The DRL parser requires that the argument expression to a "from" CE be a function call or a chained call to methods. The work around to that is to call the MVEL "function" "return":

$items: LinkedList (size > 1) from collect ( Model ( ) from return( object.getOriginal(null) in spatialIndex.query(...) ) )

   This way, the parser will passthrough whatever he finds inside the return( ... ) to MVEL. Let us know if it works for you. I never tested that.

   []s
   Edson



2009/8/5 Simon Thum <simon.thum@gmx.de>
Edson Tirelli wrote:
>    Simon,
>
>    Can you show us what syntax are you trying?
Sure, I was just speculating it's known or trivial.

Works:
$items: LinkedList (size > 1) from collect ( Model ( ) from
spatialIndex.query(...) )

Fails:

$items: LinkedList (size > 1) from collect ( Model ( ) from
>object.getOriginal(null) in spatialIndex.query(...)< )

The angle brackets aren't typed, they just mark what's intended as mvel.

>
>    []s
>    Edson
>
> 2009/8/5 Simon Thum <simon.thum@gmx.de>
>
>> Hi all,
>>
>> I've stumbled on some mvel integration issues in 5.0.1. I'm using drools
>> to do, among others, spatial reasoning. At insertion time I maintain a
>> specialized index, which can be queried later using [collect] from. This
>> works fine in general.
>>
>> However, as soon as I use the mvel 2 projections a.k.a. 'in' keyword,
>> hell breaks loose. 'in' is described here:
>> http://mvel.codehaus.org/MVEL+2.0+Projections+and+Folds
>>
>> But I only seem to get syntax errors. If it is possible, to somehow
>> escape keywords or explicitly pipe through the mvel part, please let me
>> know!
>>
>> Needless to say, this feature would be great to have since my object
>> model is mainly fixed and 'is' allows me to compensate that. Worse, I'd
>> need to assert objects I don't want to assert to work around.
>>
>> I tried parenthesizing, only to discover that
>> ... from valid_stmt
>>
>> is fine, but
>>
>> ... from (valid_stmt)
>>
>> won't work either. Error 101, reason unknown, but it doesn't even make
>> it through the parser.
>>
>> I'd really appreciate to be given an idea why what I did went wrong.
>> Googling around didn't get me too far.
>>
>> Cheers,
>>
>> Simon
>> _______________________________________________
>> rules-users mailing list
>> rules-users@lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>
>
>
>
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--
 Edson Tirelli
 JBoss Drools Core Development
 JBoss by Red Hat @ www.jboss.com