Re: How is this code to create a stateful lazy sequence?

My version of distinct-by just took clojure.core/distinct and added a keyfn (and optional max-n). It's hard to claim this code is readable. I took this approach mostly because I knew it would be unlikely to be buggy, since it was a simple change or two from clojure.core/distinct (defn distinct-by

Re: How is this code to create a stateful lazy sequence?

Yes, I find that much clearer too. Thanks! On Saturday, July 22, 2017 at 4:50:23 PM UTC-4, tbc++ wrote: > > If we think about what we're doing here is a stateful filter, then maybe > we could leverage a few more core Clojure functions: > > > (defn distinct-by [f coll] > (let [seen (atom #{})]

Re: How is this code to create a stateful lazy sequence?

Perhaps you want to study the implementation in Medley, those are always very good quality: https://github.com/weavejester/medley/blob/254989ed3de83c30ce0101d66c7ce1b6ee257b4d/src/medley/core.cljc#L173 David -- You received this message because you are subscribed to the Google Groups "Clojure"

Re: How is this code to create a stateful lazy sequence?

If we think about what we're doing here is a stateful filter, then maybe we could leverage a few more core Clojure functions: (defn distinct-by [f coll] (let [seen (atom #{})] (filter (fn [itm] (let [m (f itm)] (when-not (@seen m) (swap!