[rules-users] using complex evaluate expressions with DSL

[Wolfgang Laun]

Do you have any comments ("#..." or "//...") between when and then? If so,
please remove and try again.

If this doesn't fix it, please post completely and exactly
- the rule from the DSLR
- the full DSL
- Drools version.

Thanks
-W



2011/1/4 maverik j <maverikj348 at gmail.com>

>
>
> 2011/1/4 Wolfgang Laun <wolfgang.laun at gmail.com>
>
>
>>
>> 2011/1/4 maverik j <maverikj348 at gmail.com>
>>
>>  is there any restriction in terms of using custom function in condition
>>> etc.
>>> If I add function evaluation to conditions its messing up with dsl. For
>>> pattern matching if I use custom function defined in drl then its not able
>>> to parse that properly
>>>
>>> [when][] {attr:\S+} follows pattern {pattern:\S+} =
>>> funcToEvalPattern({attr},( {pattern} )
>>>
>>
>> Is this exactly what you have in the DSL definition? It's syntactically
>> incorrect.
>>
>
>
>>   Sorry for that, it is actually
>>
>
>
>>  [when][] {*attr*} follows pattern {pattern} = startsWithFunction( {*attr
>> *}, {pattern} )
>>>
>>>  and is being added as last statement in DSL (for testing purpose I am
>>> using same dsl as you have shown)
>>>
>>
>
>>   in this case it is getting translated to
>>> exists(Person:Person(subordinate != null , startsWithFunction( *eval*(
>>> name, "I" ) ) )
>>> where as I was hoping this to be
>>> exists(Person:Person(subordinate != null , *eval *(startsWithFunction(
>>> name, "I" ) ) )
>>>
>>>
>>
>> I cannot reproduce this. But it may depend on the order of your entries in
>> you DSL file.
>>
>> Actually I tried changing order as well but didnt worked. I have actually
> defined these common functions in drl and added that to knowledgebase along
> with these DSL and DSLR.
>
>
>
>>  -W
>>
>>
>>
>>> Regards,
>>> -Maverik
>>>
>>> On Tue, Jan 4, 2011 at 12:24 PM, maverik j <maverikj348 at gmail.com>wrote:
>>>
>>>> cool...this was of great help, I will try this out I think it shoudl
>>>> solve the purpose.
>>>>
>>>> Thanks once again,
>>>> Maverik
>>>>
>>>> 2011/1/3 Wolfgang Laun <wolfgang.laun at gmail.com>
>>>>
>>>> Try using eval as a last resort. A better (smaller, more robust) DSL can
>>>>> be designed around facts and their attributes.
>>>>>
>>>>> "||" (and "OR") can be used, but setting parentheses in order to get
>>>>> the priority right is difficult. In constraints, you may have to resort to
>>>>> "memberof" or "not memberof".
>>>>>
>>>>> Your sample isn't self-contained. But I think that the following DSL
>>>>> and the DSLR might give you some ideas how to proceed.
>>>>>
>>>>> [keyword][]check that {conditions}= eval( {conditions} )
>>>>> [keyword][]AND = &&
>>>>> [keyword][]OR  = ||
>>>>>
>>>>> [when][][Tt]here is an? {entity}= {entity}: {entity}()
>>>>> [when][][Tt]here is at least one {entity}= exists {entity}: {entity}()
>>>>>
>>>>> [when][]the {entity:\w+}'s {attr:\w+} = {entity}.get{attr}()
>>>>>
>>>>> [when][]- with a valid {attr} = {attr}: {attr} != null
>>>>> [when][]- with {attr} not equal to {value} = {attr} != {value}
>>>>> [when][]- eval\( {whatever} \)=eval( {whatever} )
>>>>>
>>>>> [when][] {attr:\S+} follows pattern {pattern:\S+} =  {attr}.matches(
>>>>> {pattern} )
>>>>> [when][] {attr:\S+} not equals? {value:\S+} = ! {attr}.equals( {value}
>>>>> )
>>>>> [when][] {attr:\S+} is valid  =  {attr} != null
>>>>>
>>>>> rule "Rule 5"
>>>>> when
>>>>>     There is a Department
>>>>>     There is at least one Person
>>>>>     - with name not equal to "xxx"
>>>>>     - with a valid subordinate
>>>>>     - check that the Person's Id is valid AND the Department's Id
>>>>> follows pattern "I" AND the Department's HeadOfDpt not equal name
>>>>> then
>>>>> end
>>>>>
>>>>> Notice that "-check that..." must be written as a single line.
>>>>>
>>>>> -W
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2011/1/3 maverik j <maverikj348 at gmail.com>
>>>>>
>>>>>>   Hi,
>>>>>>
>>>>>>  We are planning to use DSL/DSRL approach with generic DSL template
>>>>>> like say
>>>>>>
>>>>>> [condition][]The {object} has valid {field}={object}({field} != null )
>>>>>>
>>>>>> [condition][]there is object {*obj*} that = {*obj*}()
>>>>>>
>>>>>> [condition][]- has {*attr*} equal {*val*} = {*attr*} == {*val*}
>>>>>>
>>>>>> [condition][]- has valid {*attr*} = {*attr*} != null
>>>>>>
>>>>>> [condition][]- and has {*attr*} equal {value}= && {*attr*} == {value}
>>>>>>
>>>>>> But there are quite few of requirements like to have DSL rules that
>>>>>> can generate expression as follows:
>>>>>> exists Employee(
>>>>>>    attribute name not equals "xxx"
>>>>>>    && the attribute subOrdinate is not null
>>>>>>    && eval(
>>>>>>    the attribute $dept.getId() is not null
>>>>>>    && attribute $dept.getId() follows pattern "I"
>>>>>>    && ( ! (the attribute $dept.getHeadOfDpt() equals name)
>>>>>>    )
>>>>>> )
>>>>>>
>>>>>> I am not sure if this is possible with DSL. Using '-' operator we
>>>>>> cannot really add '&&', '||' conditions it by-default expands to ','
>>>>>> separated and conditions. And wirtting generic rules with and/or is not
>>>>>> really dynamic to allow any number of expressions in evaluation.
>>>>>>
>>>>>> i am struggling to get this run since long time so any help/thoughts
>>>>>> on this would be  highly appriciable !!!
>>>>>>
>>>>>> Thanks & Regards,
>>>>>> -Maverik
>>>>>>
>>>>>> _______________________________________________
>>>>>> rules-users mailing list
>>>>>> rules-users at lists.jboss.org
>>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> rules-users mailing list
>>>>> rules-users at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>>
>>>>>
>>>>
>>>
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110104/204c0494/attachment.html