blob: a9ce3fb3df593573f82ab003271313141984c61b (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id: HashSet.scala 16884 2009-01-09 16:52:09Z cunei $
package scalax.collection.immutable
import generic.SetTemplate
/** A default implementation of immutable sets.
* This is currently implemented as a proxy for an immutable HashSet,
* except that its builder returns specialized representations EmptySet,Set1,..., Set4
* for sets of size <= 4.
*/
class DefaultSet[A] private (hset: HashSet[A])
extends Set[A]
with SetTemplate[Set, A] {
def this() = this(new HashSet[A])
def contains(elem: A): Boolean = hset.contains(elem)
def + (elem: A): Set[A] = hset + elem
/** Keeps underlying HashSet representation, but switches back to EmptySet if
* result does not contain any elements
*/
def - (elem: A): Set[A] = {
val hset1 = hset - elem
if (hset1.isEmpty) new EmptySet[A]
else new DefaultSet(hset)
}
def size: Int = hset.size
def elements: Iterator[A] = hset.elements
override def foreach(f: A => Unit): Unit = hset.foreach(f)
}
|
