/** * Optimizes descendant-or-self steps and static types. * * @param ctx query context */ void optSteps(final QueryContext ctx) { boolean opt = false; Expr[] st = steps; for (int l = 1; l < st.length; ++l) { if (!(st[l - 1] instanceof Step && st[l] instanceof Step)) continue; final Step prev = (Step) st[l - 1]; final Step curr = (Step) st[l]; if (!prev.simple(DESCORSELF, false)) continue; if (curr.axis == CHILD && !curr.has(Flag.FCS)) { // descendant-or-self::node()/child::X -> descendant::X final int sl = st.length; final Expr[] tmp = new Expr[sl - 1]; System.arraycopy(st, 0, tmp, 0, l - 1); System.arraycopy(st, l, tmp, l - 1, sl - l); st = tmp; curr.axis = DESC; opt = true; } else if (curr.axis == ATTR && !curr.has(Flag.FCS)) { // descendant-or-self::node()/@X -> descendant-or-self::*/@X prev.test = new NameTest(false); opt = true; } } if (opt) ctx.compInfo(OPTDESC); // set atomic type for single attribute steps to speedup predicate tests if (root == null && st.length == 1 && st[0] instanceof Step) { final Step curr = (Step) st[0]; if (curr.axis == ATTR && curr.test.mode == Mode.STD) curr.type = SeqType.NOD_ZO; } steps = st; }