class Sass::Engine

def parse_constant(line)
  name, op, value = line.scan(Sass::Constant::MATCH)[0]
  unless name && value
    raise SyntaxError.new("Invalid constant: \"#{line}\".", @line)
  end
  constant = Sass::Constant.parse(value, @constants, @line)
  if op == '||='
    @constants[name] ||= constant
  else
    @constants[name] = constant
  end
  :constant
end