new doc comment generation, including some new ...

new doc comment generation, including some new style doc comments in
collection classes.

8 files changed, 560 insertions, 337 deletions

diff --git a/src/library/scala/collection/IndexedSeqLike.scala b/src/library/scala/collection/IndexedSeqLike.scala
index 68862e4aed..7041078229 100644
--- a/src/library/scala/collection/IndexedSeqLike.scala
+++ b/src/library/scala/collection/IndexedSeqLike.scala
@@ -77,7 +77,18 @@ trait IndexedSeqLike[+A, +Repr] extends SeqLike[A, Repr] { self =>
     val i = prefixLength(!p(_))
     if (i < length) Some(this(i)) else None
   }
-
+/*
+  override def mapFind[B](f: A => Option[B]): Option[B] = {
+    var i = 0
+    var res: Option[B] = None
+    val len = length
+    while (res.isEmpty && i < len) {
+      res = f(this(i))
+      i += 1
+    }
+    res
+  }
+*/
   @tailrec
   private def foldl[B](start: Int, end: Int, z: B, op: (B, A) => B): B =
     if (start == end) z
diff --git a/src/library/scala/collection/IterableLike.scala b/src/library/scala/collection/IterableLike.scala
index f1401f1221..66f63dd2f5 100644
--- a/src/library/scala/collection/IterableLike.scala
+++ b/src/library/scala/collection/IterableLike.scala
@@ -14,7 +14,7 @@ import immutable.{List, Stream}
 import annotation.unchecked.uncheckedVariance
 
 /** <p>
- *    A template trait for iterable collections.
+ *    A template trait for iterable collections of type `Iterable[A]`.
  *  </p>
  *  <p>
  *    Collection classes mixing in this trait provide a method
@@ -36,11 +36,27 @@ import annotation.unchecked.uncheckedVariance
  *    <code>Iterable</code></a>.
  *  </p>
  *
- *  @note  This trait replaces every method that uses breaks in the original by an iterator version.
+ *  Note: This trait replaces every method that uses breaks in the original by an iterator version.
+ *
+ *  @see Iterable
  *
  *  @author Martin Odersky
  *  @version 2.8
  *  @since   2.8
+ *
+ *  @tparam A    the element type of the collection
+ *  @tparam Repr the type of the actual collection containing the elements.
+ *
+ *  @define Coll Iterable
+ *  @define coll iterable collection
+ *  @define zipthatinfo the class of the returned collection. Where possible, `That` is
+ *    the same class as the current collection class `Repr`, but this
+ *    depends on the element type `(A1, B)` being admissible for that class,
+ *    which means that an implicit instance of type `CanBuildFrom[Repr, (A1, B), That]`.
+ *    is found.
+ *  @define zipbfinfo  an implicit value of class `CanBuildFrom` which determines the
+ *    result class `That` from the current representation type `Repr`
+ *    and the new element type `(A1, B)`.
  */
 trait IterableLike[+A, +Repr] extends Equals with TraversableLike[A, Repr] {
 self =>
@@ -58,102 +74,50 @@ self =>
   @deprecated("use `iterator' instead")
   def elements = iterator
 
-  /** Apply a function <code>f</code> to all elements of this
-   *  iterable object.
-   *
-   *  @param  f   A function that is applied for its side-effect to every element.
-   *              The result (of arbitrary type U) of function `f` is discarded.
-   *
-   *  @note This method underlies the implementation of most other bulk operations.
-   *        Implementing `foreach` with `iterator` is often suboptimal.
-   *        So `foreach` should be overridden in concrete collection classes if a more
-   *        efficient implementation is available.
-   */
-  def foreach[U](f: A => U): Unit = iterator.foreach(f)
-
-
-  /** Return true iff the given predicate `p` yields true for all elements
-   *  of this iterable.
-   *
-   *  @note May not terminate for infinite-sized collections.
-   *  @param   p     the predicate
-   */
-  override def forall(p: A => Boolean): Boolean = iterator.forall(p)
-
-  /** Return true iff there is an element in this iterable for which the
-   *  given predicate `p` yields true.
-   *
-   *  @note May not terminate for infinite-sized collections.
-   *  @param   p     the predicate
-   */
-  override def exists(p: A => Boolean): Boolean = iterator.exists(p)
-
-  /** Find and return the first element of the iterable object satisfying a
-   *  predicate, if any.
+  /** Applies a function `f` to all elements of this $coll.
    *
-   *  @note may not terminate for infinite-sized collections.
-   *  @note Might return different results for different runs, unless this iterable is ordered.
-   *  @param p the predicate
-   *  @return an option containing the first element in the iterable object
-   *  satisfying <code>p</code>, or <code>None</code> if none exists.
-   */
-  override def find(p: A => Boolean): Option[A] = iterator.find(p)
-
-  /** Does this iterable contain no elements?
-   */
-  override def isEmpty: Boolean = !this.iterator.hasNext
-
-  /** Combines the elements of this iterable together using the binary
-   *  function <code>f</code>, from right to left, and starting with
-   *  the value <code>z</code>.
+   *    Note: this method underlies the implementation of most other bulk operations.
+   *    Subclasses should re-implement this method if a more efficient implementation exists.
    *
-   *  @note Will not terminate for infinite-sized collections.
-   *  @note Might return different results for different runs, unless this iterable is ordered, or
-   *        the operator is associative and commutative.
-   *  @return <code>f(a<sub>0</sub>, f(a<sub>1</sub>, f(..., f(a<sub>n</sub>, z)...)))</code>
-   *          if the iterable is <code>[a<sub>0</sub>, a1, ..., a<sub>n</sub>]</code>.
-   */
-  override def foldRight[B](z: B)(op: (A, B) => B): B =
-    this.iterator.foldRight(z)(op)
-
-  /** Combines the elements of this iterable object together using the binary
-   *  operator <code>op</code>, from right to left
-   *  @note Will not terminate for infinite-sized collections.
-   *  @note Might return different results for different runs, unless this iterable is ordered, or
-   *        the operator is associative and commutative.
-   *  @param op  The operator to apply
+   *  @param  f   the function that is applied for its side-effect to every element.
+   *              The result of function `f` is discarded.
    *
-   *  @return <code>a<sub>0</sub> op (... op (a<sub>n-1</sub> op a<sub>n</sub>)...)</code>
-   *          if the iterable object has elements <code>a<sub>0</sub>, a<sub>1</sub>, ...,
-   *          a<sub>n</sub></code>.
+   *  @tparam  U  the type parameter describing the result of function `f`.
+   *              This result will always be ignored. Typically `U` is `Unit`,
+   *              but this is not necessary.
    *
-   *  @throws Predef.UnsupportedOperationException if the iterator is empty.
-   */
-  override def reduceRight[B >: A](op: (A, B) => B): B =
-    this.iterator.reduceRight(op)
-
-  /** The iterable itself */
-  override def toIterable: Iterable[A] = thisCollection
-
-  /** The first element of this iterable.
+   *  @usecase def foreach(f: A => Unit): Unit
    *
-   *  @note  Might return different results for different runs, unless this iterable is ordered
-   *  @throws Predef.NoSuchElementException if the iterable is empty.
+   *  @param  f   the function that is applied for its side-effect to every element.
+   *              The result of function `f` is discarded.
    */
-  override def head: A =
-    if (isEmpty)
-      throw new NoSuchElementException
-    else
-      this.iterator.next
-
-  /** Return an iterable consisting only of the first <code>n</code>
-   *  elements of this iterable, or else the whole iterable, if it has less
-   *  than <code>n</code> elements.
-   *
-   *  @param n the number of elements to take
-   *  @note  Might return different results for different runs, unless this iterable is ordered
-   */
-  override def take(n: Int): Repr = {
+  def foreach[U](f: A => U): Unit =
+    iterator.foreach(f)
+
+  override /*TraversableLike*/ def forall(p: A => Boolean): Boolean =
+    iterator.forall(p)
+  override /*TraversableLike*/ def exists(p: A => Boolean): Boolean =
+    iterator.exists(p)
+  override /*TraversableLike*/ def find(p: A => Boolean): Option[A] =
+    iterator.find(p)
+/*
+  override /*TraversableLike*/ def mapFind[B](f: A => Option[B]): Option[B] =
+    iterator.mapFind(f)
+*/
+  override /*TraversableLike*/ def isEmpty: Boolean =
+    !iterator.hasNext
+  override /*TraversableLike*/ def foldRight[B](z: B)(op: (A, B) => B): B =
+    iterator.foldRight(z)(op)
+  override /*TraversableLike*/ def reduceRight[B >: A](op: (A, B) => B): B =
+    iterator.reduceRight(op)
+  override /*TraversableLike*/ def toIterable: Iterable[A] =
+    thisCollection
+
+  override /*TraversableLike*/ def head: A =
+    if (isEmpty) throw new NoSuchElementException
+    else iterator.next
+
+  override /*TraversableLike*/ def take(n: Int): Repr = {
     val b = newBuilder
     var i = 0
     val it = iterator
@@ -164,17 +128,7 @@ self =>
     b.result
   }
 
