Removing unused locals and making vars into vals.

According to "git diff" the difference from master to this
commit includes:

   Minus: 112 vals, 135 vars
    Plus: 165 vals, 2 vars

Assuming all the removed ones were vals, which is true from 10K feet,
it suggests I removed 80 unused vals and turned 133 vars into vals.
There are a few other -Xlint driven improvements bundled with this,
like putting double-parentheses around Some((x, y)) so it doesn't
trigger the "adapting argument list" warning.

20 files changed, 29 insertions, 46 deletions

diff --git a/src/library/scala/collection/SeqLike.scala b/src/library/scala/collection/SeqLike.scala
index a1749a480b..33b6ab4165 100644
--- a/src/library/scala/collection/SeqLike.scala
+++ b/src/library/scala/collection/SeqLike.scala
@@ -103,7 +103,7 @@ trait SeqLike[+A, +Repr] extends Any with IterableLike[A, Repr] with GenSeqLike[
 
   def segmentLength(p: A => Boolean, from: Int): Int = {
     var i = 0
-    var it = iterator.drop(from)
+    val it = iterator.drop(from)
     while (it.hasNext && p(it.next()))
       i += 1
     i
@@ -111,7 +111,7 @@ trait SeqLike[+A, +Repr] extends Any with IterableLike[A, Repr] with GenSeqLike[
 
   def indexWhere(p: A => Boolean, from: Int): Int = {
     var i = from
-    var it = iterator.drop(from)
+    val it = iterator.drop(from)
     while (it.hasNext) {
       if (p(it.next())) return i
       else i += 1
@@ -177,10 +177,10 @@ trait SeqLike[+A, +Repr] extends Any with IterableLike[A, Repr] with GenSeqLike[
       result
     }
     private def swap(i: Int, j: Int) {
-      var tmpI = idxs(i)
+      val tmpI = idxs(i)
       idxs(i) = idxs(j)
       idxs(j) = tmpI
-      var tmpE = elms(i)
+      val tmpE = elms(i)
       elms(i) = elms(j)
       elms(j) = tmpE
     }
@@ -777,7 +777,7 @@ object SeqLike {
         val iter = S.iterator.drop(m0)
         val Wopt = kmpOptimizeWord(W, n0, n1, true)
         val T = kmpJumpTable(Wopt, n1-n0)
-        var cache = new Array[AnyRef](n1-n0)  // Ring buffer--need a quick way to do a look-behind
+        val cache = new Array[AnyRef](n1-n0)  // Ring buffer--need a quick way to do a look-behind
         var largest = 0
         var i, m = 0
         var answer = -1
diff --git a/src/library/scala/collection/concurrent/TrieMap.scala b/src/library/scala/collection/concurrent/TrieMap.scala
index b0736ecace..231f8157e4 100644
--- a/src/library/scala/collection/concurrent/TrieMap.scala
+++ b/src/library/scala/collection/concurrent/TrieMap.scala
@@ -545,7 +545,7 @@ private[collection] final class CNode[K, V](val bitmap: Int, val array: Array[Ba
   //   removed (those existing when the op began)
   // - if there are only null-i-nodes below, returns null
   def toCompressed(ct: TrieMap[K, V], lev: Int, gen: Gen) = {
-    var bmp = bitmap
+    val bmp = bitmap
     var i = 0
     val arr = array
     val tmparray = new Array[BasicNode](arr.length)
diff --git a/src/library/scala/collection/immutable/HashMap.scala b/src/library/scala/collection/immutable/HashMap.scala
index ee41e2aa3c..9b6183c0a4 100644
--- a/src/library/scala/collection/immutable/HashMap.scala
+++ b/src/library/scala/collection/immutable/HashMap.scala
@@ -471,9 +471,6 @@ time { mNew.iterator.foreach( p => ()) }
             // condition below is due to 2 things:
             // 1) no unsigned int compare on JVM
             // 2) 0 (no lsb) should always be greater in comparison
-            val a = thislsb - 1
-            val b = thatlsb - 1
-
             if (unsignedCompare(thislsb - 1, thatlsb - 1)) {
               val m = thiselems(thisi)
               totalelems += m.size
diff --git a/src/library/scala/collection/immutable/TrieIterator.scala b/src/library/scala/collection/immutable/TrieIterator.scala
index e8e904f1f9..3f1c5ea57a 100644
--- a/src/library/scala/collection/immutable/TrieIterator.scala
+++ b/src/library/scala/collection/immutable/TrieIterator.scala
@@ -177,7 +177,6 @@ private[collection] abstract class TrieIterator[+T](elems: Array[Iterable[T]]) e
       if (depth > 0) {
         // 2) topmost comes before (is not) arrayD
         //    steal a portion of top to create a new iterator
-        val topmost = arrayStack(0)
         if (posStack(0) == arrayStack(0).length - 1) {
           // 2a) only a single entry left on top
           // this means we have to modify this iterator - pop topmost
diff --git a/src/library/scala/collection/immutable/Vector.scala b/src/library/scala/collection/immutable/Vector.scala
index 1f90436636..7e1f3eadd0 100644
--- a/src/library/scala/collection/immutable/Vector.scala
+++ b/src/library/scala/collection/immutable/Vector.scala
@@ -242,8 +242,8 @@ override def companion: GenericCompanion[Vector] = Vector
 
