class Regexp::Lexer

def break_literal(token)
  lead, last, _ = token.text.partition(/.\z/mu)
  return if lead.empty?
  token_1 = Regexp::Token.new(:literal, :literal, lead,
            token.ts, (token.te - last.length),
            nesting, set_nesting, conditional_nesting)
  token_2 = Regexp::Token.new(:literal, :literal, last,
            (token.ts + lead.length), token.te,
            nesting, set_nesting, conditional_nesting)
  token_1.previous = preprev_token
  token_1.next = token_2
  token_2.previous = token_1 # .next will be set by #lex
  [token_1, token_2]
end