package org.basex.query.expr;
import org.basex.query.QueryContext;
import org.basex.query.QueryException;
import org.basex.query.item.AtomType;
import org.basex.query.item.Item;
import org.basex.query.item.Str;
import org.basex.util.InputInfo;
import org.basex.util.TokenBuilder;
/**
* StringConcat expression.
*
* @author BaseX Team 2005-12, BSD License
* @author Christian Gruen
*/
public final class Concat extends Arr {
/**
* Constructor.
* @param ii input info
* @param e expressions to be concatenated
*/
public Concat(final InputInfo ii, final Expr... e) {
super(ii, e);
}
@Override
public Expr comp(final QueryContext ctx) throws QueryException {
super.comp(ctx);
if(allAreValues()) return optPre(item(ctx, input), ctx);
type = AtomType.STR.seqType();
size = 1;
return this;
}
@Override
public Item item(final QueryContext ctx, final InputInfo ii)
throws QueryException {
final TokenBuilder tb = new TokenBuilder();
for(final Expr a : expr) {
final Item it = a.item(ctx, input);
if(it != null) tb.add(it.string(input));
}
return Str.get(tb.finish());
}
@Override
public String toString() {
return toString(" || ");
}
}