-  /** A sub-iterable starting at index `from`
-   *  and extending up to (but not including) index `until`.
-   *
-   *  @note c.slice(from, to)  is equivalent to (but possibly more efficient than)
-   *  c.drop(from).take(to - from)
-   *
-   *  @param from   The index of the first element of the returned subsequence
-   *  @param until  The index of the element following the returned subsequence
-   *  @note  Might return different results for different runs, unless this iterable is ordered
-   */
-  override def slice(from: Int, until: Int): Repr = {
+  override /*TraversableLike*/ def slice(from: Int, until: Int): Repr = {
     val b = newBuilder
     var i = from
     val it = iterator drop from
@@ -185,13 +139,7 @@ self =>
     b.result
   }
 
-  /** Returns the longest prefix of this iterable whose elements satisfy
-   *  the predicate <code>p</code>.
-   *
-   *  @param p the test predicate.
-   *  @note  Might return different results for different runs, unless this iterable is ordered
-   */
-  override def takeWhile(p: A => Boolean): Repr = {
+  override /*TraversableLike*/ def takeWhile(p: A => Boolean): Repr = {
     val b = newBuilder
     val it = iterator
     while (it.hasNext) {
@@ -202,10 +150,12 @@ self =>
     b.result
   }
 
-  /** Returns the rightmost <code>n</code> elements from this iterable.
+  /** Selects last ''n'' elements.
+   *  $orderDependent
    *
    *  @param n the number of elements to take
-   *  @note  Might return different results for different runs, unless this iterable is ordered
+   *  @return a $coll consisting only of the last `n` elements of this $coll, or else the
+   *          whole $coll, if it has less than `n` elements.
    */
   def takeRight(n: Int): Repr = {
     val b = newBuilder
@@ -219,10 +169,12 @@ self =>
     b.result
   }
 
-  /** Returns the iterable wihtout its rightmost <code>n</code> elements.
+  /** Selects all elements except first ''n'' ones.
+   *  $orderDependent
    *
-   *  @param n the number of elements to take
-   *  @note  Might return different results for different runs, unless this iterable is ordered
+   *  @param  n    The number of elements to take
+   *  @return a $coll consisting of all elements of this $coll except the first `n` ones, or else the
+   *          empty $coll, if this $coll has less than `n` elements.
    */
   def dropRight(n: Int): Repr = {
     val b = newBuilder
@@ -235,17 +187,7 @@ self =>
     b.result
   }
 
-  /** Fills the given array <code>xs</code> with at most `len` elements of
-   *  this iterable starting at position `start`.
-   *  Copying will stop once either the end of the current iterable is reached or
-   *  `len` elements have been copied or the end of the array is reached.
-   *
-   *  @note Will not terminate for infinite-sized collections.
-   *  @param  xs the array to fill.
-   *  @param  start starting index.
-   *  @param  len number of elements to copy
-   */
-  override def copyToArray[B >: A](xs: Array[B], start: Int, len: Int) {
+  override /*TraversableLike*/ def copyToArray[B >: A](xs: Array[B], start: Int, len: Int) {
     var i = start
     val end = (start + len) min xs.length
     val it = iterator
@@ -255,10 +197,29 @@ self =>
     }
   }
 
-  /** Returns an iterable formed from this iterable and another iterable
+  /** Returns a $coll formed from this $coll and another iterable collection
    *  by combining corresponding elements in pairs.
-   *  If one of the two iterables is longer than the other, its remaining elements are ignored.
+   *  If one of the two collections is longer than the other, its remaining elements are ignored.
+   *
+   *  $orderDependent
+   *
    *  @param   that  The iterable providing the second half of each result pair
+   *  @tparam  A1    the type of the first half of the returned pairs (this is always a supertype
+   *                 of the collection's element type `A`).
+   *  @tparam  B     the type of the second half of the returned pairs
+   *  @tparam  That  $zipthatinfo
+   *  @param   bf    $zipbfinfo
+   *  @return        a new collection of type `That` containing pairs consisting of
+   *                 corresponding elements of this $coll and `that`. The length
+   *                 of the returned collection is the minimum of the lengths of this $coll$ and `that`.
+   *
+   *  @usecase def zip[B](that: Iterable[B]): $Coll[(A, B)]
+   *
+   *  @param   that  The iterable providing the second half of each result pair
+   *  @tparam  B     the type of the second half of the returned pairs
+   *  @return        a new $coll containing pairs consisting of
+   *                 corresponding elements of this $coll and `that`. The length
+   *                 of the returned collection is the minimum of the lengths of this $coll$ and `that`.
    */
   def zip[A1 >: A, B, That](that: Iterable[B])(implicit bf: CanBuildFrom[Repr, (A1, B), That]): That = {
     val b = bf(repr)
@@ -269,25 +230,33 @@ self =>
     b.result
   }
 
-  /** Returns an iterable formed from this iterable and the specified iterable
-   *  <code>that</code> by associating each element of the former with
-   *  the element at the same position in the latter.
+  /** Returns a $coll formed from this $coll and another iterable collection
+   *  by combining corresponding elements in pairs.
+   *  If one of the two collections is shorter than the other,
+   *  placeholder elements are used to extend the collection to the longer length.
    *
-   *  @param that     iterable <code>that</code> may have a different length
-   *                  as the self iterable.
-   *  @param thisElem element <code>thisElem</code> is used to fill up the
-   *                  resulting iterable if the self iterable is shorter than
-   *                  <code>that</code>
-   *  @param thatElem element <code>thatElem</code> is used to fill up the
-   *                  resulting iterable if <code>that</code> is shorter than
-   *                  the self iterable
-   *  @return         <code>Sequence((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>.
+   *  $orderDependent
    *
+   *  @param that     the iterable providing the second half of each result pair
+   *  @param thisElem the element to be used to fill up the result if this $coll is shorter than `that`.
+   *  @param thatElem the element to be used to fill up the result if `that` is shorter than this $coll.
+   *  @return        a new collection of type `That` containing pairs consisting of
+   *                 corresponding elements of this $coll and `that`. The length
+   *                 of the returned collection is the maximum of the lengths of this $coll$ and `that`.
+   *                 If this $coll is shorter than `that`, `thisElem` values are used to pad the result.
+   *                 If `that` is shorter than this $coll, `thatElem` values are used to pad the result.
+   *
+   *  @usecase def zipAll[B](that: Iterable[B], thisElem: A, thatElem: B): $Coll[(A, B)]
+   *
+   *  @param   that  The iterable providing the second half of each result pair
+   *  @param thisElem the element to be used to fill up the result if this $coll is shorter than `that`.
+   *  @param thatElem the element to be used to fill up the result if `that` is shorter than this $coll.
+   *  @tparam  B     the type of the second half of the returned pairs
+   *  @return        a new $coll containing pairs consisting of
+   *                 corresponding elements of this $coll and `that`. The length
+   *                 of the returned collection is the maximum of the lengths of this $coll$ and `that`.
+   *                 If this $coll is shorter than `that`, `thisElem` values are used to pad the result.
+   *                 If `that` is shorter than this $coll, `thatElem` values are used to pad the result.
    */
   def zipAll[B, A1 >: A, That](that: Iterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[Repr, (A1, B), That]): That = {
     val b = bf(repr)
@@ -302,7 +271,30 @@ self =>
     b.result
   }
 
