removing Marshal and dependency on java.io in s...

removing Marshal and dependency on java.io in scalax..List for msil

2 files changed, 1200 insertions, 0 deletions

diff --git a/src/dotnet-library/scala/util/Marshal.scala b/src/dotnet-library/scala/util/Marshal.scala
new file mode 100644
index 0000000000..4817f34c93
--- /dev/null
+++ b/src/dotnet-library/scala/util/Marshal.scala
@@ -0,0 +1 @@
+/* Marshal does not exist for the dotnet target */
diff --git a/src/dotnet-library/scalax/collection/immutable/List.scala b/src/dotnet-library/scalax/collection/immutable/List.scala
new file mode 100644
index 0000000000..845cf6ed5a
--- /dev/null
+++ b/src/dotnet-library/scalax/collection/immutable/List.scala
@@ -0,0 +1,1199 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2008, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id: List.scala 16287 2008-10-18 13:41:36Z nielsen $
+
+
+package scalax.collection.immutable
+
+import mutable.ListBuffer
+import generic.covariant.SequenceTemplate
+
+/** A class representing an ordered collection of elements of type
+ *  <code>a</code>. This class comes with two implementing case
+ *  classes <code>scala.Nil</code> and <code>scala.::</code> that
+ *  implement the abstract members <code>isEmpty</code>,
+ *  <code>head</code> and <code>tail</code>.
+ *
+ *  @author  Martin Odersky and others
+ *  @version 1.0, 16/07/2003
+ */
+sealed abstract class List[+A] extends Sequence[A] with SequenceTemplate[List, A] with Product {
+
+  /** Returns true if the list does not contain any elements.
+   *  @return <code>true</code>, iff the list is empty.
+   */
+  def isEmpty: Boolean
+
+  /** Returns this first element of the list.
+   *
+   *  @return the first element of this list.
+   *  @throws Predef.NoSuchElementException if the list is empty.
+   */
+  def head: A
+
+  /** Returns this list without its first element.
+   *
+   *  @return this list without its first element.
+   *  @throws Predef.NoSuchElementException if the list is empty.
+   */
+  def tail: List[A]
+
+  def newBuilder[B]: Builder[List, B] = new ListBuffer[B]
+
+  /** <p>
+   *    Add an element <code>x</code> at the beginning of this list.
+   *  </p>
+   *
+   *  @param x the element to prepend.
+   *  @return  the list with <code>x</code> added at the beginning.
+   *  @ex <code>1 :: List(2, 3) = List(2, 3).::(1) = List(1, 2, 3)</code>
+   */
+  def ::[B >: A] (x: B): List[B] =
+    new scalax.collection.immutable.::(x, this)
+
+  /** <p>
+   *    Returns a list resulting from the concatenation of the given
+   *    list <code>prefix</code> and this list.
+   *  </p>
+   *
+   *  @param prefix the list to concatenate at the beginning of this list.
+   *  @return the concatenation of the two lists.
+   *  @ex <code>List(1, 2) ::: List(3, 4) = List(3, 4).:::(List(1, 2)) = List(1, 2, 3, 4)</code>
+   */
+  def :::[B >: A](prefix: List[B]): List[B] =
+    if (isEmpty) prefix
+    else (new ListBuffer[B] ++ prefix).prependToList(this)
+
+  /** Appends two list objects.
+   */
+  override def ++[B >: A](that: Iterable[B]): List[B] =
+    this ::: that.toList
+
+  /** Reverse the given prefix and append the current list to that.
+   *  This function is equivalent to an application of <code>reverse</code>
+   *  on the prefix followed by a call to <code>:::</code>, but more
+   *  efficient (and tail recursive).
+   *
+   *  @param prefix the prefix to reverse and then prepend
+   *  @return       the concatenation of the reversed prefix and the current list.
+   */
+  def reverse_:::[B >: A](prefix: List[B]): List[B] = {
+    var these: List[B] = this
+    var pres = prefix
+    while (!pres.isEmpty) {
+      these = pres.head :: these
+      pres = pres.tail
+    }
+    these
+  }
+
+  /** Returns the number of elements in the list.
+   *
+   *  @return the number of elements in the list.
+   */
+  def length: Int = {
+    var these = this
+    var len = 0
+    while (!these.isEmpty) {
+      len += 1
+      these = these.tail
+    }
+    len
+  }
+
+  /** Returns the elements in the list as an iterator
+   *
+   *  @return an iterator on the list elements.
+   */
+  override def elements: Iterator[A] = new Iterator[A] {
+    var these = List.this
+    def hasNext: Boolean = !these.isEmpty
+    def next: A =
+      if (!hasNext)
+        throw new NoSuchElementException("next on empty Iterator")
+      else {
+        val result = these.head; these = these.tail; result
+      }
+    override def toList: List[A] = these
+  }
+
+  /** Overrides the method in Iterable for efficiency.
+   *
+   *  @return  the list itself
+   */
+  override def toList: List[A] = this
+
+  /** Returns the <code>n</code> first elements of this list, or else the whole
+   *  list, if it has less than <code>n</code> elements.
+   *
+   *  @param n the number of elements to take.
+   *  @return the <code>n</code> first elements of this list.