   private[immutable] def appendFront[B>:A](value: B): Vector[B] = {
     if (endIndex != startIndex) {
-      var blockIndex = (startIndex - 1) & ~31
-      var lo = (startIndex - 1) & 31
+      val blockIndex = (startIndex - 1) & ~31
+      val lo = (startIndex - 1) & 31
 
       if (startIndex != blockIndex + 32) {
         val s = new Vector(startIndex - 1, endIndex, blockIndex)
@@ -339,8 +339,8 @@ override def companion: GenericCompanion[Vector] = Vector
 //    //println("------- append " + value)
 //    debug()
     if (endIndex != startIndex) {
-      var blockIndex = endIndex & ~31
-      var lo = endIndex & 31
+      val blockIndex = endIndex & ~31
+      val lo = endIndex & 31
 
       if (endIndex != blockIndex) {
         //println("will make writable block (from "+focus+") at: " + blockIndex)
@@ -574,9 +574,7 @@ override def companion: GenericCompanion[Vector] = Vector
   }
 
   private def dropFront0(cutIndex: Int): Vector[A] = {
-    var blockIndex = cutIndex & ~31
-    var lo = cutIndex & 31
-
+    val blockIndex = cutIndex & ~31
     val xor = cutIndex ^ (endIndex - 1)
     val d = requiredDepth(xor)
     val shift = (cutIndex & ~((1 << (5*d))-1))
@@ -606,9 +604,7 @@ override def companion: GenericCompanion[Vector] = Vector
   }
 
   private def dropBack0(cutIndex: Int): Vector[A] = {
-    var blockIndex = (cutIndex - 1) & ~31
-    var lo = ((cutIndex - 1) & 31) + 1
-
+    val blockIndex = (cutIndex - 1) & ~31
     val xor = startIndex ^ (cutIndex - 1)
     val d = requiredDepth(xor)
     val shift = (startIndex & ~((1 << (5*d))-1))
diff --git a/src/library/scala/collection/mutable/FlatHashTable.scala b/src/library/scala/collection/mutable/FlatHashTable.scala
index 74f576b0f7..f1301d2011 100644
--- a/src/library/scala/collection/mutable/FlatHashTable.scala
+++ b/src/library/scala/collection/mutable/FlatHashTable.scala
@@ -266,7 +266,7 @@ trait FlatHashTable[A] extends FlatHashTable.HashUtils[A] {
     val totalbuckets = totalSizeMapBuckets
     var bucketidx = 0
     var tableidx = 0
-    var tbl = table
+    val tbl = table
     var tableuntil = sizeMapBucketSize min tbl.length
     while (bucketidx < totalbuckets) {
       var currbucketsz = 0
diff --git a/src/library/scala/collection/mutable/ListBuffer.scala b/src/library/scala/collection/mutable/ListBuffer.scala
index bced92e663..0a61b537ce 100644
--- a/src/library/scala/collection/mutable/ListBuffer.scala
+++ b/src/library/scala/collection/mutable/ListBuffer.scala
@@ -269,7 +269,6 @@ final class ListBuffer[A]
     if (exported) copy()
     val n1 = n max 0
     val count1 = count min (len - n1)
-    var old = start.head
     if (n1 == 0) {
       var c = count1
       while (c > 0) {
diff --git a/src/library/scala/collection/parallel/Tasks.scala b/src/library/scala/collection/parallel/Tasks.scala
index d6b75202da..af32faf0aa 100644
--- a/src/library/scala/collection/parallel/Tasks.scala
+++ b/src/library/scala/collection/parallel/Tasks.scala
@@ -66,7 +66,6 @@ trait Task[R, +Tp] {
 
