| /******************************************************************************* |
| * Copyright (c) 2005, 2009 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 Steen Moeller - bug 285145 - implement full arity checking |
| *******************************************************************************/ |
| |
| package org.eclipse.wst.xml.xpath2.processor.internal.function; |
| |
| import org.eclipse.wst.xml.xpath2.processor.DynamicError; |
| import org.eclipse.wst.xml.xpath2.processor.ResultSequence; |
| import org.eclipse.wst.xml.xpath2.processor.ResultSequenceFactory; |
| import org.eclipse.wst.xml.xpath2.processor.internal.*; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.*; |
| |
| import java.util.*; |
| |
| /** |
| * Returns the absolute value of $arg. If $arg is negative returns -$arg |
| * otherwise returns $arg. If type of $arg is one of the four numeric types |
| * xs:float, xs:double, xs:decimal or xs:integer the type of the return is the |
| * same as the type of $arg. If the type of $arg is a type derived from one of |
| * the numeric types, the type of the return is the base numeric type. For |
| * xs:float and xs:double arguments, if the argument is positive zero (+0) or |
| * negative zero (-0), then positive zero (+0) is returned. If the argument is |
| * positive or negative infinity, positive infinity is returned. |
| */ |
| public class FnAbs extends Function { |
| /** |
| * Constructor for FnAbs. |
| */ |
| public FnAbs() { |
| super(new QName("abs"), 1); |
| } |
| |
| /** |
| * Evaluate arguments. |
| * |
| * @param args |
| * argument expressions. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of evaluation. |
| */ |
| @Override |
| public ResultSequence evaluate(Collection args) throws DynamicError { |
| // 1 argument only! |
| assert args.size() >= min_arity() && args.size() <= max_arity(); |
| |
| ResultSequence argument = (ResultSequence) args.iterator().next(); |
| |
| return fn_abs(argument); |
| } |
| |
| /** |
| * Absolute value operation. |
| * |
| * @param arg |
| * Result from the expressions evaluation. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of fn:abs operation. |
| */ |
| public static ResultSequence fn_abs(ResultSequence arg) throws DynamicError { |
| ResultSequence rs = ResultSequenceFactory.create_new(); |
| |
| // sanity chex |
| NumericType nt = get_single_numeric_arg(arg); |
| |
| // empty arg |
| if (nt == null) |
| return rs; |
| |
| rs.add(nt.abs()); |
| return rs; |
| } |
| |
| /** |
| * Obtain numeric value from expression. |
| * |
| * @param arg |
| * input expression. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Resulting numeric type from the operation. |
| */ |
| public static NumericType get_single_numeric_arg(ResultSequence arg) |
| throws DynamicError { |
| int size = arg.size(); |
| if (size > 1) |
| DynamicError.throw_type_error(); |
| |
| if (size == 0) |
| return null; |
| |
| AnyType at = arg.first(); |
| |
| if (!(at instanceof NumericType)) |
| DynamicError.throw_type_error(); |
| |
| return (NumericType) at; |
| } |
| |
| } |