Vendor bundled gems for deployment

1 files changed, 2584 insertions, 0 deletions

diff --git a/vendor/bundle/ruby/3.4.0/gems/rexml-3.4.1/lib/rexml/element.rb b/vendor/bundle/ruby/3.4.0/gems/rexml-3.4.1/lib/rexml/element.rb
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+# frozen_string_literal: false
+require_relative "parent"
+require_relative "namespace"
+require_relative "attribute"
+require_relative "cdata"
+require_relative "xpath"
+require_relative "parseexception"
+
+module REXML
+  # An \REXML::Element object represents an XML element.
+  #
+  # An element:
+  #
+  # - Has a name (string).
+  # - May have a parent (another element).
+  # - Has zero or more children
+  #   (other elements, text, CDATA, processing instructions, and comments).
+  # - Has zero or more siblings
+  #   (other elements, text, CDATA, processing instructions, and comments).
+  # - Has zero or more named attributes.
+  #
+  # == In a Hurry?
+  #
+  # If you're somewhat familiar with XML
+  # and have a particular task in mind,
+  # you may want to see the
+  # {tasks pages}[../doc/rexml/tasks/tocs/master_toc_rdoc.html],
+  # and in particular, the
+  # {tasks page for elements}[../doc/rexml/tasks/tocs/element_toc_rdoc.html].
+  #
+  # === Name
+  #
+  # An element has a name, which is initially set when the element is created:
+  #
+  #   e = REXML::Element.new('foo')
+  #   e.name # => "foo"
+  #
+  # The name may be changed:
+  #
+  #   e.name = 'bar'
+  #   e.name # => "bar"
+  #
+  #
+  # === \Parent
+  #
+  # An element may have a parent.
+  #
+  # Its parent may be assigned explicitly when the element is created:
+  #
+  #   e0 = REXML::Element.new('foo')
+  #   e1 = REXML::Element.new('bar', e0)
+  #   e1.parent # => <foo> ... </>
+  #
+  # Note: the representation of an element always shows the element's name.
+  # If the element has children, the representation indicates that
+  # by including an ellipsis (<tt>...</tt>).
+  #
+  # The parent may be assigned explicitly at any time:
+  #
+  #   e2 = REXML::Element.new('baz')
+  #   e1.parent = e2
+  #   e1.parent # => <baz/>
+  #
+  # When an element is added as a child, its parent is set automatically:
+  #
+  #   e1.add_element(e0)
+  #   e0.parent # => <bar> ... </>
+  #
+  # For an element that has no parent, method +parent+ returns +nil+.
+  #
+  # === Children
+  #
+  # An element has zero or more children.
+  # The children are an ordered collection
+  # of all objects whose parent is the element itself.
+  #
+  # The children may include any combination of elements, text, comments,
+  # processing instructions, and CDATA.
+  # (This example keeps things clean by controlling whitespace
+  # via a +context+ setting.)
+  #
+  #    xml_string = <<-EOT
+  #    <root>
+  #      <ele_0/>
+  #      text 0
+  #      <!--comment 0-->
+  #      <?target_0 pi_0?>
+  #      <![CDATA[cdata 0]]>
+  #      <ele_1/>
+  #      text 1
+  #      <!--comment 1-->
+  #      <?target_0 pi_1?>
+  #      <![CDATA[cdata 1]]>
+  #    </root>
+  #    EOT
+  #    context = {ignore_whitespace_nodes: :all, compress_whitespace: :all}
+  #    d = REXML::Document.new(xml_string, context)
+  #    root = d.root
+  #    root.children.size # => 10
+  #    root.each {|child| p "#{child.class}: #{child}" }
+  #
+  # Output:
+  #
+  #   "REXML::Element: <ele_0/>"
+  #   "REXML::Text: \n text 0\n "
+  #   "REXML::Comment: comment 0"
+  #   "REXML::Instruction: <?target_0 pi_0?>"
+  #   "REXML::CData: cdata 0"
+  #   "REXML::Element: <ele_1/>"
+  #   "REXML::Text: \n text 1\n "
+  #   "REXML::Comment: comment 1"
+  #   "REXML::Instruction: <?target_0 pi_1?>"
+  #   "REXML::CData: cdata 1"
+  #
+  # A child may be added using inherited methods
+  # Parent#insert_before or Parent#insert_after:
+  #
+  #   xml_string = '<root><a/><c/><d/></root>'
+  #   d = REXML::Document.new(xml_string)
+  #   root = d.root
+  #   c = d.root[1] # => <c/>
+  #   root.insert_before(c, REXML::Element.new('b'))
+  #   root.to_a # => [<a/>, <b/>, <c/>, <d/>]
+  #
+  # A child may be replaced using Parent#replace_child:
+  #
+  #   root.replace_child(c, REXML::Element.new('x'))
+  #   root.to_a # => [<a/>, <b/>, <x/>, <d/>]
+  #
+  # A child may be removed using Parent#delete:
+  #
+  #   x = root[2] # => <x/>
+  #   root.delete(x)
+  #   root.to_a # => [<a/>, <b/>, <d/>]
+  #
+  # === Siblings
+  #
+  # An element has zero or more siblings,
+  # which are the other children of the element's parent.
+  #
+  # In the example above, element +ele_1+ is between a CDATA sibling
+  # and a text sibling:
+  #
+  #   ele_1 = root[5]        # => <ele_1/>
+  #   ele_1.previous_sibling # => "cdata 0"
+  #   ele_1.next_sibling     # => "\n text 1\n "
+  #
+  # === \Attributes
+  #
+  # An element has zero or more named attributes.
+  #
+  # A new element has no attributes:
+  #
+  #   e = REXML::Element.new('foo')
+  #   e.attributes      # => {}
+  #
+  # Attributes may be added:
+  #
+  #   e.add_attribute('bar', 'baz')
+  #   e.add_attribute('bat', 'bam')
+  #   e.attributes.size # => 2
+  #   e['bar']          # => "baz"
+  #   e['bat']          # => "bam"
+  #
+  # An existing attribute may be modified:
+  #
+  #   e.add_attribute('bar', 'bad')
+  #   e.attributes.size # => 2
+  #   e['bar']          # => "bad"
+  #
+  # An existing attribute may be deleted:
+  #
+  #   e.delete_attribute('bar')
+  #   e.attributes.size # => 1
+  #   e['bar']          # => nil
+  #
+  # == What's Here
+  #
+  # To begin with, what's elsewhere?
+  #
+  # \Class \REXML::Element inherits from its ancestor classes:
+  #
+  # - REXML::Child
+  # - REXML::Parent
+  #
+  # \REXML::Element itself and its ancestors also include modules:
+  #
+  # - {Enumerable}[https://docs.ruby-lang.org/en/master/Enumerable.html]
+  # - REXML::Namespace
+  # - REXML::Node
+  # - REXML::XMLTokens
+  #
+  # === Methods for Creating an \Element
+  #
+  # ::new:: Returns a new empty element.
+  # #clone:: Returns a clone of another element.
+  #
+  # === Methods for Attributes
+  #
+  # {[attribute_name]}[#method-i-5B-5D]:: Returns an attribute value.
+  # #add_attribute:: Adds a new attribute.
+  # #add_attributes:: Adds multiple new attributes.
+  # #attribute:: Returns the attribute value for a given name and optional namespace.
+  # #delete_attribute:: Removes an attribute.
+  #
+  # === Methods for Children
+  #
+  # {[index]}[#method-i-5B-5D]:: Returns the child at the given offset.
+  # #add_element:: Adds an element as the last child.
+  # #delete_element:: Deletes a child element.
+  # #each_element:: Calls the given block with each child element.
+  # #each_element_with_attribute:: Calls the given block with each child element
+  #                                that meets given criteria,
+  #                                which can include the attribute name.
+  # #each_element_with_text:: Calls the given block with each child element
+  #                           that meets given criteria,
+  #                           which can include text.
+  # #get_elements:: Returns an array of element children that match a given xpath.
+  #
+  # === Methods for \Text Children
+  #
+  # #add_text:: Adds a text node to the element.
+  # #get_text:: Returns a text node that meets specified criteria.
+  # #text:: Returns the text string from the first node that meets specified criteria.
+  # #texts:: Returns an array of the text children of the element.
+  # #text=:: Adds, removes, or replaces the first text child of the element
+  #
+  # === Methods for Other Children
+  #
+  # #cdatas:: Returns an array of the cdata children of the element.
+  # #comments:: Returns an array of the comment children of the element.
+  # #instructions:: Returns an array of the instruction children of the element.
+  #
+  # === Methods for Namespaces
+  #
+  # #add_namespace:: Adds a namespace to the element.
+  # #delete_namespace:: Removes a namespace from the element.
+  # #namespace:: Returns the string namespace URI for the element.
+  # #namespaces:: Returns a hash of all defined namespaces in the element.
+  # #prefixes:: Returns an array of the string prefixes (names)
+  #             of all defined namespaces in the element
+  #
+  # === Methods for Querying
+  #
+  # #document:: Returns the document, if any, that the element belongs to.
+  # #root:: Returns the most distant element (not document) ancestor of the element.
+  # #root_node:: Returns the most distant ancestor of the element.
+  # #xpath:: Returns the string xpath to the element
+  #          relative to the most distant parent
+  # #has_attributes?:: Returns whether the element has attributes.
+  # #has_elements?:: Returns whether the element has elements.
+  # #has_text?:: Returns whether the element has text.
+  # #next_element:: Returns the next sibling that is an element.
+  # #previous_element:: Returns the previous sibling that is an element.
+  # #raw:: Returns whether raw mode is set for the element.
+  # #whitespace:: Returns whether whitespace is respected for the element.
+  # #ignore_whitespace_nodes:: Returns whether whitespace nodes
+  #                            are to be ignored for the element.
+  # #node_type:: Returns symbol <tt>:element</tt>.
+  #
+  # === One More Method
+  #
+  # #inspect:: Returns a string representation of the element.
