package net.sf.saxon.functions;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.sort.GenericAtomicComparer;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.TypeHierarchy;
import net.sf.saxon.type.Type;
import net.sf.saxon.type.BuiltInAtomicType;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.Int64Value;
/**
* The XPath 2.0 index-of() function
*/
public class IndexOf extends CollatingFunction {
/**
* Evaluate the function to return an iteration of selected nodes.
*/
public SequenceIterator iterate(XPathContext context) throws XPathException {
GenericAtomicComparer comparer = getAtomicComparer(2, context);
SequenceIterator seq = argument[0].iterate(context);
AtomicValue val = (AtomicValue)argument[1].evaluateItem(context);
return new IndexIterator(seq, val, comparer);
}
/**
* Iterator to return the index positions of selected items in a sequence
*/
public static class IndexIterator implements SequenceIterator {
SequenceIterator base;
AtomicValue value;
GenericAtomicComparer comparer;
int index = 0;
int position = 0;
Item current = null;
BuiltInAtomicType primitiveTypeRequired;
TypeHierarchy typeHierarchy;
/**
* Get an iterator returning the index positions of selected items in a sequence
* @param base The sequence to be searched
* @param value The value being sought
* @param comparer Comparer used to determine whether values match
*/
public IndexIterator(SequenceIterator base, AtomicValue value, GenericAtomicComparer comparer) {
this.base = base;
this.value = value;
this.comparer = comparer;
primitiveTypeRequired = value.getPrimitiveType();
}
public Item next() throws XPathException {
while (true) {
AtomicValue i = (AtomicValue)base.next();
if (i==null) break;
index++;
if (Type.isComparable(primitiveTypeRequired,
i.getPrimitiveType(), false)) {
try {
if (comparer.comparesEqual(i, value)) {
current = Int64Value.makeIntegerValue(index);
position++;
return current;
}
} catch (ClassCastException err) {
// non-comparable values are treated as not equal
// Exception shouldn't happen but we catch it anyway
}
}
}
current = null;
position = -1;
return null;
}
public Item current() {
return current;
}
public int position() {
return position;
}
public void close() {
base.close();
}
public SequenceIterator getAnother() throws XPathException {
return new IndexIterator(base.getAnother(), value, comparer);
}
/**
* 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 SequenceIterator#GROUNDED}, {@link SequenceIterator#LAST_POSITION_FINDER},
* and {@link SequenceIterator#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;
}
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//