/*
* @(#)$Id: StringJoin.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 xbird.xquery.XQueryException;
import xbird.xquery.dm.value.Item;
import xbird.xquery.dm.value.Sequence;
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:string-join($arg1 as xs:string*, $arg2 as xs:string) as xs:string.
* <DIV lang="en">
* Returns a xs:string created by concatenating the members of
* the $arg1 sequence using $arg2 as a separator.
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-string-join
*/
public final class StringJoin extends BuiltInFunction {
private static final long serialVersionUID = -5504148115942668416L;
public static final String SYMBOL = "fn:string-join";
public StringJoin() {
super(SYMBOL, StringType.STRING);
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] s = new FunctionSignature[1];
s[0] = new FunctionSignature(getName(), new Type[] { TypeRegistry.safeGet("xs:string*"),
StringType.STRING });
return s;
}
public Sequence eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv)
throws XQueryException {
assert (argv != null && argv.size() == 2);
final Item arg = argv.getItem(0);
if(arg.isEmpty()) {
// If the value of $arg1 is the empty sequence, the zero-length string is returned.
return XString.valueOf("");
}
final Item sep = argv.getItem(1);
final String separator = sep.stringValue();
final StringBuilder buf = new StringBuilder(256);
boolean first = true;
for(Item it : arg) {
if(first) {
first = false;
} else {
buf.append(separator);
}
assert (it instanceof XString);
buf.append(it.stringValue());
}
final String ret = buf.toString();
return XString.valueOf(ret);
}
}