navigation.parentProject match
+		{
+			case Some(pp) => if(n <= 1) setProject(pp, s) else gotoParent(n-1, pp, s)
+			case None => if(s.project == base) s else setProject(base, s)
+		}
+
+	def setProject(np: AnyRef, s: State): State =
+	{
+		np match { case n: Named =>
+			logger(s).info("Set current project to " + n.name)
+		}
+		s.copy(np)()
+	}
 	def exit = Command { case s => Apply( Help(exitBrief) ) {
 		case in if TerminateActions contains in.line =>
 			runExitHooks(s).exit(true)

main/MultiProject.scala

@@ -152,7 +152,12 @@ object MultiContext
 		val static = (o: Owner, s: String) => context(o).static(o, s)
 	}
 }
-
+final class MultiNavigation(val self: Project, val parentProject: Option[Project]) extends Navigation[Project]
+{
+	def initialProject(s: State): Project = MultiProject.initialProject(s, rootProject)
+	def projectClosure(s: State): Seq[Project] = MultiProject.topologicalSort(initialProject(s))
+	@tailrec final lazy val rootProject: Project = parentProject match { case Some(p) => p.navigation.rootProject; case None => self }
+}
 trait Project extends Tasked with HistoryEnabled with Member[Project] with Named with ConsoleTask with Watched
 {
 	val info: ProjectInfo
@@ -165,8 +170,7 @@ trait Project extends Tasked with HistoryEnabled with Member[Project] with Named
 	def historyPath = Some(outputRootPath / ".history")
 	def streamBase = outputRootPath / "streams"
 
-	def projectClosure(s: State): Seq[Project] = MultiProject.topologicalSort(MultiProject.initialProject(s, rootProject))
-	@tailrec final def rootProject: Project = info.parent match { case Some(p) => p.rootProject; case None => this }
+	def navigation: Navigation[Project] = new MultiNavigation(this, info.parent)
 
 	implicit def streams = Dummy.Streams
 	def input = Dummy.In