/*
* @(#)$Id: StringToCodepoint.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.*;
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.meta.IFocus;
import xbird.xquery.type.Type;
import xbird.xquery.type.TypeRegistry;
/**
* fn:string-to-codepoints($arg as xs:string?) as xs:integer*.
* <DIV lang="en">
* Returns the sequence of Unicode code points that constitute an xs:string.
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-string-to-codepoints
*/
public final class StringToCodepoint extends BuiltInFunction {
private static final long serialVersionUID = -6260437736207861399L;
public static final String SYMBOL = "fn:string-to-codepoints";
public StringToCodepoint() {
super(SYMBOL, TypeRegistry.safeGet("xs:integer*"));
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] s = new FunctionSignature[1];
s[0] = new FunctionSignature(getName(), new Type[] { TypeRegistry.safeGet("xs:string?") });
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()) {
return ValueSequence.EMPTY_SEQUENCE;
}
assert (firstItem instanceof XString);
final String arg = firstItem.stringValue();
return new CodepointEmuration(arg, dynEnv);
}
private static class CodepointEmuration extends AbstractSequence<XInteger> {
private final String _src;
CodepointEmuration(String src, DynamicContext dynEnv) {
super(dynEnv);
assert (src != null);
this._src = src;
}
public boolean next(IFocus focus) throws XQueryException {
int pos = focus.getContextPosition();
final int srclen = _src.length();
if(pos < srclen) {
int cp = _src.codePointAt(pos);
focus.setContextItem(XInteger.valueOf(cp));
return true;
} else {
return false;
}
}
public Type getType() {
return TypeRegistry.safeGet("xs:integer*");
}
@Override
public boolean isEmpty() {
return _src.length() > 0;
}
}
}