summaryrefslogtreecommitdiff
path: root/src/library/scala/xml/Null.scala
blob: 5885201acdc8a148c6fa320d9e6963cd3b3685fd (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
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
81
/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2009, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

// $Id$


package scala.xml

case object Null extends MetaData {

  /** appends given MetaData items to this MetaData list */
  override def append(m: MetaData): MetaData = m

  override def containedIn1(m: MetaData): Boolean = false

  /** returns its argument */
  def copy(next: MetaData) = next

  override def iterator = Iterator.empty

  override def filter(f: MetaData => Boolean): MetaData = this

  /** returns null */
  def getNamespace(owner: Node) = null

  final override def hasNext = false

  final override def length = 0

  final override def length(i: Int) = i

  def isPrefixed = false

  /** deep equals method */
  override def equals(that: Any) = that match {
    case m: MetaData => m.length == 0
    case _ => false
  }

  def equals1(that:MetaData) = that.length == 0

  def key = null

  def value = null

  override def map(f: MetaData => Text): List[Text] = Nil

  def next = null

  /** null */
  def apply(key: String) = {
    if(!Parsing.isNameStart (key charAt 0))
      throw new IllegalArgumentException("not a valid attribute name '"+key+"', so can never match !")
    null
  }

  /** gets value of qualified (prefixed) attribute with given key */
  def apply(namespace: String, scope: NamespaceBinding, key: String) = null

  override def hashCode(): Int = 0

  override def toString1(): String = ""

  //appends string representations of single attribute to StringBuilder
  def toString1(sb:StringBuilder) = {}

  override def toString(): String = ""

  override def buildString(sb: StringBuilder): StringBuilder = sb

  override def wellformed(scope: NamespaceBinding) = true

  def remove(key: String) = this

  def remove(namespace: String, scope: NamespaceBinding, key: String) = this
}