Add the flat classpath type aggregating flat classpath instances

There's added AggregateFlatClassPath - an equivalent of
MergedClassPath from the old implementation. It is supposed to group
classpath instances handling different files being directories, zips
or jars.

Unlike in the case of the old (recursive) implementation, there won't
be a deep, nested hierarchy of classpath instances - just one root
(aggregate) and a flat structure of its children.

AggregateFlatClassPath ensures the distinction of classpath entries
and merges corresponding entries for class and source files into one
entry. This is required as SymbolLoaders class makes use of this kind
of ClassRepresentation.

There are also added unit tests which check whether
AggregateFlatClassPath obtains correct entries from classpath
instances specified in a constructor and whether it preserves the
ordering in the case of repeated entries. There's added a test type
of flat classpath using VirtualFiles so it's easy to check the real
behaviour.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala b/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
index f1bb6010a4..bbd244b647 100644
--- a/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
+++ b/src/compiler/scala/tools/nsc/classpath/FlatClassPath.scala
@@ -47,6 +47,12 @@ object FlatClassPath {
 
 case class FlatClassPathEntries(packages: Seq[PackageEntry], classesAndSources: Seq[ClassRepClassPathEntry])
 
+object FlatClassPathEntries {
+  import scala.language.implicitConversions
+  // to have working unzip method
+  implicit def entry2Tuple(entry: FlatClassPathEntries) = (entry.packages, entry.classesAndSources)
+}
+
 sealed trait ClassRepClassPathEntry extends ClassRepresentation[AbstractFile]
 
 trait ClassFileEntry extends ClassRepClassPathEntry {