/*
* @(#)$Id: Max.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.xquery.func.agg;
import java.text.Collator;
import java.util.Iterator;
import xbird.util.resource.CollationUtils;
import xbird.xquery.DynamicError;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.value.*;
import xbird.xquery.dm.value.literal.XNumber;
import xbird.xquery.dm.value.sequence.ValueSequence;
import xbird.xquery.dm.value.xsi.DurationValue;
import xbird.xquery.dm.value.xsi.UntypedAtomicValue;
import xbird.xquery.func.BuiltInFunction;
import xbird.xquery.func.FunctionSignature;
import xbird.xquery.meta.DynamicContext;
import xbird.xquery.misc.TypeUtil;
import xbird.xquery.type.Type;
import xbird.xquery.type.TypeRegistry;
import xbird.xquery.type.xs.DoubleType;
import xbird.xquery.type.xs.StringType;
/**
* fn:max.
* <DIV lang="en">
* Selects an item from the input sequence $arg whose value is greater than or equal to
* the value of every other item in the input sequence.
* <ul>
* <li>fn:max($arg as xdt:anyAtomicType*) as xdt:anyAtomicType?</li>
* <li>fn:max($arg as xdt:anyAtomicType*, $collation as string) as xdt:anyAtomicType?</li>
* </ul>
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-max
*/
public final class Max extends BuiltInFunction {
private static final long serialVersionUID = -2738205430199375189L;
public static final String SYMBOL = "fn:max";
public Max() {
super(SYMBOL, TypeRegistry.safeGet("xs:anyAtomicType?"));
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] s = new FunctionSignature[2];
Type anyatom = TypeRegistry.safeGet("xs:anyAtomicType*");
s[0] = new FunctionSignature(getName(), new Type[] { anyatom });
s[1] = new FunctionSignature(getName(), new Type[] { anyatom, StringType.STRING });
return s;
}
public Sequence eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv)
throws XQueryException {
assert (argv != null);
// If the converted sequence is empty, the empty sequence is returned.
if(argv.isEmpty()) {
return ValueSequence.EMPTY_SEQUENCE;
}
assert (argv.size() <= 2);
Item arg = argv.getItem(0);
final Iterator<? extends Item> argItor = arg.iterator();
if(!argItor.hasNext()) {
return ValueSequence.EMPTY_SEQUENCE;
}
Item firstItem = argItor.next();
if(firstItem instanceof UntypedAtomicValue) {
// Values of type xdt:untypedAtomic in $arg are cast to xs:double.
firstItem = ((UntypedAtomicValue) firstItem).castAs(DoubleType.DOUBLE, dynEnv);
}
if(!argItor.hasNext()) {
return firstItem;
}
final Type firstType = firstItem.getType();
if(firstItem instanceof XNumber) {
XNumber max = (XNumber) firstItem;
// If the converted sequence contains the value NaN, the value NaN is returned.
if(max.isNaN()) {
return max;
}
while(argItor.hasNext()) {
Item it = argItor.next();
if(it instanceof UntypedAtomicValue) {
it = ((UntypedAtomicValue) it).castAs(DoubleType.DOUBLE, dynEnv);
} else if(!(it instanceof XNumber)) {
throw new DynamicError("err:FORG0006", "fs:plus(" + max.getType() + ", "
+ it.getType() + ") is not defined");
}
XNumber cmp = (XNumber) it;
if(cmp.isNaN()) {
return cmp;
}
if(cmp.compareTo(max) > 0) {
max = cmp;
}
}
return max;
} else if(firstItem instanceof DurationValue) {
// Duration values must either all be xdt:yearMonthDuration values
// or must all be xdt:dayTimeDuration values.
DurationValue max = (DurationValue) firstItem;
while(argItor.hasNext()) {
Item it = argItor.next();
if(it instanceof DurationValue) {
throw new DynamicError("err:FORG0006", "Duration values must all be `"
+ firstType + "`, but found `" + it.getType() + "`");
}
DurationValue cmp = (DurationValue) it;
if(cmp.compareTo(max) > 0) {
max = cmp;
}
}
return max;
} else if(TypeUtil.subtypeOf(firstType, StringType.STRING)) {
AtomicValue max = (AtomicValue) firstItem;
final int arglen = argv.size();
final Collator collator;
if(arglen == 2) {
Item sec = argv.getItem(1);
Type secType = sec.getType();
if(!TypeUtil.subtypeOf(secType, StringType.STRING)) {
throw new DynamicError("err:FORG0006", "second argument is expected to be xs:string, but was "
+ secType);
}
String uri = sec.stringValue();
collator = CollationUtils.resolve(uri, dynEnv.getStaticContext());
} else {
collator = Collator.getInstance(); // compare in default locale
}
while(argItor.hasNext()) {
Item it = argItor.next();
Type cmpType = it.getType();
if(!TypeUtil.subtypeOf(cmpType, StringType.STRING)) {
throw new DynamicError("err:FORG0006", "imcomparable xs:string and " + cmpType);
}
if(collator.compare(it, firstItem) > 0) {
max = (AtomicValue) it;
}
}
return max;
} else {
throw new DynamicError("err:FORG0006", "Invalid argument type: " + firstItem.getType());
}
}
}