Here is an equivalent XSLT-based solution -- i both cases there is no
literal function defined -- just an inline one:

<xsl:stylesheet  version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xs">
  <xsl:output method="text"/>

  <xsl:template match="/">
     <xsl:sequence select=
       "let $f := function($n as xs:integer,
       $f1 as function(xs:integer) as xs:integer
       ) as xs:integer
       {if($n eq 0)
       then 1
       else $n * $f1($n -1, $f1)
       }
       return
       $f(5, $f)
       "/>
   </xsl:template>
 </xsl:stylesheet>

Again, the correct result is produced:

120


Cheers,
Dimitre

On Sat, Oct 13, 2012 at 12:37 PM, Dimitre Novatchev
<dnovatchev@xxxxxxxxx> wrote:
> You are right, but there is an easy workaround.
>
> Here is an example with an in-line factorial function:
>
>
> declare option saxon:output "omit-xml-declaration=yes";
> let $f := function($n as xs:integer,
>                                  $f1 as function(xs:integer) as xs:integer
>                                  ) as xs:integer
>               {if($n eq 0)
>                    then 1
>                    else $n * $f1($n -1, $f1)
>               }
>    return
>      $f(5, $f)
>
> The result we get is correct:
>
> 120
>
>
> Cheers,
> Dimitre
>
> On Sat, Oct 13, 2012 at 12:03 PM, Costello, Roger L. <costello@xxxxxxxxx> wrote:
>> Hi Folks,
>>
>> Is it possible to do recursion in an anonymous function?
>>
>> Example: I would like to implement an "until" function. It has three arguments:
>>
>> 1. p is a boolean function
>> 2. f is a function on x
>> 3. x is the value being processed
>>
>> Read the following function call as: decrement 3 until it is negative
>>       $until ($isNegative, $decrement, 3)
>>
>> where
>>       $isNegative := function($x as xs:integer) {$x lt 0}
>>       $decrement := function($x as xs:integer) {$x - 1}
>>
>> Here's how I attempted to implement function until:
>>
>> $until := function(
>>                                      $p as function(item()*) as xs:boolean,
>>                                      $f as function(item()*) as item()*,
>>                                      $x as item()*
>>                                 ) as item()*
>>                          {
>>                              if ($p($x)) then
>>                                    $x
>>                              else
>>                                    $until($p, $f, $f($x))  <-- RECURSE ...THIS IS NOT ALLOWED, I THINK
>>                            }
>>
>> Is there a way to implement function until in XPath 3.0? (I know how to implement it in XSLT 3.0)
>>
>> /Roger
>>
>
>
>
> --
> Cheers,
> Dimitre Novatchev
> ---------------------------------------
> Truly great madness cannot be achieved without significant intelligence.
> ---------------------------------------
> To invent, you need a good imagination and a pile of junk
> -------------------------------------
> Never fight an inanimate object
> -------------------------------------
> To avoid situations in which you might make mistakes may be the
> biggest mistake of all
> ------------------------------------
> Quality means doing it right when no one is looking.
> -------------------------------------
> You've achieved success in your field when you don't know whether what
> you're doing is work or play
> -------------------------------------
> Facts do not cease to exist because they are ignored.
> -------------------------------------
> Typing monkeys will write all Shakespeare's works in 200yrs.Will they
> write all patents, too? :)
> -------------------------------------
> I finally figured out the only reason to be alive is to enjoy it.



-- 
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.