-  /** Zips this iterable with its indices (startiong from 0).
+  /** Zips this $coll with its indices.
+   *
+   *  $orderDependent
+   *
+   *  @tparam  A1    the type of the first half of the returned pairs (this is always a supertype
+   *                 of the collection's element type `A`).
+   *  @tparam  That  the class of the returned collection. Where possible, `That` is
+   *    the same class as the current collection class `Repr`, but this
+   *    depends on the element type `(A1, Int)` being admissible for that class,
+   *    which means that an implicit instance of type `CanBuildFrom[Repr, (A1, Int), That]`.
+   *    is found.
+   *  @tparam  bf    an implicit value of class `CanBuildFrom` which determines the
+   *    result class `That` from the current representation type `Repr`
+   *    and the new element type `(A1, Int)`.
+   *  @return        A new collection of type `That` containing pairs consisting of all elements of this
+   *                 $coll paired with their index. Indices start at `0`.
+   *
+   *  @usecase def zipWithIndex: $Coll[(A, Int)]
+   *
+   *  @return        A new $coll containing pairs consisting of all elements of this
+   *                 $coll paired with their index. Indices start at `0`.
+   *  @example
+   *    `List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))`
+   *
    */
   def zipWithIndex[A1 >: A, That](implicit bf: CanBuildFrom[Repr, (A1, Int), That]): That = {
     val b = bf(repr)
@@ -314,12 +306,19 @@ self =>
     b.result
   }
 
-  /** Checks if the other iterable object contains the same elements as this one.
+  /** Checks if the other iterable collection contains the same elements in the same order as this $coll.
+   *
+   *  $orderDependent
+   *  $willNotTerminateInf
+   *
+   *  @param that  the collection to compare with.
+   *  @tparam B    the type of the elements of collection `that`.
+   *  @return `true`, if both collections contain the same elements in the same order, `false` otherwise.
    *
-   *  @note will not terminate for infinite-sized iterables.
-   *  @param that  the other iterable
-   *  @return true, iff both iterables contain the same elements in the same order.
-   *  @note  Might return different results for different runs, unless this iterable is ordered
+   *  @usecase  def sameElements(that: Iterable[A]): Boolean
+   *
+   *  @param that  the collection to compare with.
+   *  @return `true`, if both collections contain the same elements in the same order, `false` otherwise.
    */
   def sameElements[B >: A](that: Iterable[B]): Boolean = {
     val these = this.iterator
@@ -331,44 +330,36 @@ self =>
     !these.hasNext && !those.hasNext
   }
 
-  /** Returns a stream with all elements in this iterable object.
-   */
-  override def toStream: Stream[A] = iterator.toStream
+  override /*TraversableLike*/ def toStream: Stream[A] = iterator.toStream
 
   /** Method called from equality methods, so that user-defined subclasses can
    *  refuse to be equal to other collections of the same kind.
+   *  @param   that   The object with which this $coll should be compared
+   *  @return  `true`, if this $coll can possibly equal `that`, `false` otherwise. The test
+   *           takes into consideration only the run-time types of objects but ignores their elements.
    */
-  override def canEqual(that: Any) = true
+  override /*TraversableLike*/ def canEqual(that: Any) = true
 
-  /** Creates a view of this iterable @see IterableView
-   */
-  override def view = new IterableView[A, Repr] {
+  override /*TraversableLike*/ def view = new IterableView[A, Repr] {
     protected lazy val underlying = self.repr
     override def iterator = self.iterator
   }
 
-  /** A sub-iterable view  starting at index `from`
-   *  and extending up to (but not including) index `until`.
-   *
-   *  @param from   The index of the first element of the slice
-   *  @param until  The index of the element following the slice
-   *  @note  The difference between `view` and `slice` is that `view` produces
-   *         a view of the current iterable, whereas `slice` produces a new iterable.
-   *
-   *  @note  Might return different results for different runs, unless this iterable is ordered
-   *  @note view(from, to)  is equivalent to view.slice(from, to)
-   */
-  override def view(from: Int, until: Int) = view.slice(from, until)
+  override /*TraversableLike*/ def view(from: Int, until: Int) = view.slice(from, until)
 
+  /** @deprecated use `head' instead. */
   @deprecated("use `head' instead") def first: A = head
 
-  /** <code>None</code> if iterable is empty. */
+  /** <code>None</code> if iterable is empty.
+   *  @deprecated "use `headOption' instead"
+   */
   @deprecated("use `headOption' instead") def firstOption: Option[A] = headOption
 
   /**
    * returns a projection that can be used to call non-strict <code>filter</code>,
    * <code>map</code>, and <code>flatMap</code> methods that build projections
    * of the collection.
+   * @deprecated "use `view' instead"
    */
   @deprecated("use `view' instead")
   def projection = view
diff --git a/src/library/scala/collection/Iterator.scala b/src/library/scala/collection/Iterator.scala
index fa5c2d3597..ac6cb890c4 100644
--- a/src/library/scala/collection/Iterator.scala
+++ b/src/library/scala/collection/Iterator.scala
@@ -636,6 +636,21 @@ trait Iterator[+A] { self =>
     res
   }
 
+  /** Applies option-valued function to successive elements of this iterator
+   *  until a defined value is found.
+   *
+   *  @param f    the function to be applied to successive elements.
+   *  @return     an option value containing the first defined result of
+   *              `f`, or `None` if `f` returns `None` for all all elements.
+  def mapFind[B](f: A => Option[B]): Option[B] = {
+    var res: Option[B] = None
+    while (res.isEmpty && hasNext) {
+      res = f(next())
+    }
+    res
+  }
+   */
+
   /** Returns index of the first element satisfying a predicate, or -1.
    *
    *  @note may not terminate for infinite-sized collections.
diff --git a/src/library/scala/collection/LinearSeqLike.scala b/src/library/scala/collection/LinearSeqLike.scala
index 4fb9b4ad79..08bb071da9 100644
--- a/src/library/scala/collection/LinearSeqLike.scala
+++ b/src/library/scala/collection/LinearSeqLike.scala
@@ -152,7 +152,17 @@ trait LinearSeqLike[+A, +Repr <: LinearSeqLike[A, Repr]] extends SeqLike[A, Repr
     }
     None
   }
-
+/*
+  override def mapFind[B](f: A => Option[B]): Option[B] = {
+    var res: Option[B] = None
+    var these = this
+    while (res.isEmpty && !these.isEmpty) {
+      res = f(these.head)
+      these = these.tail
+    }
+    res
+  }
+*/
   /** 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>.
diff --git a/src/library/scala/collection/MapLike.scala b/src/library/scala/collection/MapLike.scala
index a1ea657553..a9ea82b2f9 100644
--- a/src/library/scala/collection/MapLike.scala
+++ b/src/library/scala/collection/MapLike.scala
@@ -14,28 +14,30 @@ import generic._
 import mutable.{Builder, StringBuilder, MapBuilder}
 import PartialFunction._
 
