/*
* @(#)$Id: NumericFunction.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.math;
import java.util.Iterator;
import xbird.xquery.DynamicError;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.value.Item;
import xbird.xquery.dm.value.Sequence;
import xbird.xquery.dm.value.literal.XNumber;
import xbird.xquery.dm.value.sequence.ValueSequence;
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.type.Type;
import xbird.xquery.type.xs.DoubleType;
/**
*
* <DIV lang="en">
* <ul>
* <li>If the argument is the empty sequence, the empty sequence is returned.</li>
* <li>For xs:float and xs:double arguments, if the argument is "NaN", "NaN" is returned.</li>
* <li>Except for fn:abs(), for xs:float and xs:double arguments, if the argument
* is positive or negative infinity, positive or negative infinity is returned.</li>
* </ul>
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#numeric-value-functions
*/
public abstract class NumericFunction extends BuiltInFunction {
public NumericFunction(String funcName, Type retType) {
super(funcName, retType);
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] t = new FunctionSignature[1];
t[0] = new FunctionSignature(getName(), new Type[] { getReturnType() });
return t;
}
protected abstract XNumber promote(XNumber value);
public Sequence eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv) throws XQueryException {
assert (argv != null && argv.size() == 1);
Item arg = argv.getItem(0);
Iterator<? extends Item> argItor = arg.iterator();
if (!argItor.hasNext()) {
return ValueSequence.EMPTY_SEQUENCE;
}
Item firstItem = argItor.next();
assert (!argItor.hasNext());
if (firstItem instanceof UntypedAtomicValue) {
firstItem = ((UntypedAtomicValue) firstItem).castAs(DoubleType.DOUBLE, dynEnv);
}
if (firstItem instanceof XNumber) {
XNumber num = (XNumber) firstItem;
XNumber promoted = promote(num);
return promoted;
} else {
throw new DynamicError("err:FORG0006", "Invalid argument type: " + firstItem.getType());
}
}
}