什麼是我想要做的是能夠調整TreeMap中的項目的鍵順序,因此Scala :: TreeMap更新後不均衡?
- 我可能能夠通過一些「靜態」數據,以找對象,不改變
- 的對象的位置(如果該映射爲弄平)應該尊重它的「優先級」
以下測試情況下可以很好地用於numEntries = 6,但大於7的值不起作用我並沒有真正理解那裏出了什麼問題,但我懷疑這棵樹不合格在一些更新/副本之後。那麼請問有人請指教 - 是我的錯,還是Scala 2.9中的TreeMap有某種錯誤?
UPDATE如果循環
for (i <- 1 to (numEntries - 1)) {
與
for (i <- (numEntries - 1) to 1 by -1) {
取代一切工作正常。所以看起來這是TreeMap中的錯誤?
import org.scalatest.FlatSpec
import collection.immutable.TreeMap
import org.junit.runner.RunWith
import org.scalatest.junit.JUnitRunner
@RunWith(classOf[JUnitRunner])
class TreeMapTest extends FlatSpec {
//val numEntries = 6;
val numEntries = 10;
sealed case class Entry(first: Option[Int], last: Int) extends Ordered[Entry] {
def compare(that: TreeMapTest.this.type#Entry) = {
if (first.isEmpty || that.first.isEmpty) {
last compare that.last
} else {
(first.get compare that.first.get) match {
case 0 => last compare that.last
case x => x
}
}
}
def increase() = copy(first = Some(this.first.getOrElse(0) + 1))
}
type Container = TreeMap[Entry, Entry]
"TreeMap" should "allow updates" in {
var dataMap: Container = new Container() ++ (for (i <- 1 to numEntries) yield Entry(Some(0), i) -> Entry(Some(0), i))
for (i <- 1 to (numEntries - 1)) {
val key = new Entry(None, i)
dataMap.get(new Entry(None, i)) match {
case Some(e) =>
val newEntry = e.increase()
dataMap = (dataMap - key) + (newEntry -> newEntry)
case None => fail("Can not find entry " + key)
}
}
}
}
優先'1,直到numEntries'超過'1到(numEntries - 1)'。 –