Fxied bug 909;

Updated collection library

20 files changed, 44 insertions, 47 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 2bea199dbc..b964c73297 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -627,10 +627,12 @@ trait Typers requires Analyzer {
           instantiate(tree, mode, pt)
         } else if (tree.tpe <:< pt) {
           tree
-        } else if ((mode & PATTERNmode) != 0) {
-          if ((tree.symbol ne null) && tree.symbol.isModule) inferModulePattern(tree, pt)
-          tree
         } else {
+          if ((mode & PATTERNmode) != 0) {
+            if ((tree.symbol ne null) && tree.symbol.isModule)
+              inferModulePattern(tree, pt)
+            if (isPopulated(tree.tpe, pt)) return tree
+          }
           val tree1 = constfold(tree, pt) // (10) (11)
           if (tree1.tpe <:< pt) adapt(tree1, mode, pt)
           else {
@@ -2335,9 +2337,9 @@ trait Typers requires Analyzer {
         try {
 //        if (!isLocal) tree setSymbol info.sym
           val tree1 = typed1(tree, EXPRmode, pt)
-          if (settings.debug.value) log("typed implicit "+tree1+":"+tree1.tpe+", pt = "+pt)
+          //if (settings.debug.value) log("typed implicit "+tree1+":"+tree1.tpe+", pt = "+pt)
           val tree2 = adapt(tree1, EXPRmode, pt)
-          if (settings.debug.value) log("adapted implicit "+tree1.symbol+":"+tree2.tpe+" to "+pt)
+          //if (settings.debug.value) log("adapted implicit "+tree1.symbol+":"+tree2.tpe+" to "+pt)
           if (tree2.tpe.isError) EmptyTree
           else if (info.sym == tree1.symbol) tree2
           else fail("syms differ: ", tree1.symbol, info.sym)
diff --git a/src/library/scala/Option.scala b/src/library/scala/Option.scala
index 8167b5cb6a..46b659caac 100644
--- a/src/library/scala/Option.scala
+++ b/src/library/scala/Option.scala
@@ -31,10 +31,14 @@ object Option {
  */
 sealed abstract class Option[+A] extends Product {
 
-  /** True if the option is the <code>None</value>, false otherwise.
+  /** True if the option is the <code>None</code> value, false otherwise.
    */
   def isEmpty: Boolean
 
+  /** True if the option is a <code>Some</code>(...) false otherwise.
+   */
+  def isDefined: Boolean = !isEmpty
+
   /** get the value of this option.
    *  @requires that the option is nonEmpty.
    *  @throws Predef.NoSuchElementException if the option is empty.
diff --git a/src/library/scala/Predef.scala b/src/library/scala/Predef.scala
index 05f38e8688..b562fbed97 100644
--- a/src/library/scala/Predef.scala
+++ b/src/library/scala/Predef.scala
@@ -61,11 +61,11 @@ object Predef {
 
   type Function[-a,+b] = Function1[a,b]
 
-  type Map[a, b] = collection.mutable.Map[a, b]
-  type Set[a] = collection.mutable.Set[a]
+  type Map[a, b] = collection.immutable.Map[a, b]
+  type Set[a] = collection.immutable.Set[a]
 
-  val Map = collection.mutable.Map
-  val Set = collection.mutable.Set
+  val Map = collection.immutable.Map
+  val Set = collection.immutable.Set
 
 
   // errors and asserts -------------------------------------------------
diff --git a/src/library/scala/collection/immutable/Map.scala b/src/library/scala/collection/immutable/Map.scala
index 8c9b3b75b8..ef056e75f5 100644
--- a/src/library/scala/collection/immutable/Map.scala
+++ b/src/library/scala/collection/immutable/Map.scala
@@ -11,6 +11,7 @@
 
 package scala.collection.immutable
 
+import Predef._
 
 /** <p>
  *    This class extends the <code>Map</code> interface of collections
@@ -36,11 +37,11 @@ package scala.collection.immutable
 object Map {
 
   /** The empty map of this type; this is implemented as a treemap */
-  def empty[A <% Ordered[A], B] = new TreeMap[A, B]
+  def empty[A, B] = new EmptyMap[A, B]
 
