Changes suggested by @retronym and @jsuereth

Change return type to case classes, branch between functions depending
on IndexedSeq instead of IndexedSeqLike, and alter tests accordingly.
Clean up doc comments and reflect changes in them.

1 files changed, 20 insertions, 1 deletions

diff --git a/src/library/scala/collection/generic/IsSeqLike.scala b/src/library/scala/collection/generic/IsSeqLike.scala
index 47e2924d34..8eac025ed6 100644
--- a/src/library/scala/collection/generic/IsSeqLike.scala
+++ b/src/library/scala/collection/generic/IsSeqLike.scala
@@ -10,8 +10,27 @@ package scala.collection
 package generic
 
 /** Type class witnessing that a collection representation type `Repr` has
-  *  elements of type `A` and has a conversion to `SeqLike[A, Repr]`.
+  * elements of type `A` and has a conversion to `SeqLike[A, Repr]`.
   *
+  * This type enables simple enrichment of `Seq`s with extension methods which
+  * can make full use of the mechanics of the Scala collections framework in
+  * their implementation.
+  *
+  * Example usage:
+  * {{{
+  *    class FilterMapImpl[A, Repr](val r: SeqLike[A, Repr]) {
+  *      final def filterMap[B, That](f: A => Option[B])(implicit cbf: CanBuildFrom[Repr, B, That]): That =
+  *        r.flatMap(f(_))
+  *    }
+  *    implicit def filterMap[Repr, A](r: Repr)(implicit fr: IsSeqLike[Repr]): FilterMapImpl[fr.A,Repr] =
+  *      new FilterMapImpl(fr.conversion(r))
+  *
+  *    val l = List(1, 2, 3, 4, 5)
+  *    List(1, 2, 3, 4, 5) filterMap (i => if(i % 2 == 0) Some(i) else None)
+  *    // == List(2, 4)
+  * }}}
+  *
+  * @see [[scala.collection.generic.Seq]]
   * @see [[scala.collection.generic.IsTraversableLike]]
   */
 trait IsSeqLike[Repr] {