[rules-dev] rules-dev Digest, Vol 56, Issue 24

[Pierre]

Mats,

Thx for looking into this! I wonder if it wouldn't make more sense to have an automated way of marshaling the object model rather than have a dedicated compiler. Couldn't we find a nice and clean way to use a library like XStream on org.drools.rule.Rule and its like for instance?

Also, in Guvnor it's possible to export in XML so it might be relevant to see how it's done there (I still need to have a look at that myself).

All the best,
Pierre


On 8/25/2011 10:02 AM, rules-dev-request at lists.jboss.org wrote:
> Date: Wed, 24 Aug 2011 18:50:55 +0200
> From: Mats Erik Andersson<mats.andersson at gisladisker.se>
> Subject: [rules-dev] drools-compiler: Inconsistent test rules in DRL
> 	and in	XML.
> To:rules-dev at lists.jboss.org
> Message-ID:<20110824165055.GB3443 at mea.homelinux.org>
> Content-Type: text/plain; charset=us-ascii
>
> Dear all,
>
> I am working on the XML Schema (which needs repairing)
> and the XML formulated rules. In doing so I have stumbled
> across a discrepancy between the two rule formulations
>
>    drools-compiler/src/test/resources/org/drools/compiler/xml/\
>          rules/test_ParseRule.{drl,xml}
>
> which I dare claim to be in error, unless they are ment to
> express different rules!
>
>
> The left-hand side in "test_ParseRule.drl" expresses the logic
>
>     foo2 : Bar( ... )
>
>       # implicit AND
>
>     not( ... )
>
>       # implicit AND
>
>     foo3 : Bar( ... )
>
>       or
>
>     foo4 : Bar( ... )
>
>       or
>
>     foo5 : Bar( ... )
>
>       or
>
>     foo6 : Bar( ... )
>
>       or
>
>     Baz()
>
> Observe that foo3 up to foo6 and Baz are connected using OR connectives
> of constant precedence. Still, observing this, the expected counterpart
> test_ParseRule.xml of XML form expresses
>
>     <pattern identifier="foo2" ...>  ...</pattern>
>
>       <!-- implicit AND -->
>
>     <not>  ...</not>
>
>       <!-- implicit AND -->
>
>     <or-conditional-element>
>        <pattern identifier="foo3" ...>  ...</pattern>
>        <pattern identifier="foo4" ...>  ...</pattern>
>     </or-conditional.element>
>
>       <!-- implicit AND -->
>
>     <pattern identifier="foo5" ...>  ...</pattern>
>
>       <!-- implicit AND -->
>
>     <pattern identifier="foo6" ...>  ...</pattern>
>
>       <!-- implicit AND -->
>
>     <pattern identifier="foo7" ...>  ...</pattern>
>
>       <!-- implicit AND -->
>
>     <pattern object-type="Baz" />
>
> Hence foo5, foo6, foo6 and Baz have been ejected from the
> OR-clause stipulated in the DRL file, instead being part
> of the outer AND-clause.
>
> My expectation is that either DRL or XML file be generated
> after parsing from the other one, but the logical models
> being different, I conclude one of the files to be in error.
>
> Depending on hard-coded precedence model between AND and OR,
> the "or-conditional-element" should encompass only foo3,
> or the (the generally expected) all of "foo#". To single
> out only foo3 and foo4 contradicts the mathematical logic
> behind the contructs.
>
>
> Best regards,
>    Mats Andersson