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author | Dmitry Petrashko <dmitry.petrashko@gmail.com> | 2015-05-12 18:30:53 +0200 |
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committer | Dmitry Petrashko <dmitry.petrashko@gmail.com> | 2015-05-12 18:30:53 +0200 |
commit | 89bacb9c25a58454ff1878e67f7ea07ffc8c269f (patch) | |
tree | 51f1ff6c66aebe1b6109b1cffcc2bb8e4cf760a3 /tests/pending/run/t7326.scala | |
parent | a0fa33deafbea1bf53edc068c5ed9db5592822f9 (diff) | |
download | dotty-89bacb9c25a58454ff1878e67f7ea07ffc8c269f.tar.gz dotty-89bacb9c25a58454ff1878e67f7ea07ffc8c269f.tar.bz2 dotty-89bacb9c25a58454ff1878e67f7ea07ffc8c269f.zip |
Run tests as they were in scala.
Diffstat (limited to 'tests/pending/run/t7326.scala')
-rw-r--r-- | tests/pending/run/t7326.scala | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/tests/pending/run/t7326.scala b/tests/pending/run/t7326.scala new file mode 100644 index 000000000..ed9471ea8 --- /dev/null +++ b/tests/pending/run/t7326.scala @@ -0,0 +1,64 @@ +import scala.collection.immutable.ListSet +import scala.collection.immutable.HashSet + +object Test extends App { + + def testCorrectness() { + // a key that has many hashCode collisions + case class Collision(i: Int) { override def hashCode = i / 5 } + + def subsetTest[T](emptyA:Set[T], emptyB:Set[T], mkKey:Int => T, n:Int) { + val outside = mkKey(n + 1) + for(i <- 0 to n) { + val a = emptyA ++ (0 until i).map(mkKey) + // every set must be a subset of itself + require(a.subsetOf(a), "A set must be the subset of itself") + for(k <- 0 to i) { + // k <= i, so b is definitely a subset + val b = emptyB ++ (0 until k).map(mkKey) + // c has less elements than a, but contains a value that is not in a + // so it is not a subset, but that is not immediately obvious due to size + val c = b + outside + require(b.subsetOf(a), s"$b must be a subset of $a") + require(!c.subsetOf(a), s"$c must not be a subset of $a") + } + } + } + + // test the HashSet/HashSet case + subsetTest(HashSet.empty[Int], HashSet.empty[Int], identity, 100) + + // test the HashSet/other set case + subsetTest(HashSet.empty[Int], ListSet.empty[Int], identity, 100) + + // test the HashSet/HashSet case for Collision keys + subsetTest(HashSet.empty[Collision], HashSet.empty[Collision], Collision, 100) + + // test the HashSet/other set case for Collision keys + subsetTest(HashSet.empty[Collision], ListSet.empty[Collision], Collision, 100) + } + + /** + * A main performance benefit of the new subsetOf is that we do not have to call hashCode during subsetOf + * since we already have the hash codes in the HashSet1 nodes. + */ + def testNoHashCodeInvocationsDuringSubsetOf() = { + var count = 0 + + case class HashCodeCounter(i:Int) { + override def hashCode = { + count += 1 + i + } + } + + val a = HashSet.empty ++ (0 until 100).map(HashCodeCounter) + val b = HashSet.empty ++ (0 until 50).map(HashCodeCounter) + val count0 = count + val result = b.subsetOf(a) + require(count == count0, "key.hashCode must not be called during subsetOf of two HashSets") + result + } + testCorrectness() + testNoHashCodeInvocationsDuringSubsetOf() +} |