Clojurians Log v2

Is there a way to create rules without the defrule macro? I am currently pulling constraints out of a database and would like to make a bunch of rules based off of those. I noticed that the macro appears to just create a var?

(def
 do-it
 {:ns-name 'woof,
  :lhs '[{:type woof.Person, :constraints [(= name "me")]}],
  :rhs '(do (prn "99999")),
  :name "woof/do-it"})

My guess is that this is not adding that var to the clara-session?

@petr it is supported and you don’t even need vars

but you can use vars if that is convenient for you

if you do use vars, the question then becomes how is it “auto detected” via Clara’s default namespace scanning impl

and that is done via metadata

https://github.com/cerner/clara-rules/blob/0.21.0/src/main/clojure/clara/rules.cljc#L271-L305

@mikerod I would use vars or not. It just feels better than using a macro to generate defrules

this is what it does to scan built-in

so specifically for vars

if you have meta : :rule, :query, or :production-seq

it is treated as a rule container of some sort

:rule and :query are a single rule/query

:production-seq is a collection of rules/queries - aka “productions”

you don’t need macros

and you don’t need vars

if you have a more data-oriented case

mk-session takes collections of rule/query (aka production) structures

I'm open to really any approach here

well, you just have to choose what is best suited

Oh cool. so I could actually pass those "rule" maps to the mk-session?

vars are awkward to create if you’re doing it like at runtime

I agree

if you look at tests

https://github.com/cerner/clara-rules/blob/0.21.0/src/test/clojure/clara/test_rules.clj#L144

as example

you see they are almost all just based on passing rule/query maps in a collection to mk-session

so this is probably all you are really looking for

vars with metadata are basically just a convenience

for automatic rule/query detection in namespaces

which works better for cases where you are more statically writing rules via macros/DSL

Ohhh that looks useful, thank you for showing me that

no problem

I looked briefly on http://clara-rules.org and do not see any actual good documentation around “rule sources”

which I think could be improved

@mikerod thank you so much for that. This has made my day a lot easier

I think it’s lacking if we don’t include other major variants of how to load rules

We’ve taken special care in a lot of the clara stuff to make it where the DSL is optional

and to have the API accept other data-oriented options

Yeah, this is clearly very well thought out

just DSL + var/ns scan-loading is built-in for convenience and the typical, most easy examples