class RDoc::Markup::Document

def << part
  case part
  when RDoc::Markup::Document then
    unless part.empty? then
      parts.concat part.parts
      parts << RDoc::Markup::BlankLine.new
    end
  when String then
    raise ArgumentError,
          "expected RDoc::Markup::Document and friends, got String" unless
      part.empty?
  else
    parts << part
  end
end

def == other # :nodoc:
  self.class == other.class and
    @file == other.file and
    @parts == other.parts
end

def accept visitor
  visitor.start_accepting
  visitor.accept_document self
  visitor.end_accepting
end

def concat parts
  self.parts.concat parts
end

def each &block
  @parts.each(&block)
end

def empty?
  @parts.empty? or (@parts.length == 1 and merged? and @parts.first.empty?)
end

def file= location
  @file = case location
          when RDoc::TopLevel then
            location.relative_name
          else
            location
          end
end

def initialize *parts
  @parts = []
  @parts.concat parts
  @file = nil
  @omit_headings_from_table_of_contents_below = nil
end

def merge other
  if empty? then
    @parts = other.parts
    return self
  end
  other.parts.each do |other_part|
    self.parts.delete_if do |self_part|
      self_part.file and self_part.file == other_part.file
    end
    self.parts << other_part
  end
  self
end

def merged?
  RDoc::Markup::Document === @parts.first
end

def pretty_print q # :nodoc:
  start = @file ? "[doc (#{@file}): " : '[doc: '
  q.group 2, start, ']' do
    q.seplist @parts do |part|
      q.pp part
    end
  end
end

def push *parts
  self.parts.concat parts
end

def table_of_contents
  accept RDoc::Markup::ToTableOfContents.to_toc
end