+   */
+  override def take(n: Int): List[A] = {
+    val b = new ListBuffer[A]
+    var i = 0
+    var these = this
+    while (!these.isEmpty && i < n) {
+      i += 1
+      b += these.head
+      these = these.tail
+    }
+    if (these.isEmpty) this
+    else b.toList
+  }
+
+  /** Returns the list with elements belonging to the given index range.
+   *
+   *  @param start the start position of the list slice.
+   *  @param end   the end position (exclusive) of the list slice.
+   *  @return the list with elements belonging to the given index range.
+   */
+  override def slice(start: Int, end: Int): List[A] = {
+    val s = start max 0
+    val e = end min this.length
+    drop(s) take (e - s)
+  }
+
+  /** Returns the list without its <code>n</code> first elements.
+   *  If this list has less than <code>n</code> elements, the empty list is returned.
+   *
+   *  @param n the number of elements to drop.
+   *  @return the list without its <code>n</code> first elements.
+   */
+  override def drop(n: Int): List[A] = {
+    var these = this
+    var count = n
+    while (!these.isEmpty && count > 0) {
+      these = these.tail
+      count -= 1
+    }
+    these
+  }
+
+  /** Returns the rightmost <code>n</code> elements from this list.
+   *
+   *  @param n the number of elements to take
+   *  @return the suffix of length <code>n</code> of the list
+   */
+  override def takeRight(n: Int): List[A] = {
+    def loop(lead: List[A], lag: List[A]): List[A] = lead match {
+      case Nil => lag
+      case _ :: tail => loop(tail, lag.tail)
+    }
+    loop(drop(n), this)
+  }
+
+  /** Returns the list wihout its rightmost <code>n</code> elements.
+   *
+   *  @param n the number of elements to take
+   *  @return the list without its rightmost <code>n</code> elements
+   */
+  override def dropRight(n: Int): List[A] = {
+    def loop(lead: List[A], lag: List[A]): List[A] = lead match {
+      case Nil => Nil
+      case _ :: tail => lag.head :: loop(tail, lag.tail)
+    }
+    loop(drop(n), this)
+  }
+
+  /** Split the list at a given point and return the two parts thus
+   *  created.
+   *
+   *  @param n the position at which to split
+   *  @return  a pair of lists composed of the first <code>n</code>
+   *           elements, and the other elements.
+   */
+  override def splitAt(n: Int): (List[A], List[A]) = {
+    val b = new ListBuffer[A]
+    var i = 0
+    var these = this
+    while (!these.isEmpty && i < n) {
+      i += 1
+      b += these.head
+      these = these.tail
+    }
+    (b.toList, these)
+  }
+
+  /** Returns the longest prefix of this list whose elements satisfy
+   *  the predicate <code>p</code>.
+   *
+   *  @param p the test predicate.
+   *  @return  the longest prefix of this list whose elements satisfy
+   *           the predicate <code>p</code>.
+   */
+  override def takeWhile(p: A => Boolean): List[A] = {
+    val b = new ListBuffer[A]
+    var these = this
+    while (!these.isEmpty && p(these.head)) {
+      b += these.head
+      these = these.tail
+    }
+    b.toList
+  }
+
+  /** Returns the longest suffix of this list whose first element
+   *  does not satisfy the predicate <code>p</code>.
+   *
+   *  @param p the test predicate.
+   *  @return  the longest suffix of the list whose first element
+   *           does not satisfy the predicate <code>p</code>.
+   */
+  override def dropWhile(p: A => Boolean): List[A] =
+    if (isEmpty || !p(head)) this
+    else tail dropWhile p
+
+  /** Returns the longest prefix of the list whose elements all satisfy
+   *  the given predicate, and the rest of the list.
+   *
+   *  @param p the test predicate
+   *  @return  a pair consisting of the longest prefix of the list whose
+   *           elements all satisfy <code>p</code>, and the rest of the list.
+   */
+  override def span(p: A => Boolean): (List[A], List[A]) = {
+    val b = new ListBuffer[A]
+    var these = this
+    while (!these.isEmpty && p(these.head)) {
+      b += these.head
+      these = these.tail
+    }
+    (b.toList, these)
+  }
+
+  /** Returns the <code>n</code>-th element of this list. The first element
+   *  (head of the list) is at position 0.
+   *
+   *  @param n index of the element to return
+   *  @return  the element at position <code>n</code> in this list.
+   *  @throws Predef.NoSuchElementException if the list is too short.
+   */
+  def apply(n: Int): A = drop(n).head
+
+  /** Returns the list resulting from applying the given function <code>f</code> to each
+   *  element of this list.
+   *
+   *  @param f function to apply to each element.
+   *  @return <code>[f(a0), ..., f(an)]</code> if this list is <code>[a0, ..., an]</code>.
+   */
+  final override def map[B](f: A => B): List[B] = {
+    val b = new ListBuffer[B]
+    var these = this
+    while (!these.isEmpty) {
+      b += f(these.head)
+      these = these.tail
+    }
+    b.toList
+  }
+
+  /** Apply a function to all the elements of the list, and return the
+   *  reversed list of results. This is equivalent to a call to <code>map</code>
+   *  followed by a call to <code>reverse</code>, but more efficient.
+   *
+   *  @param f the function to apply to each elements.
+   *  @return  the reversed list of results.
