Leveraged -Xmigration to burn off some warts wh...

Leveraged -Xmigration to burn off some warts which arose in the new
collections. Warnings put in place for behavioral changes, allowing the
following. 1) Buffers: create new collections on

++ and -- like all the other collections.  2) Maps: eliminated
never-shipped redundant method valuesIterable and supplied these
return types:

  def keys: Iterable[A]
  def keysIterator: Iterator[A]
  def values: Iterable[B]
  def valuesIterator: Iterator[B]
  def keySet: Set[A]

I concluded that keys should return Iterable because keySet also exists
on Map, and is not solely in the province of Maps even if we wanted to
change it: it's defined on Sorted and also appears in some Sets. So it
seems sensible to have keySet return a Set and keys return the more
general type.

Closes #3089, #3145.  Review by odersky.

1 files changed, 6 insertions, 7 deletions

diff --git a/src/library/scala/collection/mutable/ImmutableMapAdaptor.scala b/src/library/scala/collection/mutable/ImmutableMapAdaptor.scala
index d6b3115b81..fba28e7c2a 100644
--- a/src/library/scala/collection/mutable/ImmutableMapAdaptor.scala
+++ b/src/library/scala/collection/mutable/ImmutableMapAdaptor.scala
@@ -12,6 +12,7 @@
 package scala.collection
 package mutable
 
+import annotation.migration
 
 /** This class can be used as an adaptor to create mutable maps from
  *  immutable map implementations. Only method <code>empty</code> has
@@ -41,19 +42,17 @@ extends Map[A, B]
 
   override def isDefinedAt(key: A) = imap.isDefinedAt(key)
 
-  override def keySet: scala.collection.Set[A] = imap.keySet
+  override def keySet: collection.Set[A] = imap.keySet
 
   override def keysIterator: Iterator[A] = imap.keysIterator
 
-  @deprecated("use `keysIterator' instead")
-  override def keys: Iterator[A] = imap.keysIterator
-
-  override def valuesIterable: scala.collection.Iterable[B] = imap.valuesIterable
+  @migration(2, 8, "As of 2.8, keys returns Iterable[A] rather than Iterator[A].")
+  override def keys: collection.Iterable[A] = imap.keys
 
   override def valuesIterator: Iterator[B] = imap.valuesIterator
 
-  @deprecated("use `valuesIterator' instead")
-  override def values: Iterator[B] = imap.valuesIterator
+  @migration(2, 8, "As of 2.8, values returns Iterable[B] rather than Iterator[B].")
+  override def values: collection.Iterable[B] = imap.values
 
   def iterator: Iterator[(A, B)] = imap.iterator