+  #
+  # === Accessors
+  #
+  # #elements:: Returns the REXML::Elements object for the element.
+  # #attributes:: Returns the REXML::Attributes object for the element.
+  # #context:: Returns or sets the context hash for the element.
+  #
+  class Element < Parent
+    include Namespace
+
+    UNDEFINED = "UNDEFINED";            # The default name
+
+    # Mechanisms for accessing attributes and child elements of this
+    # element.
+    attr_reader :attributes, :elements
+    # The context holds information about the processing environment, such as
+    # whitespace handling.
+    attr_accessor :context
+
+    # :call-seq:
+    #   Element.new(name = 'UNDEFINED', parent = nil, context = nil) -> new_element
+    #   Element.new(element, parent = nil, context = nil) -> new_element
+    #
+    # Returns a new \REXML::Element object.
+    #
+    # When no arguments are given,
+    # returns an element with name <tt>'UNDEFINED'</tt>:
+    #
+    #   e = REXML::Element.new # => <UNDEFINED/>
+    #   e.class                # => REXML::Element
+    #   e.name                 # => "UNDEFINED"
+    #
+    # When only argument +name+ is given,
+    # returns an element of the given name:
+    #
+    #   REXML::Element.new('foo') # => <foo/>
+    #
+    # When only argument +element+ is given, it must be an \REXML::Element object;
+    # returns a shallow copy of the given element:
+    #
+    #   e0 = REXML::Element.new('foo')
+    #   e1 = REXML::Element.new(e0) # => <foo/>
+    #
+    # When argument +parent+ is also given, it must be an REXML::Parent object:
+    #
+    #   e = REXML::Element.new('foo', REXML::Parent.new)
+    #   e.parent # => #<REXML::Parent @parent=nil, @children=[<foo/>]>
+    #
+    # When argument +context+ is also given, it must be a hash
+    # representing the context for the element;
+    # see {Element Context}[../doc/rexml/context_rdoc.html]:
+    #
+    #   e = REXML::Element.new('foo', nil, {raw: :all})
+    #   e.context # => {:raw=>:all}
+    #
+    def initialize( arg = UNDEFINED, parent=nil, context=nil )
+      super(parent)
+
+      @elements = Elements.new(self)
+      @attributes = Attributes.new(self)
+      @context = context
+
+      if arg.kind_of? String
+        self.name = arg
+      elsif arg.kind_of? Element
+        self.name = arg.expanded_name
+        arg.attributes.each_attribute{ |attribute|
+          @attributes << Attribute.new( attribute )
+        }
+        @context = arg.context
+      end
+    end
+
+    # :call-seq:
+    #   inspect -> string
+    #
+    # Returns a string representation of the element.
+    #
+    # For an element with no attributes and no children, shows the element name:
+    #
+    #   REXML::Element.new.inspect # => "<UNDEFINED/>"
+    #
+    # Shows attributes, if any:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.add_attributes({'bar' => 0, 'baz' => 1})
+    #   e.inspect # => "<foo bar='0' baz='1'/>"
+    #
+    # Shows an ellipsis (<tt>...</tt>), if there are child elements:
+    #
+    #   e.add_element(REXML::Element.new('bar'))
+    #   e.add_element(REXML::Element.new('baz'))
+    #   e.inspect # => "<foo bar='0' baz='1'> ... </>"
+    #
+    def inspect
+      rv = "<#@expanded_name"
+
+      @attributes.each_attribute do |attr|
+        rv << " "
+        attr.write( rv, 0 )
+      end
+
+      if children.size > 0
+        rv << "> ... </>"
+      else
+        rv << "/>"
+      end
+    end
+
+    # :call-seq:
+    #   clone -> new_element
+    #
+    # Returns a shallow copy of the element, containing the name and attributes,
+    # but not the parent or children:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.add_attributes({'bar' => 0, 'baz' => 1})
+    #   e.clone # => <foo bar='0' baz='1'/>
+    #
+    def clone
+      self.class.new self
+    end
+
+    # :call-seq:
+    #   root_node -> document or element
+    #
+    # Returns the most distant ancestor of +self+.
+    #
+    # When the element is part of a document,
+    # returns the root node of the document.
+    # Note that the root node is different from the document element;
+    # in this example +a+ is document element and the root node is its parent:
+    #
+    #   d = REXML::Document.new('<a><b><c/></b></a>')
+    #   top_element = d.first      # => <a> ... </>
+    #   child = top_element.first  # => <b> ... </>
+    #   d.root_node == d           # => true
+    #   top_element.root_node == d # => true
+    #   child.root_node == d       # => true
+    #
+    # When the element is not part of a document, but does have ancestor elements,
+    # returns the most distant ancestor element:
+    #
+    #   e0 = REXML::Element.new('foo')
+    #   e1 = REXML::Element.new('bar')
+    #   e1.parent = e0
+    #   e2 = REXML::Element.new('baz')
+    #   e2.parent = e1
+    #   e2.root_node == e0 # => true
+    #
+    # When the element has no ancestor elements,
+    # returns +self+:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.root_node == e # => true
+    #
+    # Related: #root, #document.
+    #
+    def root_node
+      parent.nil? ? self : parent.root_node
+    end
+
+    # :call-seq:
+    #   root -> element
+    #
+    # Returns the most distant _element_ (not document) ancestor of the element:
+    #
+    #   d = REXML::Document.new('<a><b><c/></b></a>')
+    #   top_element = d.first
+    #   child = top_element.first
+    #   top_element.root == top_element # => true
+    #   child.root == top_element       # => true
+    #
+    # For a document, returns the topmost element:
+    #
+    #   d.root == top_element # => true
+    #
+    # Related: #root_node, #document.
+    #
+    def root
+      target = self
+      while target
+        return target.elements[1] if target.kind_of? Document
+        parent = target.parent
+        return target if parent.kind_of? Document or parent.nil?
+        target = parent
+      end
+      nil
+    end
+
+    # :call-seq:
+    #   document -> document or nil
+    #
+    # If the element is part of a document, returns that document:
+    #
+    #   d = REXML::Document.new('<a><b><c/></b></a>')
+    #   top_element = d.first
+    #   child = top_element.first
+    #   top_element.document == d # => true
+    #   child.document == d       # => true
+    #
+    # If the element is not part of a document, returns +nil+:
+    #
+    #   REXML::Element.new.document # => nil
+    #
+    # For a document, returns +self+:
+    #
+    #   d.document == d           # => true
+    #
+    # Related: #root, #root_node.
+    #
+    def document
+      rt = root
+      rt.parent if rt
+    end
+
+    # :call-seq:
+    #   whitespace
+    #
+    # Returns +true+ if whitespace is respected for this element,
+    # +false+ otherwise.
+    #
+    # See {Element Context}[../doc/rexml/context_rdoc.html].
+    #
+    # The evaluation is tested against the element's +expanded_name+,
+    # and so is namespace-sensitive.
+    def whitespace
+      @whitespace = nil
+      if @context
+        if @context[:respect_whitespace]
+          @whitespace = (@context[:respect_whitespace] == :all or
+                         @context[:respect_whitespace].include? expanded_name)
+        end
+        @whitespace = false if (@context[:compress_whitespace] and
+                                (@context[:compress_whitespace] == :all or
+                                 @context[:compress_whitespace].include? expanded_name)
+                               )
+      end
+      @whitespace = true unless @whitespace == false
+      @whitespace
+    end
+
+    # :call-seq:
+    #   ignore_whitespace_nodes
+    #
+    # Returns +true+ if whitespace nodes are ignored for the element.
+    #
+    # See {Element Context}[../doc/rexml/context_rdoc.html].
+    #
+    def ignore_whitespace_nodes
+      @ignore_whitespace_nodes = false
+      if @context
+        if @context[:ignore_whitespace_nodes]
+          @ignore_whitespace_nodes =
+            (@context[:ignore_whitespace_nodes] == :all or
+             @context[:ignore_whitespace_nodes].include? expanded_name)
+        end
+      end
+    end
+
+    # :call-seq:
+    #   raw
+    #
+    # Returns +true+ if raw mode is set for the element.
+    #
+    # See {Element Context}[../doc/rexml/context_rdoc.html].
+    #
+    # The evaluation is tested against +expanded_name+, and so is namespace
+    # sensitive.
+    def raw
+      @raw = (@context and @context[:raw] and
+              (@context[:raw] == :all or
+               @context[:raw].include? expanded_name))
+      @raw
+    end
+
+    #once :whitespace, :raw, :ignore_whitespace_nodes
+
+    #################################################
+    # Namespaces                                    #
+    #################################################
+
+    # :call-seq:
+    #   prefixes -> array_of_namespace_prefixes
+    #
+    # Returns an array of the string prefixes (names) of all defined namespaces
+    # in the element and its ancestors:
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #        <a xmlns:x='1' xmlns:y='2'>
+    #          <b/>
+    #          <c xmlns:z='3'/>
+    #        </a>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string, {compress_whitespace: :all})
+    #   d.elements['//a'].prefixes # => ["x", "y"]
+    #   d.elements['//b'].prefixes # => ["x", "y"]
+    #   d.elements['//c'].prefixes # => ["x", "y", "z"]
+    #
+    def prefixes
+      prefixes = []
+      prefixes = parent.prefixes if parent
+      prefixes |= attributes.prefixes
+      return prefixes
+    end
+
+    # :call-seq:
+    #    namespaces -> array_of_namespace_names
+    #
+    # Returns a hash of all defined namespaces
+    # in the element and its ancestors:
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #        <a xmlns:x='1' xmlns:y='2'>
+    #          <b/>
+    #          <c xmlns:z='3'/>
+    #        </a>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   d.elements['//a'].namespaces # => {"x"=>"1", "y"=>"2"}
+    #   d.elements['//b'].namespaces # => {"x"=>"1", "y"=>"2"}
+    #   d.elements['//c'].namespaces # => {"x"=>"1", "y"=>"2", "z"=>"3"}
+    #
+    def namespaces
+      namespaces = {}
+      namespaces = parent.namespaces if parent
+      namespaces = namespaces.merge( attributes.namespaces )
+      return namespaces
+    end
+
+    # :call-seq:
+    #   namespace(prefix = nil) -> string_uri or nil
+    #
+    # Returns the string namespace URI for the element,
+    # possibly deriving from one of its ancestors.
