1  require 'rexml/parsers/streamparser'
   2  require 'rexml/parsers/baseparser'
   3 
   4  module REXML
   5    module Parsers
   6      class UltraLightParser
   7        def initialize stream
   8          @stream = stream
   9          @parser = REXML::Parsers::BaseParser.new( stream )
  10        end
  11 
  12        def add_listener( listener )
  13          @parser.add_listener( listener )
  14        end
  15 
  16        def rewind
  17          @stream.rewind
  18          @parser.stream = @stream
  19        end
  20 
  21        def parse
  22          root = context = []
  23          while true
  24            event = @parser.pull
  25            case event[0]
  26            when :end_document
  27              break
  28            when :end_doctype
  29              context = context[1]
  30            when :start_element, :doctype
  31              context << event
  32              event[1,0] = [context]
  33              context = event
  34            when :end_element
  35              context = context[1]
  36            else
  37              context << event
  38            end
  39          end
  40          root
  41        end
  42      end
  43 
  44      # An element is an array.  The array contains:
  45      #  0      The parent element
  46      #  1      The tag name
  47      #  2      A hash of attributes
  48      #  3..-1  The child elements
  49      # An element is an array of size > 3
  50      # Text is a String
  51      # PIs are [ :processing_instruction, target, data ]
  52      # Comments are [ :comment, data ]
  53      # DocTypes are DocType structs
  54      # The root is an array with XMLDecls, Text, DocType, Array, Text
  55    end
  56  end