Esempio n. 1
0
 @Override
 public final boolean has(final Flag flag) {
   // first step or root expression will be used as context
   if (flag == Flag.CTX) return root == null || root.has(flag);
   for (final Expr s : steps) if (s.has(flag)) return true;
   return root != null && root.has(flag);
 }
Esempio n. 2
0
 @Override
 public void checkUp() throws QueryException {
   for (final Let c : copies) c.checkUp();
   final Expr m = expr[0];
   m.checkUp();
   if (!m.isVacuous() && !m.has(Flag.UPD)) throw UPMODIFY.get(info);
   checkNoUp(expr[1]);
 }
Esempio n. 3
0
  /**
   * Merges expensive descendant-or-self::node() steps.
   *
   * @param qc query context
   * @return original or new expression
   */
  private Expr mergeSteps(final QueryContext qc) {
    boolean opt = false;
    final int sl = steps.length;
    final ExprList stps = new ExprList(sl);
    for (int s = 0; s < sl; s++) {
      final Expr step = steps[s];
      // check for simple descendants-or-self step with succeeding step
      if (s < sl - 1 && step instanceof Step) {
        final Step curr = (Step) step;
        if (curr.simple(DESCORSELF, false)) {
          // check succeeding step
          final Expr next = steps[s + 1];
          // descendant-or-self::node()/child::X -> descendant::X
          if (simpleChild(next)) {
            ((Step) next).axis = DESC;
            opt = true;
            continue;
          }
          // descendant-or-self::node()/(X, Y) -> (descendant::X | descendant::Y)
          Expr e = mergeList(next);
          if (e != null) {
            steps[s + 1] = e;
            opt = true;
            continue;
          }
          // //(X, Y)[text()] -> (/descendant::X | /descendant::Y)[text()]
          if (next instanceof Filter && !next.has(Flag.FCS)) {
            final Filter f = (Filter) next;
            e = mergeList(f.root);
            if (e != null) {
              f.root = e;
              opt = true;
              continue;
            }
          }
        }
      }
      stps.add(step);
    }

    if (opt) {
      qc.compInfo(OPTDESC);
      return get(info, root, stps.finish());
    }
    return this;
  }
Esempio n. 4
0
 @Override
 public boolean has(final Flag flag) {
   if (occ != null) for (final Expr o : occ) if (o.has(flag)) return true;
   return query.has(flag);
 }