+   */
+  def reverseMap[B](f: A => B): List[B] = {
+    def loop(l: List[A], res: List[B]): List[B] = l match {
+      case Nil => res
+      case head :: tail => loop(tail, f(head) :: res)
+    }
+    loop(this, Nil)
+  }
+
+  /** Apply the given function <code>f</code> to each element of this list
+   *  (while respecting the order of the elements).
+   *
+   *  @param f the treatment to apply to each element.
+   */
+  final override def foreach(f: A => Unit) {
+    var these = this
+    while (!these.isEmpty) {
+      f(these.head)
+      these = these.tail
+    }
+  }
+
+  /** Returns all the elements of this list that satisfy the
+   *  predicate <code>p</code>. The order of the elements is preserved.
+   *  It is guarenteed that the receiver list itself is returned iff all its
+   *  elements satisfy the predicate `p'. Hence the following equality is valid:
+   *
+   *  (xs filter p) eq xs  ==  xs forall p
+   *
+   *  @param p the predicate used to filter the list.
+   *  @return the elements of this list satisfying <code>p</code>.
+   */
+  final override def filter(p: A => Boolean): List[A] = {
+    // return same list if all elements satisfy p
+    var these = this
+    while (!these.isEmpty && p(these.head)) {
+      these = these.tail
+    }
+    if (these.isEmpty) this
+    else {
+      val b = new ListBuffer[A]
+      var these1 = this
+      while (these1 ne these) {
+        b += these1.head
+        these1 = these1.tail
+      }
+
+      these = these.tail // prevent the second evaluation of the predicate
+                         // on the element on which it first failed
+      while (!these.isEmpty) {
+        if (p(these.head)) b += these.head
+        these = these.tail
+      }
+      b.toList
+    }
+  }
+
+  /** <p>
+   *    Sort the list according to the comparison function
+   *    <code>&lt;(e1: a, e2: a) =&gt; Boolean</code>,
+   *    which should be true iff <code>e1</code> is smaller than
+   *    <code>e2</code>.
+   *  </p>
+   *
+   *  @param lt the comparison function
+   *  @return   a list sorted according to the comparison function
+   *            <code>&lt;(e1: a, e2: a) =&gt; Boolean</code>.
+   *  @ex <pre>
+   *    List("Steve", "Tom", "John", "Bob")
+   *      .sort((e1, e2) => (e1 compareTo e2) &lt; 0) =
+   *    List("Bob", "John", "Steve", "Tom")</pre>
+   */
+  def sort(lt : (A,A) => Boolean): List[A] = {
+    /** Merge two already-sorted lists */
+    def merge(l1: List[A], l2: List[A]): List[A] = {
+      val res = new ListBuffer[A]
+      var left1 = l1
+      var left2 = l2
+
+      while (!left1.isEmpty && !left2.isEmpty) {
+	if(lt(left1.head, left2.head)) {
+	  res += left1.head
+	  left1 = left1.tail
+	} else {
+	  res += left2.head
+	  left2 = left2.tail
+	}
+      }
+
+      res ++= left1
+      res ++= left2
+
+      res.toList
+    }
+
+    /** Split a list into two lists of about the same size */
+    def split(lst: List[A]) = {
+      val res1 = new ListBuffer[A]
+      val res2 = new ListBuffer[A]
+      var left = lst
+
+      while (!left.isEmpty) {
+	res1 += left.head
+	left = left.tail
+	if (!left.isEmpty) {
+	  res2 += left.head
+	  left = left.tail
+	}
+      }
+
+      (res1.toList, res2.toList)
+    }
+
+
+    /** Merge-sort the specified list */
+    def ms(lst: List[A]): List[A] =
+      lst match {
+	case Nil => lst
+	case x :: Nil => lst
+	case x :: y :: Nil =>
+	  if (lt(x,y))
+	    lst
+	  else
+	    y :: x :: Nil
+
+	case lst =>
+          val (l1, l2) = split(lst)
+          val l1s = ms(l1)
+          val l2s = ms(l2)
+          merge(l1s, l2s)
+      }
+
+    ms(this)
+  }
+
+  /** Tests if the predicate <code>p</code> is satisfied by all elements
+   *  in this list.
+   *
+   *  @param p the test predicate.
+   *  @return  <code>true</code> iff all elements of this list satisfy the
+   *           predicate <code>p</code>.
+   */
+  override def forall(p: A => Boolean): Boolean = {
+    var these = this
+    while (!these.isEmpty) {
+      if (!p(these.head)) return false
+      these = these.tail
+    }
+    true
+  }
+
+  /** Tests the existence in this list of an element that satisfies the
+   *  predicate <code>p</code>.
+   *
+   *  @param p the test predicate.
+   *  @return  <code>true</code> iff there exists an element in this list that
+   *           satisfies the predicate <code>p</code>.
+   */
+  override def exists(p: A => Boolean): Boolean = {
+    var these = this
+    while (!these.isEmpty) {
+      if (p(these.head)) return true
+      these = these.tail
+    }
+    false
+  }
+
+  /** Find and return the first element of the list satisfying a
+   *  predicate, if any.
+   *
+   *  @param p the predicate
+   *  @return the first element in the list satisfying <code>p</code>,
+   *  or <code>None</code> if none exists.
