[rules-users] Is there a "extends" for the "declare" of a new type?

[Wolfgang Laun]

I was following almost literally the example given in the "Drools
Introduction", Section 2.1.1.4., Type Declaration 'extends'.

It appears that Drools is very similar to
Eleusis<http://en.wikipedia.org/wiki/Eleusis_%28card_game%29>;-)

-W

2011/5/29 Mark Proctor <mproctor at codehaus.org>
>
> This is what's in the unit test "test_ExtLegacy.drl":
> declare BetterLegacy extends LegacyBean
>     // novel field
>     oneMoreField  : String = "Hello"
>
>     // inherited fields redeclared to set initial value
>     doubleField  : Double    = 3.3                @position(1)  // tag
inherited field, will be 1st field
>     strField : String = "XX"
>     intField : int = 245
>     prop : boolean = true
>     // objField is not redeclared
> end
>
> and this one "test_Extends.drl"
> declare Person
>     age  : int     = 99          @position(2)
>     name : String  = "john doe"  @key    @position(1)
> end
>
> declare Student extends Person
>     school : String @key   @position(3)
> end
>
>
> declare LongTermStudent extends Student
>     years : int @key @position(5)
>     course : String @position(4)
> end
>
>
> On 28/05/2011 18:22, Wolfgang Laun wrote:
>
> It doesn't work:
>
>    declare Customer extends Person
>
> is declined with
>
>    Cannot extend supertype 'date.cust.Person' (not a declared type)
>
> -W
>
> 2011/5/28 Edson Tirelli <ed.tirelli at gmail.com>
>>
>>    Wolfgang,
>>    I think Davide's implementation supports extending existing java
classes... did you tried? What is not possible is to implement interfaces,
since you can't define methods in the declare statement.
>>    Edson
>>
>> 2011/5/28 Wolfgang Laun <wolfgang.laun at gmail.com>
>>>
>>> There is, since 5.2.0, the option of extending a class declared in DRL:
>>>
>>> declare A
>>>    i : int
>>> end
>>>
>>> declare B extends A
>>>   ...
>>> end
>>>
>>> Any class origninating from Java code cannot be extended  in DRL.
>>>
>>> -W
>>>
>>>
>>> On 28 May 2011 10:56, Tomas Olsson <tol at sics.se> wrote:
>>>>
>>>> Hi,
>>>> I have tried to look this up but cannot find any clear answer on the
web.
>>>> Does drools support extension of existing classes for new type
declarations?
>>>> That would be very nice if this would be possible.
>>>>
>>>> /Tomas
>>>> _______________________________________________
>>>> 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
>>>
>>
>>
>>
>> --
>>   Edson Tirelli
>>   JBoss Drools Core Development
>>   JBoss by Red Hat @ www.jboss.com
>>
>> _______________________________________________
>> 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/20110529/a0dd0855/attachment.html