class Sass::Tree::PropNode

def ==(other)
  self.class == other.class && name == other.name && value == other.value && super
end

def declaration
  (@prop_syntax == :new ? "#{name}: #{value}" : ":#{name} #{value}").strip
end

def initialize(name, value, prop_syntax)
  @name = name
  @value = value
  @prop_syntax = prop_syntax
  super()
end

def invalid_child?(child)
  if !child.is_a?(PropNode) && !child.is_a?(CommentNode)
    "Illegal nesting: Only properties may be nested beneath properties."
  end
end

def perform!(environment)
  @name = interpolate(@name, environment)
  @value = @value.is_a?(String) ? interpolate(@value, environment) : @value.perform(environment).to_s
  super
end

def pseudo_class_selector_message
  return "" if @prop_syntax == :new || !value.empty?
  "\nIf #{declaration.dump} should be a selector, use \"\\#{declaration}\" instead."
end

def to_s(tabs, parent_name = nil)
  if @options[:property_syntax] == :old && @prop_syntax == :new
    raise Sass::SyntaxError.new("Illegal property syntax: can't use new syntax when :property_syntax => :old is set.", @line)
  elsif @options[:property_syntax] == :new && @prop_syntax == :old
    raise Sass::SyntaxError.new("Illegal property syntax: can't use old syntax when :property_syntax => :new is set.", @line)
  end
  if value[-1] == ?;
    raise Sass::SyntaxError.new("Invalid property: #{declaration.dump} (no \";\" required at end-of-line).", @line)
  end
  real_name = name
  real_name = "#{parent_name}-#{real_name}" if parent_name
  
  if value.empty? && children.empty?
    message = "Invalid property: #{declaration.dump} (no value)." +
      pseudo_class_selector_message
    raise Sass::SyntaxError.new(message, @line)
  end
  
  join_string = case style
                when :compact; ' '
                when :compressed; ''
                else "\n"
                end
  spaces = '  ' * (tabs - 1)
  to_return = ''
  if !value.empty?
    to_return << "#{spaces}#{real_name}:#{style == :compressed ? '' : ' '}#{value};#{join_string}"
  end
  
  children.each do |kid|
    next if kid.invisible?
    to_return << kid.to_s(tabs, real_name) << join_string
  end
  
  (style == :compressed && parent_name) ? to_return : to_return[0...-1]
end

def to_sass(tabs, opts = {})
  "#{'  ' * tabs}#{opts[:old] ? ':' : ''}#{name}#{opts[:old] ? '' : ':'} #{value}\n"
end