/*
* @(#)$Id: Translate.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:translate($arg as xs:string?, $mapString as xs:string, $transString as xs:string) as xs:string.
* <DIV lang="en">
* Returns the value of $arg modified so that every character in the value of $arg
* that occurs at some position N in the value of $mapString has been replaced by
* the character that occurs at position N in the value of $transString.
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-translate
*/
public final class Translate extends BuiltInFunction {
private static final long serialVersionUID = -4608970269678484243L;
public static final String SYMBOL = "fn:translate";
/** high surrogate (0xD800-0xDBFF) */
private static final char[] HIGH_SURROGATE_RANGE = { 0xD800, 0xDBFF };
/** low surrogate (0xDC00-0xDFFF) */
private static final char[] IND_LOW_SURROGATE_RANGE = { 0xDC00, 0xDFFF };
public Translate() {
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, StringType.STRING });
return s;
}
public XString eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv)
throws XQueryException {
Item firstItem = argv.getItem(0);
if(firstItem.isEmpty()) {
// If the value of $arg is the empty sequence, the zero-length string is returned.
return XString.valueOf("");
}
Item secItem = argv.getItem(1);
Item thirdItem = argv.getItem(2);
String src = firstItem.stringValue();
String map = secItem.stringValue();
String trans = thirdItem.stringValue();
String translated = translate(src, map, trans);
return XString.valueOf(translated);
}
private static String translate(String src, String map, String trans) {
final int srclen = src.length();
final StringBuilder buf = new StringBuilder(srclen);
final int translen = trans.length();
for(int i = 0; i < srclen; i++) {
final char srcc = src.charAt(i);
final int cindex = map.indexOf(srcc);
if(cindex < translen) {
final char newchar = cindex < 0 ? srcc : trans.charAt(cindex);
if(srcc >= HIGH_SURROGATE_RANGE[0] && srcc <= HIGH_SURROGATE_RANGE[1]) {
assert (srclen >= i + 1);
final char lowChar = src.charAt(i + 1);
assert (lowChar >= HIGH_SURROGATE_RANGE[0] && lowChar <= HIGH_SURROGATE_RANGE[1]);
final int entity = (srclen - HIGH_SURROGATE_RANGE[0]) * 0x400
+ (lowChar - IND_LOW_SURROGATE_RANGE[0]) + 0x10000 /* BMP */;
buf.append(entity);
} else {
buf.append(newchar);
}
}
}
return buf.toString();
}
}