-/** <p>
- *    A generic template for maps from keys of type <code>A</code> to values
- *    of type <code>B</code>.<br/>
- *    To implement a concrete map, you need to provide implementations of the
- *    following methods (where <code>This</code> is the type of the map in
+/**
+ *    A generic template for maps from keys of type `A` to values
+ *    of type `B`.
+ *
+ *    To implement a concrete map, 'you' need to provide implementations of the
+ *    following methods (where `This` is the type of the map in
  *    question):
- *  </p>
- *  <pre>
- *    <b>def</b> get(key: A): Option[B]
- *    <b>def</b> iterator: Iterator[(A, B)]
- *    <b>def</b> + [B1 >: B](kv: (A, B1)): This
- *    <b>def</b> -(key: A): This</pre>
- *  <p>
+ *    {{{
+ *       def get(key: A): Option[B]
+ *
+ *       def iterator: Iterator[(A, B)]
+ *
+ *       def + [B1 >: B](kv: (A, B1)): This
+ *
+ *       def -(key: A): This</pre>
+ *    }}}
  *    If you wish that methods <code>like</code>, <code>take</code>, <code>drop</code>,
  *    <code>filter</code> return the same kind of map, you should also override:
- *  </p>
- *  <pre>
- *   <b>def</b> empty: This</pre>
- *  <p>
- *    It is also good idea to override methods <code>foreach</code> and
- *    <code>size</code> for efficiency.
- *  </p>
+ *    {{{
+ *       def empty: This
+ *    }}}
+ *
+ *    It is also good idea to override methods `foreach` and
+ *    `size` for efficiency.
  *
  *  @author  Martin Odersky
  *  @version 2.8
diff --git a/src/library/scala/collection/SeqLike.scala b/src/library/scala/collection/SeqLike.scala
index 4d096a88c6..5e7ea8ebfa 100644
--- a/src/library/scala/collection/SeqLike.scala
+++ b/src/library/scala/collection/SeqLike.scala
@@ -10,20 +10,19 @@
 
 
 package scala.collection
-import generic._
+
 import mutable.{ListBuffer, HashMap, GenericArray}
 import immutable.{List, Range}
-
-// import immutable.{List, Nil, ::}
 import generic._
 
-/** Contains a KMP implementation, based on the undoubtedly reliable wikipedia entry.
- *
- *  @author paulp
- *  @since  2.8
+/** The companion object for trait `SeqLike`.
  */
 object SeqLike {
 
+  /**  A KMP implementation, based on the undoubtedly reliable wikipedia entry.
+   *  @author paulp
+   *  @since  2.8
+   */
   private def KMP[B](S: Seq[B], W: Seq[B]): Option[Int] = {
     // trivial cases
     if (W.isEmpty) return Some(0)
@@ -73,6 +72,8 @@ object SeqLike {
     None
   }
 
+  /** Waiting for a doc comment from Paul
+   */
   def indexOf[B](
     source: Seq[B], sourceOffset: Int, sourceCount: Int,
     target: Seq[B], targetOffset: Int, targetCount: Int,
@@ -82,6 +83,8 @@ object SeqLike {
         case Some(x) => x + fromIndex
       }
 
+  /** Waiting for a doc comment from Paul
+   */
   def lastIndexOf[B](
     source: Seq[B], sourceOffset: Int, sourceCount: Int,
     target: Seq[B], targetOffset: Int, targetCount: Int,
@@ -96,41 +99,89 @@ object SeqLike {
     }
 }
 
-/** Class <code>Seq[A]</code> represents sequences of elements
- *  of type <code>A</code>.
- *  It adds the following methods to class Iterable:
- *   `length`, `lengthCompare`, `apply`, `isDefinedAt`, `segmentLength`, `prefixLength`,
- *   `indexWhere`, `indexOf`, `lastIndexWhere`, `lastIndexOf`, `reverse`, `reverseIterator`,
- *   `startsWith`, `endsWith`, `indexOfSlice`, , `zip`, `zipAll`, `zipWithIndex`.
+/** A template trait for sequences of type `Seq[A]`, representing
+ *  sequences of elements of type <code>A</code>.
+ *
+ *  Sequences are special cases of iterable collections of class `Iterable`.
+ *  Unlike iterables, sequences always have a defined order of elements.
+ *  Sequences provide a method `apply` for indexing. Indices range from `0` up the the `length` of
+ *  a sequence. Sequences support a number to find occurrences of elements or subsequences, including
+ *  `segmentLength`, `prefixLength`, `indexWhere`, `indexOf`, `lastIndexWhere`, `lastIndexOf`,
+ *  `startsWith`, `endsWith`, `indexOfSlice`.
  *
+ *  Another way to see a sequence is as a `PartialFunction` from `Int` values
+ *  to the element type of the sequence. The `isDefinedAt` method of a sequence
+ *  returns `true` for the interval from `0` until `length`.
+ *
+ *  Sequences can be accessed in reverse order of their elements, using methods
+ *  `reverse` and `reverseIterator`.
+ *
+ *  Sequences have two principle subtraits, `IndexedSeq` and `LinearSeq`, which give different guarantees for performance.
+ *  An `IndexedSeq` provides fast random-access of elements and a fast `length` operation.
+ *  A `LinearSeq` provides fast access only to the first element via `head`, but also
+ *  has a fast `tail` operation.
  *
  *  @author  Martin Odersky
  *  @author  Matthias Zenger
  *  @version 1.0, 16/07/2003
  *  @since   2.8
+ *
+ *  @tparam A    the element type of the collection
+ *  @tparam Repr the type of the actual collection containing the elements.
+ *
+ *  @define Coll Seq
+ *  @define coll sequence
+ *  @define thatinfo the class of the returned collection. Where possible, `That` is
+ *    the same class as the current collection class `Repr`, but this
+ *    depends on the element type `B` being admissible for that class,
+ *    which means that an implicit instance of type `CanBuildFrom[Repr, B, That]`
+ *    is found.
+ *  @define bfinfo an implicit value of class `CanBuildFrom` which determines the
+ *    result class `That` from the current representation type `Repr`
+ *    and the new element type `B`.
+ *  @define orderDependent
+ *  @define orderDependentFold
+ *  @define mayNotTerminateInf
+ *
+ *    Note: may not terminate for infinite-sized collections.
+ *  @define willNotTerminateInf
+ *
+ *    Note: will not terminate for infinite-sized collections.
  */
 trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
 
   override protected[this] def thisCollection: Seq[A] = this.asInstanceOf[Seq[A]]
   override protected[this] def toCollection(repr: Repr): Seq[A] = repr.asInstanceOf[Seq[A]]
 
-  /** Returns the length of the sequence.
+  /** The length of the $coll.
+   *
+   *  $willNotTerminateInf
+   *
+   *  Note: `xs.length` and `xs.size` yield the same result.
+   *
+   *  @return     the number of elements in this $coll.
    */
   def length: Int
 
-  /** Returns the elements at position `idx`
+  /** Selects an element by its index in the $coll
+   *
+   *  @param  idx  The index to select
+   *  @return the element of tyh
    */
   def apply(idx: Int): A
 
