I found a version that works. In the original version I must not have been using tail recursion correctly. Here is the version that works. Can anyone explain why the first version doesn't properly trigger tail recursion?

```

xquery version "3.1";

declare function local:get-random-numbers($how-many as xs:integer, $generator as map(*), $accumulator) {
if ($how-many ge 1) then
local:get-random-numbers($how-many - 1, $generator?next(), ($accumulator, $generator?number))
else
$accumulator
};

declare function local:get-random-numbers($how-many as xs:integer) {
local:get-random-numbers($how-many, random-number-generator(), ())
};

let $n := 2000
return
local:get-random-numbers($n) => count()

```

On Mon, May 11, 2020 at 5:20 PM Joe Wicentowski <joewiz@gmail.com> wrote:

Hi all,

I encountered a stack overflow error with the following code, which is designed to return as many random numbers as the user requests. BaseX's error suggested, "Try tail recursion?" I think I am already using tail recursion. Changing the $n variable from 1407 to 1406 or lower avoids the error. Any number 1407 or higher triggers the error.

Thank you for any hints!
Joe

```
xquery version "3.1";

declare function local:get-random-numbers($how-many as xs:integer, $generator as map(*)) {
if ($how-many ge 1) then
(
$generator?number,
local:get-random-numbers($how-many - 1, $generator?next())
)
else
()
};

declare function local:get-random-numbers($how-many as xs:integer) {
local:get-random-numbers($how-many, random-number-generator())
};

let $n := 1407
return
local:get-random-numbers($n) => count()
```