@Override
public Iter iter(final QueryContext ctx) throws QueryException {
final Iter iter = ctx.iter(root);
final Value cv = ctx.value;
final long cs = ctx.size;
final long cp = ctx.pos;
// cache results to support last() function
final ItemCache ic = new ItemCache();
for (Item i; (i = iter.next()) != null; ) ic.add(i);
// evaluate predicates
for (final Expr p : pred) {
final long is = ic.size();
ctx.size = is;
ctx.pos = 1;
int c = 0;
for (int s = 0; s < is; ++s) {
ctx.value = ic.get(s);
if (p.test(ctx, input) != null) ic.set(ic.get(s), c++);
ctx.pos++;
}
ic.size(c);
}
ctx.value = cv;
ctx.size = cs;
ctx.pos = cp;
return ic;
}
@Override
public Iter iter(final QueryContext ctx) throws QueryException {
switch (def) {
case ERROR:
final int al = expr.length;
if (al == 0) FUNERR1.thrw(input);
String code = FUNERR1.code();
String msg = FUNERR1.desc;
final Item it = expr[0].item(ctx, input);
if (it == null) {
if (al == 1) XPEMPTY.thrw(input, desc());
} else {
code = Token.string(((QNm) checkType(it, AtomType.QNM)).ln());
}
if (al > 1) msg = Token.string(checkEStr(expr[1], ctx));
final Value val = al > 2 ? expr[2].value(ctx) : null;
final QueryException ex = new QueryException(input, code, val, msg);
throw ex;
case TRACE:
return new Iter() {
final Iter ir = expr[0].iter(ctx);
final byte[] s = checkEStr(expr[1], ctx);
@Override
public Item next() throws QueryException {
final Item i = ir.next();
if (i != null) {
final TokenBuilder tb = new TokenBuilder(s);
if (s.length != 0) tb.add(": ");
tb.add(i.toString());
// if GUI is used, or if user is no admin, trace info is cached
if (Prop.gui || !ctx.context.user.perm(User.ADMIN)) {
ctx.evalInfo(tb.finish());
} else {
Util.errln(tb);
}
}
return i;
}
};
case ENVARS:
final ItemCache ic = new ItemCache();
for (final Object k : System.getenv().keySet().toArray()) {
ic.add(Str.get(k));
}
return ic;
default:
return super.iter(ctx);
}
}
/**
* Creates an item iterator for the given XML fragment.
*
* @param xml fragment
* @param frag fragment flag
* @return iterator
*/
private ItemCache toIter(final String xml, final boolean frag) {
final ItemCache it = new ItemCache();
try {
String str = frag ? "<X>" + xml + "</X>" : xml;
final Data d = CreateDB.xml(IO.get(str), context);
for (int p = frag ? 2 : 0; p < d.meta.size; p += d.size(p, d.kind(p)))
it.add(new DBNode(d, p));
} catch (final IOException ex) {
return new ItemCache(new Item[] {Str.get(Long.toString(System.nanoTime()))}, 1);
}
return it;
}