[rules-dev] drools-compiler: Inconsistent test rules in DRL and in XML.

[Mats Erik Andersson]

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