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Diffstat (limited to 'libjava/gnu/xml/xpath/NumberFunction.java')
-rw-r--r-- | libjava/gnu/xml/xpath/NumberFunction.java | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/libjava/gnu/xml/xpath/NumberFunction.java b/libjava/gnu/xml/xpath/NumberFunction.java new file mode 100644 index 00000000000..94365338169 --- /dev/null +++ b/libjava/gnu/xml/xpath/NumberFunction.java @@ -0,0 +1,96 @@ +/* NumberFunction.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., 59 Temple Place, Suite 330, Boston, MA +02111-1307 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 org.w3c.dom.Node; + +/** + * The <code>number</code> function converts its argument to a number as + * follows: + * <ul> + * <li>a string that consists of optional whitespace followed by an optional + * minus sign followed by a Number followed by whitespace is converted to + * the IEEE 754 number that is nearest (according to the IEEE 754 + * round-to-nearest rule) to the mathematical value represented by the + * string; any other string is converted to NaN</li> + * <li>boolean true is converted to 1; boolean false is converted to 0</li> + * <li>a node-set is first converted to a string as if by a call to the + * string function and then converted in the same way as a string + * argument</li> + * <li>an object of a type other than the four basic types is converted to a + * number 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 NumberFunction + extends Expr +{ + + final Expr arg; + + NumberFunction(List args) + { + this(args.size() > 0 ? (Expr) args.get(0) : null); + } + + NumberFunction(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 new Double(_number(context, val)); + } + + public Expr clone(Object context) + { + return new NumberFunction(arg.clone(context)); + } + + public String toString() + { + return "number(" + arg + ")"; + } + +} |