+   */
+  override def find(p: A => Boolean): Option[A] = {
+    var these = this
+    while (!these.isEmpty) {
+      if (p(these.head)) return Some(these.head)
+      these = these.tail
+    }
+    None
+  }
+
+  /** Combines the elements of this list together using the binary
+   *  function <code>f</code>, from left to right, and starting with
+   *  the value <code>z</code>.
+   *
+   *  @return <code>f(... (f(f(z, a<sub>0</sub>), a<sub>1</sub>) ...),
+   *          a<sub>n</sub>)</code> if the list is
+   *          <code>[a<sub>0</sub>, a<sub>1</sub>, ..., a<sub>n</sub>]</code>.
+   */
+  override def foldLeft[B](z: B)(f: (B, A) => B): B = {
+    var acc = z
+    var these = this
+    while (!these.isEmpty) {
+      acc = f(acc, these.head)
+      these = these.tail
+    }
+    acc
+  }
+
+  /** Combines the elements of this list together using the binary
+   *  function <code>f</code>, from right to left, and starting with
+   *  the value <code>z</code>.
+   *
+   *  @return <code>f(a<sub>0</sub>, f(a<sub>1</sub>, f(..., f(a<sub>n</sub>, z)...)))</code>
+   *          if the list is <code>[a<sub>0</sub>, a1, ..., a<sub>n</sub>]</code>.
+   */
+  override def foldRight[B](z: B)(f: (A, B) => B): B = this match {
+    case Nil => z
+    case x :: xs => f(x, xs.foldRight(z)(f))
+  }
+
+  /** Combines the elements of this list together using the binary
+   *  operator <code>op</code>, from left to right
+   *  @param op  The operator to apply
+   *  @return <code>op(... op(a<sub>0</sub>,a<sub>1</sub>), ..., a<sub>n</sub>)</code>
+      if the list has elements
+   *          <code>a<sub>0</sub>, a<sub>1</sub>, ..., a<sub>n</sub></code>.
+   *  @throws Predef.UnsupportedOperationException if the list is empty.
+   */
+  override def reduceLeft[B >: A](f: (B, A) => B): B = this match {
+    case Nil => throw new UnsupportedOperationException("Nil.reduceLeft")
+    case x :: Nil => x
+    case x0 :: x1 :: xs =>
+      var acc : B = f(x0, x1)
+      var these : List[A] = xs
+      while (!these.isEmpty) {
+        acc = f(acc, these.head)
+        these = these.tail
+      }
+      acc
+  }
+
+  /** Combines the elements of this list together using the binary
+   *  operator <code>op</code>, from right to left
+   *  @param op  The operator to apply
+   *
+   *  @return <code>a<sub>0</sub> op (... op (a<sub>n-1</sub> op a<sub>n</sub>)...)</code>
+   *          if the list has elements <code>a<sub>0</sub>, a<sub>1</sub>, ...,
+   *          a<sub>n</sub></code>.
+   *
+   *  @throws Predef.UnsupportedOperationException if the list is empty.
+   */
+  override def reduceRight[B >: A](f: (A, B) => B): B = this match {
+    case Nil => throw new UnsupportedOperationException("Nil.reduceRight")
+    case x :: Nil => x
+    case x :: xs => f(x, xs reduceRight f)
+  }
+
+  /** Applies the given function <code>f</code> to each element of
+   *  this list, then concatenates the results.
+   *
+   *  @param f the function to apply on each element.
+   *  @return  <code>f(a<sub>0</sub>) ::: ... ::: f(a<sub>n</sub>)</code> if
+   *           this list is <code>[a<sub>0</sub>, ..., a<sub>n</sub>]</code>.
+   */
+  final override def flatMap[B](f: A => Iterable[B]): List[B] = {
+    val b = new ListBuffer[B]
+    var these = this
+    while (!these.isEmpty) {
+      var those = f(these.head).elements
+      while (those.hasNext) {
+        b += those.next
+      }
+      these = these.tail
+    }
+    b.toList
+  }
+
+  /** A list consisting of all elements of this list in reverse order.
+   */
+  override def reverse: List[A] = {
+    var result: List[A] = Nil
+    var these = this
+    while (!these.isEmpty) {
+      result = these.head :: result
+      these = these.tail
+    }
+    result
+  }
+
+  /** Returns a list formed from this list and the specified list
+   *  <code>that</code> by associating each element of the former with
+   *  the element at the same position in the latter.
+   *  If one of the two lists is longer than the other, its remaining elements are ignored.
+   *
+   *  @return     <code>List((a<sub>0</sub>,b<sub>0</sub>), ...,
+   *              (a<sub>min(m,n)</sub>,b<sub>min(m,n)</sub>))</code> when
+   *              <code>List(a<sub>0</sub>, ..., a<sub>m</sub>)
+   *              zip List(b<sub>0</sub>, ..., b<sub>n</sub>)</code> is invoked.
+   */
+  def zip[B](that: List[B]): List[(A, B)] = {
+    val b = new ListBuffer[(A, B)]
+    var these = this
+    var those = that
+    while (!these.isEmpty && !those.isEmpty) {
+      b += ((these.head, those.head))
+      these = these.tail
+      those = those.tail
+    }
+    b.toList
+  }
+
+  /** Returns a list formed from this list and the specified list
+   *  <code>that</code> by associating each element of the former with
+   *  the element at the same position in the latter.
+   *
+   *  @param that     list <code>that</code> may have a different length
+   *                  as the self list.