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #        <a xmlns='1' xmlns:y='2'>
+    #          <b/>
+    #          <c xmlns:z='3'/>
+    #        </a>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   b = d.elements['//b']
+    #   b.namespace      # => "1"
+    #   b.namespace('y') # => "2"
+    #   b.namespace('nosuch') # => nil
+    #
+    def namespace(prefix=nil)
+      if prefix.nil?
+        prefix = prefix()
+      end
+      if prefix == ''
+        prefix = "xmlns"
+      else
+        prefix = "xmlns:#{prefix}" unless prefix[0,5] == 'xmlns'
+      end
+      ns = nil
+      target = self
+      while ns.nil? and target
+        ns = target.attributes[prefix]
+        target = target.parent
+      end
+      ns = '' if ns.nil? and prefix == 'xmlns'
+      return ns
+    end
+
+    # :call-seq:
+    #   add_namespace(prefix, uri = nil) -> self
+    #
+    # Adds a namespace to the element; returns +self+.
+    #
+    # With the single argument +prefix+,
+    # adds a namespace using the given +prefix+ and the namespace URI:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.add_namespace('bar')
+    #   e.namespaces # => {"xmlns"=>"bar"}
+    #
+    # With both arguments +prefix+ and +uri+ given,
+    # adds a namespace using both arguments:
+    #
+    #   e.add_namespace('baz', 'bat')
+    #   e.namespaces # => {"xmlns"=>"bar", "baz"=>"bat"}
+    #
+    def add_namespace( prefix, uri=nil )
+      unless uri
+        @attributes["xmlns"] = prefix
+      else
+        prefix = "xmlns:#{prefix}" unless prefix =~ /^xmlns:/
+        @attributes[ prefix ] = uri
+      end
+      self
+    end
+
+    # :call-seq:
+    #   delete_namespace(namespace = 'xmlns') -> self
+    #
+    # Removes a namespace from the element.
+    #
+    # With no argument, removes the default namespace:
+    #
+    #   d = REXML::Document.new "<a xmlns:foo='bar' xmlns='twiddle'/>"
+    #   d.to_s # => "<a xmlns:foo='bar' xmlns='twiddle'/>"
+    #   d.root.delete_namespace # => <a xmlns:foo='bar'/>
+    #   d.to_s # => "<a xmlns:foo='bar'/>"
+    #
+    # With argument +namespace+, removes the specified namespace:
+    #
+    #   d.root.delete_namespace('foo')
+    #   d.to_s # => "<a/>"
+    #
+    # Does nothing if no such namespace is found:
+    #
+    #   d.root.delete_namespace('nosuch')
+    #   d.to_s # => "<a/>"
+    #
+    def delete_namespace namespace="xmlns"
+      namespace = "xmlns:#{namespace}" unless namespace == 'xmlns'
+      attribute = attributes.get_attribute(namespace)
+      attribute.remove unless attribute.nil?
+      self
+    end
+
+    #################################################
+    # Elements                                      #
+    #################################################
+
+    # :call-seq:
+    #   add_element(name, attributes = nil) -> new_element
+    #   add_element(element, attributes = nil) -> element
+    #
+    # Adds a child element, optionally setting attributes
+    # on the added element; returns the added element.
+    #
+    # With string argument +name+, creates a new element with that name
+    # and adds the new element as a child:
+    #
+    #   e0 = REXML::Element.new('foo')
+    #   e0.add_element('bar')
+    #   e0[0] # => <bar/>
+    #
+    #
+    # With argument +name+ and hash argument +attributes+,
+    # sets attributes on the new element:
+    #
+    #   e0.add_element('baz', {'bat' => '0', 'bam' => '1'})
+    #   e0[1] # => <baz bat='0' bam='1'/>
+    #
+    # With element argument +element+, adds that element as a child:
+    #
+    #   e0 = REXML::Element.new('foo')
+    #   e1 = REXML::Element.new('bar')
+    #   e0.add_element(e1)
+    #   e0[0] # => <bar/>
+    #
+    # With argument +element+ and hash argument +attributes+,
+    # sets attributes on the added element:
+    #
+    #   e0.add_element(e1, {'bat' => '0', 'bam' => '1'})
+    #   e0[1] # => <bar bat='0' bam='1'/>
+    #
+    def add_element element, attrs=nil
+      raise "First argument must be either an element name, or an Element object" if element.nil?
+      el = @elements.add(element)
+      attrs.each do |key, value|
+        el.attributes[key]=value
+      end       if attrs.kind_of? Hash
+      el
+    end
+
+    # :call-seq:
+    #   delete_element(index) -> removed_element or nil
+    #   delete_element(element) -> removed_element or nil
+    #   delete_element(xpath) -> removed_element or nil
+    #
+    # Deletes a child element.
+    #
+    # When 1-based integer argument +index+ is given,
+    # removes and returns the child element at that offset if it exists;
+    # indexing does not include text nodes;
+    # returns +nil+ if the element does not exist:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   a = d.root          # => <a> ... </>
+    #   a.delete_element(1) # => <b/>
+    #   a.delete_element(1) # => <c/>
+    #   a.delete_element(1) # => nil
+    #
+    # When element argument +element+ is given,
+    # removes and returns that child element if it exists,
+    # otherwise returns +nil+:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   a = d.root          # => <a> ... </>
+    #   c = a[2]            # => <c/>
+    #   a.delete_element(c) # => <c/>
+    #   a.delete_element(c) # => nil
+    #
+    # When xpath argument +xpath+ is given,
+    # removes and returns the element at xpath if it exists,
+    # otherwise returns +nil+:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   a = d.root              # => <a> ... </>
+    #   a.delete_element('//c') # => <c/>
+    #   a.delete_element('//c') # => nil
+    #
+    def delete_element element
+      @elements.delete element
+    end
+
+    # :call-seq:
+    #   has_elements?
+    #
+    # Returns +true+ if the element has one or more element children,
+    # +false+ otherwise:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   a = d.root              # => <a> ... </>
+    #   a.has_elements? # => true
+    #   b = a[0]        # => <b/>
+    #   b.has_elements? # => false
+    #
+    def has_elements?
+      !@elements.empty?
+    end
+
+    # :call-seq:
+    #   each_element_with_attribute(attr_name, value = nil, max = 0, xpath = nil) {|e| ... }
+    #
+    # Calls the given block with each child element that meets given criteria.
+    #
+    # When only string argument +attr_name+ is given,
+    # calls the block with each child element that has that attribute:
+    #
+    #   d = REXML::Document.new '<a><b id="1"/><c id="2"/><d id="1"/><e/></a>'
+    #   a = d.root
+    #   a.each_element_with_attribute('id') {|e| p e }
+    #
+    # Output:
+    #
+    #   <b id='1'/>
+    #   <c id='2'/>
+    #   <d id='1'/>
+    #
+    # With argument +attr_name+ and string argument +value+ given,
+    # calls the block with each child element that has that attribute
+    # with that value:
+    #
+    #   a.each_element_with_attribute('id', '1') {|e| p e }
+    #
+    # Output:
+    #
+    #   <b id='1'/>
+    #   <d id='1'/>
+    #
+    # With arguments +attr_name+, +value+, and integer argument +max+ given,
+    # calls the block with at most +max+ child elements:
+    #
+    #   a.each_element_with_attribute('id', '1', 1) {|e| p e }
+    #
+    # Output:
+    #
+    #   <b id='1'/>
+    #
+    # With all arguments given, including +xpath+,
+    # calls the block with only those child elements
+    # that meet the first three criteria,
+    # and also match the given +xpath+:
+    #
+    #   a.each_element_with_attribute('id', '1', 2, '//d') {|e| p e }
+    #
+    # Output:
+    #
+    #   <d id='1'/>
+    #
+    def each_element_with_attribute( key, value=nil, max=0, name=nil, &block ) # :yields: Element
+      each_with_something( proc {|child|
+        if value.nil?
+          child.attributes[key] != nil
+        else
+          child.attributes[key]==value
+        end
+      }, max, name, &block )
+    end
+
+    # :call-seq:
+    #   each_element_with_text(text = nil, max = 0, xpath = nil) {|e| ... }
+    #
+    # Calls the given block with each child element that meets given criteria.
+    #
+    # With no arguments, calls the block with each child element that has text:
+    #
+    #   d = REXML::Document.new '<a><b>b</b><c>b</c><d>d</d><e/></a>'
+    #   a = d.root
+    #   a.each_element_with_text {|e| p e }
+    #
+    # Output:
+    #
+    #   <b> ... </>
+    #   <c> ... </>
+    #   <d> ... </>
+    #
+    # With the single string argument +text+,
+    # calls the block with each element that has exactly that text:
+    #
+    #   a.each_element_with_text('b') {|e| p e }
+    #
+    # Output:
+    #
+    #   <b> ... </>
+    #   <c> ... </>
+    #
+    # With argument +text+ and integer argument +max+,
+    # calls the block with at most +max+ elements:
+    #
+    #   a.each_element_with_text('b', 1) {|e| p e }
+    #
+    # Output:
+    #
+    #   <b> ... </>
+    #
+    # With all arguments given, including +xpath+,
+    # calls the block with only those child elements
+    # that meet the first two criteria,
+    # and also match the given +xpath+:
+    #
+    #   a.each_element_with_text('b', 2, '//c') {|e| p e }
+    #
+    # Output:
+    #
+    #   <c> ... </>
+    #
+    def each_element_with_text( text=nil, max=0, name=nil, &block ) # :yields: Element
+      each_with_something( proc {|child|
+        if text.nil?