-  /** Result of comparing <code>length</code> with operand <code>len</code>.
-   *  returns <code>x</code> where
-   *  <code>x &lt; 0</code>    iff    <code>this.length &lt; len</code>
-   *  <code>x == 0</code>   iff    <code>this.length == len</code>
-   *  <code>x &gt; 0</code>    iff    <code>this.length &gt; len</code>.
+  /** Compares the length of this $coll to a test value.
    *
-   *  The method as implemented here does not call length directly; its running time
-   *  is O(length min len) instead of O(length). The method should be overwritten
-   *  if computing length is cheap.
+   *   @param   len   the test value that gets compared with the length.
+   *   @return  A value `x` where
+   *   {{{
+   *        x <  0       if this.length <  len
+   *        x == 0       if this.length == len
+   *        x >  0       if this.length >  len
+   *   }}}
+   *  The method as implemented here does not call `length` directly; its running time
+   *  is `O(length min len)` instead of `O(length)`. The method should be overwritten
+   *  if computing `length` is cheap.
    */
   def lengthCompare(len: Int): Int = {
     var i = 0
@@ -142,18 +193,32 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     i - len
   }
 
-  /** Should always be <code>length</code> */
+  /** The size of this $coll, equivalent to `length`.
+   *
+   *  $willNotTerminateInf
+   *
+   *  @return    the number of elements in this $coll.
+   */
   override def size = length
 
-  /** Is this partial function defined for the index <code>x</code>?
+  /** Tests whether this $coll contains given index.
+   *
+   *  The implementations of methods `apply` and `isDefinedAt` turn a `Seq[A]` into
+   *  a `PartialFunction[Int, A]`.
+   *
+   * @param    idx     the index to test
+   * @return   `true` if this $coll contains an element at position `idx`, `false` otherwise.
    */
-  def isDefinedAt(x: Int): Boolean = (x >= 0) && (x < length)
+  def isDefinedAt(idx: Int): Boolean = (idx >= 0) && (idx < length)
 
-  /** Returns length of longest segment starting from a start index `from`
-   *  such that every element of the segment satisfies predicate `p`.
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  p the predicate
-   *  @param  from  the start index
+  /** Computes length of longest segment whose elements all satisfy some preficate.
+   *
+   *  $mayNotTerminateInf
+   *
+   *  @param   p     the predicate used to test elements.
+   *  @param   from  the index where the search starts.
+   *  @return  the length of the longest segment of this $coll starting from index `from`
+   *           such that every element of the segment satisfies the predicate `p`.
    */
   def segmentLength(p: A => Boolean, from: Int): Int = {
     var i = 0
@@ -163,26 +228,34 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     i
   }
 
-  /** Returns length of longest prefix of this seqence
-   *  such that every element of the prefix satisfies predicate `p`.
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  p the predicate
+  /** Returns the length of the longest prefix whose elements all satisfy some preficate.
+   *
+   *  $mayNotTerminateInf
+   *
+   *  @param   p     the predicate used to test elements.
+   *  @return  the length of the longest prefix of this $coll
+   *           such that every element of the segment satisfies the predicate `p`.
    */
   def prefixLength(p: A => Boolean) = segmentLength(p, 0)
 
-  /** Returns index of the first element satisfying a predicate, or -1, if none exists.
+  /** Finds index of first element satisfying some predicate.
    *
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  p the predicate
+   *  $mayNotTerminateInf
+   *
+   *  @param   p     the predicate used to test elements.
+   *  @return  the index of the first element of this $coll that satisfies the predicate `p`,
+   *           or `-1`, if none exists.
    */
   def indexWhere(p: A => Boolean): Int = indexWhere(p, 0)
 
-  /** Returns index of the first element starting from a start index
-   *  satisying a predicate, or -1, if none exists.
+  /** Finds index of the first element satisfying some predicate after or at some start index.
+   *
+   *  $mayNotTerminateInf
    *
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  p the predicate
-   *  @param  from  the start index
+   *  @param   p     the predicate used to test elements.
+   *  @param   from   the start index
+   *  @return  the index `>= from` of the first element of this $coll that satisfies the predicate `p`,
+   *           or `-1`, if none exists.
    */
   def indexWhere(p: A => Boolean, from: Int): Int = {
     var i = from
@@ -192,63 +265,95 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     if (it.hasNext) i else -1
   }
 
-  /** Returns index of the first element satisying a predicate, or -1. */
-  @deprecated("Use `indexWhere' instead")
+  /** Returns index of the first element satisying a predicate, or `-1`.
+   *  @deprecated "Use `indexWhere` instead"
+   */
   def findIndexOf(p: A => Boolean): Int = indexWhere(p)
 
-  /** Returns the index of the first occurence of the specified
-   *  object in this sequence.
+  /** Finds index of first occurrence of some value in this $coll.
    *
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  elem  element to search for.
-   *  @return the index in this sequence of the first occurence of the
-   *          specified element, or -1 if the sequence does not contain
-   *          this element.
+   *  $mayNotTerminateInf
+   *
+   *  @param   elem   the element value to search for.
+   *  @tparam  B      the type of the element `elem`.
+   *  @return  the index of the first element of this $coll that is equal (wrt `==`)
+   *           tp `elem`, or `-1`, if none exists.
+   *
+   *  @usecase def indexOf(elem: A): Int
+   *
+   *  @param   elem   the element value to search for.
+   *  @return  the index of the first element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
    */
   def indexOf[B >: A](elem: B): Int = indexOf(elem, 0)
 
-  /** Returns the index of the first occurence of the specified
-   *  object in this sequence, starting from a start index, or
-   *  -1, if none exists.
+  /** Finds index of first occurrence of some value in this $coll after or at some start index.
+   *
+   *  $mayNotTerminateInf
    *
-   *  @note may not terminate for infinite-sized collections.
-   *  @param  elem  element to search for.
+   *  @param   elem   the element value to search for.
+   *  @tparam  B      the type of the element `elem`.
+   *  @param   from   the start index
+   *  @return  the index `>= from` of the first element of this $coll that is equal (wrt `==`)
+   *           tp `elem`, or `-1`, if none exists.
+   *
+   *  @usecase def indexOf(elem: A): Int
+   *
+   *  @param   elem   the element value to search for.
+   *  @param   from   the start index
+   *  @return  the index `>= from` of the first element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
    */
   def indexOf[B >: A](elem: B, from: Int): Int = indexWhere(elem ==, from)
 
- /** Returns the index of the last occurence of the specified element
-   *  in this sequence, or -1 if the sequence does not contain this element.
+  /** Finds index of last occurrence of some value in this $coll.
+   *
+   *  $willNotTerminateInf
+   *
+   *  @param   elem   the element value to search for.
+   *  @tparam  B      the type of the element `elem`.
+   *  @return  the index of the last element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
    *
-   *  @param  elem   element to search for.
-   *  @return the index in this sequence of the last occurence of the
-   *          specified element, or -1 if the sequence does not contain
-   *          this element.
+   *  @usecase def lastIndexOf(elem: A): Int
+   *
+   *  @param   elem   the element value to search for.
+   *  @return  the index of the last element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
    */
   def lastIndexOf[B >: A](elem: B): Int = lastIndexWhere(elem ==)
 
