static boolean regex_literal(PsiBuilder b, int l) {
    if (!recursion_guard_(b, l, "regex_literal")) return false;
    if (!nextTokenIsFast(b, DOLLAR_SLASHY_BEGIN, SLASHY_BEGIN)) return false;
    boolean r;
    r = slashy_literal(b, l + 1);
    if (!r) r = dollar_slashy_literal(b, l + 1);
    return r;
  }
static boolean regex_literal(PsiBuilder b, int l)