added Array.fromFunction. Fixed #768 in HashSet

2 files changed, 43 insertions, 2 deletions

diff --git a/src/library/scala/Array.scala b/src/library/scala/Array.scala
index edd508e6ef..05335ddfd2 100644
--- a/src/library/scala/Array.scala
+++ b/src/library/scala/Array.scala
@@ -184,6 +184,43 @@ object Array {
     a
   }
 
+  /** Create an array containing the values of a given function <code>f</code>
+   *  over given range <code>[0..n)</code>
+   */
+  def fromFunction[A](f: Int => A)(n: Int): Array[A] = {
+    val a = new Array[A](n)
+    var i = 0
+    while (i < n) {
+      a(i) = f(i)
+      i += 1
+    }
+    a
+  }
+
+  /** Create an array containing the values of a given function <code>f</code>
+   *  over given range <code>[0..n1, 0..n2)</code>
+   */
+  def fromFunction[A](f: (Int, Int) => A)(n1: Int, n2: Int): Array[Array[A]] =
+    fromFunction(i => fromFunction(f(i, _))(n2))(n1)
+
+  /** Create an array containing the values of a given function <code>f</code>
+   *  over given range <code>[0..n1, 0..n2, 0..n3)</code>
+   */
+  def fromFunction[A](f: (Int, Int, Int) => A)(n1: Int, n2: Int, n3: Int): Array[Array[Array[A]]] =
+    fromFunction(i => fromFunction(f(i, _, _))(n2, n3))(n1)
+
+  /** Create an array containing the values of a given function <code>f</code>
+   *  over given range <code>[0..n1, 0..n2, 0..n3, 0..n4)</code>
+   */
+  def fromFunction[A](f: (Int, Int, Int, Int) => A)(n1: Int, n2: Int, n3: Int, n4: Int): Array[Array[Array[Array[A]]]] =
+    fromFunction(i => fromFunction(f(i, _, _, _))(n2, n3, n4))(n1)
+
+  /** Create an array containing the values of a given function <code>f</code>
+   *  over given range <code>[0..n1, 0..n2, 0..n3, 0..n4, 0..n5)</code>
+   */
+  def fromFunction[A](f: (Int, Int, Int, Int, Int) => A)(n1: Int, n2: Int, n3: Int, n4: Int, n5: Int): Array[Array[Array[Array[Array[A]]]]] =
+    fromFunction(i => fromFunction(f(i, _, _, _, _))(n2, n3, n4, n5))(n1)
+
  /** This method is called as a result of a pattern match { case Array(...) => } or val Array(...) = ....
    *
    *  @param x the selector value
diff --git a/src/library/scala/collection/immutable/HashSet.scala b/src/library/scala/collection/immutable/HashSet.scala
index 22488ec79f..0bcc58693d 100644
--- a/src/library/scala/collection/immutable/HashSet.scala
+++ b/src/library/scala/collection/immutable/HashSet.scala
@@ -26,7 +26,11 @@ object HashSet {
   def apply[A](elems: A*) = empty[A] ++ elems
 }
 
-/** This class implements immutable sets using a hash table.
+/** This class implements immutable maps/sets using a hash table.
+  * It is optimized for sequential accesses where the last updated table is accessed most often.
+  * It supports with reasonable efficiency accesses to previous versions of the table by keeping
+  * a change log that's regularly compacted.
+  * It needs to synchronize most methods, so it is less suitable for highly concurrent accesses.
   *
   *  @author  Martin Odersky
   *  @version 2.0, 19/01/2007
@@ -80,7 +84,7 @@ class HashSet[A] extends Set[A] with mutable.FlatHashTable[A] {
       cnt += 1
       m = m.later
     }
-    s += tableSize
+    s += m.tableSize
     if (cnt > logLimit) makeCopy(m)
     s
   }