-  /** Returns the index of the last
-    *  occurence of the specified element in this sequence
-    *  before or at a given end index,
-    *  or -1 if the sequence does not contain this element.
-    *
-    *  @param  elem   element to search for.
-    *  @param  end    the end index
-    */
+  /** Finds index of last occurrence of some value in this $coll before or at a given end index.
+   *
+   *  @param   elem   the element value to search for.
+   *  @param   end    the end index.
+   *  @tparam  B      the type of the element `elem`.
+   *  @return  the index `<= end` of the last element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
+   *
+   *  @usecase def lastIndexOf(elem: A): Int
+   *
+   *  @param   elem   the element value to search for.
+   *  @return  the index `<= end` of the last element of this $coll that is equal (wrt `==`)
+   *           to `elem`, or `-1`, if none exists.
+   */
   def lastIndexOf[B >: A](elem: B, end: Int): Int = lastIndexWhere(elem ==, end)
 
-  /** Returns index of the last element satisying a predicate, or -1, if none exists.
+  /** Finds index of last element satisfying some predicate.
+   *
+   *  $willNotTerminateInf
    *
-   *  @param  p the predicate
-   *  @return   the index of the last element satisfying <code>p</code>,
-   *            or -1 if such an element does not exist
+   *  @param   p     the predicate used to test elements.
+   *  @return  the index of the last element of this $coll that satisfies the predicate `p`,
+   *           or `-1`, if none exists.
    */
   def lastIndexWhere(p: A => Boolean): Int = lastIndexWhere(p, length - 1)
 
-  /** Returns index of the last element not exceeding a given end index
-   *  and satisying a predicate, or -1 if none exists.
+  /** Finds index of last element satisfying some predicate before or at given end index.
    *
-   *  @param  end the end index
-   *  @param  p the predicate
+   *  @param   p     the predicate used to test elements.
+   *  @return  the index `<= end` of the last element of this $coll that satisfies the predicate `p`,
+   *           or `-1`, if none exists.
    */
   def lastIndexWhere(p: A => Boolean, end: Int): Int = {
     var i = length - 1
@@ -257,8 +362,11 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     i
   }
 
-  /** A sequence of type <code>C</code> consisting of all elements of
-   *  this sequence in reverse order.
+  /** Returns new $coll wih elements in reversed order.
+   *
+   *  $willNotTerminateInf
+   *
+   *  @return A new $coll with all elements of this $coll in reversed order.
    */
   def reverse: Repr = {
     var xs: List[A] = List()
@@ -270,18 +378,34 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     b.result
   }
 
-  /** Apply a function to all the elements of the sequence, and return the
-   *  reversed sequence of results. This is equivalent to a call to <code>reverse</code>
-   *  followed by a call to <code>map</code>, but more efficient.
+  /**
+   *  Builds a new collection by applying a function to all elements of this $coll and
+   *  collecting the results in reversed order.
+   *
+   *  $willNotTerminateInf
+   *
+   *  Note: `xs.reverseMap(f)` is the same as `xs.reverse.map(f)` but might be more efficient.
+   *
+   *  @param f      the function to apply to each element.
+   *  @tparam B     the element type of the returned collection.
+   *  @tparam That  $thatinfo
+   *  @param bf     $bfinfo
+   *  @return       a new collection of type `That` resulting from applying the given function
+   *                `f` to each element of this $coll and collecting the results in reversed order.
+   *
+   *  @usecase def reverseMap[B](f: A => B): $Coll[B]
+   *
+   *  Note: `xs.reverseMap(f)` is the same as `xs.reverse.map(f)` but might be more efficient.
    *
-   *  @param f the function to apply to each elements.
-   *  @return  the reversed seq of results.
+   *  @param f      the function to apply to each element.
+   *  @tparam B     the element type of the returned collection.
+   *  @return       a new $coll resulting from applying the given function
+   *                `f` to each element of this $coll and collecting the results in reversed order.
    */
   def reverseMap[B, That](f: A => B)(implicit bf: CanBuildFrom[Repr, B, That]): That = {
     var xs: List[A] = List()
     for (x <- this)
       xs = x :: xs
-
     val b = bf(repr)
     for (x <- xs)
       b += f(x)
@@ -289,25 +413,30 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     b.result
   }
 
-  /** The elements of this sequence in reversed order
+  /** An iterator yielding elements in reversed order.
+   *
+   *   $willNotTerminateInf
+   *
+   * Note: `xs.reverseIterator` is the same as `xs.reverse.iterator` but might be more efficient.
+   *
+   *  @return  an iterator yielding the elements of this $coll in reversed order
    */
   def reverseIterator: Iterator[A] = toCollection(reverse).iterator
 
+  /** @deprecated use `reverseIterator` instead */
   @deprecated("use `reverseIterator' instead")
   def reversedElements = reverseIterator
 
-  /**
-   * Checks whether the argument sequence is contained at the
-   * specified index within the receiver object.
+  /** Checks whether this $coll contains the given sequence at a given index.
    *
    * If the both the receiver object, <code>this</code> and
    * the argument, <code>that</code> are infinite sequences
    * this method may not terminate.
    *
-   * @return true if <code>that</code> is contained in
-   * <code>this</code>, at the specified index, otherwise false
-   *
-   * @see String.startsWith
+   * @param  that    the candidate sequence
+   * @param  offset  the index where the sequence is searched.
+   * @return `true` if the sequence `that` is contained in this $coll at index `offset`,
+   *         otherwise `false`.
    */
   def startsWith[B](that: Seq[B], offset: Int): Boolean = {
     val i = this.iterator drop offset
@@ -319,10 +448,10 @@ trait SeqLike[+A, +Repr] extends IterableLike[A, Repr] { self =>
     !j.hasNext
   }
 
-  /**
-   * Check whether the receiver object starts with the argument sequence.
+  /** Checks whether this $coll starts with the given sequence.
    *
-   * @return true if <code>that</code> is a prefix of <code>this</code>,
+   * @param  that    the candidate sequence
+   * @return `true` if this collection has `that` as a prefix, `false` otherwise.
    * otherwise false
    */
   def startsWith[B](that: Seq[B]): Boolean = startsWith(that, 0)
diff --git a/src/library/scala/collection/TraversableLike.scala b/src/library/scala/collection/TraversableLike.scala
index 44cb7ced63..0ff6227a3a 100644
--- a/src/library/scala/collection/TraversableLike.scala
+++ b/src/library/scala/collection/TraversableLike.scala
@@ -63,14 +63,12 @@ import immutable.{List, Stream, Nil, ::}
  *
  *  @define Coll Traversable
  *  @define coll traversable collection
- *  @define thatinfo
- *    the class of the returned collection. Where possible, `That` is
+ *  @define thatinfo the class of the returned collection. Where possible, `That` is
  *    the same class as the current collection class `Repr`, but this
  *    depends on the element type `B` being admissible for that class,
  *    which means that an implicit instance of type `CanBuildFrom[Repr, B, That]`
  *    is found.
- *  @define bfinfo
- *    an implicit value of class `CanBuildFrom` which determines the
+ *  @define bfinfo an implicit value of class `CanBuildFrom` which determines the
  *    result class `That` from the current representation type `Repr`
  *    and the new element type `B`.
  *  @define orderDependent
@@ -100,12 +98,13 @@ self =>
    */
   def repr: Repr = this.asInstanceOf[Repr]
 
-  /** The underlying collection seen as an instance of `Traversable`.
-   *  By default this is implemented as the `TraversableLike` object itself, but this can be overridden.
+  /** The underlying collection seen as an instance of `$Coll`.
+   *  By default this is implemented as the current collection object itself,
+   *  but this can be overridden.
    */
   protected[this] def thisCollection: Traversable[A] = this.asInstanceOf[Traversable[A]]
 
