Clojurians Log v2

Let’s say I have datoms like this:

[{:edge/y 60 :db/id 1}
 {:edge/x 20 :db/id 2}
 {:edge/x 60 :db/id 3}
 {:edge/y 0 :db/id 4}]

And I want to merge edges all the edges that have the same y or the same x.

What’s the best way to express that as a query and transaction?

Also, there are entities that reference those db/id’s, so I need to replace those references with whatever the result is.

My first attempt is just pulling every edge:

'[:find ?id2 ?x
   :in $
  :where [?id1 :edge/x ?x]
  [?id2 :edge/x ?x]]

This query finds the right edges, but is more verbose than I expected:

'[:find ?id2 ?x1
                       :in $
                       :where
                       [?id1 :edge/x ?x1]
                       [?id2 :edge/x ?x2]
                       [(= ?x1 ?x2)]
                       [(!= ?id1 ?id2)]]

For the curious, this is where I’m landing for now:

(d/q '[:find ?id2 ?a ?v
                       :in $ [?id1 ...]
                       :where
                       [?id1 ?a ?v]
                       [?id2 ?a ?v]
                       [(!= ?id1 ?id2)]] @conn ids)

Even as a total novice, the Datalog way of doing things is soooooo nice for this stuff. It feels like the engine is doing all the code for me. Great work, all the contributors!