+          child.has_text?
+        else
+          child.text == text
+        end
+      }, max, name, &block )
+    end
+
+    # :call-seq:
+    #   each_element {|e| ... }
+    #
+    # Calls the given block with each child element:
+    #
+    #   d = REXML::Document.new '<a><b>b</b><c>b</c><d>d</d><e/></a>'
+    #   a = d.root
+    #   a.each_element {|e| p e }
+    #
+    # Output:
+    #
+    #   <b> ... </>
+    #   <c> ... </>
+    #   <d> ... </>
+    #   <e/>
+    #
+    def each_element( xpath=nil, &block ) # :yields: Element
+      @elements.each( xpath, &block )
+    end
+
+    # :call-seq:
+    #   get_elements(xpath)
+    #
+    # Returns an array of the elements that match the given +xpath+:
+    #
+    #   xml_string = <<-EOT
+    #   <root>
+    #     <a level='1'>
+    #       <a level='2'/>
+    #     </a>
+    #   </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   d.root.get_elements('//a') # => [<a level='1'> ... </>, <a level='2'/>]
+    #
+    def get_elements( xpath )
+      @elements.to_a( xpath )
+    end
+
+    # :call-seq:
+    #   next_element
+    #
+    # Returns the next sibling that is an element if it exists,
+    # +niL+ otherwise:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   d.root.elements['b'].next_element #-> <c/>
+    #   d.root.elements['c'].next_element #-> nil
+    #
+    def next_element
+      element = next_sibling
+      element = element.next_sibling until element.nil? or element.kind_of? Element
+      return element
+    end
+
+    # :call-seq:
+    #   previous_element
+    #
+    # Returns the previous sibling that is an element if it exists,
+    # +niL+ otherwise:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   d.root.elements['c'].previous_element #-> <b/>
+    #   d.root.elements['b'].previous_element #-> nil
+    #
+    def previous_element
+      element = previous_sibling
+      element = element.previous_sibling until element.nil? or element.kind_of? Element
+      return element
+    end
+
+
+    #################################################
+    # Text                                          #
+    #################################################
+
+    # :call-seq:
+    #   has_text? -> true or false
+    #
+    # Returns +true+ if the element has one or more text noded,
+    # +false+ otherwise:
+    #
+    #   d = REXML::Document.new '<a><b/>text<c/></a>'
+    #   a = d.root
+    #   a.has_text? # => true
+    #   b = a[0]
+    #   b.has_text? # => false
+    #
+    def has_text?
+      not text().nil?
+    end
+
+    # :call-seq:
+    #   text(xpath = nil) -> text_string or nil
+    #
+    # Returns the text string from the first text node child
+    # in a specified element, if it exists, +nil+ otherwise.
+    #
+    # With no argument, returns the text from the first text node in +self+:
+    #
+    #   d = REXML::Document.new "<p>some text <b>this is bold!</b> more text</p>"
+    #   d.root.text.class # => String
+    #   d.root.text       # => "some text "
+    #
+    # With argument +xpath+, returns text from the first text node
+    # in the element that matches +xpath+:
+    #
+    #   d.root.text(1) # => "this is bold!"
+    #
+    # Note that an element may have multiple text nodes,
+    # possibly separated by other non-text children, as above.
+    # Even so, the returned value is the string text from the first such node.
+    #
+    # Note also that the text note is retrieved by method get_text,
+    # and so is always normalized text.
+    #
+    def text( path = nil )
+      rv = get_text(path)
+      return rv.value unless rv.nil?
+      nil
+    end
+
+    # :call-seq:
+    #   get_text(xpath = nil) -> text_node or nil
+    #
+    # Returns the first text node child in a specified element, if it exists,
+    # +nil+ otherwise.
+    #
+    # With no argument, returns the first text node from +self+:
+    #
+    #   d = REXML::Document.new "<p>some text <b>this is bold!</b> more text</p>"
+    #   d.root.get_text.class # => REXML::Text
+    #   d.root.get_text       # => "some text "
+    #
+    # With argument +xpath+, returns the first text node from the element
+    # that matches +xpath+:
+    #
+    #   d.root.get_text(1) # => "this is bold!"
+    #
+    def get_text path = nil
+      rv = nil
+      if path
+        element = @elements[ path ]
+        rv = element.get_text unless element.nil?
+      else
+        rv = @children.find { |node| node.kind_of? Text }
+      end
+      return rv
+    end
+
+    # :call-seq:
+    #   text = string -> string
+    #   text = nil -> nil
+    #
+    # Adds, replaces, or removes the first text node child in the element.
+    #
+    # With string argument +string+,
+    # creates a new \REXML::Text node containing that string,
+    # honoring the current settings for whitespace and row,
+    # then places the node as the first text child in the element;
+    # returns +string+.
+    #
+    # If the element has no text child, the text node is added:
+    #
+    #   d = REXML::Document.new '<a><b/></a>'
+    #   d.root.text = 'foo' #-> '<a><b/>foo</a>'
+    #
+    # If the element has a text child, it is replaced:
+    #
+    #   d.root.text = 'bar' #-> '<a><b/>bar</a>'
+    #
+    # With argument +nil+, removes the first text child:
+    #
+    #   d.root.text = nil   #-> '<a><b/><c/></a>'
+    #
+    def text=( text )
+      if text.kind_of? String
+        text = Text.new( text, whitespace(), nil, raw() )
+      elsif !text.nil? and !text.kind_of? Text
+        text = Text.new( text.to_s, whitespace(), nil, raw() )
+      end
+      old_text = get_text
+      if text.nil?
+        old_text.remove unless old_text.nil?
+      else
+        if old_text.nil?
+          self << text
+        else
+          old_text.replace_with( text )
+        end
+      end
+      return self
+    end
+
+    # :call-seq:
+    #   add_text(string) -> nil
+    #   add_text(text_node) -> self
+    #
+    # Adds text to the element.
+    #
+    # When string argument +string+ is given, returns +nil+.
+    #
+    # If the element has no child text node,
+    # creates a \REXML::Text object using the string,
+    # honoring the current settings for whitespace and raw,
+    # then adds that node to the element:
+    #
+    #   d = REXML::Document.new('<a><b/></a>')
+    #   a = d.root
+    #   a.add_text('foo')
+    #   a.to_a # => [<b/>, "foo"]
+    #
+    # If the element has child text nodes,
+    # appends the string to the _last_ text node:
+    #
+    #   d = REXML::Document.new('<a>foo<b/>bar</a>')
+    #   a = d.root
+    #   a.add_text('baz')
+    #   a.to_a # => ["foo", <b/>, "barbaz"]
+    #   a.add_text('baz')
+    #   a.to_a # => ["foo", <b/>, "barbazbaz"]
+    #
+    # When text node argument +text_node+ is given,
+    # appends the node as the last text node in the element;
+    # returns +self+:
+    #
+    #   d = REXML::Document.new('<a>foo<b/>bar</a>')
+    #   a = d.root
+    #   a.add_text(REXML::Text.new('baz'))
+    #   a.to_a # => ["foo", <b/>, "bar", "baz"]
+    #   a.add_text(REXML::Text.new('baz'))
+    #   a.to_a # => ["foo", <b/>, "bar", "baz", "baz"]
+    #
+    def add_text( text )
+      if text.kind_of? String
+        if @children[-1].kind_of? Text
+          @children[-1] << text
+          return
+        end
+        text = Text.new( text, whitespace(), nil, raw() )
+      end
+      self << text unless text.nil?
+      return self
+    end
+
+    # :call-seq:
+    #   node_type -> :element
+    #
+    # Returns symbol <tt>:element</tt>:
+    #
+    #   d = REXML::Document.new('<a/>')
+    #   a = d.root  # => <a/>
+    #   a.node_type # => :element
+    #
+    def node_type
+      :element
+    end
+
+    # :call-seq:
+    #   xpath -> string_xpath
+    #
+    # Returns the string xpath to the element
+    # relative to the most distant parent:
+    #
+    #   d = REXML::Document.new('<a><b><c/></b></a>')
+    #   a = d.root # => <a> ... </>
+    #   b = a[0]   # => <b> ... </>
+    #   c = b[0]   # => <c/>
+    #   d.xpath    # => ""
+    #   a.xpath    # => "/a"
+    #   b.xpath    # => "/a/b"
+    #   c.xpath    # => "/a/b/c"
+    #
+    # If there is no parent, returns the expanded name of the element:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.xpath    # => "foo"
+    #
+    def xpath
+      path_elements = []
+      cur = self
+      path_elements << __to_xpath_helper( self )
+      while cur.parent
+        cur = cur.parent
+        path_elements << __to_xpath_helper( cur )
+      end
+      return path_elements.reverse.join( "/" )
+    end
+
+    #################################################
+    # Attributes                                    #
+    #################################################
+
+    # :call-seq:
+    #   [index] -> object
+    #   [attr_name] -> attr_value
+    #   [attr_sym] -> attr_value
+    #
+    # With integer argument +index+ given,
+    # returns the child at offset +index+, or +nil+ if none:
+    #
+    #   d = REXML::Document.new '><root><a/>text<b/>more<c/></root>'
+    #   root = d.root
+    #   (0..root.size).each do |index|
+    #     node = root[index]
+    #     p "#{index}: #{node} (#{node.class})"
+    #   end
+    #
+    # Output:
+    #
+    #   "0: <a/> (REXML::Element)"
+    #   "1: text (REXML::Text)"
+    #   "2: <b/> (REXML::Element)"
+    #   "3: more (REXML::Text)"
+    #   "4: <c/> (REXML::Element)"
+    #   "5:  (NilClass)"
+    #
+    # With string argument +attr_name+ given,
+    # returns the string value for the given attribute name if it exists,
+    # otherwise +nil+:
+    #
+    #   d = REXML::Document.new('<root attr="value"></root>')
+    #   root = d.root
+    #   root['attr']   # => "value"
+    #   root['nosuch'] # => nil
+    #
+    # With symbol argument +attr_sym+ given,
+    # returns <tt>[attr_sym.to_s]</tt>:
+    #
+    #   root[:attr]   # => "value"
+    #   root[:nosuch] # => nil
+    #
+    def [](name_or_index)
+      case name_or_index
+      when String
+        attributes[name_or_index]
+      when Symbol
+        attributes[name_or_index.to_s]
+      else
+        super
+      end
+    end
+
+
+    # :call-seq:
+    #   attribute(name, namespace = nil)
+    #
+    # Returns the string value for the given attribute name.
