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
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package collection
package mutable
import generic._
/** A base trait for maps that can be mutated.
* $mapNote
* $mapTags
* @since 1.0
* @author Matthias Zenger
*/
trait Map[A, B]
extends Iterable[(A, B)]
// with GenMap[A, B]
with scala.collection.Map[A, B]
with MapLike[A, B, Map[A, B]] {
override def empty: Map[A, B] = Map.empty
override def seq: Map[A, B] = this
/** The same map with a given default function.
*
* Invoking transformer methods (e.g. `map`) will not preserve the default value.
*
* @param d the function mapping keys to values, used for non-present keys
* @return a wrapper of the map with a default value
*/
def withDefault(d: A => B): mutable.Map[A, B] = new Map.WithDefault[A, B](this, d)
/** The same map with a given default value.
*
* Invoking transformer methods (e.g. `map`) will not preserve the default value.
*
* @param d default value used for non-present keys
* @return a wrapper of the map with a default value
*/
def withDefaultValue(d: B): mutable.Map[A, B] = new Map.WithDefault[A, B](this, x => d)
}
/** $factoryInfo
* The current default implementation of a $Coll is a `HashMap`.
* @define coll mutable map
* @define Coll `mutable.Map`
*/
object Map extends MutableMapFactory[Map] {
/** $canBuildFromInfo */
implicit def canBuildFrom[A, B]: CanBuildFrom[Coll, (A, B), Map[A, B]] = new MapCanBuildFrom[A, B]
def empty[A, B]: Map[A, B] = new HashMap[A, B]
class WithDefault[A, B](underlying: Map[A, B], d: A => B) extends scala.collection.Map.WithDefault(underlying, d) with Map[A, B] {
override def += (kv: (A, B)) = {underlying += kv; this}
def -= (key: A) = {underlying -= key; this}
override def empty = new WithDefault(underlying.empty, d)
override def updated[B1 >: B](key: A, value: B1): WithDefault[A, B1] = new WithDefault[A, B1](underlying.updated[B1](key, value), d)
override def + [B1 >: B](kv: (A, B1)): WithDefault[A, B1] = updated(kv._1, kv._2)
override def - (key: A): WithDefault[A, B] = new WithDefault(underlying - key, d)
/** If these methods aren't overridden to thread through the underlying map,
* successive calls to withDefault* have no effect.
*/
override def withDefault(d: A => B): mutable.Map[A, B] = new WithDefault[A, B](underlying, d)
override def withDefaultValue(d: B): mutable.Map[A, B] = new WithDefault[A, B](underlying, x => d)
}
}
/** Explicit instantiation of the `Map` trait to reduce class file size in subclasses. */
abstract class AbstractMap[A, B] extends scala.collection.AbstractMap[A, B] with Map[A, B]
|
