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-rw-r--r--src/library/scala/collection/immutable/LongMap.scala16
-rw-r--r--test/files/run/longmap.check0
-rw-r--r--test/files/run/longmap.scala8
3 files changed, 24 insertions, 0 deletions
diff --git a/src/library/scala/collection/immutable/LongMap.scala b/src/library/scala/collection/immutable/LongMap.scala
index fab1b7f00b..60300c2a9e 100644
--- a/src/library/scala/collection/immutable/LongMap.scala
+++ b/src/library/scala/collection/immutable/LongMap.scala
@@ -12,6 +12,7 @@ package immutable
import scala.collection.generic.{ CanBuildFrom, BitOperations }
import scala.collection.mutable.{ Builder, MapBuilder }
+import scala.annotation.tailrec
/** Utility class for long maps.
* @author David MacIver
@@ -416,5 +417,20 @@ extends AbstractMap[Long, T]
def ++[S >: T](that: LongMap[S]) =
this.unionWith[S](that, (key, x, y) => y)
+
+ @tailrec
+ final def firstKey: Long = this match {
+ case LongMap.Bin(_, _, l, r) => l.firstKey
+ case LongMap.Tip(k, v) => k
+ case LongMap.Nil => sys.error("Empty set")
+ }
+
+ @tailrec
+ final def lastKey: Long = this match {
+ case LongMap.Bin(_, _, l, r) => r.lastKey
+ case LongMap.Tip(k , v) => k
+ case LongMap.Nil => sys.error("Empty set")
+ }
+
}
diff --git a/test/files/run/longmap.check b/test/files/run/longmap.check
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/files/run/longmap.check
diff --git a/test/files/run/longmap.scala b/test/files/run/longmap.scala
new file mode 100644
index 0000000000..1f18eebd31
--- /dev/null
+++ b/test/files/run/longmap.scala
@@ -0,0 +1,8 @@
+object Test extends App{
+ import scala.collection.immutable.LongMap;
+
+ val it = LongMap(8L -> 2, 11L -> 3, 1L -> 2, 7L -> 13);
+
+ assert(it.firstKey == 1L);
+ assert(it.lastKey == 11L);
+}