+    #
+    # With only argument +name+ given,
+    # returns the value of the named attribute if it exists, otherwise +nil+:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns="ns0">
+    #       <a xmlns="ns1" attr="value"></a>
+    #       <b xmlns="ns2" attr="value"></b>
+    #       <c attr="value"/>
+    #    </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   root = d.root
+    #   a = root[1] # => <a xmlns='ns1' attr='value'/>
+    #   a.attribute('attr') # => attr='value'
+    #   a.attribute('nope') # => nil
+    #
+    # With arguments +name+ and +namespace+ given,
+    # returns the value of the named attribute if it exists, otherwise +nil+:
+    #
+    #   xml_string = "<root xmlns:a='a' a:x='a:x' x='x'/>"
+    #   document = REXML::Document.new(xml_string)
+    #   document.root.attribute("x")      # => x='x'
+    #   document.root.attribute("x", "a") # => a:x='a:x'
+    #
+    def attribute( name, namespace=nil )
+      prefix = namespaces.key(namespace) if namespace
+      prefix = nil if prefix == 'xmlns'
+
+      ret_val =
+        attributes.get_attribute( prefix ? "#{prefix}:#{name}" : name )
+
+      return ret_val unless ret_val.nil?
+      return nil if prefix.nil?
+
+      # now check that prefix'es namespace is not the same as the
+      # default namespace
+      return nil unless ( namespaces[ prefix ] == namespaces[ 'xmlns' ] )
+
+      attributes.get_attribute( name )
+
+    end
+
+    # :call-seq:
+    #   has_attributes? -> true or false
+    #
+    # Returns +true+ if the element has attributes, +false+ otherwise:
+    #
+    #   d = REXML::Document.new('<root><a attr="val"/><b/></root>')
+    #   a, b = *d.root
+    #   a.has_attributes? # => true
+    #   b.has_attributes? # => false
+    #
+    def has_attributes?
+      return !@attributes.empty?
+    end
+
+    # :call-seq:
+    #   add_attribute(name, value) -> value
+    #   add_attribute(attribute) -> attribute
+    #
+    # Adds an attribute to this element, overwriting any existing attribute
+    # by the same name.
+    #
+    # With string argument +name+ and object +value+ are given,
+    # adds the attribute created with that name and value:
+    #
+    #   e = REXML::Element.new
+    #   e.add_attribute('attr', 'value') # => "value"
+    #   e['attr'] # => "value"
+    #   e.add_attribute('attr', 'VALUE') # => "VALUE"
+    #   e['attr'] # => "VALUE"
+    #
+    # With only attribute object +attribute+ given,
+    # adds the given attribute:
+    #
+    #   a = REXML::Attribute.new('attr', 'value')
+    #   e.add_attribute(a) # => attr='value'
+    #   e['attr'] # => "value"
+    #   a = REXML::Attribute.new('attr', 'VALUE')
+    #   e.add_attribute(a) # => attr='VALUE'
+    #   e['attr'] # => "VALUE"
+    #
+    def add_attribute( key, value=nil )
+      if key.kind_of? Attribute
+        @attributes << key
+      else
+        @attributes[key] = value
+      end
+    end
+
+    # :call-seq:
+    #   add_attributes(hash) -> hash
+    #   add_attributes(array)
+    #
+    # Adds zero or more attributes to the element;
+    # returns the argument.
+    #
+    # If hash argument +hash+ is given,
+    # each key must be a string;
+    # adds each attribute created with the key/value pair:
+    #
+    #   e = REXML::Element.new
+    #   h = {'foo' => 'bar', 'baz' => 'bat'}
+    #   e.add_attributes(h)
+    #
+    # If argument +array+ is given,
+    # each array member must be a 2-element array <tt>[name, value];
+    # each name must be a string:
+    #
+    #   e = REXML::Element.new
+    #   a = [['foo' => 'bar'], ['baz' => 'bat']]
+    #   e.add_attributes(a)
+    #
+    def add_attributes hash
+      if hash.kind_of? Hash
+        hash.each_pair {|key, value| @attributes[key] = value }
+      elsif hash.kind_of? Array
+        hash.each { |value| @attributes[ value[0] ] = value[1] }
+      end
+    end
+
+    # :call-seq:
+    #   delete_attribute(name) -> removed_attribute or nil
+    #
+    # Removes a named attribute if it exists;
+    # returns the removed attribute if found, otherwise +nil+:
+    #
+    #   e = REXML::Element.new('foo')
+    #   e.add_attribute('bar', 'baz')
+    #   e.delete_attribute('bar') # => <bar/>
+    #   e.delete_attribute('bar') # => nil
+    #
+    def delete_attribute(key)
+      attr = @attributes.get_attribute(key)
+      attr.remove unless attr.nil?
+    end
+
+    #################################################
+    # Other Utilities                               #
+    #################################################
+
+    # :call-seq:
+    #   cdatas -> array_of_cdata_children
+    #
+    # Returns a frozen array of the REXML::CData children of the element:
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #       <![CDATA[foo]]>
+    #       <![CDATA[bar]]>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   cds = d.root.cdatas      # => ["foo", "bar"]
+    #   cds.frozen?              # => true
+    #   cds.map {|cd| cd.class } # => [REXML::CData, REXML::CData]
+    #
+    def cdatas
+      find_all { |child| child.kind_of? CData }.freeze
+    end
+
+    # :call-seq:
+    #   comments -> array_of_comment_children
+    #
+    # Returns a frozen array of the REXML::Comment children of the element:
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #       <!--foo-->
+    #       <!--bar-->
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   cs = d.root.comments
+    #   cs.frozen?            # => true
+    #   cs.map {|c| c.class } # => [REXML::Comment, REXML::Comment]
+    #   cs.map {|c| c.to_s }  # => ["foo", "bar"]
+    #
+    def comments
+      find_all { |child| child.kind_of? Comment }.freeze
+    end
+
+    # :call-seq:
+    #   instructions -> array_of_instruction_children
+    #
+    # Returns a frozen array of the REXML::Instruction children of the element:
+    #
+    #   xml_string = <<-EOT
+    #     <root>
+    #       <?target0 foo?>
+    #       <?target1 bar?>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   is = d.root.instructions
+    #   is.frozen?             # => true
+    #   is.map {|i| i.class } # => [REXML::Instruction, REXML::Instruction]
+    #   is.map {|i| i.to_s }  # => ["<?target0 foo?>", "<?target1 bar?>"]
+    #
+    def instructions
+      find_all { |child| child.kind_of? Instruction }.freeze
+    end
+
+    # :call-seq:
+    #   texts -> array_of_text_children
+    #
+    # Returns a frozen array of the REXML::Text children of the element:
+    #
+    #   xml_string = '<root><a/>text<b/>more<c/></root>'
+    #   d = REXML::Document.new(xml_string)
+    #   ts = d.root.texts
+    #   ts.frozen?            # => true
+    #   ts.map {|t| t.class } # => [REXML::Text, REXML::Text]
+    #   ts.map {|t| t.to_s }  # => ["text", "more"]
+    #
+    def texts
+      find_all { |child| child.kind_of? Text }.freeze
+    end
+
+    # == DEPRECATED
+    # See REXML::Formatters
+    #
+    # Writes out this element, and recursively, all children.
+    # output::
+    #     output an object which supports '<< string'; this is where the
+    #   document will be written.
+    # indent::
+    #   An integer.  If -1, no indenting will be used; otherwise, the
+    #   indentation will be this number of spaces, and children will be
+    #   indented an additional amount.  Defaults to -1
+    # transitive::
+    #   If transitive is true and indent is >= 0, then the output will be
+    #   pretty-printed in such a way that the added whitespace does not affect
+    #   the parse tree of the document
+    # ie_hack::
+    #   This hack inserts a space before the /> on empty tags to address
+    #   a limitation of Internet Explorer.  Defaults to false
+    #
+    #  out = ''
+    #  doc.write( out )     #-> doc is written to the string 'out'
+    #  doc.write( $stdout ) #-> doc written to the console
+    def write(output=$stdout, indent=-1, transitive=false, ie_hack=false)
+      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters", uplevel: 1)
+      formatter = if indent > -1
+          if transitive
+            require_relative "formatters/transitive"
+            REXML::Formatters::Transitive.new( indent, ie_hack )
+          else
+            REXML::Formatters::Pretty.new( indent, ie_hack )
+          end
+        else
+          REXML::Formatters::Default.new( ie_hack )
+        end
+      formatter.write( self, output )
+    end
+
+
+    private
+    def __to_xpath_helper node
+      rv = node.expanded_name.clone
+      if node.parent
+        results = node.parent.find_all {|n|
+          n.kind_of?(REXML::Element) and n.expanded_name == node.expanded_name
+        }
+        if results.length > 1
+          idx = results.index( node )
+          rv << "[#{idx+1}]"
+        end
+      end
+      rv
+    end
+
+    # A private helper method
+    def each_with_something( test, max=0, name=nil )
+      num = 0
+      @elements.each( name ){ |child|
+        yield child if test.call(child) and num += 1
+        return if max>0 and num == max
+      }
+    end
+  end
+
+  ########################################################################
+  # ELEMENTS                                                             #
+  ########################################################################
+
+  # A class which provides filtering of children for Elements, and
+  # XPath search support.  You are expected to only encounter this class as
+  # the <tt>element.elements</tt> object.  Therefore, you are
+  # _not_ expected to instantiate this yourself.