   private[parallel] def tryMerge(t: Tp @uncheckedVariance) {
     val that = t.asInstanceOf[Task[R, Tp]]
-    val local = result // ensure that any effects of modifying `result` are detected
     if (this.throwable == null && that.throwable == null) merge(t)
     mergeThrowables(that)
   }
@@ -167,7 +166,6 @@ trait AdaptiveWorkStealingTasks extends Tasks {
 
       while (last.next != null) {
         // val lastresult = Option(last.body.result)
-        val beforelast = last
         last = last.next
         if (last.tryCancel()) {
           // println("Done with " + beforelast.body + ", next direct is " + last.body)
diff --git a/src/library/scala/collection/parallel/mutable/ParArray.scala b/src/library/scala/collection/parallel/mutable/ParArray.scala
index 5ac2725f11..7527c9a71a 100644
--- a/src/library/scala/collection/parallel/mutable/ParArray.scala
+++ b/src/library/scala/collection/parallel/mutable/ParArray.scala
@@ -184,7 +184,7 @@ self =>
     override def aggregate[S](z: =>S)(seqop: (S, T) => S, combop: (S, S) => S): S = foldLeft[S](z)(seqop)
 
     override def sum[U >: T](implicit num: Numeric[U]): U = {
-      var s = sum_quick(num, arr, until, i, num.zero)
+      val s = sum_quick(num, arr, until, i, num.zero)
       i = until
       s
     }
@@ -200,7 +200,7 @@ self =>
     }
 
     override def product[U >: T](implicit num: Numeric[U]): U = {
-        var p = product_quick(num, arr, until, i, num.one)
+        val p = product_quick(num, arr, until, i, num.one)
         i = until
         p
     }
@@ -432,7 +432,7 @@ self =>
     private def filter2combiner_quick[U >: T, This](pred: T => Boolean, cb: Builder[U, This], a: Array[Any], ntil: Int, from: Int) {
       var j = i
       while(j < ntil) {
-        var curr = a(j).asInstanceOf[T]
+        val curr = a(j).asInstanceOf[T]
         if (pred(curr)) cb += curr
         j += 1
       }
@@ -447,7 +447,7 @@ self =>
     private def filterNot2combiner_quick[U >: T, This](pred: T => Boolean, cb: Builder[U, This], a: Array[Any], ntil: Int, from: Int) {
       var j = i
       while(j < ntil) {
-        var curr = a(j).asInstanceOf[T]
+        val curr = a(j).asInstanceOf[T]
         if (!pred(curr)) cb += curr
         j += 1
       }
diff --git a/src/library/scala/collection/parallel/mutable/ParHashMap.scala b/src/library/scala/collection/parallel/mutable/ParHashMap.scala
index 3b2c66763e..d8f846dd10 100644
--- a/src/library/scala/collection/parallel/mutable/ParHashMap.scala
+++ b/src/library/scala/collection/parallel/mutable/ParHashMap.scala
@@ -231,7 +231,7 @@ extends scala.collection.parallel.BucketCombiner[(K, V), ParHashMap[K, V], Defau
     def setSize(sz: Int) = tableSize = sz
     def insertEntry(/*block: Int, */e: DefaultEntry[K, V]) = {
       var h = index(elemHashCode(e.key))
-      var olde = table(h).asInstanceOf[DefaultEntry[K, V]]
+      val olde = table(h).asInstanceOf[DefaultEntry[K, V]]
 
       // check if key already exists
       var ce = olde
diff --git a/src/library/scala/collection/parallel/mutable/ParHashSet.scala b/src/library/scala/collection/parallel/mutable/ParHashSet.scala
index 22f22c8305..cbfb09bfdd 100644
--- a/src/library/scala/collection/parallel/mutable/ParHashSet.scala
+++ b/src/library/scala/collection/parallel/mutable/ParHashSet.scala
@@ -263,12 +263,12 @@ with scala.collection.mutable.FlatHashTable.HashUtils[T] {
       (elemsIn + leftoversIn, elemsLeft concat leftoversLeft)
     }
     private def insertAll(atPos: Int, beforePos: Int, elems: UnrolledBuffer[Any]): (Int, UnrolledBuffer[Any]) = {
-      var leftovers = new UnrolledBuffer[Any]
+      val leftovers = new UnrolledBuffer[Any]
       var inserted = 0
 
