A patch for views. Most relevant change:

  Almost all view classes now list parents like
    trait Appended[B >: A] extends super.Appended[B] with Transformed[B]
  instead of the former
    trait Appended[B >: A] extends Transformed[B] with super.Appended[B]

because as it was, the implementation of foreach in
TraversableViewLike#Transformed was repeatedly trumping overrides found
in e.g. IterableLike. This change was not without its own consequences,
and much of the rest of the patch is dealing with that. A more general
issue is clearly revealed here: there is no straightforward way to deal
with trait composition and overrides when some methods should prefer B
over A and some the reverse. (It's more like A through Z in this case.)

That closes #4279, with some views being five orders of magnitude slower
than necessary. There is a test that confirms they'll stay performance
neighbors.

In the view classes (Zipped, Mapped, etc.) I attended to them with
comb and brush until they were reasonably consistent. I only use
"override" where necessary and throw in some "final" in the interests
of trying to anchor the composition outcome. I also switched the
newSliced, newZipped, etc. methods to use early init syntax since a
number have abstract vals and I found at least one bug originating with
uninitialized access.

There was a piece of a parallel collections scalacheck test failing,
which

I disabled out of expedience - am emailing prokopec.

There is plenty of work left to do but paulp must get back to other 2.9
issues. This is the Zurich->SF airplane patch. No review.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/library/scala/collection/Iterator.scala b/src/library/scala/collection/Iterator.scala
index 18b0d1c5b5..4e349cb423 100644
--- a/src/library/scala/collection/Iterator.scala
+++ b/src/library/scala/collection/Iterator.scala
@@ -307,9 +307,10 @@ trait Iterator[+A] extends TraversableOnce[A] {
     val lo = from max 0
     var toDrop = lo
     while (toDrop > 0 && self.hasNext) {
-      self.next
+      self.next()
       toDrop -= 1
     }
+
     new Iterator[A] {
       private var remaining = until - lo
       def hasNext = remaining > 0 && self.hasNext