+  #
+  #   xml_string = <<-EOT
+  #   <?xml version="1.0" encoding="UTF-8"?>
+  #   <bookstore>
+  #     <book category="cooking">
+  #       <title lang="en">Everyday Italian</title>
+  #       <author>Giada De Laurentiis</author>
+  #       <year>2005</year>
+  #       <price>30.00</price>
+  #     </book>
+  #     <book category="children">
+  #       <title lang="en">Harry Potter</title>
+  #       <author>J K. Rowling</author>
+  #       <year>2005</year>
+  #       <price>29.99</price>
+  #     </book>
+  #     <book category="web">
+  #       <title lang="en">XQuery Kick Start</title>
+  #       <author>James McGovern</author>
+  #       <author>Per Bothner</author>
+  #       <author>Kurt Cagle</author>
+  #       <author>James Linn</author>
+  #       <author>Vaidyanathan Nagarajan</author>
+  #       <year>2003</year>
+  #       <price>49.99</price>
+  #     </book>
+  #     <book category="web" cover="paperback">
+  #       <title lang="en">Learning XML</title>
+  #       <author>Erik T. Ray</author>
+  #       <year>2003</year>
+  #       <price>39.95</price>
+  #     </book>
+  #   </bookstore>
+  #   EOT
+  #   d = REXML::Document.new(xml_string)
+  #   elements = d.root.elements
+  #   elements # => #<REXML::Elements @element=<bookstore> ... </>>
+  #
+  class Elements
+    include Enumerable
+    # :call-seq:
+    #   new(parent) -> new_elements_object
+    #
+    # Returns a new \Elements object with the given +parent+.
+    # Does _not_ assign <tt>parent.elements = self</tt>:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   eles = REXML::Elements.new(d.root)
+    #   eles # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles == d.root.elements # => false
+    #
+    def initialize parent
+      @element = parent
+    end
+
+    # :call-seq:
+    #   parent
+    #
+    # Returns the parent element cited in creating the \Elements object.
+    # This element is also the default starting point for searching
+    # in the \Elements object.
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = REXML::Elements.new(d.root)
+    #   elements.parent == d.root # => true
+    #
+    def parent
+      @element
+    end
+
+    # :call-seq:
+    #   elements[index] -> element or nil
+    #   elements[xpath] -> element or nil
+    #   elements[n, name] -> element or nil
+    #
+    # Returns the first \Element object selected by the arguments,
+    # if any found, or +nil+ if none found.
+    #
+    # Notes:
+    # - The +index+ is 1-based, not 0-based, so that:
+    #   - The first element has index <tt>1</tt>
+    #   - The _nth_ element has index +n+.
+    # - The selection ignores non-\Element nodes.
+    #
+    # When the single argument +index+ is given,
+    # returns the element given by the index, if any; otherwise, +nil+:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   eles = d.root.elements
+    #   eles # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles[1] # => <book category='cooking'> ... </>
+    #   eles.size # => 4
+    #   eles[4] # => <book category='web' cover='paperback'> ... </>
+    #   eles[5] # => nil
+    #
+    # The node at this index is not an \Element, and so is not returned:
+    #
+    #   eles = d.root.first.first # => <title lang='en'> ... </>
+    #   eles.to_a # => ["Everyday Italian"]
+    #   eles[1] # => nil
+    #
+    # When the single argument +xpath+ is given,
+    # returns the first element found via that +xpath+, if any; otherwise, +nil+:
+    #
+    #   eles = d.root.elements # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles['/bookstore']                    # => <bookstore> ... </>
+    #   eles['//book']                        # => <book category='cooking'> ... </>
+    #   eles['//book [@category="children"]'] # => <book category='children'> ... </>
+    #   eles['/nosuch']                       # => nil
+    #   eles['//nosuch']                      # => nil
+    #   eles['//book [@category="nosuch"]']   # => nil
+    #   eles['.']                             # => <bookstore> ... </>
+    #   eles['..'].class                      # => REXML::Document
+    #
+    # With arguments +n+ and +name+ given,
+    # returns the _nth_ found element that has the given +name+,
+    # or +nil+ if there is no such _nth_ element:
+    #
+    #   eles = d.root.elements # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles[1, 'book'] # => <book category='cooking'> ... </>
+    #   eles[4, 'book'] # => <book category='web' cover='paperback'> ... </>
+    #   eles[5, 'book'] # => nil
+    #
+    def []( index, name=nil)
+      if index.kind_of? Integer
+        raise "index (#{index}) must be >= 1" if index < 1
+        name = literalize(name) if name
+        num = 0
+        @element.find { |child|
+          child.kind_of? Element and
+          (name.nil? ? true : child.has_name?( name )) and
+          (num += 1) == index
+        }
+      else
+        return XPath::first( @element, index )
+        #{ |element|
+        #       return element if element.kind_of? Element
+        #}
+        #return nil
+      end
+    end
+
+    # :call-seq:
+    #  elements[] = index, replacement_element -> replacement_element or nil
+    #
+    # Replaces or adds an element.
+    #
+    # When <tt>eles[index]</tt> exists, replaces it with +replacement_element+
+    # and returns +replacement_element+:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   eles = d.root.elements # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles[1] # => <book category='cooking'> ... </>
+    #   eles[1] = REXML::Element.new('foo')
+    #   eles[1] # => <foo/>
+    #
+    # Does nothing (or raises an exception)
+    # if +replacement_element+ is not an \Element:
+    #   eles[2] # => <book category='web' cover='paperback'> ... </>
+    #   eles[2] = REXML::Text.new('bar')
+    #   eles[2] # => <book category='web' cover='paperback'> ... </>
+    #
+    # When <tt>eles[index]</tt> does not exist,
+    # adds +replacement_element+ to the element and returns
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   eles = d.root.elements # => #<REXML::Elements @element=<bookstore> ... </>>
+    #   eles.size # => 4
+    #   eles[50] = REXML::Element.new('foo') # => <foo/>
+    #   eles.size # => 5
+    #   eles[5] # => <foo/>
+    #
+    # Does nothing (or raises an exception)
+    # if +replacement_element+ is not an \Element:
+    #
+    #   eles[50] = REXML::Text.new('bar') # => "bar"
+    #   eles.size # => 5
+    #
+    def []=( index, element )
+      previous = self[index]
+      if previous.nil?
+        @element.add element
+      else
+        previous.replace_with element
+      end
+      return previous
+    end
+
+    # :call-seq:
+    #   empty? -> true or false
+    #
+    # Returns +true+ if there are no children, +false+ otherwise.
+    #
+    #   d = REXML::Document.new('')
+    #   d.elements.empty? # => true
+    #   d = REXML::Document.new(xml_string)
+    #   d.elements.empty? # => false
+    #
+    def empty?
+      @element.find{ |child| child.kind_of? Element}.nil?
+    end
+
+    # :call-seq:
+    #   index(element)
+    #
+    # Returns the 1-based index of the given +element+, if found;
+    # otherwise, returns -1:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   ele_1, ele_2, ele_3, ele_4 = *elements
+    #   elements.index(ele_4) # => 4
+    #   elements.delete(ele_3)
+    #   elements.index(ele_4) # => 3
+    #   elements.index(ele_3) # => -1
+    #
+    def index element
+      rv = 0
+      found = @element.find do |child|
+        child.kind_of? Element and
+        (rv += 1) and
+        child == element
+      end
+      return rv if found == element
+      return -1
+    end
+
+    # :call-seq:
+    #   delete(index) -> removed_element or nil
+    #   delete(element) -> removed_element or nil
+    #   delete(xpath) -> removed_element or nil
+    #
+    # Removes an element; returns the removed element, or +nil+ if none removed.
+    #
+    # With integer argument +index+ given,
+    # removes the child element at that offset:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.size # => 4
+    #   elements[2] # => <book category='children'> ... </>
+    #   elements.delete(2) # => <book category='children'> ... </>
+    #   elements.size # => 3
+    #   elements[2] # => <book category='web'> ... </>
+    #   elements.delete(50) # => nil
+    #
+    # With element argument +element+ given,
+    # removes that child element:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   ele_1, ele_2, ele_3, ele_4 = *elements
+    #   elements.size # => 4
+    #   elements[2] # => <book category='children'> ... </>
+    #   elements.delete(ele_2) # => <book category='children'> ... </>
+    #   elements.size # => 3
+    #   elements[2] # => <book category='web'> ... </>
+    #   elements.delete(ele_2) # => nil
+    #
+    # With string argument +xpath+ given,
+    # removes the first element found via that xpath:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.delete('//book') # => <book category='cooking'> ... </>
+    #   elements.delete('//book [@category="children"]') # => <book category='children'> ... </>
+    #   elements.delete('//nosuch') # => nil
+    #
+    def delete element
+      if element.kind_of? Element
+        @element.delete element
+      else
+        el = self[element]
+        el.remove if el
+      end
+    end
+
+    # :call-seq:
+    #   delete_all(xpath)
+    #
+    # Removes all elements found via the given +xpath+;
+    # returns the array of removed elements, if any, else +nil+.
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.size # => 4
+    #   deleted_elements = elements.delete_all('//book [@category="web"]')
+    #   deleted_elements.size # => 2
+    #   elements.size # => 2
+    #   deleted_elements = elements.delete_all('//book')
+    #   deleted_elements.size # => 2
+    #   elements.size # => 0
+    #   elements.delete_all('//book') # => []
+    #
+    def delete_all( xpath )
+      rv = []
+      XPath::each( @element, xpath) {|element|
+        rv << element if element.kind_of? Element
+      }
+      rv.each do |element|
+        @element.delete element
+        element.remove
+      end
+      return rv
+    end
+
+    # :call-seq:
+    #   add -> new_element
+    #   add(name) -> new_element
+    #   add(element) -> element
+    #
+    # Adds an element; returns the element added.
+    #
+    # With no argument, creates and adds a new element.
