| /* SubstringFunction.java -- |
| Copyright (C) 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath 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; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.xml.xpath; |
| |
| import java.util.List; |
| import javax.xml.namespace.QName; |
| import org.w3c.dom.Node; |
| |
| /** |
| * The substring function returns the substring of the first argument |
| * starting at the position specified in the second argument with length |
| * specified in the third argument. For example, substring("12345",2,3) |
| * returns "234". If the third argument is not specified, it returns the |
| * substring starting at the position specified in the second argument and |
| * continuing to the end of the string. For example, substring("12345",2) |
| * returns "2345". |
| * |
| * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> |
| */ |
| final class SubstringFunction |
| extends Expr |
| { |
| |
| final Expr arg1; |
| final Expr arg2; |
| final Expr arg3; |
| |
| SubstringFunction(List args) |
| { |
| this((Expr) args.get(0), (Expr) args.get(1), |
| (args.size() > 2) ? (Expr) args.get(2) : null); |
| } |
| |
| SubstringFunction(Expr arg1, Expr arg2, Expr arg3) |
| { |
| this.arg1 = arg1; |
| this.arg2 = arg2; |
| this.arg3 = arg3; |
| } |
| |
| public Object evaluate(Node context, int pos, int len) |
| { |
| Object val1 = arg1.evaluate(context, pos, len); |
| Object val2 = arg2.evaluate(context, pos, len); |
| String s = _string(context, val1); |
| int p = Expr.intValue(val2) - 1; |
| if (p < 0) |
| p = 0; |
| |
| int l = s.length() - p; |
| if (l <= 0) |
| return ""; |
| |
| if (arg3 != null) |
| { |
| Object val3 = arg3.evaluate(context, pos, len); |
| int v3 = Expr.intValue(val3); |
| if (v3 < l) |
| l = v3; |
| } |
| |
| return s.substring(p, p + l); |
| } |
| |
| public Expr clone(Object context) |
| { |
| return new SubstringFunction(arg1.clone(context), arg2.clone(context), |
| (arg3 == null) ? null : arg3.clone(context)); |
| } |
| |
| public boolean references(QName var) |
| { |
| return (arg1.references(var) || arg2.references(var) || |
| (arg3 == null) ? false : arg3.references(var)); |
| } |
| |
| public String toString() |
| { |
| return (arg3 == null) ? "substring(" + arg1 + "," + arg2 + ")" : |
| "substring(" + arg1 + "," + arg2 + "," + arg3 + ")"; |
| } |
| |
| } |