Some accumulated cleanup done while profiling a...

Some accumulated cleanup done while profiling and reducing uses of
length. No review.

11 files changed, 47 insertions, 80 deletions

diff --git a/src/library/scala/collection/IterableLike.scala b/src/library/scala/collection/IterableLike.scala
index 00c2275ab5..70009391a2 100644
--- a/src/library/scala/collection/IterableLike.scala
+++ b/src/library/scala/collection/IterableLike.scala
@@ -6,10 +6,10 @@
 **                          |/                                          **
 \*                                                                      */
 
-
 package scala.collection
+
 import generic._
-import immutable.{List, Stream}
+import immutable.{ List, Stream }
 import annotation.unchecked.uncheckedVariance
 
 /** A template trait for iterable collections of type `Iterable[A]`.
diff --git a/src/library/scala/collection/IterableViewLike.scala b/src/library/scala/collection/IterableViewLike.scala
index a7578e9a01..a580fd7097 100644
--- a/src/library/scala/collection/IterableViewLike.scala
+++ b/src/library/scala/collection/IterableViewLike.scala
@@ -6,12 +6,9 @@
 **                          |/                                          **
 \*                                                                      */
 
-
-
 package scala.collection
 
 import generic._
-import collection.immutable.Stream
 import TraversableView.NoBuilder
 
 /** A template trait for non-strict views of iterable collections.
diff --git a/src/library/scala/collection/LinearSeqLike.scala b/src/library/scala/collection/LinearSeqLike.scala
index 8bf45348db..397e4131c7 100644
--- a/src/library/scala/collection/LinearSeqLike.scala
+++ b/src/library/scala/collection/LinearSeqLike.scala
@@ -7,10 +7,9 @@
 \*                                                                      */
 
 
-
 package scala.collection
-import generic._
 
+import generic._
 import mutable.ListBuffer
 import immutable.List
 import scala.util.control.Breaks._
diff --git a/src/library/scala/collection/generic/TraversableForwarder.scala b/src/library/scala/collection/generic/TraversableForwarder.scala
index 3995a5258b..ef42a7dcc0 100644
--- a/src/library/scala/collection/generic/TraversableForwarder.scala
+++ b/src/library/scala/collection/generic/TraversableForwarder.scala
@@ -6,14 +6,11 @@
 **                          |/                                          **
 \*                                                                      */
 
-
-
 package scala.collection.generic
-import scala.collection._
 
-import mutable.{Buffer, StringBuilder}
-import immutable.{List, Stream}
-// import immutable.{List, Nil, ::, Stream}
+import scala.collection._
+import mutable.{ Buffer, StringBuilder }
+import immutable.{ List, Stream }
 
 /** <p>
  *    This trait implements a forwarder for traversable objects. It forwards
diff --git a/src/library/scala/collection/mutable/LazyBuilder.scala b/src/library/scala/collection/mutable/LazyBuilder.scala
index db6ca19f2b..aef47801c8 100644
--- a/src/library/scala/collection/mutable/LazyBuilder.scala
+++ b/src/library/scala/collection/mutable/LazyBuilder.scala
@@ -6,12 +6,9 @@
 **                          |/                                          **
 \*                                                                      */
 
-
 package scala.collection
 package mutable
 
-import immutable.{List, Nil}
-
 /** A builder that constructs its result lazily. Iterators or iterables to
  *  be added to this builder with `++=` are not evaluated until `result` is called.
  *
diff --git a/src/library/scala/reflect/Tree.scala b/src/library/scala/reflect/Tree.scala
index ff7fc73c8a..7917d27166 100644
--- a/src/library/scala/reflect/Tree.scala
+++ b/src/library/scala/reflect/Tree.scala
@@ -7,11 +7,8 @@
 \*                                                                      */
 
 
-
 package scala.reflect
 
-import collection.immutable.{List, Nil}
-
 /** This type is required by the compiler and <b>should not be used in client code</b>. */
 abstract class Tree
 
diff --git a/src/library/scala/util/automata/BaseBerrySethi.scala b/src/library/scala/util/automata/BaseBerrySethi.scala
index 63eb0aba9f..4e7c7c4f02 100644
--- a/src/library/scala/util/automata/BaseBerrySethi.scala
+++ b/src/library/scala/util/automata/BaseBerrySethi.scala
@@ -10,12 +10,8 @@
 
 package scala.util.automata
 
-
 import scala.util.regexp.{ Base }
-
 import scala.collection.{ mutable, immutable }
-import mutable.{ HashMap }
-import immutable.{ Set }
 