+    # The new element has:
+    #
+    # - No name.
+    # - \Parent from the \Elements object.
+    # - Context from the that parent.
+    #
+    # Example:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   parent = elements.parent     # => <bookstore> ... </>
+    #   parent.context = {raw: :all}
+    #   elements.size                # => 4
+    #   new_element = elements.add   # => </>
+    #   elements.size                # => 5
+    #   new_element.name             # => nil
+    #   new_element.parent           # => <bookstore> ... </>
+    #   new_element.context          # => {:raw=>:all}
+    #
+    # With string argument +name+, creates and adds a new element.
+    # The new element has:
+    #
+    # - Name +name+.
+    # - \Parent from the \Elements object.
+    # - Context from the that parent.
+    #
+    # Example:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   parent = elements.parent          # => <bookstore> ... </>
+    #   parent.context = {raw: :all}
+    #   elements.size                     # => 4
+    #   new_element = elements.add('foo') # => <foo/>
+    #   elements.size                     # => 5
+    #   new_element.name                  # => "foo"
+    #   new_element.parent                # => <bookstore> ... </>
+    #   new_element.context               # => {:raw=>:all}
+    #
+    # With argument +element+,
+    # creates and adds a clone of the given +element+.
+    # The new element has name, parent, and context from the given +element+.
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.size                 # => 4
+    #   e0 = REXML::Element.new('foo')
+    #   e1 = REXML::Element.new('bar', e0, {raw: :all})
+    #   element = elements.add(e1) # => <bar/>
+    #   elements.size                 # => 5
+    #   element.name                  # => "bar"
+    #   element.parent                # => <bookstore> ... </>
+    #   element.context               # => {:raw=>:all}
+    #
+    def add element=nil
+      if element.nil?
+        Element.new("", self, @element.context)
+      elsif not element.kind_of?(Element)
+        Element.new(element, self, @element.context)
+      else
+        @element << element
+        element.context = @element.context
+        element
+      end
+    end
+
+    alias :<< :add
+
+    # :call-seq:
+    #    each(xpath = nil) {|element| ... } -> self
+    #
+    # Iterates over the elements.
+    #
+    # With no argument, calls the block with each element:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.each {|element| p element }
+    #
+    # Output:
+    #
+    #   <book category='cooking'> ... </>
+    #   <book category='children'> ... </>
+    #   <book category='web'> ... </>
+    #   <book category='web' cover='paperback'> ... </>
+    #
+    # With argument +xpath+, calls the block with each element
+    # that matches the given +xpath+:
+    #
+    #   elements.each('//book [@category="web"]') {|element| p element }
+    #
+    # Output:
+    #
+    #   <book category='web'> ... </>
+    #   <book category='web' cover='paperback'> ... </>
+    #
+    def each( xpath=nil )
+      XPath::each( @element, xpath ) {|e| yield e if e.kind_of? Element }
+    end
+
+    # :call-seq:
+    #   collect(xpath = nil) {|element| ... } -> array
+    #
+    # Iterates over the elements; returns the array of block return values.
+    #
+    # With no argument, iterates over all elements:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.collect {|element| element.size } # => [9, 9, 17, 9]
+    #
+    # With argument +xpath+, iterates over elements that match
+    # the given +xpath+:
+    #
+    #   xpath = '//book [@category="web"]'
+    #   elements.collect(xpath) {|element| element.size } # => [17, 9]
+    #
+    def collect( xpath=nil )
+      collection = []
+      XPath::each( @element, xpath ) {|e|
+        collection << yield(e)  if e.kind_of?(Element)
+      }
+      collection
+    end
+
+    # :call-seq:
+    #   inject(xpath = nil, initial = nil) -> object
+    #
+    # Calls the block with elements; returns the last block return value.
+    #
+    # With no argument, iterates over the elements, calling the block
+    # <tt>elements.size - 1</tt> times.
+    #
+    # - The first call passes the first and second elements.
+    # - The second call passes the first block return value and the third element.
+    # - The third call passes the second block return value and the fourth element.
+    # - And so on.
+    #
+    # In this example, the block returns the passed element,
+    # which is then the object argument to the next call:
+    #
+    #   d = REXML::Document.new(xml_string)
+    #   elements = d.root.elements
+    #   elements.inject do |object, element|
+    #     p [elements.index(object), elements.index(element)]
+    #     element
+    #   end
+    #
+    # Output:
+    #
+    #   [1, 2]
+    #   [2, 3]
+    #   [3, 4]
+    #
+    # With the single argument +xpath+, calls the block only with
+    # elements matching that xpath:
+    #
+    #   elements.inject('//book [@category="web"]') do |object, element|
+    #     p [elements.index(object), elements.index(element)]
+    #     element
+    #   end
+    #
+    # Output:
+    #
+    #  [3, 4]
+    #
+    # With argument +xpath+ given as +nil+
+    # and argument +initial+ also given,
+    # calls the block once for each element.
+    #
+    # - The first call passes the +initial+ and the first element.
+    # - The second call passes the first block return value and the second element.
+    # - The third call passes the second block return value and the third element.
+    # - And so on.
+    #
+    # In this example, the first object index is <tt>-1</tt>
+    #
+    #   elements.inject(nil, 'Initial') do |object, element|
+    #     p [elements.index(object), elements.index(element)]
+    #     element
+    #   end
+    #
+    # Output:
+    #
+    #   [-1, 1]
+    #   [1, 2]
+    #   [2, 3]
+    #   [3, 4]
+    #
+    # In this form the passed object can be used as an accumulator:
+    #
+    #   elements.inject(nil, 0) do |total, element|
+    #     total += element.size
+    #   end # => 44
+    #
+    # With both arguments +xpath+ and +initial+ are given,
+    # calls the block only with elements matching that xpath:
+    #
+    #   elements.inject('//book [@category="web"]', 0) do |total, element|
+    #     total += element.size
+    #   end # => 26
+    #
+    def inject( xpath=nil, initial=nil )
+      first = true
+      XPath::each( @element, xpath ) {|e|
+        if (e.kind_of? Element)
+          if (first and initial == nil)
+            initial = e
+            first = false
+          else
+            initial = yield( initial, e ) if e.kind_of? Element
+          end
+        end
+      }
+      initial
+    end
+
+    # :call-seq:
+    #   size -> integer
+    #
+    # Returns the count of \Element children:
+    #
+    #   d = REXML::Document.new '<a>sean<b/>elliott<b/>russell<b/></a>'
+    #   d.root.elements.size # => 3 # Three elements.
+    #   d.root.size          # => 6 # Three elements plus three text nodes..
+    #
+    def size
+      count = 0
+      @element.each {|child| count+=1 if child.kind_of? Element }
+      count
+    end
+
+    # :call-seq:
+    #   to_a(xpath = nil) -> array_of_elements
+    #
+    # Returns an array of element children (not including non-element children).
+    #
+    # With no argument, returns an array of all element children:
+    #
+    #   d = REXML::Document.new '<a>sean<b/>elliott<c/></a>'
+    #   elements = d.root.elements
+    #   elements.to_a # => [<b/>, <c/>]               # Omits non-element children.
+    #   children = d.root.children
+    #   children # => ["sean", <b/>, "elliott", <c/>] # Includes non-element children.
+    #
+    # With argument +xpath+, returns an array of element children
+    # that match the xpath:
+    #
+    #   elements.to_a('//c') # => [<c/>]
+    #
+    def to_a( xpath=nil )
+      rv = XPath.match( @element, xpath )
+      return rv.find_all{|e| e.kind_of? Element} if xpath
+      rv
+    end
+
+    private
+    # Private helper class.  Removes quotes from quoted strings
+    def literalize name
+      name = name[1..-2] if name[0] == ?' or name[0] == ?"               #'
+      name
+    end
+  end
+
+  ########################################################################
+  # ATTRIBUTES                                                           #
+  ########################################################################
+
+  # A class that defines the set of Attributes of an Element and provides
+  # operations for accessing elements in that set.
+  class Attributes < Hash
+
+    # :call-seq:
+    #   new(element)
+    #
+    # Creates and returns a new \REXML::Attributes object.
+    # The element given by argument +element+ is stored,
+    # but its own attributes are not modified:
+    #
+    #   ele = REXML::Element.new('foo')
+    #   attrs = REXML::Attributes.new(ele)
+    #   attrs.object_id == ele.attributes.object_id # => false
+    #
+    # Other instance methods in class \REXML::Attributes may refer to:
+    #
+    # - +element.document+.
+    # - +element.prefix+.
+    # - +element.expanded_name+.
+    #
+    def initialize element
+      @element = element
+    end
+
+    # :call-seq:
+    #   [name] -> attribute_value or nil
+    #
+    # Returns the value for the attribute given by +name+,
+    # if it exists; otherwise +nil+.
+    # The value returned is the unnormalized attribute value,
+    # with entities expanded:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   ele.attributes['att']     # => "<"
+    #   ele.attributes['bar:att'] # => "2"
+    #   ele.attributes['nosuch']  # => nil
+    #
+    # Related: get_attribute (returns an \Attribute object).
+    #
+    def [](name)
+      attr = get_attribute(name)
+      return attr.value unless attr.nil?
+      return nil
+    end
+
+    # :call-seq:
+    #   to_a -> array_of_attribute_objects
+    #
+    # Returns an array of \REXML::Attribute objects representing
+    # the attributes:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele']   # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes.to_a      # => [foo:att='1', bar:att='2', att='&lt;']
+    #   attrs.first.class                # => REXML::Attribute
+    #
+    def to_a
+      enum_for(:each_attribute).to_a
+    end
+
+    # :call-seq:
+    #   length
+    #
+    # Returns the count of attributes:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele']   # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   ele.attributes.length # => 3
+    #
+    def length
+      c = 0
+      each_attribute { c+=1 }
+      c
+    end
+    alias :size :length
+
+    # :call-seq:
+    #   each_attribute {|attr| ... }
+    #
+    # Calls the given block with each \REXML::Attribute object:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele']   # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   ele.attributes.each_attribute do |attr|
+    #     p [attr.class, attr]
+    #   end
+    #
+    # Output:
+    #
+    #   [REXML::Attribute, foo:att='1']
+    #   [REXML::Attribute, bar:att='2']
+    #   [REXML::Attribute, att='&lt;']
+    #
+    def each_attribute # :yields: attribute
+      return to_enum(__method__) unless block_given?
