diff -r 0d2114eb412a -r 5539322f68c9 src/Pure/System/session_manager.scala
--- a/src/Pure/System/session_manager.scala	Fri Jul 20 22:29:25 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,48 +0,0 @@
-/*  Title:      Pure/System/isabelle_manager.scala
-    Author:     Makarius
-
-Isabelle session manager.
-*/
-
-package isabelle
-
-
-import java.io.{File, FileFilter}
-
-
-class Session_Manager
-{
-  val ROOT_NAME = "session.root"
-
-  def is_session_file(file: File): Boolean =
-    file.isFile && file.getName == ROOT_NAME
-
-  def is_session_dir(dir: File): Boolean =
-    dir.isDirectory && (new File(dir, ROOT_NAME)).isFile
-
-
-  // FIXME handle (potentially cyclic) directory graph
-  private def find_sessions(reverse_prefix: List[String], reverse_sessions: List[List[String]],
-    dir: File): List[List[String]] =
-  {
-    val (reverse_prefix1, reverse_sessions1) =
-      if (is_session_dir(dir)) {
-        val name = dir.getName  // FIXME from root file
-        val reverse_prefix1 = name :: reverse_prefix
-        val reverse_sessions1 = reverse_prefix1.reverse :: reverse_sessions
-        (reverse_prefix1, reverse_sessions1)
-      }
-      else (reverse_prefix, reverse_sessions)
-
-    val subdirs =
-      dir.listFiles(new FileFilter { def accept(entry: File) = entry.isDirectory })
-    (reverse_sessions1 /: subdirs)(find_sessions(reverse_prefix1, _, _))
-  }
-
-  def component_sessions(): List[List[String]] =
-  {
-    val toplevel_sessions =
-      Isabelle_System.components().map(Isabelle_System.platform_file).filter(is_session_dir)
-    ((Nil: List[List[String]]) /: toplevel_sessions)(find_sessions(Nil, _, _)).reverse
-  }
-}