 // todo: replace global variable pos with acc
 
@@ -30,7 +26,7 @@ abstract class BaseBerrySethi {
   protected var pos = 0
 
   // results which hold all info for the NondetWordAutomaton
-  protected var follow: HashMap[Int, Set[Int]] = _
+  protected var follow: mutable.HashMap[Int, Set[Int]] = _
 
   protected var finalTag: Int = _
 
diff --git a/src/library/scala/util/automata/DetWordAutom.scala b/src/library/scala/util/automata/DetWordAutom.scala
index e1e19589c2..0af49e9d40 100644
--- a/src/library/scala/util/automata/DetWordAutom.scala
+++ b/src/library/scala/util/automata/DetWordAutom.scala
@@ -6,12 +6,9 @@
 **                          |/                                          **
 \*                                                                      */
 
-
-
 package scala.util.automata
 
-
-import scala.collection.{Set, Map}
+import scala.collection.{ mutable, immutable }
 
 /** A deterministic automaton. States are integers, where
  *  0 is always the only initial state. Transitions are represented
@@ -24,21 +21,14 @@ import scala.collection.{Set, Map}
  *  @version 1.0
  */
 abstract class DetWordAutom[T <: AnyRef] {
-
   val nstates: Int
   val finals: Array[Int]
-  val delta: Array[Map[T,Int]]
+  val delta: Array[mutable.Map[T, Int]]
   val default: Array[Int]
 
-  def isFinal(q: Int) = finals(q) != 0
-  def isSink(q: Int) = delta(q).isEmpty && default(q) == q
-
-  def next(q: Int, label: T) = {
-    delta(q).get(label) match {
-      case Some(p) => p
-      case _       => default(q)
-    }
-  }
+  def isFinal(q: Int)        = finals(q) != 0
+  def isSink(q: Int)         = delta(q).isEmpty && default(q) == q
+  def next(q: Int, label: T) = delta(q).getOrElse(label, default(q))
 
   override def toString() = {
     val sb = new StringBuilder("[DetWordAutom  nstates=")
diff --git a/src/library/scala/util/automata/NondetWordAutom.scala b/src/library/scala/util/automata/NondetWordAutom.scala
index 4434ed395d..ed3da00832 100644
--- a/src/library/scala/util/automata/NondetWordAutom.scala
+++ b/src/library/scala/util/automata/NondetWordAutom.scala
@@ -7,11 +7,9 @@
 \*                                                                      */
 
 
-
 package scala.util.automata
 
-import scala.collection.{ immutable, mutable, Set, Seq, Map }
-import immutable.{ BitSet }
+import scala.collection.{ immutable, mutable }
 
 /** A nondeterministic automaton. States are integers, where
  *  0 is always the only initial state. Transitions are represented
@@ -20,13 +18,13 @@ import immutable.{ BitSet }
  *  All states are reachable. Accepting states are those for which
  *  the partial function 'finals' is defined.
  */
-abstract class NondetWordAutom[T <: AnyRef]
-{
+abstract class NondetWordAutom[T <: AnyRef] {
+  import immutable.BitSet
+
   val nstates: Int
   val labels: Seq[T]
-
   val finals: Array[Int] // 0 means not final
-  val delta: Array[Map[T, BitSet]]
+  val delta: Array[mutable.Map[T, BitSet]]
   val default: Array[BitSet]
 
   /** returns true if the state is final */
@@ -41,10 +39,10 @@ abstract class NondetWordAutom[T <: AnyRef]
   /** returns true if there are no accepting states */
   final def isEmpty = (0 until nstates) forall (x => !isFinal(x))
 
-  /** returns a bitset with the next states for given state and label */
+  /** returns a BitSet with the next states for given state and label */
   def next(q: Int, a: T): BitSet = delta(q).getOrElse(a, default(q))
 
