Factored common interface of UnprefixedAttribut...

Factored common interface of UnprefixedAttribute and PrefixedAttribute
out into an Attribute trait; added Attribute object with various
convenience methods for creations; created extractors for all three.

3 files changed, 81 insertions, 10 deletions

diff --git a/src/library/scala/xml/Attribute.scala b/src/library/scala/xml/Attribute.scala
new file mode 100644
index 0000000000..261e9d9c86
--- /dev/null
+++ b/src/library/scala/xml/Attribute.scala
@@ -0,0 +1,61 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2009, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id$
+
+package scala.xml
+
+/** Attribute defines the interface shared by both
+ *  PrefixedAttribute and UnprefixedAttribute
+ */
+
+object Attribute {
+  def unapply(x: Attribute) = x match {
+    case PrefixedAttribute(_, key, value, next) => Some(key, value, next)
+    case UnprefixedAttribute(key, value, next)  => Some(key, value, next)
+    case _                                      => None
+  }
+
+  /** Convenience functions which choose Un/Prefixedness appropriately */
+  def apply(key: String, value: Seq[Node], next: MetaData): Attribute =
+    new UnprefixedAttribute(key, value, next)
+
+  def apply(pre: String, key: String, value: String, next: MetaData): Attribute =
+    if (pre == null || pre == "") new UnprefixedAttribute(key, value, next)
+    else new PrefixedAttribute(pre, key, value, next)
+
+  def apply(pre: String, key: String, value: Seq[Node], next: MetaData): Attribute =
+    if (pre == null || pre == "") new UnprefixedAttribute(key, value, next)
+    else new PrefixedAttribute(pre, key, value, next)
+
+  def apply(pre: Option[String], key: String, value: Seq[Node], next: MetaData): Attribute =
+    pre match {
+      case None     => new UnprefixedAttribute(key, value, next)
+      case Some(p)  => new PrefixedAttribute(p, key, value, next)
+    }
+}
+
+abstract trait Attribute extends MetaData
+{
+  val key: String
+  val value: Seq[Node]
+  val next: MetaData
+
+  def apply(key: String): Seq[Node]
+  def apply(namespace: String, scope: NamespaceBinding, key: String): Seq[Node]
+  def copy(next: MetaData): Attribute
+  def remove(key: String): MetaData
+  def remove(namespace: String, scope: NamespaceBinding, key: String): MetaData
+
+  def isPrefixed: Boolean
+  def getNamespace(owner: Node): String
+  def wellformed(scope: NamespaceBinding): Boolean
+
+  def equals1(m: MetaData): Boolean
+  def toString1(sb: StringBuilder): Unit
+}
\ No newline at end of file
diff --git a/src/library/scala/xml/PrefixedAttribute.scala b/src/library/scala/xml/PrefixedAttribute.scala
index 11f4f2dab3..13ed201634 100644
--- a/src/library/scala/xml/PrefixedAttribute.scala
+++ b/src/library/scala/xml/PrefixedAttribute.scala
@@ -18,12 +18,14 @@ package scala.xml
  *  @param value the attribute value, which may not be null
  *  @param next  ...
  */
-class PrefixedAttribute(val pre: String,
-                        val key: String,
-                        val value: Seq[Node],
-                        val next: MetaData) extends MetaData {
-
-  if(value eq null)
+class PrefixedAttribute(
+  val pre: String,
+  val key: String,
+  val value: Seq[Node],
+  val next: MetaData)
+extends Attribute
+{
+  if (value eq null)
     throw new UnsupportedOperationException("value is null")
 
   /** same as this(key, Utility.parseAttributeValue(value), next) */
@@ -97,4 +99,6 @@ class PrefixedAttribute(val pre: String,
       next.remove(namespace, scope, key)
 
 }
-
+object PrefixedAttribute {
+  def unapply(x: PrefixedAttribute) = Some(x.pre, x.key, x.value, x.next)
+}
diff --git a/src/library/scala/xml/UnprefixedAttribute.scala b/src/library/scala/xml/UnprefixedAttribute.scala
index 4b4de6bb01..59d43d6856 100644
--- a/src/library/scala/xml/UnprefixedAttribute.scala
+++ b/src/library/scala/xml/UnprefixedAttribute.scala
@@ -15,8 +15,12 @@ package scala.xml
  *
  *  @author Burak Emir
  */
-class UnprefixedAttribute(val key: String, val value: Seq[Node], next1: MetaData) extends MetaData {
-
+class UnprefixedAttribute(
+  val key: String,
+  val value: Seq[Node],
+  next1: MetaData)
+extends Attribute
+{
   val next = if (value ne null) next1 else next1.remove(key)
 
   /** same as this(key, Text(value), next) */
@@ -88,4 +92,6 @@ class UnprefixedAttribute(val key: String, val value: Seq[Node], next1: MetaData
     next.remove(namespace, scope, key)
 
 }
-
+object UnprefixedAttribute {
+  def unapply(x: UnprefixedAttribute) = Some(x.key, x.value, x.next)
+}