Help writing rules about wongi-engine HOT 8 CLOSED

This could be the facts -

engine << [ "CompanyA", "offers", "serviceA" ]
engine << [ "CompanyB", "offers", "serviceB" ]
engine << [ "CompanyA", "offers", "serviceB" ]
engine << [ "CompanyB", "offers", "serviceC" ]
engine << [ "IncidentA", "requires", "serviceC" ]
engine << [ "IncidentA", "requires", "serviceA" ]

from wongi-engine.

One way of doing it:

q = engine.query( "demo" ) {
  search_on :Incident
  forall {
    has :Incident, "requires", :Service
    has :Company, "offers", :Service
  }
}

engine.execute "demo", Incident: "IncidentA"
q.tokens.each do |token|
  puts token[:Company]
end

from wongi-engine.

Or do you mean that a single company should satisfy all requirements?

from wongi-engine.

Thanks @ulfurinn. yes that's exactly it. It should satisfy all requirements i.e we need companies that offer all the services required by the Incident. Would love a pointer as to how I can do that :)

from wongi-engine.

In that case:

engine.query( "demo" ) {
  search_on :Incident
  forall {
    has :Incident, "requires", :Service
    has :Company, "offers", :Service
    none {
      has :Incident, "requires", :OtherService
      neg :Company, "offers", :OtherService
    }
  }
}

Translated back into English, "if a company offers one of the services, there do not exist any other services that are required but not offered by the same company".

from wongi-engine.

Wow. That's awesome man. Thanks for this 👍

from wongi-engine.

@ulfurinn I understand now how to write these rules. But I still cant understand how I can use Rails models in place of these strings (services, incidents & companies). Do I just use a string representation of the model - like service_#{service.id}?

Are there any best practices to load the facts into the engine? Initializing the engine in the app, etc.

from wongi-engine.

Any Ruby value with a sane implementation of operator == can be used inside fact triples, expect symbols with special meanings.

from wongi-engine.