-  /** A conversion from collections of type `Repr` to `Traversable` objects.
+  /** A conversion from collections of type `Repr` to `$Coll` objects.
    *  By default this is implemented as just a cast, but this can be overridden.
    */
   protected[this] def toCollection(repr: Repr): Traversable[A] = repr.asInstanceOf[Traversable[A]]
@@ -116,8 +115,9 @@ self =>
 
   /** Applies a function `f` to all elements of this $coll.
    *
-   *  Note: this method underlies the implementation of most other bulk operations.
-   *  It's important to implement this method in an efficient way.
+   *    Note: this method underlies the implementation of most other bulk operations.
+   *    It's important to implement this method in an efficient way.
+   *
    *
    *  @param  f   the function that is applied for its side-effect to every element.
    *              The result of function `f` is discarded.
@@ -126,7 +126,7 @@ self =>
    *              This result will always be ignored. Typically `U` is `Unit`,
    *              but this is not necessary.
    *
-   *  @usage def foreach(f: A => Unit): Unit
+   *  @usecase def foreach(f: A => Unit): Unit
    *
    *  @param  f   the function that is applied for its side-effect to every element.
    *              The result of function `f` is discarded.
@@ -184,7 +184,7 @@ self =>
    *  @return       a new collection of type `That` which contains all elements of this $coll
    *                followed by all elements of `that`.
    *
-   *  @usage def ++(that: Traversable[A]): $Coll[A]
+   *  @usecase def ++(that: Traversable[A]): $Coll[A]
    *
    *  @param that   the traversable to append.
    *  @return       a new $coll which contains all elements of this $coll
@@ -206,7 +206,7 @@ self =>
    *  @return       a new collection of type `That` which contains all elements of this $coll
    *                followed by all elements of `that`.
    *
-   *  @usage def ++(that: Iterator[A]): $Coll[A]
+   *  @usecase def ++(that: Iterator[A]): $Coll[A]
    *
    *  @param that   the iterator to append.
    *  @return       a new $coll which contains all elements of this $coll
@@ -228,7 +228,7 @@ self =>
    *  @return       a new collection of type `That` resulting from applying the given function
    *                `f` to each element of this $coll and collecting the results.
    *
-   *  @usage def map[B](f: A => B): $Coll[B]
+   *  @usecase def map[B](f: A => B): $Coll[B]
    *
    *  @param f      the function to apply to each element.
    *  @tparam B     the element type of the returned collection.
@@ -251,7 +251,7 @@ self =>
    *  @return       a new collection of type `That` resulting from applying the given collection-valued function
    *                `f` to each element of this $coll and concatenating the results.
    *
-   *  @usage def flatMap[B](f: A => Traversable[B]): $Coll[B]
+   *  @usecase def flatMap[B](f: A => Traversable[B]): $Coll[B]
    *
    *  @param f      the function to apply to each element.
    *  @tparam B     the element type of the returned collection.
@@ -266,7 +266,7 @@ self =>
 
   /** Selects all elements of this $coll which satisfy a predicate.
    *
-   *  @param p     the predicate used used to test elements.
+   *  @param p     the predicate used to test elements.
    *  @return      a new $coll consisting of all elements of this $coll that satisfy the given
    *               predicate `p`. The order of the elements is preserved.
    */
@@ -296,7 +296,7 @@ self =>
    *                `pf` to each element on which it is defined and collecting the results.
    *                The order of the elements is preserved.
    *
-   *  @usage def partialMap[B](pf: PartialFunction[Any, B]): $Coll[B]
+   *  @usecase def partialMap[B](pf: PartialFunction[Any, B]): $Coll[B]
    *
    *  @param pf     the partial function which filters and maps the $coll.
    *  @return       a new $coll resulting from applying the given partial function
@@ -309,6 +309,34 @@ self =>
     b.result
   }
 
+  /** Builds a new collection by applying an option-valued function to all elements of this $coll
+   *  on which the function is defined.
+   *
+   *  @param f      the option-valued function which filters and maps the $coll.
+   *  @tparam B     the element type of the returned collection.
+   *  @tparam That  $thatinfo
+   *  @param bf     $bfinfo
+   *  @return       a new collection of type `That` resulting from applying the option-valued function
+   *                `f` to each element and collecting all defined results.
+   *                The order of the elements is preserved.
+   *
+   *  @usecase def filterMap[B](f: A => Option[B]): $Coll[B]
+   *
+   *  @param pf     the partial function which filters and maps the $coll.
+   *  @return       a new $coll resulting from applying the given option-valued function
+   *                `f` to each element and collecting all defined results.
+   *                The order of the elements is preserved.
+  def filterMap[B, That](f: A => Option[B])(implicit bf: CanBuildFrom[Repr, B, That]): That = {
+    val b = bf(repr)
+    for (x <- this)
+      f(x) match {
+        case Some(y) => b += y
+        case _ =>
+      }
+    b.result
+  }
+   */
+
   /** Partitions this $coll in two ${coll}s according to a predicate.
    *
    *  @param p the predicate on which to partition.
@@ -356,7 +384,7 @@ self =>
    *
    *  $mayNotTerminateInf
    *
-   *  @param   p     the predicate used used to test elements.
+   *  @param   p     the predicate used to test elements.
    *  @return        `true` if the given predicate `p` holds for all elements
    *                 of this $coll, otherwise `false`.
    */
@@ -373,7 +401,7 @@ self =>
    *
    *  $mayNotTerminateInf
    *
-   *  @param   p     the predicate used used to test elements.
+   *  @param   p     the predicate used to test elements.
    *  @return        `true` if the given predicate `p` holds for some of the elements
    *                 of this $coll, otherwise `false`.
    */
@@ -388,7 +416,7 @@ self =>
 
   /** Counts the number of elements in the $coll which satisfy a predicate.
    *
-   *  @param p     the predicate  used used to test elements.
+   *  @param p     the predicate  used to test elements.
    *  @return      the number of elements satisfying the predicate `p`.
    *
    *
@@ -406,7 +434,7 @@ self =>
    *  $mayNotTerminateInf
    *  $orderDependent
    *
-   *  @param p    the predicate used used to test elements.
+   *  @param p    the predicate used to test elements.
    *  @return     an option value containing the first element in the $coll
    *              that satisfies `p`, or `None` if none exists.
    */
@@ -419,6 +447,28 @@ self =>
     result
   }
 
+  /** Applies option-valued function to successive elements of this $coll
+   *  until a defined value is found.
+   *
+   *  $mayNotTerminateInf
+   *  $orderDependent
+   *
+   *  @param f    the function to be applied to successive elements.
+   *  @return     an option value containing the first defined result of
+   *              `f`, or `None` if `f` returns `None` for all all elements.
+  def mapFind[B](f: A => Option[B]): Option[B] = {
+    var result: Option[B] = None
+    breakable {
+      for (x <- this)
+        f(x) match {
+          case s @ Some(_) => result = s; break
+          case _ =>
+        }
+    }
+    result
+  }
+   */
+
   /** Applies a binary operator to a start value and all elements of this $coll, going left to right.
    *
    *  $willNotTerminateInf
@@ -430,9 +480,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going left to right with the start value `z` on the left:
    *           {{{
-   *             op(...op(z, x_1), x_2, ..., x_n)
+   *             op(...op(z, x,,1,,), x,,2,,, ..., x,,n,,)
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    *
    */
   def foldLeft[B](z: B)(op: (B, A) => B): B = {
@@ -454,9 +504,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going left to right with the start value `z` on the left:
    *           {{{
-   *             op(...op(op(z, x_1), x_2), ..., x_n)
+   *             op(...op(op(z, x,,1,,), x,,2,,), ..., x,,n,,)
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    */
   def /: [B](z: B)(op: (B, A) => B): B = foldLeft(z)(op)
 
