| /* StringFunction.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 <code>string function converts an object to a string as follows: |
| * <ul> |
| * <li>A node-set is converted to a string by returning the string-value of |
| * the node in the node-set that is first in document order. If the node-set |
| * is empty, an empty string is returned.</li> |
| * <li>A number is converted to a string as follows |
| * <ul> |
| * <li>NaN is converted to the string NaN</li> |
| * <li>positive zero is converted to the string 0</li> |
| * <li>negative zero is converted to the string 0</li> |
| * <li>positive infinity is converted to the string Infinity</li> |
| * <li>negative infinity is converted to the string -Infinity</li> |
| * <li>if the number is an integer, the number is represented in decimal |
| * form as a Number with no decimal point and no leading zeros, preceded by |
| * a minus sign (-) if the number is negative</li> |
| * <li>otherwise, the number is represented in decimal form as a Number |
| * including a decimal point with at least one digit before the decimal |
| * point and at least one digit after the decimal point, preceded by a minus |
| * sign (-) if the number is negative; there must be no leading zeros before |
| * the decimal point apart possibly from the one required digit immediately |
| * before the decimal point; beyond the one required digit after the decimal |
| * point there must be as many, but only as many, more digits as are needed |
| * to uniquely distinguish the number from all other IEEE 754 numeric |
| * values.</li> |
| * </ul> |
| * </li> |
| * <li>The boolean false value is converted to the string false. The boolean |
| * true value is converted to the string true.</li> |
| * <li>An object of a type other than the four basic types is converted to a |
| * string in a way that is dependent on that type.</li> |
| * </ul> |
| * If the argument is omitted, it defaults to a node-set with the context |
| * node as its only member. |
| * |
| * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> |
| */ |
| final class StringFunction |
| extends Expr |
| { |
| |
| final Expr arg; |
| |
| StringFunction(List args) |
| { |
| this(args.size() > 0 ? (Expr) args.get(0) : null); |
| } |
| |
| StringFunction(Expr arg) |
| { |
| this.arg = arg; |
| } |
| |
| public Object evaluate(Node context, int pos, int len) |
| { |
| Object val = (arg == null) ? null : arg.evaluate(context, pos, len); |
| return _string(context, val); |
| } |
| |
| public Expr clone(Object context) |
| { |
| return new StringFunction((arg == null) ? null : |
| arg.clone(context)); |
| } |
| |
| public boolean references(QName var) |
| { |
| return (arg == null) ? false : arg.references(var); |
| } |
| |
| public String toString() |
| { |
| return (arg == null) ? "string()" : "string(" + arg + ")"; |
| } |
| |
| } |