Assuming that the absence of any "transform" fact with a "source" slot
equal to the "id" slot of a new "source" fact is the criterion for
creating the "transform" facts:
(defrule makeTransforms
?s <- (source (id ?id)(templates $?templates))
(not (transform (source ?id)))
=>
(foreach ?temp $?templates
(assert (transform (source ?id) (template ?temp))))
)
kr
Wolfgang
Hal Hildebrand wrote:
I have a system where I need to ensure that for every member of a list,
there is a fact which contains that member. For example, here's my domain:
(deftemplate source (slot id) (multislot templates))
(deftemplate transform (slot source) (slot template))
What I would like is to write some rules that ensure that for ever member of
the templates slot of a "source", I have a corresponding transform. If I
assert:
(assert source (id 1) (templates (create$ a b c)))
I would like to see three facts asserted in response:
(assert transform (source 1) (template a))
(assert transform (source 1) (template b))
(assert transform (source 1) (template c))
I have accomplished this by creating an intermediary fact and some rules
which essentially cycle through the list of templates in the source,
asserting a transform for each. However, this just feels wrong. It seems
like I should be able to express this without the intermediary facts.
Perhaps this is where backward chaining would be useful? Or perhaps I can
use the new "accumulate" CE? Or, have I already found the solution using an
intermediary fact to cycle through the list of templates?
Any help/suggestions would be appreciated.
--------------------------------------------------------------------
To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]'
in the BODY of a message to [EMAIL PROTECTED], NOT to the list
(use your own address!) List problems? Notify [EMAIL PROTECTED]
--------------------------------------------------------------------
--------------------------------------------------------------------
To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]'
in the BODY of a message to [EMAIL PROTECTED], NOT to the list
(use your own address!) List problems? Notify [EMAIL PROTECTED]
--------------------------------------------------------------------
