package client.net.sf.saxon.ce.functions;
import client.net.sf.saxon.ce.expr.XPathContext;
import client.net.sf.saxon.ce.om.Item;
import client.net.sf.saxon.ce.om.SequenceIterator;
import client.net.sf.saxon.ce.trans.XPathException;
import client.net.sf.saxon.ce.value.AtomicValue;
import client.net.sf.saxon.ce.value.NumericValue;
/**
* The XPath 2.0 insert-before() function
*/
public class Insert extends SystemFunction {
public Insert newInstance() {
return new Insert();
}
/**
* Evaluate the function to return an iteration of selected nodes.
*/
public SequenceIterator iterate(XPathContext context) throws XPathException {
SequenceIterator seq = argument[0].iterate(context);
AtomicValue n0 = (AtomicValue)argument[1].evaluateItem(context);
NumericValue n = (NumericValue)n0;
int pos = (int)n.intValue();
SequenceIterator ins = argument[2].iterate(context);
return new InsertIterator(seq, ins, pos);
}
public static class InsertIterator implements SequenceIterator {
private SequenceIterator base;
private SequenceIterator insert;
private int insertPosition;
private int position = 0;
private Item current = null;
private boolean inserting = false;
public InsertIterator(SequenceIterator base, SequenceIterator insert, int insertPosition) {
this.base = base;
this.insert = insert;
this.insertPosition = (insertPosition<1 ? 1 : insertPosition);
this.inserting = (insertPosition==1);
}
public Item next() throws XPathException {
Item nextItem;
if (inserting) {
nextItem = insert.next();
if (nextItem == null) {
inserting = false;
nextItem = base.next();
}
} else {
if (position == insertPosition-1) {
nextItem = insert.next();
if (nextItem == null) {
nextItem = base.next();
} else {
inserting = true;
}
} else {
nextItem = base.next();
if (nextItem==null && position < insertPosition-1) {
inserting = true;
nextItem = insert.next();
}
}
}
if (nextItem == null) {
current = null;
position = -1;
return null;
} else {
current = nextItem;
position++;
return current;
}
}
public Item current() {
return current;
}
public int position() {
return position;
}
public SequenceIterator getAnother() throws XPathException {
return new InsertIterator( base.getAnother(),
insert.getAnother(),
insertPosition);
}
/**
* Get properties of this iterator, as a bit-significant integer.
*
* @return the properties of this iterator. This will be some combination of
* properties such as {@link #GROUNDED}, {@link #LAST_POSITION_FINDER},
* and {@link #LOOKAHEAD}. It is always
* acceptable to return the value zero, indicating that there are no known special properties.
* It is acceptable for the properties of the iterator to change depending on its state.
*/
public int getProperties() {
return 0;
}
}
}
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.