-  /** returns a bitset with the next states for given state and label */
+  /** returns a BitSet with the next states for given state and label */
   def next(Q: BitSet, a: T): BitSet = next(Q, next(_, a))
   def nextDefault(Q: BitSet): BitSet = next(Q, default)
 
diff --git a/src/library/scala/util/automata/SubsetConstruction.scala b/src/library/scala/util/automata/SubsetConstruction.scala
index d5b1a19083..5b5df33b11 100644
--- a/src/library/scala/util/automata/SubsetConstruction.scala
+++ b/src/library/scala/util/automata/SubsetConstruction.scala
@@ -6,21 +6,21 @@
 **                          |/                                          **
 \*                                                                      */
 
-
 package scala.util.automata
 
+import scala.collection.{ mutable, immutable }
+
 class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T]) {
   import nfa.labels
-  import collection.{ mutable, Map }
-  import collection.immutable.BitSet
+  import immutable.BitSet
 
   def selectTag(Q: BitSet, finals: Array[Int]) =
     Q map finals filter (_ > 0) min
 
   def determinize: DetWordAutom[T] = {
     // for assigning numbers to bitsets
-    var indexMap    = Map[BitSet, Int]()
-    var invIndexMap = Map[Int, BitSet]()
+    var indexMap    = collection.Map[BitSet, Int]()
+    var invIndexMap = collection.Map[Int, BitSet]()
     var ix = 0
 
     // we compute the dfa with states = bitsets
@@ -29,10 +29,10 @@ class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T]) {
 
     var states = Set(q0, sink)    // initial set of sets
     val delta    = new mutable.HashMap[BitSet, mutable.HashMap[T, BitSet]]
-    var deftrans = Map(q0 -> sink, sink -> sink)  // initial transitions
-    var finals: Map[BitSet, Int]  = Map()
-
+    var deftrans = mutable.Map(q0 -> sink, sink -> sink)  // initial transitions
+    var finals: mutable.Map[BitSet, Int]  = mutable.Map()
     val rest = new mutable.Stack[BitSet]
+
     rest.push(sink, q0)
 
     def addFinal(q: BitSet) {
@@ -40,8 +40,8 @@ class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T]) {
         finals = finals.updated(q, selectTag(q, nfa.finals))
     }
     def add(Q: BitSet) {
-      if (!states.contains(Q)) {
-        states = states + Q
+      if (!states(Q)) {
+        states += Q
         rest push Q
         addFinal(Q)
       }
@@ -74,7 +74,7 @@ class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T]) {
 
     // create DetWordAutom, using indices instead of sets
     val nstatesR = states.size
-    val deltaR = new Array[Map[T,Int]](nstatesR)
+    val deltaR = new Array[mutable.Map[T, Int]](nstatesR)
     val defaultR = new Array[Int](nstatesR)
     val finalsR = new Array[Int](nstatesR)
 
@@ -83,7 +83,7 @@ class SubsetConstruction[T <: AnyRef](val nfa: NondetWordAutom[T]) {
       val trans = delta(Q)
       val transDef = deftrans(Q)
       val qDef = indexMap(transDef)
-      val ntrans = new mutable.HashMap[T,Int]()
+      val ntrans = new mutable.HashMap[T, Int]()
 
       for ((label, value) <- trans) {
         val p = indexMap(value)
diff --git a/src/library/scala/util/automata/WordBerrySethi.scala b/src/library/scala/util/automata/WordBerrySethi.scala
index 4a41cbbf5a..26f48441d8 100644
--- a/src/library/scala/util/automata/WordBerrySethi.scala
+++ b/src/library/scala/util/automata/WordBerrySethi.scala
@@ -10,8 +10,7 @@
 
 package scala.util.automata
 
-import scala.collection.{ immutable, mutable, Map }
-import immutable.{ Set }
+import scala.collection.{ immutable, mutable }
 import mutable.{ HashSet, HashMap }
 import scala.util.regexp.WordExp
 
@@ -25,17 +24,14 @@ import scala.util.regexp.WordExp
 abstract class WordBerrySethi extends BaseBerrySethi {
   override val lang: WordExp
 
