[xquery-talk] flowrrr - how to structure a function?

[Peter]

Rob,

Without trying it, what you have written seems fine to me. You could inline
some things but it should, at least in theory, not make a difference

One thing to be aware of is that you have no guarantee (again in theory)
that the order in which function calls are evaluated match the order in
which you write them.

So theoretically an XQuery engine might choose to first evaluate 

session:set-attribute($project-key,
$group-name),response:redirect-to(xs:anyURI("./project/"))

before it evaluates the other function calls in the deepest return.

Hth,

Peter


> -----Original Message-----
> From: talk-bounces at x-query.com [mailto:talk-bounces at x-query.com] On Behalf
> Of Robert Koberg
> Sent: Tuesday, October 17, 2006 12:16 PM
> To: talk at x-query.com
> Subject: [xquery-talk] flowrrr - how to structure a function?
> 
> Hi, (I am a newbie)
> 
> Is it appropriate (necessary?) to nest return statements.
> 
> Is there a better way to write the function below? I only want to get
> the $db-ref string and $db-instance nodeset 'if the user is valid'.
> 
> -------------------------------
> declare function local:enter-project() as element()? {
>    let $is-valid := local:is-valid-user-for-group()
>    return
>      if ($is-valid) then
>        let $db-ref := request:get-parameter("db-ref", ""),
>            $db-instance := doc(databases.xml")/*/instance[@id=$db-ref]
>        return
>          (
>            session:set-attribute("rest-db-uri",
> fn:string($db-instance/rest-uri)),
>            session:set-attribute("xmlprc-db-uri",
> fn:string($db-instance/xmlprc-uri)),
>            session:set-attribute("webdav-db-uri",
> fn:string($db-instance/webdav-uri)),
>            session:set-attribute($project-key, $group-name),
>            response:redirect-to(xs:anyURI("./project/"))
>          )
>      else
>        <p class="warn">Could not find credentials to let you enter the
> project.</p>
> };
> 
> thanks,
> -Rob
> 
> 
> 
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