+      each_value do |val|
+        if val.kind_of? Attribute
+          yield val
+        else
+          val.each_value { |atr| yield atr }
+        end
+      end
+    end
+
+    # :call-seq:
+    #   each {|expanded_name, value| ... }
+    #
+    # Calls the given block with each expanded-name/value pair:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele']   # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   ele.attributes.each do |expanded_name, value|
+    #     p [expanded_name, value]
+    #   end
+    #
+    # Output:
+    #
+    #   ["foo:att", "1"]
+    #   ["bar:att", "2"]
+    #   ["att", "<"]
+    #
+    def each
+      return to_enum(__method__) unless block_given?
+      each_attribute do |attr|
+        yield [attr.expanded_name, attr.value]
+      end
+    end
+
+    # :call-seq:
+    #   get_attribute(name) -> attribute_object or nil
+    #
+    # Returns the \REXML::Attribute object for the given +name+:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs.get_attribute('foo:att')       # => foo:att='1'
+    #   attrs.get_attribute('foo:att').class # => REXML::Attribute
+    #   attrs.get_attribute('bar:att')       # => bar:att='2'
+    #   attrs.get_attribute('att')           # => att='&lt;'
+    #   attrs.get_attribute('nosuch')        # => nil
+    #
+    def get_attribute( name )
+      attr = fetch( name, nil )
+      if attr.nil?
+        return nil if name.nil?
+        # Look for prefix
+        name =~ Namespace::NAMESPLIT
+        prefix, n = $1, $2
+        if prefix
+          attr = fetch( n, nil )
+          # check prefix
+          if attr == nil
+          elsif attr.kind_of? Attribute
+            return attr if prefix == attr.prefix
+          else
+            attr = attr[ prefix ]
+            return attr
+          end
+        end
+        element_document = @element.document
+        if element_document and element_document.doctype
+          expn = @element.expanded_name
+          expn = element_document.doctype.name if expn.size == 0
+          attr_val = element_document.doctype.attribute_of(expn, name)
+          return Attribute.new( name, attr_val ) if attr_val
+        end
+        return nil
+      end
+      if attr.kind_of? Hash
+        attr = attr[ @element.prefix ]
+      end
+      return attr
+    end
+
+    # :call-seq:
+    #   [name] = value -> value
+    #
+    # When +value+ is non-+nil+,
+    # assigns that to the attribute for the given +name+,
+    # overwriting the previous value if it exists:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs['foo:att'] = '2' # => "2"
+    #   attrs['baz:att'] = '3' # => "3"
+    #
+    # When +value+ is +nil+, deletes the attribute if it exists:
+    #
+    #   attrs['baz:att'] = nil
+    #   attrs.include?('baz:att') # => false
+    #
+    def []=( name, value )
+      if value.nil?             # Delete the named attribute
+        attr = get_attribute(name)
+        delete attr
+        return
+      end
+
+      unless value.kind_of? Attribute
+        if @element.document and @element.document.doctype
+          value = Text::normalize( value, @element.document.doctype )
+        else
+          value = Text::normalize( value, nil )
+        end
+        value = Attribute.new(name, value)
+      end
+      value.element = @element
+      old_attr = fetch(value.name, nil)
+      if old_attr.nil?
+        store(value.name, value)
+      elsif old_attr.kind_of? Hash
+        old_attr[value.prefix] = value
+      elsif old_attr.prefix != value.prefix
+        store value.name, {old_attr.prefix => old_attr,
+                           value.prefix    => value}
+      else
+        store value.name, value
+      end
+      return @element
+    end
+
+    # :call-seq:
+    #   prefixes -> array_of_prefix_strings
+    #
+    # Returns an array of prefix strings in the attributes.
+    # The array does not include the default
+    # namespace declaration, if one exists.
+    #
+    #   xml_string = '<a xmlns="foo" xmlns:x="bar" xmlns:y="twee" z="glorp"/>'
+    #   d = REXML::Document.new(xml_string)
+    #   d.root.attributes.prefixes # => ["x", "y"]
+    #
+    def prefixes
+      ns = []
+      each_attribute do |attribute|
+        ns << attribute.name if attribute.prefix == 'xmlns'
+      end
+      if @element.document and @element.document.doctype
+        expn = @element.expanded_name
+        expn = @element.document.doctype.name if expn.size == 0
+        @element.document.doctype.attributes_of(expn).each {
+          |attribute|
+          ns << attribute.name if attribute.prefix == 'xmlns'
+        }
+      end
+      ns
+    end
+
+    # :call-seq:
+    #   namespaces
+    #
+    # Returns a hash of name/value pairs for the namespaces:
+    #
+    #   xml_string = '<a xmlns="foo" xmlns:x="bar" xmlns:y="twee" z="glorp"/>'
+    #   d = REXML::Document.new(xml_string)
+    #   d.root.attributes.namespaces # => {"xmlns"=>"foo", "x"=>"bar", "y"=>"twee"}
+    #
+    def namespaces
+      namespaces = {}
+      each_attribute do |attribute|
+        namespaces[attribute.name] = attribute.value if attribute.prefix == 'xmlns' or attribute.name == 'xmlns'
+      end
+      if @element.document and @element.document.doctype
+        expn = @element.expanded_name
+        expn = @element.document.doctype.name if expn.size == 0
+        @element.document.doctype.attributes_of(expn).each {
+          |attribute|
+          namespaces[attribute.name] = attribute.value if attribute.prefix == 'xmlns' or attribute.name == 'xmlns'
+        }
+      end
+      namespaces
+    end
+
+    # :call-seq:
+    #    delete(name) -> element
+    #    delete(attribute) -> element
+    #
+    # Removes a specified attribute if it exists;
+    # returns the attributes' element.
+    #
+    # When string argument +name+ is given,
+    # removes the attribute of that name if it exists:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs.delete('foo:att') # => <ele bar:att='2' att='&lt;'/>
+    #   attrs.delete('foo:att') # => <ele bar:att='2' att='&lt;'/>
+    #
+    # When attribute argument +attribute+ is given,
+    # removes that attribute if it exists:
+    #
+    #   attr = REXML::Attribute.new('bar:att', '2')
+    #   attrs.delete(attr) # => <ele att='&lt;'/> # => <ele att='&lt;'/>
+    #   attrs.delete(attr) # => <ele att='&lt;'/> # => <ele/>
+    #
+    def delete( attribute )
+      name = nil
+      prefix = nil
+      if attribute.kind_of? Attribute
+        name = attribute.name
+        prefix = attribute.prefix
+      else
+        attribute =~ Namespace::NAMESPLIT
+        prefix, name = $1, $2
+        prefix = '' unless prefix
+      end
+      old = fetch(name, nil)
+      if old.kind_of? Hash # the supplied attribute is one of many
+        old.delete(prefix)
+        if old.size == 1
+          repl = nil
+          old.each_value{|v| repl = v}
+          store name, repl
+        end
+      elsif old.nil?
+        return @element
+      else # the supplied attribute is a top-level one
+        super(name)
+      end
+      @element
+    end
+
+    # :call-seq:
+    #   add(attribute) -> attribute
+    #
+    # Adds attribute +attribute+, replacing the previous
+    # attribute of the same name if it exists;
+    # returns +attribute+:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs # => {"att"=>{"foo"=>foo:att='1', "bar"=>bar:att='2', ""=>att='&lt;'}}
+    #   attrs.add(REXML::Attribute.new('foo:att', '2')) # => foo:att='2'
+    #   attrs.add(REXML::Attribute.new('baz', '3')) # => baz='3'
+    #   attrs.include?('baz') # => true
+    #
+    def add( attribute )
+      self[attribute.name] = attribute
+    end
+
+    alias :<< :add
+
+    # :call-seq:
+    #   delete_all(name) -> array_of_removed_attributes
+    #
+    # Removes all attributes matching the given +name+;
+    # returns an array of the removed attributes:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs.delete_all('att') # => [att='&lt;']
+    #
+    def delete_all( name )
+      rv = []
+      each_attribute { |attribute|
+        rv << attribute if attribute.expanded_name == name
+      }
+      rv.each{ |attr| attr.remove }
+      return rv
+    end
+
+    # :call-seq:
+    #   get_attribute_ns(namespace, name)
+    #
+    # Returns the \REXML::Attribute object among the attributes
+    # that matches the given +namespace+ and +name+:
+    #
+    #   xml_string = <<-EOT
+    #     <root xmlns:foo="http://foo" xmlns:bar="http://bar">
+    #        <ele foo:att='1' bar:att='2' att='&lt;'/>
+    #     </root>
+    #   EOT
+    #   d = REXML::Document.new(xml_string)
+    #   ele = d.root.elements['//ele'] # => <a foo:att='1' bar:att='2' att='&lt;'/>
+    #   attrs = ele.attributes
+    #   attrs.get_attribute_ns('http://foo', 'att')    # => foo:att='1'
+    #   attrs.get_attribute_ns('http://foo', 'nosuch') # => nil
+    #
+    def get_attribute_ns(namespace, name)
+      result = nil
+      each_attribute() { |attribute|
+        if name == attribute.name &&
+          namespace == attribute.namespace() &&
+          ( !namespace.empty? || !attribute.fully_expanded_name.index(':') )
+          # foo will match xmlns:foo, but only if foo isn't also an attribute
+          result = attribute if !result or !namespace.empty? or
+                                !attribute.fully_expanded_name.index(':')
+        end
+      }
+      result
+    end
+  end
+end