| /******************************************************************************* |
| * 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 |
| * David Carver - bug 262765 - eased restriction on data type...convert numerics to XSDouble. |
| * Jesper S Moller - bug 285806 - fixed fn:subsequence for indexes starting before 1 |
| * Mukul Gandhi - bug 280798 - PsychoPath support for JDK 1.4 |
| * Mukul Gandhi - bug 338999 - improving compliance of function 'fn:subsequence'. implementing full arity support. |
| *******************************************************************************/ |
| |
| package org.eclipse.wst.xml.xpath2.processor.internal.function; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| |
| import org.eclipse.wst.xml.xpath2.api.Item; |
| import org.eclipse.wst.xml.xpath2.api.ResultBuffer; |
| import org.eclipse.wst.xml.xpath2.api.ResultSequence; |
| import org.eclipse.wst.xml.xpath2.processor.DynamicError; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.AnyType; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.NumericType; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.QName; |
| import org.eclipse.wst.xml.xpath2.processor.internal.types.XSDouble; |
| |
| /** |
| * Returns the contiguous sequence of items in the value of $sourceSeq beginning |
| * at the position indicated by the value of $startingLoc and continuing for the |
| * number of items indicated by the value of $length. More specifically, returns |
| * the items in $sourceString whose position $p obeys: - fn:round($startingLoc) |
| * <= $p < fn:round($startingLoc) + fn:round($length) |
| */ |
| public class FnSubsequence extends Function { |
| |
| /** |
| * Constructor for FnSubsequence. |
| */ |
| public FnSubsequence() { |
| super(new QName("subsequence"), 2, 3); |
| } |
| |
| /** |
| * Evaluate arguments. |
| * |
| * @param args |
| * argument expressions. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of evaluation. |
| */ |
| public ResultSequence evaluate(Collection args, org.eclipse.wst.xml.xpath2.api.EvaluationContext ec) throws DynamicError { |
| return subsequence(args); |
| } |
| |
| /** |
| * Subsequence operation. |
| * |
| * @param args |
| * Result from the expressions evaluation. |
| * @throws DynamicError |
| * Dynamic error. |
| * @return Result of fn:subsequence operation. |
| */ |
| public static ResultSequence subsequence(Collection args) throws DynamicError { |
| ResultBuffer rs = new ResultBuffer(); |
| |
| // get args |
| Iterator citer = args.iterator(); |
| |
| ResultSequence seq = (ResultSequence) citer.next(); |
| if (seq.empty()) |
| return ResultBuffer.EMPTY; |
| |
| ResultSequence startLoc = (ResultSequence) citer.next(); |
| ResultSequence length = null; |
| if (citer.hasNext()) { |
| length = (ResultSequence) citer.next(); |
| } |
| |
| Item at = startLoc.first(); |
| if (!(at instanceof NumericType)) { |
| DynamicError.throw_type_error(); |
| } |
| |
| at = new XSDouble(at.getStringValue()); |
| |
| int start = (int) ((XSDouble) at).double_value(); |
| int effectiveNoItems = 0; // no of items beyond index >= 1 that are added to the result |
| |
| if (length != null) { |
| // the 3rd argument is present |
| if (length.size() != 1) |
| DynamicError.throw_type_error(); |
| at = length.first(); |
| if (!(at instanceof NumericType)) { |
| DynamicError.throw_type_error(); |
| } |
| at = new XSDouble(at.getStringValue()); |
| int len = (int) ((XSDouble) at).double_value(); |
| if (len < 0) { |
| DynamicError.throw_type_error(); |
| } |
| |
| if (start <= 0) { |
| effectiveNoItems = start + len - 1; |
| start = 1; |
| } |
| else { |
| effectiveNoItems = len; |
| } |
| } |
| else { |
| // 3rd argument is absent |
| if (start <= 0) { |
| start = 1; |
| effectiveNoItems = seq.size(); |
| } |
| else { |
| effectiveNoItems = seq.size() - start + 1; |
| } |
| } |
| |
| int pos = 1; // index running parallel to the iterator |
| int addedItems = 0; |
| if (effectiveNoItems > 0) { |
| for (Iterator seqIter = seq.iterator(); seqIter.hasNext();) { |
| at = (AnyType) seqIter.next(); |
| if (start <= pos && addedItems < effectiveNoItems) { |
| rs.add(at); |
| addedItems++; |
| } |
| pos++; |
| } |
| } |
| |
| return rs.getSequence(); |
| } |
| |
| } |