+   *  @param thisElem element <code>thisElem</code> is used to fill up the
+   *                  resulting list if the self list is shorter than
+   *                  <code>that</code>
+   *  @param thatElem element <code>thatElem</code> is used to fill up the
+   *                  resulting list if <code>that</code> is shorter than
+   *                  the self list
+   *  @return         <code>List((a<sub>0</sub>,b<sub>0</sub>), ...,
+   *                  (a<sub>n</sub>,b<sub>n</sub>), (elem,b<sub>n+1</sub>),
+   *                  ..., {elem,b<sub>m</sub>})</code>
+   *                  when <code>[a<sub>0</sub>, ..., a<sub>n</sub>] zip
+   *                  [b<sub>0</sub>, ..., b<sub>m</sub>]</code> is
+   *                  invoked where <code>m &gt; n</code>.
+   */
+  def zipAll[B, C >: A, D >: B](that: List[B], thisElem: C, thatElem: D): List[(C, D)] = {
+    val b = new ListBuffer[(C, D)]
+    var these = this
+    var those = that
+    while (!these.isEmpty && !those.isEmpty) {
+      b += ((these.head, those.head))
+      these = these.tail
+      those = those.tail
+    }
+    while (!these.isEmpty) {
+      b += ((these.head, thatElem))
+      these = these.tail
+    }
+    while (!those.isEmpty) {
+      b += ((thisElem, those.head))
+      those = those.tail
+    }
+    b.toList
+  }
+
+  /** Computes the union of this list and the given list
+   *  <code>that</code>.
+   *
+   *  @param that the list of elements to add to the list.
+   *  @return     a list without doubles containing the elements of this
+   *              list and those of the given list <code>that</code>.
+   */
+  def union[B >: A](that: List[B]): List[B] = {
+    val b = new ListBuffer[B]
+    var these = this
+    while (!these.isEmpty) {
+      if (!that.contains(these.head)) b += these.head
+      these = these.tail
+    }
+    b.prependToList(that)
+  }
+
+  /** Computes the difference between this list and the given list
+   *  <code>that</code>.
+   *
+   *  @param that the list of elements to remove from this list.
+   *  @return     this list without the elements of the given list
+   *              <code>that</code>.
+   *  @deprecated use <code>--</code> instead
+   */
+  @deprecated
+  def diff[B >: A](that: List[B]): List[B] = this -- that
+
+  /** Computes the difference between this list and the given list
+   *  <code>that</code>.
+   *
+   *  @param that the list of elements to remove from this list.
+   *  @return     this list without the elements of the given list
+   *              <code>that</code>.
+   */
+  def -- [B >: A](that: List[B]): List[B] = {
+    val b = new ListBuffer[B]
+    var these = this
+    while (!these.isEmpty) {
+      if (!that.contains(these.head)) b += these.head
+      these = these.tail
+    }
+    b.toList
+  }
+
+  /** Computes the difference between this list and the given object
+   *  <code>x</code>.
+   *
+   *  @param x    the object to remove from this list.
+   *  @return     this list without the elements of the given object
+   *              <code>x</code>.
+   */
+  def - [B >: A](x: B): List[B] = {
+    val b = new ListBuffer[B]
+    var these = this
+    while (!these.isEmpty) {
+      if (these.head != x) b += these.head
+      these = these.tail
+    }
+    b.toList
+  }
+
+  /** Concatenate the elements of this list. The elements of this list
+   *  should be a <code>Iterables</code>.
+   *
+   *  Note: The compiler might not be able to infer the type parameter.
+   *
+   *  @param f    An implicit conversion to an <code>Iterable</code> instance.
+   *  @return     The concatenation of all elements of iterables in this list.
+   */
+  def flatten[B](implicit f : A => Iterable[B]) : List[B] = {
+    val buf = new ListBuffer[B]
+    foreach(f(_).foreach(buf += _))
+    buf.toList
+  }
+
+  override def stringPrefix = "List"
+
+  override def toStream : Stream[A] = null // !!!
+  /*new Stream.Definite[A] {
+    override def force : List[A] = List.this
+    override def isEmpty = List.this.isEmpty
+    override def head = List.this.head
+    override def tail = List.this.tail.toStream
+    protected def addDefinedElems(buf: StringBuilder, prefix: String): StringBuilder = if (!isEmpty) {
+      var prefix0 = prefix
+      var buf1 = buf.append(prefix0).append(head)
+      prefix0 = ", "
+      var tail0 = tail
+      while (!tail0.isEmpty) {
+        buf1 = buf.append(prefix0).append(tail0.head)
+        tail0 = tail0.tail
+      }
+      buf1
+    } else buf
+  }*/
+
+}
+
+/** The empty list.
+ *
+ *  @author  Martin Odersky
+ *  @version 1.0, 15/07/2003
+ */
+@SerialVersionUID(0 - 8256821097970055419L)
+case object Nil extends List[Nothing] {
+  override def isEmpty = true
+  override def head: Nothing =
+    throw new NoSuchElementException("head of empty list")
+  override def tail: List[Nothing] =
+    throw new NoSuchElementException("tail of empty list")
+}
+
+/** A non empty list characterized by a head and a tail.