   /** The canonical factory for this type
    */
-  def apply[A <% Ordered[A], B](elems: Pair[A, B]*) = empty[A, B] ++ elems
+  def apply[A, B](elems: Pair[A, B]*) = empty[A, B] ++ elems
 }
 
 trait Map[A, +B] extends collection.Map[A, B] {
diff --git a/src/library/scala/collection/immutable/Set.scala b/src/library/scala/collection/immutable/Set.scala
index eadc656470..3ecd3df5e2 100644
--- a/src/library/scala/collection/immutable/Set.scala
+++ b/src/library/scala/collection/immutable/Set.scala
@@ -27,7 +27,7 @@ package scala.collection.immutable
 object Set {
   /** The empty set of this type
    */
-  def empty[A <% Ordered[A]] = new TreeSet[A]
+  def empty[A] = new EmptySet[A]
 
   /** The canonical factory for this type
    */
diff --git a/src/library/scala/collection/mutable/ArrayBuffer.scala b/src/library/scala/collection/mutable/ArrayBuffer.scala
index ab68478b87..f840fc3a2a 100644
--- a/src/library/scala/collection/mutable/ArrayBuffer.scala
+++ b/src/library/scala/collection/mutable/ArrayBuffer.scala
@@ -144,7 +144,7 @@ class ArrayBuffer[A] extends Buffer[A] with ResizableArray[A] {
 
   /** Clears the buffer contents.
    */
-  def clear: Unit = {
+  def clear(): Unit = {
     size = 0
   }
 
diff --git a/src/library/scala/collection/mutable/BitSet.scala b/src/library/scala/collection/mutable/BitSet.scala
index 02e876ba80..610b86e3ee 100644
--- a/src/library/scala/collection/mutable/BitSet.scala
+++ b/src/library/scala/collection/mutable/BitSet.scala
@@ -77,7 +77,7 @@ class BitSet(initSize: Int) extends collection.BitSet with Set[Int] {
 
   /** Clears all bits of the set.
    */
-  def clear: Unit = {
+  override def clear(): Unit = {
     java.util.Arrays.fill(arr, 0)
     size = 0
   }
diff --git a/src/library/scala/collection/mutable/Buffer.scala b/src/library/scala/collection/mutable/Buffer.scala
index 4bf49e3c57..5d8f24393c 100644
--- a/src/library/scala/collection/mutable/Buffer.scala
+++ b/src/library/scala/collection/mutable/Buffer.scala
@@ -196,7 +196,7 @@ trait Buffer[A] extends AnyRef
 
   /** Clears the buffer contents.
    */
-  def clear: Unit
+  def clear(): Unit
 
   /** Send a message to this scriptable object.
    *
diff --git a/src/library/scala/collection/mutable/BufferProxy.scala b/src/library/scala/collection/mutable/BufferProxy.scala
index c43b34ef2b..5f1d60e333 100644
--- a/src/library/scala/collection/mutable/BufferProxy.scala
+++ b/src/library/scala/collection/mutable/BufferProxy.scala
@@ -136,7 +136,7 @@ trait BufferProxy[A] extends Buffer[A] with Proxy {
 
   /** Clears the buffer contents.
    */
-  def clear: Unit = self.clear
+  def clear(): Unit = self.clear
 
   /** Send a message to this scriptable object.
    *
diff --git a/src/library/scala/collection/mutable/DefaultMapModel.scala b/src/library/scala/collection/mutable/DefaultMapModel.scala
index f5f6befcb0..9bf8b803b5 100644
--- a/src/library/scala/collection/mutable/DefaultMapModel.scala
+++ b/src/library/scala/collection/mutable/DefaultMapModel.scala
@@ -40,9 +40,6 @@ trait DefaultMapModel[A, B] extends Map[A, B] {
     else e.value = value
   }
 
-  def elements = entries map (e => Pair(e.key, e.value))
+  def elements = entries map {e => {e.key, e.value}}
 }
 
