docs: def p_case_list(p):
      '''case_list : empty
                   | case_list CASE expr case_separator inner_statement_list
                   | case_list DEFAULT case_separator inner_statement_list'''
      if len(p) == 6:
          p[0] = p[1] + [ast.Case(p[3], p[5], lineno=p.lineno(2))]
      elif len(p) == 5:
          p[0] = p[1] + [ast.Default(p[4], lineno=p.lineno(2))]
      else:
          p[0] = []