| /******************************************************************************* |
| * Copyright (c) 2005, 2010 Andrea Bittau, University College London, and others |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Andrea Bittau - initial API and implementation from the PsychoPath XPath 2.0 |
| * Jesper Moller - bug 280555 - Add pluggable collation support |
| * David Carver (STAR) - bug 262765 - fixed promotion issue |
| * Jesper Moller - bug 281028 - fix promotion rules for fn:max |
| * Mukul Gandhi - bug 280798 - PsychoPath support for JDK 1.4 |
| *******************************************************************************/ |
| |
| package org.eclipse.wst.xml.xpath2.processor.internal.function; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| |
| import org.eclipse.wst.xml.xpath2.api.DynamicContext; |
| import org.eclipse.wst.xml.xpath2.api.EvaluationContext; |
| import org.eclipse.wst.xml.xpath2.api.ResultSequence; |
| import org.eclipse.wst.xml.xpath2.processor.DynamicError; |
| import org.eclipse.wst.xml.xpath2.processor.ResultSequenceFactory; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.AnyAtomicType; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.AnyType; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.QName; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.XSDouble; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.XSFloat; |
| import org.eclipse.wst.xml.xpath2.processor.internal.utils.ComparableTypePromoter; |
| import org.eclipse.wst.xml.xpath2.processor.internal.utils.TypePromoter; |
| |
| /** |
| * 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. If there are |
| * two or more such items, then the specific item whose value is returned is |
| * implementation dependent. |
| */ |
| public class FnMax extends Function { |
| /** |
| * Constructor for FnMax. |
| */ |
| public FnMax() { |
| super(new QName("max"), 1); |
| } |
| |
| /** |
| * Evaluate arguments. |
| * |
| * @param args |
| * argument expressions. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of evaluation. |
| */ |
| public ResultSequence evaluate(Collection args, EvaluationContext ec) { |
| return max(args, ec.getDynamicContext()); |
| } |
| |
| /** |
| * Max operation. |
| * |
| * @param args |
| * Result from the expressions evaluation. |
| * @param context |
| * Relevant dynamic context |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of fn:max operation. |
| */ |
| public static ResultSequence max(Collection args, DynamicContext dynamicContext) throws DynamicError { |
| |
| ResultSequence arg = get_arg(args, CmpGt.class); |
| if (arg.empty()) |
| return ResultSequenceFactory.create_new(); |
| |
| CmpGt max = null; |
| |
| TypePromoter tp = new ComparableTypePromoter(); |
| tp.considerSequence(arg); |
| |
| for (Iterator i = arg.iterator(); i.hasNext();) { |
| AnyAtomicType conv = tp.promote((AnyType) i.next()); |
| |
| if (conv instanceof XSDouble && ((XSDouble)conv).nan() || conv instanceof XSFloat && ((XSFloat)conv).nan()) { |
| return ResultSequenceFactory.create_new(tp.promote(new XSFloat(Float.NaN))); |
| } |
| if (max == null || ((CmpGt)conv).gt((AnyType)max, dynamicContext)) { |
| max = (CmpGt)conv; |
| } |
| } |
| return ResultSequenceFactory.create_new((AnyType) max); |
| } |
| |
| /** |
| * Obtain arguments. |
| * |
| * @param args |
| * input expressions. |
| * @param op |
| * input class. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of operation. |
| */ |
| public static ResultSequence get_arg(Collection args, Class op) |
| throws DynamicError { |
| assert args.size() == 1; |
| |
| ResultSequence arg = (ResultSequence) args.iterator().next(); |
| |
| return arg; |
| } |
| } |