+ *
+ *  @author  Martin Odersky
+ *  @version 1.0, 15/07/2003
+ */
+@SerialVersionUID(0L - 8476791151983527571L)
+final case class ::[B](private var hd: B, private[scalax] var tl: List[B]) extends List[B] {
+  override def head : B = hd
+  override def tail : List[B] = tl
+  override def isEmpty: Boolean = false
+}
+
+/** Only used for list serialization */
+@SerialVersionUID(0L - 8476791151975527571L)
+private[scalax] case object ListSerializeEnd
+/** This object provides methods for creating specialized lists, and for
+ *  transforming special kinds of lists (e.g. lists of lists).
+ *
+ *  @author  Martin Odersky and others
+ *  @version 1.0, 15/07/2003
+ */
+object List {
+
+  /** Create a list with given elements.
+   *
+   *  @param xs the elements to put in the list
+   *  @return the list containing elements xs.
+   */
+  def apply[A](xs: A*): List[A] = (xs.asInstanceOf[Iterable[A]]).toList // !!!
+
+  /** for unapply matching
+   */
+  def unapplySeq[A](x: List[A]): Some[List[A]] = Some(x)
+
+  /** Create a sorted list of all integers in a range.
+   *
+   *  @param from the start value of the list
+   *  @param end the end value of the list
+   *  @return the sorted list of all integers in range [from;end).
+   */
+  def range(start: Int, end: Int): List[Int] =
+    range(start, end, 1)
+
+  /** Create a list with element values
+   * <code>v<sub>n+1</sub> = v<sub>n</sub> + step</code>
+   * where <code>v<sub>0</sub> = start</code>
+   * and elements are in the range between <code>start</code> (inclusive)
+   * and <code>end</code> (exclusive)
+   *
+   *  @param start the start value of the list
+   *  @param end  the end value of the list
+   *  @param step the increment value of the list
+   *  @return     the sorted list of all integers in range [start;end).
+   */
+  def range(start: Int, end: Int, step: Int): List[Int] = {
+    val b = new ListBuffer[Int]
+    var i = start
+    while ((step <= 0 || i < end) && (step >= 0 || i > end)) {
+      b += i
+      i += step
+    }
+    b.toList
+  }
+
+  /** Create a sorted list with element values
+   * <code>v<sub>n+1</sub> = step(v<sub>n</sub>)</code>
+   * where <code>v<sub>0</sub> = start</code>
+   * and elements are in the range between <code>start</code> (inclusive)
+   * and <code>end</code> (exclusive)
+   *
+   *  @param start the start value of the list
+   *  @param end  the end value of the list
+   *  @param step the increment function of the list, must be monotonically increasing or decreasing
+   *  @return     the sorted list of all integers in range [start;end).
+   */
+  def range(start: Int, end: Int, step: Int => Int): List[Int] = {
+    val up = step(start) > start
+    val down = step(start) < start
+    val b = new ListBuffer[Int]
+    var i = start
+    while ((!up || i < end) && (!down || i > end)) {
+      b += i
+      i += step(i)
+    }
+    b.toList
+  }
+
+  /** Create a list containing several copies of an element.
+   *
+   *  @param n    the length of the resulting list
+   *  @param elem the element composing the resulting list
+   *  @return     a list composed of n elements all equal to elem
+   */
+  def make[A](n: Int, elem: A): List[A] = {
+    val b = new ListBuffer[A]
+    var i = 0
+    while (i < n) {
+      b += elem
+      i += 1
+    }
+    b.toList
+  }
+
+  /** Create a list by applying a function to successive integers.
+   *
+   *  @param n     the length of the resulting list
+   *  @param maker the procedure which, given an integer <code>n</code>,
+   *               returns the nth element of the resulting list, where
+   *               <code>n</code> is in interval <code>[0;n)</code>.
+   *  @return      the list obtained by applying the maker function to
+   *               successive integers from 0 to n (exclusive).
+   */
+  def tabulate[A](n: Int, maker: Int => A): List[A] = {
+    val b = new ListBuffer[A]
+    var i = 0
+    while (i < n) {
+      b += maker(i)
+      i += 1
+    }
+    b.toList
+  }
+
+  /** Concatenate all the elements of a given list of lists.
+   *
+   *  @param xss the list of lists that are to be concatenated
+   *  @return    the concatenation of all the lists
+   */
+  def flatten[A](xss: List[List[A]]): List[A] = {
+    val b = new ListBuffer[A]
+    for (xs <- xss) {
+      var xc = xs
+      while (!xc.isEmpty) {
+        b += xc.head
+        xc = xc.tail
+      }
+    }
+    b.toList
+  }
+
+  /** Concatenate all the argument lists into a single list.
+   *
+   *  @param xss the lists that are to be concatenated
+   *  @return the concatenation of all the lists
+   */
+  def concat[A](xss: List[A]*): List[A] = {
+    val b = new ListBuffer[A]
+    for (xs <- xss) {
+      var xc = xs
+      while (!xc.isEmpty) {
+        b += xc.head
+        xc = xc.tail
+      }
+    }
+    b.toList
+  }
+
+  /** Transforms a list of pairs into a pair of lists.
+   *
+   *  @param xs the list of pairs to unzip
+   *  @return a pair of lists.
