Overhaul of JavaConver{sions,ters}.

Initially motivated by SI-5580, then just motivated.  I broke up
the opaquely named JavaConversions and JavaConverters into the following
traits encapsulating some permutation of

  { to java, to scala, bidirectional }
  { wrappers, decorators }

I named everything consistently in terms of either Wrappers
or Decorators.  Decorators install those asJava/asScala methods
onto collections of the right kind; Wrappers hide the process.

JavaConversions then reduces to an object which (ill-advisedly)
extends both WrapAsJava and WrapAsScala.  And JavaConverters is
an object extending DecorateAsScala and DecorateAsJava.  However
other more clearly named vals exist in the newly created
scala.collection.convert package object.

  val decorateAsJava  = new DecorateAsJava { }
  val decorateAsScala = new DecorateAsScala { }
  val decorateAll     = new DecorateAsJava with DecorateAsScala { }
  val wrapAsJava      = new WrapAsJava { }
  val wrapAsScala     = new WrapAsScala { }
  val wrapAll         = new WrapAsJava with WrapAsScala { }

So for instance to import asScala decorators, and only those:

  scala> import scala.collection.convert.decorateAsScala._
  import scala.collection.convert.decorateAsScala._

  scala> new java.util.ArrayList[String].asScala groupBy (x => x)
  res0: scala.collection.immutable.Map[String,scala.collection.mutable.Buffer[String]] = Map()

I propose we put those vals or a subset of them in the scala
package object rather than way down in scala.collection.convert.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/library/scala/collection/mutable/WeakHashMap.scala b/src/library/scala/collection/mutable/WeakHashMap.scala
index 89d7c7a695..4e09755acf 100644
--- a/src/library/scala/collection/mutable/WeakHashMap.scala
+++ b/src/library/scala/collection/mutable/WeakHashMap.scala
@@ -6,14 +6,11 @@
 **                          |/                                          **
 \*                                                                      */
 
-
-
 package scala.collection
 package mutable
 
-import JavaConversions._
 import generic._
-
+import convert.Wrappers._
 
 /** A hash map with references to entries which are weakly reachable. Entries are
  *  removed from this map when the key is no longer (strongly) referenced. This class wraps