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author | Paul Phillips <paulp@improving.org> | 2011-03-11 12:13:58 +0000 |
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committer | Paul Phillips <paulp@improving.org> | 2011-03-11 12:13:58 +0000 |
commit | be49752855a1a6997d4112eeff351e1c119a8a93 (patch) | |
tree | ee2cef3642b675420d47ff30bda9ddb2b74f1c30 /src/partest | |
parent | 67c461b2d9c19d51e40e1f3ff23455cead1413b5 (diff) | |
download | scala-be49752855a1a6997d4112eeff351e1c119a8a93.tar.gz scala-be49752855a1a6997d4112eeff351e1c119a8a93.tar.bz2 scala-be49752855a1a6997d4112eeff351e1c119a8a93.zip |
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.
Diffstat (limited to 'src/partest')
-rw-r--r-- | src/partest/scala/tools/partest/TestUtil.scala | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/src/partest/scala/tools/partest/TestUtil.scala b/src/partest/scala/tools/partest/TestUtil.scala new file mode 100644 index 0000000000..b86a8e2c7f --- /dev/null +++ b/src/partest/scala/tools/partest/TestUtil.scala @@ -0,0 +1,36 @@ +package scala.tools.partest + +trait TestUtil { + /** Given function and block of code, evaluates code block, + * calls function with nanoseconds elapsed, and returns block result. + */ + def timed[T](f: Long => Unit)(body: => T): T = { + val start = System.nanoTime + val result = body + val end = System.nanoTime + + f(end - start) + result + } + /** Times body and returns (nanos, result). + */ + def alsoNanos[T](body: => T): (Long, T) = { + var nanos = 0L + val result = timed(nanos = _)(body) + + (nanos, result) + } + def nanos(body: => Unit): Long = alsoNanos(body)._1 + + def verifySpeed(body1: => Unit, body2: => Unit, acceptableMultiple: Double) = { + val t1 = nanos(body1).toDouble + val t2 = nanos(body2).toDouble + val mult = if (t1 > t2) t1 / t2 else t2 / t1 + + assert(mult <= acceptableMultiple, "Performance difference too great: multiple = " + mult) + } +} + +object TestUtil extends TestUtil { + +}
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