       var unrolled = elems.headPtr
       var i = 0
-      var t = table
+      val t = table
       while (unrolled ne null) {
         val chunkarr = unrolled.array
         val chunksz = unrolled.size
diff --git a/src/library/scala/collection/parallel/mutable/ParHashTable.scala b/src/library/scala/collection/parallel/mutable/ParHashTable.scala
index bb9a7b7823..b203ef8e5d 100644
--- a/src/library/scala/collection/parallel/mutable/ParHashTable.scala
+++ b/src/library/scala/collection/parallel/mutable/ParHashTable.scala
@@ -110,7 +110,7 @@ trait ParHashTable[K, Entry >: Null <: HashEntry[K, Entry]] extends scala.collec
     } else Seq(this.asInstanceOf[IterRepr])
 
     private def convertToArrayBuffer(chainhead: Entry): mutable.ArrayBuffer[T] = {
-      var buff = mutable.ArrayBuffer[Entry]()
+      val buff = mutable.ArrayBuffer[Entry]()
       var curr = chainhead
       while (curr ne null) {
         buff += curr
diff --git a/src/library/scala/collection/parallel/mutable/ResizableParArrayCombiner.scala b/src/library/scala/collection/parallel/mutable/ResizableParArrayCombiner.scala
index 68f37137f8..f78de073d6 100644
--- a/src/library/scala/collection/parallel/mutable/ResizableParArrayCombiner.scala
+++ b/src/library/scala/collection/parallel/mutable/ResizableParArrayCombiner.scala
@@ -26,7 +26,7 @@ trait ResizableParArrayCombiner[T] extends LazyCombiner[T, ParArray[T], ExposedA
   override def sizeHint(sz: Int) = if (chain.length == 1) chain(0).sizeHint(sz)
 
   // public method with private[mutable] type ExposedArrayBuffer in parameter type; cannot be overridden.
-  def newLazyCombiner(c: ArrayBuffer[ExposedArrayBuffer[T]]) = ResizableParArrayCombiner(c)
+  final def newLazyCombiner(c: ArrayBuffer[ExposedArrayBuffer[T]]) = ResizableParArrayCombiner(c)
 
   def allocateAndCopy = if (chain.size > 1) {
     val arrayseq = new ArraySeq[T](size)
diff --git a/src/library/scala/collection/script/Message.scala b/src/library/scala/collection/script/Message.scala
index 7466f2ac3e..43cb8a6138 100644
--- a/src/library/scala/collection/script/Message.scala
+++ b/src/library/scala/collection/script/Message.scala
@@ -69,7 +69,7 @@ class Script[A] extends ArrayBuffer[Message[A]] with Message[A] {
 
   override def toString(): String = {
     var res = "Script("
-    var it = this.iterator
+    val it = this.iterator
     var i = 1
     while (it.hasNext) {
       if (i > 1)
diff --git a/src/library/scala/util/automata/WordBerrySethi.scala b/src/library/scala/util/automata/WordBerrySethi.scala
index b648d179c6..07d5d2ff08 100644
--- a/src/library/scala/util/automata/WordBerrySethi.scala
+++ b/src/library/scala/util/automata/WordBerrySethi.scala
@@ -140,7 +140,6 @@ abstract class WordBerrySethi extends BaseBerrySethi {
 
         val delta1      = immutable.Map(deltaq.zipWithIndex map (_.swap): _*)
         val finalsArr   = (0 until pos map (k => finals.getOrElse(k, 0))).toArray  // 0 == not final
-        val initialsArr = initials.toArray
 
         val deltaArr: Array[mutable.Map[_labelT, immutable.BitSet]] =
           (0 until pos map { x =>
diff --git a/src/library/scala/util/parsing/input/OffsetPosition.scala b/src/library/scala/util/parsing/input/OffsetPosition.scala
index 3366584ab2..115741b9e9 100644
--- a/src/library/scala/util/parsing/input/OffsetPosition.scala
+++ b/src/library/scala/util/parsing/input/OffsetPosition.scala
@@ -22,7 +22,7 @@ case class OffsetPosition(source: java.lang.CharSequence, offset: Int) extends P
 