+   */
+  def unzip[A,B](xs: List[(A,B)]): (List[A], List[B]) = {
+    val b1 = new ListBuffer[A]
+    val b2 = new ListBuffer[B]
+    var xc = xs
+    while (!xc.isEmpty) {
+      b1 += xc.head._1
+      b2 += xc.head._2
+      xc = xc.tail
+    }
+    (b1.toList, b2.toList)
+  }
+
+  /** Transforms an iterable of pairs into a pair of lists.
+   *
+   *  @param xs the iterable of pairs to unzip
+   *  @return a pair of lists.
+   */
+  def unzip[A,B](xs: Iterable[(A,B)]): (List[A], List[B]) =
+      xs.foldRight[(List[A], List[B])]((Nil, Nil)) {
+        case ((x, y), (xs, ys)) => (x :: xs, y :: ys)
+      }
+
+  /**
+   * Returns the <code>Left</code> values in the given <code>Iterable</code> of <code>Either</code>s.
+   */
+  def lefts[A, B](es: Iterable[Either[A, B]]) =
+    es.foldRight[List[A]](Nil)((e, as) => e match {
+      case Left(a) => a :: as
+      case Right(_) => as
+    })
+
+  /**
+   * Returns the <code>Right</code> values in the given<code>Iterable</code> of  <code>Either</code>s.
+   */
+  def rights[A, B](es: Iterable[Either[A, B]]) =
+    es.foldRight[List[B]](Nil)((e, bs) => e match {
+      case Left(_) => bs
+      case Right(b) => b :: bs
+    })
+
+  /** Transforms an Iterable of Eithers into a pair of lists.
+   *
+   *  @param xs the iterable of Eithers to separate
+   *  @return a pair of lists.
+   */
+  def separate[A,B](es: Iterable[Either[A,B]]): (List[A], List[B]) =
+      es.foldRight[(List[A], List[B])]((Nil, Nil)) {
+      case (Left(a), (lefts, rights)) => (a :: lefts, rights)
+      case (Right(b), (lefts, rights)) => (lefts, b :: rights)
+    }
+
+  /** Converts an iterator to a list.
+   *
+   *  @param it the iterator to convert
+   *  @return   a list that contains the elements returned by successive
+   *            calls to <code>it.next</code>
+   */
+  def fromIterator[A](it: Iterator[A]): List[A] = it.toList
+
+  /** Converts an array into a list.
+   *
+   *  @param arr the array to convert
+   *  @return    a list that contains the same elements than <code>arr</code>
+   *             in the same order
+   */
+  def fromArray[A](arr: Array[A]): List[A] = fromArray(arr, 0, arr.length)
+
+  /** Converts a range of an array into a list.
+   *
+   *  @param arr   the array to convert
+   *  @param start the first index to consider
+   *  @param len   the lenght of the range to convert
+   *  @return      a list that contains the same elements than <code>arr</code>
+   *               in the same order
+   */
+  def fromArray[A](arr: Array[A], start: Int, len: Int): List[A] = {
+    var res: List[A] = Nil
+    var i = start + len
+    while (i > start) {
+      i -= 1
+      res = arr(i) :: res
+    }
+    res
+  }
+
+  /** Parses a string which contains substrings separated by a
+   *  separator character and returns a list of all substrings.
+   *
+   *  @param str       the string to parse
+   *  @param separator the separator character
+   *  @return          the list of substrings
+   */
+  def fromString(str: String, separator: Char): List[String] = {
+    var words: List[String] = Nil
+    var pos = str.length()
+    while (pos > 0) {
+      val pos1 = str.lastIndexOf(separator, pos - 1)
+      if (pos1 + 1 < pos)
+        words = str.substring(pos1 + 1, pos) :: words
+      pos = pos1
+    }
+    words
+  }
+
+  /** Returns the given string as a list of characters.
+   *
+   *  @param str the string to convert.
+   *  @return    the string as a list of characters.
+   *  @deprecated use <code>str.toList</code> instead
+   */
+  @deprecated def fromString(str: String): List[Char] =
+    str.toList.asInstanceOf[List[Char]] // !!!
+
+  /** Returns the given list of characters as a string.
+   *
+   *  @param xs the list to convert.
+   *  @return   the list in form of a string.
+   */
+  def toString(xs: List[Char]): String = {
+    val sb = new StringBuilder()
+    var xc = xs
+    while (!xc.isEmpty) {
+      sb.append(xc.head)
+      xc = xc.tail
+    }
+    sb.toString()
+  }
+
+  /** Like xs map f, but returns <code>xs</code> unchanged if function
+   *  <code>f</code> maps all elements to themselves.
+   *
+   *  @param xs ...
+   *  @param f  ...
+   *  @return   ...
+   */
+  def mapConserve[A <: AnyRef](xs: List[A])(f: A => A): List[A] = {
+    def loop(ys: List[A]): List[A] =
+      if (ys.isEmpty) xs
+      else {
+        val head0 = ys.head
+        val head1 = f(head0)
+        if (head1 eq head0) {
+          loop(ys.tail)
+        } else {
+          val ys1 = head1 :: mapConserve(ys.tail)(f)
+          if (xs eq ys) ys1
+          else {
+            val b = new ListBuffer[A]
+            var xc = xs
+            while (xc ne ys) {
+              b += xc.head
+              xc = xc.tail
+            }
+            b.prependToList(ys1)
+          }
+        }
+      }
+    loop(xs)
+  }
+
+  /** Returns the list resulting from applying the given function <code>f</code>
+   *  to corresponding elements of the argument lists.
