# File lib/heckle.rb, line 381
  def mutate_lit(exp)
    case exp[1]
    when Fixnum, Float, Bignum
      s(:lit, exp[1] + rand_number)
    when Symbol
      s(:lit, rand_symbol)
    when Regexp
      s(:lit, Regexp.new(Regexp.escape(rand_string.gsub(/\//, '\\/'))))
    when Range
      s(:lit, rand_range)
    end
  end