-[serializable]
-final class DefaultEntry[A, B](val key: A, var value: B)
-      extends HashEntry[A, DefaultEntry[A, B]]
diff --git a/src/library/scala/collection/mutable/HashMap.scala b/src/library/scala/collection/mutable/HashMap.scala
index d7bd56498f..863a535aef 100644
--- a/src/library/scala/collection/mutable/HashMap.scala
+++ b/src/library/scala/collection/mutable/HashMap.scala
@@ -34,10 +34,7 @@ class HashMap[A, B] extends Map[A,B] with HashTable[A] with DefaultMapModel[A,B]
 
   def -= (key: A) { removeEntry(key) }
 
-  override def clear = {
-    initTable()
-    tableSize = 0
-  }
+  override def clear() = super.clear()
 
   override def clone(): Map[A, B] = new HashMap[A, B] ++ this
 }
diff --git a/src/library/scala/collection/mutable/HashSet.scala b/src/library/scala/collection/mutable/HashSet.scala
index 3d53c7e223..c1c6096fa9 100644
--- a/src/library/scala/collection/mutable/HashSet.scala
+++ b/src/library/scala/collection/mutable/HashSet.scala
@@ -28,22 +28,16 @@ object HashSet {
 }
 
 [serializable]
-class HashSet[A] extends Set[A] with HashTable[A] {
+class HashSet[A] extends Set[A] with FlatHashTable[A] {
 
-  def contains(elem: A): Boolean = findEntry(elem) != null
+  def contains(elem: A): Boolean = containsEntry(elem)
 
-  def +=(elem: A) { if (findEntry(elem) == null) addEntry(new SetEntry(elem)) }
+  def +=(elem: A) { addEntry(elem) }
 
   def -=(elem: A) { removeEntry(elem) }
 
-  def elements = entries map (.key)
-
-  def clear {initTable(); tableSize = 0 }
-
-  protected type Entry = SetEntry[A]
+  override def clear() = super.clear()
 
   override def clone(): Set[A] = new HashSet[A] ++ this
 }
 
-[serializable]
-final class SetEntry[A](val key: A) extends HashEntry[A, SetEntry[A]]
diff --git a/src/library/scala/collection/mutable/HashTable.scala b/src/library/scala/collection/mutable/HashTable.scala
index cb52e6cb4a..e82a27e506 100644
--- a/src/library/scala/collection/mutable/HashTable.scala
+++ b/src/library/scala/collection/mutable/HashTable.scala
@@ -34,11 +34,11 @@ trait HashTable[A] extends AnyRef {
 
   /** The load factor for the hash table.
    */
-  protected val loadFactor: Float = 0.75f
+  protected def loadFactor: Float = 0.75f
 
   /** The initial size of the hash table.
    */
-  protected val initialSize: Int = 16
+  protected def initialSize: Int = 16
 
   /** The initial threshold
    */
@@ -46,7 +46,8 @@ trait HashTable[A] extends AnyRef {
 
   /** The actual hash table.
    */
-  protected var table: Array[Entry] = new Array(initialSize)
+  protected var table: Array[Entry] =
+    if (initialSize == 0) null else new Array(initialSize)
 
   /** The number of mappings contained in this hash table.
    */
@@ -56,7 +57,7 @@ trait HashTable[A] extends AnyRef {
    */
   protected var threshold: Int = initialThreshold
 
-  /** Returns the size of this hash map.
+  /** Returns the size of this hash table.
    */
   def size = tableSize
 
@@ -117,9 +118,10 @@ trait HashTable[A] extends AnyRef {
     }
   }
 
-  protected def initTable() {
+  def clear() {
     var i = table.length - 1
     while (i >= 0) { table(i) = null; i = i - 1 }
+    tableSize = 0
   }
 
   private def newThreshold(size: Int) =
diff --git a/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala b/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala
index 93323b750f..57570f327d 100644
--- a/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala
+++ b/src/library/scala/collection/mutable/ImmutableSetAdaptor.scala
@@ -44,6 +44,6 @@ class ImmutableSetAdaptor[A](protected var set: immutable.Set[A]) extends Set[A]
 
   def -=(elem: A): Unit = { set = set - elem }
 
-  def clear: Unit = { set = set.empty }
+  override def clear: Unit = { set = set.empty }
 
