anchor.diff:  }
   
   static void lexer_init(lexer_state *lexer) {
  -  int cs = 0;
  -  %% write init;
  -  lexer->cs = cs;
     lexer->content_start = 0;
     lexer->content_end = 0;
     lexer->content_len = 0;
  
positive.code:     assert(*pe == '\0' && "pointer does not end on NULL");
      assert(pe - p == len && "pointers aren't same distance");
      
      %% write exec;
      
      assert(p <= pe && "data overflow after parsing execute");
  
negative.code: #define PTR_TO(P) (data + lexer->P)
  
  typedef struct lexer_state {
    int content_len;
    int line_number;
    int current_line;
  