(:**************************************************************:)
(: Test: functx-functx-is-a-number-all                                  :)
(: Written by: Priscilla Walmsley (Frans Englich is maintainer) :)
(: Date: 2008-05-16+02:00                                       :)
(:**************************************************************:)

declare namespace functx = "http://www.example.com/";
(:~
 : Whether a value is numeric 
 :
 : @author  Priscilla Walmsley, Datypic 
 : @version 1.0 
 : @see     http://www.xqueryfunctions.com/xq/functx_is-a-number.html 
 : @param   $value the value to test 
 :) 
declare function functx:is-a-number 
  ( $value as xs:anyAtomicType? )  as xs:boolean {
       
   string(number($value)) != 'NaN'
 } ;

let $in-xml := <in-xml>
   <a>123</a>
   <b>abc</b>
</in-xml>
return (functx:is-a-number('123'), functx:is-a-number(123), functx:is-a-number('  123  '), functx:is-a-number(''), functx:is-a-number('123abc'), functx:is-a-number('NaN'), functx:is-a-number($in-xml/a), functx:is-a-number($in-xml/b))