/** * Checks if the path can be rewritten for iterative evaluation. * * @param root root expression; can be a {@code null} reference * @param steps path steps * @return result of check */ private static boolean iterative(final Expr root, final Expr... steps) { if (root == null || !root.iterable()) return false; final int sl = steps.length; for (int s = 0; s < sl; ++s) { switch (((Step) steps[s]).axis) { // reverse axes - don't iterate case ANC: case ANCORSELF: case PREC: case PRECSIBL: return false; // multiple, unsorted results - only iterate at last step, // or if last step uses attribute axis case DESC: case DESCORSELF: case FOLL: case FOLLSIBL: return s + 1 == sl || s + 2 == sl && ((Step) steps[s + 1]).axis == Axis.ATTR; // allow iteration for CHILD, ATTR, PARENT and SELF axes default: } } return true; }