 }
diff --git a/src/library/scala/collection/mutable/JavaSetAdaptor.scala b/src/library/scala/collection/mutable/JavaSetAdaptor.scala
index 31e12c598e..141c527caa 100644
--- a/src/library/scala/collection/mutable/JavaSetAdaptor.scala
+++ b/src/library/scala/collection/mutable/JavaSetAdaptor.scala
@@ -36,7 +36,7 @@ class JavaSetAdaptor[A](jset: java.util.Set) extends Set[A] {
 
   def -=(elem: A): Unit = { val x = jset.remove(elem); }
 
-  def clear: Unit = jset.clear()
+  override def clear: Unit = jset.clear()
 
   override def clone(): Set[A] = {
     val res = new HashSet[A]
diff --git a/src/library/scala/collection/mutable/LinkedHashSet.scala b/src/library/scala/collection/mutable/LinkedHashSet.scala
index b87ca30838..c55c16201c 100644
--- a/src/library/scala/collection/mutable/LinkedHashSet.scala
+++ b/src/library/scala/collection/mutable/LinkedHashSet.scala
@@ -37,7 +37,7 @@ class LinkedHashSet[A](private val set0 : java.util.LinkedHashSet) extends Set[A
     def next = i.next().asInstanceOf[A]
   }
 
-  def clear = set0.clear()
+  override def clear = set0.clear()
 
   def size = set0.size()
 
diff --git a/src/library/scala/collection/mutable/Map.scala b/src/library/scala/collection/mutable/Map.scala
index c94f9a6617..ce7bdcabf0 100644
--- a/src/library/scala/collection/mutable/Map.scala
+++ b/src/library/scala/collection/mutable/Map.scala
@@ -152,7 +152,7 @@ trait Map[A, B] extends AnyRef
   /** Removes all mappings from the map. After this operation is
    *  completed, the map is empty.
    */
-  def clear: Unit = keys foreach -=
+  def clear(): Unit = keys foreach -=
 
   /** This function transforms all the values of mappings contained
    *  in this map with function <code>f</code>.
diff --git a/src/library/scala/collection/mutable/Set.scala b/src/library/scala/collection/mutable/Set.scala
index c05bfebfd6..7ac715d136 100644
--- a/src/library/scala/collection/mutable/Set.scala
+++ b/src/library/scala/collection/mutable/Set.scala
@@ -187,7 +187,7 @@ trait Set[A] extends collection.Set[A] with Scriptable[Message[A]] {
   /** Removes all elements from the set. After this operation is completed,
    *  the set will be empty.
    */
-  def clear: Unit
+  def clear(): Unit = elements foreach -=
 
   /** Send a message to this scriptable object.
    *
diff --git a/src/library/scala/collection/mutable/SetProxy.scala b/src/library/scala/collection/mutable/SetProxy.scala
index 739f2398c3..b13132c682 100644
--- a/src/library/scala/collection/mutable/SetProxy.scala
+++ b/src/library/scala/collection/mutable/SetProxy.scala
@@ -44,7 +44,7 @@ trait SetProxy[A] extends Set[A] with collection.SetProxy[A] {
 
   override def intersect(that: Set[A]): Unit = self.intersect(that)
 
-  def clear: Unit = self.clear
+  override def clear: Unit = self.clear
 
   override def retain(p: A => Boolean): Unit =  self.retain(p)
 
diff --git a/src/library/scala/xml/Atom.scala b/src/library/scala/xml/Atom.scala
index 7f45458101..deea2c00e8 100644
--- a/src/library/scala/xml/Atom.scala
+++ b/src/library/scala/xml/Atom.scala
@@ -22,7 +22,7 @@ import compat.StringBuilder
 [serializable]
 class Atom[+A](val data: A) extends SpecialNode {
 
-  data match {
+  data.asInstanceOf[AnyRef] match {
     case null => new IllegalArgumentException("cannot construct Atom(null)")
     case _ =>
   }