class Haml::Parser

def tag(line)
  tag_name, attributes, attributes_hashes, object_ref, nuke_outer_whitespace,
    nuke_inner_whitespace, action, value, last_line = parse_tag(line.text)
  preserve_tag = @options.preserve.include?(tag_name)
  nuke_inner_whitespace ||= preserve_tag
  escape_html = (action == '&' || (action != '!' && @options.escape_html))
  case action
  when '/'; self_closing = true
  when '~'; parse = preserve_script = true
  when '='
    parse = true
    if value[0] == ?=
      value = unescape_interpolation(value[1..-1].strip, escape_html)
      escape_html = false
    end
  when '&', '!'
    if value[0] == ?= || value[0] == ?~
      parse = true
      preserve_script = (value[0] == ?~)
      if value[1] == ?=
        value = unescape_interpolation(value[2..-1].strip, escape_html)
        escape_html = false
      else
        value = value[1..-1].strip
      end
    elsif contains_interpolation?(value)
      value = unescape_interpolation(value, escape_html)
      parse = true
      escape_html = false
    end
  else
    if contains_interpolation?(value)
      value = unescape_interpolation(value, escape_html)
      parse = true
      escape_html = false
    end
  end
  attributes = Parser.parse_class_and_id(attributes)
  dynamic_attributes = DynamicAttributes.new
  if attributes_hashes[:new]
    static_attributes, attributes_hash = attributes_hashes[:new]
    AttributeBuilder.merge_attributes!(attributes, static_attributes) if static_attributes
    dynamic_attributes.new = attributes_hash
  end
  if attributes_hashes[:old]
    static_attributes = parse_static_hash(attributes_hashes[:old])
    AttributeBuilder.merge_attributes!(attributes, static_attributes) if static_attributes
    dynamic_attributes.old = attributes_hashes[:old] unless static_attributes || @options.suppress_eval
  end
  raise SyntaxError.new(Error.message(:illegal_nesting_self_closing), @next_line.index) if block_opened? && self_closing
  raise SyntaxError.new(Error.message(:no_ruby_code, action), last_line - 1) if parse && value.empty?
  raise SyntaxError.new(Error.message(:self_closing_content), last_line - 1) if self_closing && !value.empty?
  if block_opened? && !value.empty? && !is_ruby_multiline?(value)
    raise SyntaxError.new(Error.message(:illegal_nesting_line, tag_name), @next_line.index)
  end
  self_closing ||= !!(!block_opened? && value.empty? && @options.autoclose.any? {|t| t === tag_name})
  value = nil if value.empty? && (block_opened? || self_closing)
  line.text = value
  line = handle_ruby_multiline(line) if parse
  ParseNode.new(:tag, line.index + 1, :name => tag_name, :attributes => attributes,
    :dynamic_attributes => dynamic_attributes, :self_closing => self_closing,
    :nuke_inner_whitespace => nuke_inner_whitespace,
    :nuke_outer_whitespace => nuke_outer_whitespace, :object_ref => object_ref,
    :escape_html => escape_html, :preserve_tag => preserve_tag,
    :preserve_script => preserve_script, :parse => parse, :value => line.text)
end