   /** An index that contains all line starts, including first line, and eof. */
   private lazy val index: Array[Int] = {
-    var lineStarts = new ArrayBuffer[Int]
+    val lineStarts = new ArrayBuffer[Int]
     lineStarts += 0
     for (i <- 0 until source.length)
       if (source.charAt(i) == '\n') lineStarts += (i + 1)
diff --git a/src/library/scala/xml/PrettyPrinter.scala b/src/library/scala/xml/PrettyPrinter.scala
index da82aca33a..8c0a101c2a 100755
--- a/src/library/scala/xml/PrettyPrinter.scala
+++ b/src/library/scala/xml/PrettyPrinter.scala
@@ -47,7 +47,6 @@ class PrettyPrinter(width: Int, step: Int) {
     val tmp = width - cur
     if (s.length <= tmp)
       return List(Box(ind, s))
-    val sb = new StringBuilder()
     var i = s indexOf ' '
     if (i > tmp || i == -1) throw new BrokenException() // cannot break
 
diff --git a/src/library/scala/xml/dtd/ElementValidator.scala b/src/library/scala/xml/dtd/ElementValidator.scala
index f97da1c8a3..5260d87b04 100644
--- a/src/library/scala/xml/dtd/ElementValidator.scala
+++ b/src/library/scala/xml/dtd/ElementValidator.scala
@@ -61,7 +61,7 @@ class ElementValidator() extends Function1[Node,Boolean] {
    */
   def check(md: MetaData): Boolean = {
     val len: Int = exc.length
-    var ok = new mutable.BitSet(adecls.length)
+    val ok = new mutable.BitSet(adecls.length)
 
     for (attr <- md) {
       def attrStr = attr.value.toString
diff --git a/src/library/scala/xml/include/sax/XIncludeFilter.scala b/src/library/scala/xml/include/sax/XIncludeFilter.scala
index 52ddf6b476..ac5a8c8331 100644
--- a/src/library/scala/xml/include/sax/XIncludeFilter.scala
+++ b/src/library/scala/xml/include/sax/XIncludeFilter.scala
@@ -275,7 +275,7 @@ class XIncludeFilter extends XMLFilterImpl {
     try {
       val uc = source.openConnection()
       val in = new BufferedInputStream(uc.getInputStream())
-      var encodingFromHeader = uc.getContentEncoding()
+      val encodingFromHeader = uc.getContentEncoding()
       var contentType = uc.getContentType()
       if (encodingFromHeader != null)
         encoding = encodingFromHeader
diff --git a/src/library/scala/xml/parsing/MarkupParser.scala b/src/library/scala/xml/parsing/MarkupParser.scala
index d4dc6da14d..8f8c25805c 100755
--- a/src/library/scala/xml/parsing/MarkupParser.scala
+++ b/src/library/scala/xml/parsing/MarkupParser.scala
@@ -154,7 +154,7 @@ trait MarkupParser extends MarkupParserCommon with TokenTests
     var info_enc: Option[String] = None
     var info_stdl: Option[Boolean] = None
 
-    var m = xmlProcInstr()
+    val m = xmlProcInstr()
     var n = 0
 
     if (isProlog)
@@ -303,10 +303,8 @@ trait MarkupParser extends MarkupParserCommon with TokenTests
     var scope: NamespaceBinding = pscope
     var aMap: MetaData = Null
     while (isNameStart(ch)) {
-      val pos = this.pos
-
       val qname = xName
-      val _     = xEQ
+      xEQ // side effect
       val value = xAttributeValue()
 
       Utility.prefix(qname) match {
@@ -423,7 +421,7 @@ trait MarkupParser extends MarkupParserCommon with TokenTests
    *  content1 ::=  '<' content1 | '&' charref ...
    *  }}} */
   def content(pscope: NamespaceBinding): NodeSeq = {
-    var ts = new NodeBuffer
+    val ts = new NodeBuffer
     var exit = eof
     // todo: optimize seq repr.
     def done = new NodeSeq { val theSeq = ts.toList }
@@ -582,7 +580,6 @@ trait MarkupParser extends MarkupParserCommon with TokenTests
     var exit = false
     while (! exit) {
       putChar(ch)
-      val opos = pos
       nextch
 
       exit = eof || ( ch == '<' ) || ( ch == '&' )
@@ -828,7 +825,6 @@ trait MarkupParser extends MarkupParserCommon with TokenTests
    *  }}} */
   def entityDecl() = {
     var isParameterEntity = false
-    var entdef: EntityDef = null
     xToken("NTITY")
     xSpace
     if ('%' == ch) {