private int formatString(ParsingList l, int start) {
   int end = l.size();
   String s = "";
   for (int i = start; i < end; i++) {
     ParsingExpression e = l.get(i);
     if (e instanceof ParsingByte) {
       char c = (char) (((ParsingByte) e).byteChar);
       if (c >= ' ' && c < 127) {
         s += c;
         continue;
       }
     }
     end = i;
     break;
   }
   if (s.length() > 1) {
     this.formatString(Utils.quoteString('\'', s, '\''));
   }
   return end - 1;
 }
 protected void formatSequence(ParsingList l) {
   for (int i = 0; i < l.size(); i++) {
     if (i > 0) {
       this.formatString(" ");
     }
     int n = formatString(l, i);
     if (n > i) {
       i = n;
       continue;
     }
     ParsingExpression e = l.get(i);
     if (e instanceof ParsingChoice || e instanceof ParsingSequence) {
       this.formatString("( ");
       e.visit(this);
       this.formatString(" )");
       continue;
     }
     e.visit(this);
   }
 }