package net.sf.saxon.functions;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.BooleanValue;
import net.sf.saxon.value.NumericValue;
/**
* This class implements the saxon:is-whole-number() extension function,
* which is specially-recognized by the system because calls are generated by the optimizer.
*
* <p>The function signature is <code>saxon:is-whole-number($arg as numeric?) as boolean</code></p>
*
* <p>The result is true if $arg is not empty and is equal to some integer.</p>
*/
public class IsWholeNumber extends SystemFunction {
/**
* Get the effective boolean value of the expression. This returns false if the value
* is the empty sequence, a zero-length string, a number equal to zero, or the boolean
* false. Otherwise it returns true.
*
* @param context The context in which the expression is to be evaluated
* @return the effective boolean value
* @throws net.sf.saxon.trans.XPathException
* if any dynamic error occurs evaluating the
* expression
*/
public boolean effectiveBooleanValue(XPathContext context) throws XPathException {
NumericValue val = (NumericValue)argument[0].evaluateItem(context);
return val != null && val.isWholeNumber();
}
/**
* Evaluate in a general context
*/
public Item evaluateItem(XPathContext context) throws XPathException {
return BooleanValue.get(effectiveBooleanValue(context));
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Contributor(s):
//