summaryrefslogtreecommitdiff
path: root/src/library/scala/collection/immutable
diff options
context:
space:
mode:
Diffstat (limited to 'src/library/scala/collection/immutable')
-rw-r--r--src/library/scala/collection/immutable/HashSet.scala1
-rw-r--r--src/library/scala/collection/immutable/ListSet.scala2
-rw-r--r--src/library/scala/collection/immutable/MapLike.scala5
-rw-r--r--src/library/scala/collection/immutable/Set.scala34
-rw-r--r--src/library/scala/collection/immutable/SortedMap.scala6
5 files changed, 43 insertions, 5 deletions
diff --git a/src/library/scala/collection/immutable/HashSet.scala b/src/library/scala/collection/immutable/HashSet.scala
index 6b71c0fa66..603d97c3ad 100644
--- a/src/library/scala/collection/immutable/HashSet.scala
+++ b/src/library/scala/collection/immutable/HashSet.scala
@@ -194,6 +194,7 @@ class HashSet[A] extends AbstractSet[A]
protected def writeReplace(): AnyRef = new HashSet.SerializationProxy(this)
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[HashSet[B]]
}
/** $factoryInfo
diff --git a/src/library/scala/collection/immutable/ListSet.scala b/src/library/scala/collection/immutable/ListSet.scala
index 2e17677359..adc975479a 100644
--- a/src/library/scala/collection/immutable/ListSet.scala
+++ b/src/library/scala/collection/immutable/ListSet.scala
@@ -179,4 +179,6 @@ class ListSet[A] extends AbstractSet[A]
override def tail: ListSet[A] = self
}
+
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[ListSet[B]]
}
diff --git a/src/library/scala/collection/immutable/MapLike.scala b/src/library/scala/collection/immutable/MapLike.scala
index 94a5b7929a..bd5b9c9faf 100644
--- a/src/library/scala/collection/immutable/MapLike.scala
+++ b/src/library/scala/collection/immutable/MapLike.scala
@@ -113,6 +113,11 @@ self =>
override def - (elem: A): immutable.Set[A] =
if (this(elem)) immutable.Set[A]() ++ this - elem
else this
+
+ // ImmutableDefaultKeySet is only protected, so we won't warn on override.
+ // Someone could override in a way that makes widening not okay
+ // (e.g. by overriding +, though the version in this class is fine)
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
}
/** This function transforms all the values of mappings contained
diff --git a/src/library/scala/collection/immutable/Set.scala b/src/library/scala/collection/immutable/Set.scala
index 0fbf7942d4..a115469b83 100644
--- a/src/library/scala/collection/immutable/Set.scala
+++ b/src/library/scala/collection/immutable/Set.scala
@@ -35,12 +35,22 @@ trait Set[A] extends Iterable[A]
override def companion: GenericCompanion[Set] = Set
- /** Returns this $coll as an immutable map.
- *
- * A new map will not be built; lazy collections will stay lazy.
+ /** Returns this $coll as an immutable set, perhaps accepting a
+ * wider range of elements. Since it already is an
+ * immutable set, it will only be rebuilt if the underlying structure
+ * cannot be expanded to include arbitrary element types.
+ * For instance, `BitSet` and `SortedSet` will be rebuilt, as
+ * they require `Int` and sortable elements respectively.
+ *
+ * When in doubt, the set will be rebuilt. Rebuilt sets never
+ * need to be rebuilt again.
*/
- @deprecatedOverriding("Immutable sets should do nothing on toSet but return themselves cast as a Set.", "2.11.0")
- override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]]
+ override def toSet[B >: A]: Set[B] = {
+ // This way of building sets typically has the best benchmarks, surprisingly!
+ val sb = Set.newBuilder[B]
+ foreach(sb += _)
+ sb.result()
+ }
override def seq: Set[A] = this
protected override def parCombiner = ParSet.newCombiner[A] // if `immutable.SetLike` gets introduced, please move this there!
@@ -62,6 +72,7 @@ object Set extends ImmutableSetFactory[Set] {
def - (elem: Any): Set[Any] = this
def iterator: Iterator[Any] = Iterator.empty
override def foreach[U](f: Any => U): Unit = {}
+ override def toSet[B >: Any]: Set[B] = this.asInstanceOf[Set[B]]
}
private[collection] def emptyInstance: Set[Any] = EmptySet
@@ -92,6 +103,10 @@ object Set extends ImmutableSetFactory[Set] {
if (f(elem1)) Some(elem1)
else None
}
+ // Why is Set1 non-final? Need to fix that!
+ @deprecatedOverriding("This immutable set should do nothing on toSet but cast itself to a Set with a wider element type.", "2.11.8")
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set1[B]]
+
}
/** An optimized representation for immutable sets of size 2 */
@@ -123,6 +138,9 @@ object Set extends ImmutableSetFactory[Set] {
else if (f(elem2)) Some(elem2)
else None
}
+ // Why is Set2 non-final? Need to fix that!
+ @deprecatedOverriding("This immutable set should do nothing on toSet but cast itself to a Set with a wider element type.", "2.11.8")
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set2[B]]
}
/** An optimized representation for immutable sets of size 3 */
@@ -156,6 +174,9 @@ object Set extends ImmutableSetFactory[Set] {
else if (f(elem3)) Some(elem3)
else None
}
+ // Why is Set3 non-final? Need to fix that!
+ @deprecatedOverriding("This immutable set should do nothing on toSet but cast itself to a Set with a wider element type.", "2.11.8")
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set3[B]]
}
/** An optimized representation for immutable sets of size 4 */
@@ -191,6 +212,9 @@ object Set extends ImmutableSetFactory[Set] {
else if (f(elem4)) Some(elem4)
else None
}
+ // Why is Set4 non-final? Need to fix that!
+ @deprecatedOverriding("This immutable set should do nothing on toSet but cast itself to a Set with a wider element type.", "2.11.8")
+ override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set4[B]]
}
}
diff --git a/src/library/scala/collection/immutable/SortedMap.scala b/src/library/scala/collection/immutable/SortedMap.scala
index f1493551ab..682788e18e 100644
--- a/src/library/scala/collection/immutable/SortedMap.scala
+++ b/src/library/scala/collection/immutable/SortedMap.scala
@@ -53,6 +53,12 @@ self =>
val map = self.rangeImpl(from, until)
new map.DefaultKeySortedSet
}
+ override def toSet[C >: A]: Set[C] = {
+ // This way of building sets typically has the best benchmarks, surprisingly!
+ val sb = Set.newBuilder[C]
+ foreach(sb += _)
+ sb.result()
+ }
}
/** Add a key/value pair to this map.