module Nokogiri::Decorators::Hpricot::NodeSet

def filter(rule)

node_set.filter('a[@id="link2"]') # selects nodes from the set with child node
node_set.filter('a#link2') # selects nodes from the set with child node
node_set.filter('.ohmy') # selects nodes from the set with class "ohmy"
example:

Note that positional rules (like :nth()) aren't currently supported.
Select nodes matching the supplied rule. 
def filter(rule)
  filter_transformer( lambda {|j| j}, rule ) # identity transformer
end

def filter_transformer(transformer, rule) # :nodoc:

:nodoc: 
def filter_transformer(transformer, rule) # :nodoc:
  sub_set = XML::NodeSet.new(document)
  document.decorate(sub_set)
  if rule.is_a?(XML::Node)
    each { |node| sub_set << node if transformer.call(node == rule) }
    return sub_set
  end
  ctx = CSS.parse(rule.to_s)
  visitor = CSS::XPathVisitor.new
  visitor.extend(Hpricot::XPathVisitor)
  each do |node|
    if transformer.call(node.at(".//self::" + visitor.accept(ctx.first)))
      sub_set << node
    end
  end
  sub_set
end

def not(rule)


node_set.not(node_to_exclude) # selects all nodes EXCEPT node_to_exclude
present):
rule to remove that object from the node set (if it is
Also note that you can pass a XML::Node object instead of a

See filter for examples.

Note that positional rules (like :nth()) aren't currently supported.
The complement to filter, select nodes not matching the supplied rule. 
def not(rule)
  filter_transformer( lambda {|j| !j}, rule ) # negation transformer
end