/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.bigdata.rdf.internal.constraints;
import java.util.Map;
import org.openrdf.model.Literal;
import org.openrdf.model.URI;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IValueExpression;
import com.bigdata.rdf.error.SparqlTypeErrorException;
import com.bigdata.rdf.internal.IV;
import com.bigdata.rdf.model.BigdataLiteral;
import com.bigdata.rdf.sparql.ast.GlobalAnnotations;
/**
* This function has an origin of ONE (1) not ZERO (0). The start and offset
* parameters are doubles and are ROUNDED using xpath:numeric-round to obtain
* the appropriate integer values. A negative or zero starting offset is treated
* as indicating the first character in the string, which is at index ONE (1).
* When the length parameter is not specified then it is assumed to be infinite.
*
* @see http://www.w3.org/TR/xpath-functions/#func-substring
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class SubstrBOp extends IVValueExpression<IV> implements INeedsMaterialization {
private static final long serialVersionUID = -7022953617164154412L;
@SuppressWarnings("rawtypes")
public SubstrBOp(//
final IValueExpression<? extends IV> x,
final IValueExpression<? extends IV> start,
final IValueExpression<? extends IV> length,
final GlobalAnnotations globals) {
this(new BOp[] { x, start, length }, anns(globals));
}
public SubstrBOp(BOp[] args, Map<String, Object> anns) {
super(args, anns);
if (args.length < 2 || args[0] == null || args[1] == null)
throw new IllegalArgumentException();
}
public SubstrBOp(SubstrBOp op) {
super(op);
}
@Override
public Requirement getRequirement() {
return Requirement.SOMETIMES;
}
@Override
@SuppressWarnings("rawtypes")
public IV get(final IBindingSet bs) throws SparqlTypeErrorException {
// The literal.
final Literal lit = getAndCheckLiteralValue(0, bs);
/*
* The starting offset for the substring.
*/
final IV startArg = get(1).get(bs);
// Negative values and zero are treated as ONE.
final int start = Math.max(1,
(int) Math.round(asLiteral(startArg).doubleValue()));
/*
* The length of the substring (optional argument).
*/
String label = lit.getLabel();
if (arity() > 2 && get(2) != null) {
/*
* substr(start,length)
*/
final IV lengthArg = get(2).get(bs);
final int length = Math.min(label.length(),
(int) Math.round(asLiteral(lengthArg).doubleValue()));
// final int length = (int) Math.round(literalValue(lengthArg).doubleValue());
label = label
.substring(start-1, Math.min(label.length(), start-1+length));
} else {
label = label.substring(start-1);
}
/*
* Generate appropriate literal.
*/
final String lang = lit.getLanguage();
final URI dt = lit.getDatatype();
if (lang != null) {
/*
* Language code literal.
*/
final BigdataLiteral str = getValueFactory().createLiteral(label,
lang);
return super.asIV(str, bs);
} else if (dt != null) {
/*
* Datatype literal.
*/
final BigdataLiteral str = getValueFactory().createLiteral(label,
dt);
return super.asIV(str, bs);
} else {
/*
* Return new simple literal using Literal.getLabel()
*/
final BigdataLiteral str = getValueFactory().createLiteral(label);
return super.asIV(str, bs);
}
}
}