/*
* @(#)$Id: CodepointsToString.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.string;
import java.util.Iterator;
import xbird.util.xml.XMLUtils;
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.XInteger;
import xbird.xquery.dm.value.literal.XString;
import xbird.xquery.dm.value.sequence.ValueSequence;
import xbird.xquery.func.BuiltInFunction;
import xbird.xquery.func.FunctionSignature;
import xbird.xquery.meta.DynamicContext;
import xbird.xquery.type.Type;
import xbird.xquery.type.TypeRegistry;
import xbird.xquery.type.xs.StringType;
/**
* fn:codepoints-to-string($arg as xs:integer*) as xs:string.
* <DIV lang="en">
* Creates an xs:string from a sequence of Unicode code points.
* Returns the zero-length string if $arg is the empty sequence.
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-codepoints-to-string
*/
public final class CodepointsToString extends BuiltInFunction {
private static final long serialVersionUID = -8033267999983702537L;
public static final String SYMBOL = "fn:codepoints-to-string";
public CodepointsToString() {
super(SYMBOL, StringType.STRING);
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] s = new FunctionSignature[1];
s[0] = new FunctionSignature(getName(), new Type[] { TypeRegistry.safeGet("xs:integer*") });
return s;
}
public Sequence eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv) throws XQueryException {
assert (argv != null && argv.size() == 1);
Item firstItem = argv.getItem(0);
if(firstItem.isEmpty()) {
// Returns the zero-length string if $arg is the empty sequence.
return ValueSequence.EMPTY_SEQUENCE;
}
// If any of the code points in $arg is not a legal XML character,
// an error is raised [err:FOCH0001].
Iterator<? extends Item> argItor = firstItem.iterator();
assert (argItor.hasNext());
final StringBuilder buf = new StringBuilder(64);
while(argItor.hasNext()) {
Item it = argItor.next();
assert (it instanceof XInteger);
final int cp = (int) ((XInteger) it).getValue();
if(!XMLUtils.isValid(cp)) {
throw new DynamicError("err:FOCH0001", "Invalid XML char was detected: `" + cp
+ "`!");
}
final char[] chars = Character.toChars(cp);
buf.append(chars);
}
final String ret = buf.toString();
return XString.valueOf(ret);
}
}