@@ -467,9 +517,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going right to left with the start value `z` on the right:
    *           {{{
-   *             op(x_1, op(x_2, ... op(x_n, z)...))
+   *             op(x,,1,,, op(x,,2,,, ... op(x,,n,,, z)...))
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    *
    *  $willNotTerminateInf
    *  $orderDependentFold
@@ -492,9 +542,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going right to left with the start value `z` on the right:
    *           {{{
-   *             op(x_1, op(x_2, ... op(x_n, z)...))
+   *             op(x,,1,,, op(x,,2,,, ... op(x,,n,,, z)...))
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    */
   def :\ [B](z: B)(op: (A, B) => B): B = foldRight(z)(op)
 
@@ -507,9 +557,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going left to right:
    *           {{{
-   *             op(...(op(x_1, x_2), ... ) , x_n)
+   *             op(...(op(x,,1,,, x,,2,,), ... ) , x,,n,,)
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    *  @throws `UnsupportedOperationException` if this $coll is empty.
    */
   def reduceLeft[B >: A](op: (B, A) => B): B = {
@@ -544,9 +594,9 @@ self =>
    *  @return  the result of inserting `op` between consecutive elements of this $coll$,
    *           going right to left:
    *           {{{
-   *             op(x_1, op(x_2, ..., op(x_(n-1), x_n)...))
+   *             op(x,,1,,, op(x,,2,,, ..., op(x,,n-1,,, x,,n,,)...))
    *           }}}
-   *           where `x_1, ..., x_n` are the elements of this $coll.
+   *           where `x,,1,,, ..., x,,n,,` are the elements of this $coll.
    *  @throws `UnsupportedOperationException` if this $coll is empty.
    */
   def reduceRight[B >: A](op: (A, B) => B): B = {
@@ -576,9 +626,13 @@ self =>
    *   @tparam  B    the result type of the `+` operator.
    *   @return       the sum of all elements of this $coll with respect to the `+` operator in `num`.
    *
-   *   @usage sum: Num
-   *   @return       the sum of all elements in this $coll of numbers of type `Num`.
-   *                 `Num` must be a numeric type such as `Int`, `Double`, `BigDecimal`.
+   *   @usecase def sum: Int
+   *
+   *   @return       the sum of all elements in this $coll of numbers of type `Int`.
+   *   Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation
+   *   can be used as element type of the $coll and as result type of `sum`.
+   *   Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.
+   *
    */
   def sum[B >: A](implicit num: Numeric[B]): B = {
     var acc = num.zero
@@ -593,9 +647,12 @@ self =>
    *   @tparam  B    the result type of the `*` operator.
    *   @return       the product of all elements of this $coll with respect to the `*` operator in `num`.
    *
-   *   @usage product: Num
-   *   @return       the product of all elements in this $coll of numbers of type `Num`.
-   *                 `Num` must be a numeric type such as `Int`, `Double`, `BigDecimal`.
+   *   @usecase def product: Int
+   *
+   *   @return       the product of all elements in this $coll of numbers of type `Int`.
+   *   Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation
+   *   can be used as element type of the $coll and as result type of `product`.
+   *   Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.
    */
   def product[B >: A](implicit num: Numeric[B]): B = {
     var acc = num.one
@@ -609,7 +666,7 @@ self =>
    *  @tparam   B     The type over which the ordering is defined.
    *  @return   the smallest element of this $coll with respect to the ordering `cmp`.
    *
-   *  @usage min: A
+   *  @usecase def min: A
    *  @return   the smallest element of this $coll
    */
   def min[B >: A](implicit cmp: Ordering[B]): A = {
@@ -626,7 +683,7 @@ self =>
    *  @tparam   B     The type over which the ordering is defined.
    *  @return   the largest element of this $coll with respect to the ordering `cmp`.
    *
-   *  @usage min: A
+   *  @usecase def min: A
    *  @return   the largest element of this $coll.
    */
   def max[B >: A](implicit cmp: Ordering[B]): A = {
@@ -861,7 +918,7 @@ self =>
    *  @tparam B      the type of the elements of the array.
    *
    *
-   *  @usage copyToArray(xs: Array[A], start: Int, len: Int): Unit
+   *  @usecase def copyToArray(xs: Array[A], start: Int, len: Int): Unit
    *
    *  @param  xs     the array to fill.
    *  @param  start  the starting index.
@@ -891,7 +948,7 @@ self =>
    *  @param  start  the starting index.
    *  @tparam B      the type of the elements of the array.
    *
-   *  @usage def copyToArray(xs: Array[A], start: Int): Unit
+   *  @usecase def copyToArray(xs: Array[A], start: Int): Unit
    *
    *  @param  xs     the array to fill.
    *  @param  start  the starting index.
@@ -907,7 +964,7 @@ self =>
    *               be available.
    *  @return  an array containing all elements of this $coll.
    *
-   *  @usage toArray: Array[A]
+   *  @usecase def toArray: Array[A]
    *  @return  an array containing all elements of this $coll.
    *           A `ClassManifest` must be available for the element type of this $coll.
    */
@@ -1054,7 +1111,6 @@ self =>
   /** Creates a non-strict view of this $coll.
    *
    *  @return a non-strict view of this $coll.
-   *  @see TraversableView
    */
   def view = new TraversableView[A, Repr] {
     protected lazy val underlying = self.repr
@@ -1107,7 +1163,7 @@ self =>
      *                `f` to each element of the outer $coll that satisfies predicate `p`
      *                and collecting the results.
      *
-     *  @usage def map[B](f: A => B): $Coll[B]
+     *  @usecase def map[B](f: A => B): $Coll[B]
      *
      *  @param f      the function to apply to each element.
      *  @tparam B     the element type of the returned collection.
@@ -1132,7 +1188,7 @@ self =>
      *  @return       a new collection of type `That` resulting from applying the given collection-valued function
      *                `f` to each element of the outer $coll that satisfies predicate `p` and concatenating the results.
      *
-     *  @usage def flatMap[B](f: A => Traversable[B]): $Coll[B]
+     *  @usecase def flatMap[B](f: A => Traversable[B]): $Coll[B]
      *
      *  @param f      the function to apply to each element.
      *  @tparam B     the element type of the returned collection.
@@ -1156,7 +1212,7 @@ self =>
      *              This result will always be ignored. Typically `U` is `Unit`,
      *              but this is not necessary.
      *
-     *  @usage def foreach(f: A => Unit): Unit
+     *  @usecase def foreach(f: A => Unit): Unit
      *
      *  @param  f   the function that is applied for its side-effect to every element.
      *              The result of function `f` is discarded.
diff --git a/src/library/scala/collection/mutable/MapLike.scala b/src/library/scala/collection/mutable/MapLike.scala
index d03858a68f..92f1b5bba6 100644
--- a/src/library/scala/collection/mutable/MapLike.scala
+++ b/src/library/scala/collection/mutable/MapLike.scala
@@ -103,6 +103,15 @@ trait MapLike[A, B, +This <: MapLike[A, B, This] with Map[A, B]]
    */
   override def updated[B1 >: B](key: A, value: B1): mutable.Map[A, B1] = this + ((key, value))
 
+  /** If given key is already in this map, returns associated value
+   *  Otherwise, computes value from given expression `op`, stores with key
+   *  in map and returns that value.
+   */
+  def cached(key: A, op: => B) = get(key) match {
+    case Some(v) => v
+    case None => val v = op; update(key, v); v
+  }
+
   /** Add a new key/value mapping and return the map itself.
    *
    *  @param kv    the key/value mapping to be added