static boolean mandatory_expression(PsiBuilder b, int l) {
    if (!recursion_guard_(b, l, "mandatory_expression")) return false;
    if (!nextTokenIsFast(b, T_AT, T_LBRACK)) return false;
    boolean r, p;
    Marker m = enter_section_(b, l, _NONE_);
    r = mandatory_expression_0(b, l + 1);
    r = r && consumeToken(b, T_LBRACK);
    p = r; // pin = 2
    r = r && report_error_(b, expression(b, l + 1, -1));
    r = p && consumeToken(b, T_RBRACK) && r;
    exit_section_(b, l, m, r, p, null);
    return r || p;
  }
static boolean mandatory_expression(PsiBuilder b, int l)