-  import lang.{ Alt, Eps, Letter, Meta, RegExp, Sequ, Star }
+  import lang.{ Alt, Eps, Letter, Meta, RegExp, Sequ, Star, _labelT }
 
-  protected var labels: HashSet[lang._labelT] = _
+  protected var labels: HashSet[_labelT]                   = _
   // don't let this fool you, only labelAt is a real, surjective mapping
-  protected var labelAt: immutable.Map[Int, lang._labelT] = _ // new alphabet "gamma"
-
-  protected var deltaq: Array[HashMap[lang._labelT, List[Int]]] = _ // delta
-
-  protected var defaultq: Array[List[Int]] = _ // default transitions
-
-  protected var initials: Set[Int] = _
+  protected var labelAt: Map[Int, _labelT]                 = _ // new alphabet "gamma"
+  protected var deltaq: Array[HashMap[_labelT, List[Int]]] = _ // delta
+  protected var defaultq: Array[List[Int]]                 = _ // default transitions
+  protected var initials: Set[Int]                         = _
 
   /** Computes <code>first(r)</code> where the word regexp <code>r</code>.
    *
@@ -75,13 +71,13 @@ abstract class WordBerrySethi extends BaseBerrySethi {
    */
 
   /** called at the leaves of the regexp */
-  protected def seenLabel(r: RegExp, i: Int, label: lang._labelT) {
+  protected def seenLabel(r: RegExp, i: Int, label: _labelT) {
     labelAt = labelAt.updated(i, label)
     this.labels += label
   }
 
   // overridden in BindingBerrySethi
-  protected def seenLabel(r: RegExp, label: lang._labelT): Int = {
+  protected def seenLabel(r: RegExp, label: _labelT): Int = {
     pos += 1
     seenLabel(r, pos, label)
     pos
@@ -95,7 +91,7 @@ abstract class WordBerrySethi extends BaseBerrySethi {
   }
 
 
-  protected def makeTransition(src: Int, dest: Int, label: lang._labelT) {
+  protected def makeTransition(src: Int, dest: Int, label: _labelT) {
     val q = deltaq(src)
     q.update(label, dest :: q.getOrElse(label, Nil))
   }
@@ -114,11 +110,11 @@ abstract class WordBerrySethi extends BaseBerrySethi {
 
   protected def initializeAutom() {
     finals   = immutable.Map.empty[Int, Int]                    // final states
-    deltaq   = new Array[HashMap[lang._labelT, List[Int]]](pos) // delta
+    deltaq   = new Array[HashMap[_labelT, List[Int]]](pos) // delta
     defaultq = new Array[List[Int]](pos)                        // default transitions
 
     for (j <- 0 until pos) {
-      deltaq(j) = HashMap[lang._labelT, List[Int]]()
+      deltaq(j) = HashMap[_labelT, List[Int]]()
       defaultq(j) = Nil
     }
   }
@@ -129,7 +125,7 @@ abstract class WordBerrySethi extends BaseBerrySethi {
       else makeTransition(j, k, labelAt(k))
     }
 
-  def automatonFrom(pat: RegExp, finalTag: Int): NondetWordAutom[lang._labelT] = {
+  def automatonFrom(pat: RegExp, finalTag: Int): NondetWordAutom[_labelT] = {
     this.finalTag = finalTag
 
     pat match {
@@ -150,14 +146,14 @@ abstract class WordBerrySethi extends BaseBerrySethi {
         val finalsArr   = 0 until pos map (k => finals.getOrElse(k, 0)) toArray  // 0 == not final
         val initialsArr = initials.toArray
 
-        val deltaArr: Array[Map[lang._labelT, immutable.BitSet]] =
+        val deltaArr: Array[mutable.Map[_labelT, immutable.BitSet]] =
           (0 until pos map { x =>
             HashMap(delta1(x).toSeq map { case (k, v) => k -> immutable.BitSet(v: _*) } : _*)
-          }) toArray
+          }).toArray
 
         val defaultArr  = 0 until pos map (k => immutable.BitSet(defaultq(k): _*)) toArray
 
-        new NondetWordAutom[lang._labelT] {
+        new NondetWordAutom[_labelT] {
           val nstates  = pos
           val labels   = WordBerrySethi.this.labels.toList
           val initials = initialsArr