+   *
+   *  @param f function to apply to each pair of elements.
+   *  @return <code>[f(a0,b0), ..., f(an,bn)]</code> if the lists are
+   *          <code>[a0, ..., ak]</code>, <code>[b0, ..., bl]</code> and
+   *          <code>n = min(k,l)</code>
+   */
+  def map2[A,B,C](xs: List[A], ys: List[B])(f: (A, B) => C): List[C] = {
+    val b = new ListBuffer[C]
+    var xc = xs
+    var yc = ys
+    while (!xc.isEmpty && !yc.isEmpty) {
+      b += f(xc.head, yc.head)
+      xc = xc.tail
+      yc = yc.tail
+    }
+    b.toList
+  }
+
+  /** Returns the list resulting from applying the given function
+   *  <code>f</code> to corresponding elements of the argument lists.
+   *
+   *  @param f function to apply to each pair of elements.
+   *  @return  <code>[f(a<sub>0</sub>,b<sub>0</sub>,c<sub>0</sub>),
+   *           ..., f(a<sub>n</sub>,b<sub>n</sub>,c<sub>n</sub>)]</code>
+   *           if the lists are <code>[a<sub>0</sub>, ..., a<sub>k</sub>]</code>,
+   *           <code>[b<sub>0</sub>, ..., b<sub>l</sub>]</code>,
+   *           <code>[c<sub>0</sub>, ..., c<sub>m</sub>]</code> and
+   *           <code>n = min(k,l,m)</code>
+   */
+  def map3[A,B,C,D](xs: List[A], ys: List[B], zs: List[C])(f: (A, B, C) => D): List[D] = {
+    val b = new ListBuffer[D]
+    var xc = xs
+    var yc = ys
+    var zc = zs
+    while (!xc.isEmpty && !yc.isEmpty && !zc.isEmpty) {
+      b += f(xc.head, yc.head, zc.head)
+      xc = xc.tail
+      yc = yc.tail
+      zc = zc.tail
+    }
+    b.toList
+  }
+
+  /** Tests whether the given predicate <code>p</code> holds
+   *  for all corresponding elements of the argument lists.
+   *
+   *  @param p function to apply to each pair of elements.
+   *  @return  <code>(p(a<sub>0</sub>,b<sub>0</sub>) &amp;&amp;
+   *           ... &amp;&amp; p(a<sub>n</sub>,b<sub>n</sub>))]</code>
+   *           if the lists are <code>[a<sub>0</sub>, ..., a<sub>k</sub>]</code>;
+   *           <code>[b<sub>0</sub>, ..., b<sub>l</sub>]</code>
+   *           and <code>n = min(k,l)</code>
+   */
+  def forall2[A,B](xs: List[A], ys: List[B])(f: (A, B) => Boolean): Boolean = {
+    var xc = xs
+    var yc = ys
+    while (!xc.isEmpty && !yc.isEmpty) {
+      if (!f(xc.head, yc.head)) return false
+      xc = xc.tail
+      yc = yc.tail
+    }
+    true
+  }
+
+  /** Tests whether the given predicate <code>p</code> holds
+   *  for some corresponding elements of the argument lists.
+   *
+   *  @param p function to apply to each pair of elements.
+   *  @return  <code>n != 0 &amp;&amp; (p(a<sub>0</sub>,b<sub>0</sub>) ||
+   *           ... || p(a<sub>n</sub>,b<sub>n</sub>))]</code> if the lists are
+   *           <code>[a<sub>0</sub>, ..., a<sub>k</sub>]</code>,
+   *           <code>[b<sub>0</sub>, ..., b<sub>l</sub>]</code> and
+   *           <code>n = min(k,l)</code>
+   */
+  def exists2[A,B](xs: List[A], ys: List[B])(f: (A, B) => Boolean): Boolean = {
+    var xc = xs
+    var yc = ys
+    while (!xc.isEmpty && !yc.isEmpty) {
+      if (f(xc.head, yc.head)) return true
+      xc = xc.tail
+      yc = yc.tail
+    }
+    false
+  }
+
+  /** Transposes a list of lists.
+   *  pre: All element lists have the same length.
+   *
+   *  @param xss the list of lists
+   *  @return    the transposed list of lists
+   */
+  def transpose[A](xss: List[List[A]]): List[List[A]] = {
+    val buf = new ListBuffer[List[A]]
+    var yss = xss
+    while (!yss.head.isEmpty) {
+      buf += (yss map (_.head))
+      yss = (yss map (_.tail))
+    }
+    buf.toList
+  }
+
+  /** Lists with ordered elements are ordered
+  implicit def list2ordered[a <% Ordered[a]](x: List[a]): Ordered[List[a]] = new Ordered[List[a]] {
+    def compare [b >: List[a] <% Ordered[b]](y: b): Int = y match {
+      case y1: List[a] => compareLists(x, y1);
+      case _ => -(y compare x)
+    }
+    private def compareLists(xs: List[a], ys: List[a]): Int = {
+      if (xs.isEmpty && ys.isEmpty) 0
+      else if (xs.isEmpty) -1
+      else if (ys.isEmpty) 1
+      else {
+        val s = xs.head compare ys.head;
+        if (s != 0) s
+        else compareLists(xs.tail, ys.tail)
+      }
+    }
+  }
+   */
+}
+