/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-09 The eXist Team
*
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery.functions;
import org.exist.dom.QName;
import org.exist.util.XMLChar;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Constants;
import org.exist.xquery.Dependency;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.IntegerValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.ValueSequence;
public class FunStringToCodepoints extends BasicFunction {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("string-to-codepoints", Function.BUILTIN_FUNCTION_NS),
"Returns the sequence of unicode code points that constitute an xs:string. If $arg is a zero-length " +
"string or the empty sequence, the empty sequence is returned.",
new SequenceType[] {
new FunctionParameterSequenceType("arg", Type.STRING, Cardinality.ZERO_OR_ONE, "The input string"),
},
new FunctionReturnSequenceType(Type.INTEGER, Cardinality.ZERO_OR_MORE, "the sequence of code points"));
public FunStringToCodepoints(XQueryContext context) {
super(context, signature);
}
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
}
Sequence result;
if (args[0].isEmpty())
result = Sequence.EMPTY_SEQUENCE;
else {
result = getCodePoints(args[0].getStringValue());
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
/**
* The method <code>getCodePoints</code>
*
* @param s a <code>String</code> value
* @return a <code>ValueSequence</code> value
*/
public static ValueSequence getCodePoints(final String s) {
ValueSequence codepoints = new ValueSequence();
char ch;
IntegerValue next;
for (int i = 0; i < s.length(); i++) {
ch = s.charAt(i);
if (XMLChar.isSurrogate(ch)) {
int supp = XMLChar.supplemental(ch, s.charAt(++i));
next = new IntegerValue(supp);
} else {
next = new IntegerValue((int) ch);
}
codepoints.add(next);
}
return codepoints;
}
/** The method <code>getCodePointCount</code>
*
* @param s a <code>String</code> value
* @return a <code>ValueSequence</code> value
*/
public static int getCodePointCount(final String s) {
int count = 0;
char ch;
for (int i = 0; i < s.length(); i++) {
ch = s.charAt(i);
if (XMLChar.isSurrogate(ch)) {
i++;
}
count++;
}
return count;
}
/**
* The method <code>subSequence</code>
*
* @param seq a <code>ValueSequence</code> value
* @param start an <code>int</code> value
* @return a <code>ValueSequence</code> value
* @exception XPathException if an error occurs
*/
public static String subSequence(final ValueSequence seq, final int start)
throws XPathException {
StringBuilder substring = new StringBuilder(seq.getItemCount());
int ch;
try {
for (int i = start >= 0 ? start : 0; i < seq.getItemCount(); i++) {
ch = ((IntegerValue) seq.itemAt(i)).getInt();
if (XMLChar.isSupplemental(ch)) {
substring.append(XMLChar.highSurrogate(ch));
substring.append(XMLChar.lowSurrogate(ch));
} else {
substring.append((char) ch);
}
}
} catch (XPathException e) {
throw new XPathException("FunStringCodepoints.subSequence()/2 failure" + e.getMessage());
}
return substring.toString();
}
/**
* The method <code>subSequence</code>
*
* @param seq a <code>ValueSequence</code> value
* @param start an <code>int</code> value
* @param end an <code>int</code> value
* @return a <code>ValueSequence</code> value
* @exception XPathException if an error occurs
*/
public static String subSequence(final ValueSequence seq, final int start, final int end)
throws XPathException {
StringBuilder substring = new StringBuilder(seq.getItemCount());
int ch;
IntegerValue next;
if (seq.getItemCount() < end) {
return subSequence(seq, start);
}
try {
for (int i = start >= 0 ? start : 0; i < end; i++) {
ch = ((IntegerValue) seq.itemAt(i)).getInt();
if (XMLChar.isSupplemental(ch)) {
substring.append(XMLChar.highSurrogate(ch));
substring.append(XMLChar.lowSurrogate(ch));
} else {
substring.append((char) ch);
}
}
} catch (XPathException e) {
throw new XPathException("FunStringCodepoints.subSequence()/3 failure" + e.getMessage());
}
return substring.toString();
}
/**
* The method <code>codePointToString</code>
*
* @param value an <code>IntegerValue</code> value
* @return a <code>String</code> value
* @exception XPathException if an error occurs
*/
public static String codePointToString(final IntegerValue value)
throws XPathException {
StringBuilder string = new StringBuilder(2);
try {
int intValue = value.getInt();
if (XMLChar.isSupplemental(intValue)) {
string.append(XMLChar.highSurrogate(intValue));
string.append(XMLChar.lowSurrogate(intValue));
} else {
string.append((char) intValue);
}
} catch (XPathException e) {
throw new XPathException("FunStringCodepoints.codePointToString()/1 failure" + e.getMessage());
}
return string.toString();
}
/**
* The method <code>indexOf</code>
*
* @param seq a <code>ValueSequence</code> value
* @param value an <code>IntegerValue</code> value
* @return a <code>int</code> value
*/
public static int indexOf(final ValueSequence seq, final IntegerValue value) {
int index = Constants.STRING_NOT_FOUND;
char ch;
for (int i = 0; i < seq.getItemCount(); i++) {
if (value.compareTo(seq.itemAt(i)) == Constants.EQUAL) {
return i;
}
}
return index;
}
}