You don't want to use this class.  Really.  Use XPath, which is a wrapper for this class.  Believe me.  You don't want to poke around in here. There is strange, dark magic at work in this code.  Beware.  Go back!  Go back while you still can!
 
               # File rexml/xpath_parser.rb, line 81
def []=( variable_name, value )
  @variables[ variable_name ] = value
end
             
            Performs a depth-first (document order) XPath search, and returns the first match.  This is the fastest, lightest way to return a single result.
FIXME: This method is incomplete!
 
               # File rexml/xpath_parser.rb, line 90
def first( path_stack, node )
  return nil if path.size == 0
  case path[0]
  when :document
    # do nothing
    return first( path[1..-1], node )
  when :child
    for c in node.children
      r = first( path[1..-1], c )
      return r if r
    end
  when :qname
    name = path[2]
    if node.name == name
      return node if path.size == 3
      return first( path[3..-1], node )
    else
      return nil
    end
  when :descendant_or_self
    r = first( path[1..-1], node )
    return r if r
    for c in node.children
      r = first( path, c )
      return r if r
    end
  when :node
    return first( path[1..-1], node )
  when :any
    return first( path[1..-1], node )
  end
  return nil
end
             
             
               # File rexml/xpath_parser.rb, line 71
def get_first path, nodeset
  path_stack = @parser.parse( path )
  first( path_stack, nodeset )
end
             
             
               # File rexml/xpath_parser.rb, line 126
def match( path_stack, nodeset )
  r = expr( path_stack, nodeset )
  r
end
             
             
               # File rexml/xpath_parser.rb, line 56
def namespaces=( namespaces={} )
  Functions::namespace_context = namespaces
  @namespaces = namespaces
end
             
             
               # File rexml/xpath_parser.rb, line 66
def parse path, nodeset
  path_stack = @parser.parse( path )
  match( path_stack, nodeset )
end