compress.clj

(ns clojpression-puzzle
  (:require [clojure.test :refer [is]]))

(def compress (partial transduce (comp (partition-by identity)
                                       (mapcat (fn [[c & _ :as cs]]
                                                 [(count cs) c])))
                                 str))

(defn run [& _]
  (is (= (compress "AAABBAAC") "3A2B2A1C")))

compress.rye.red

compress: fn1 { .partition { , } |map { :a .length .concat first a } |join }

"AAAABBCCC" .compress .assert-equal "4A2B3C"

compress2.rye.red

compress-a: fn1 { .partition { , } |fold 'acc "" { :a .length .concat first a |concat* acc } }

compress-b: fn1 { .partition { , } |fold 'acc "" { :a { acc length a  first a } .eval .join } }

"AAAABBCCC" .compress-a .assert-equal "4A2B3C"

"AAAABBCCC" .compress-b .assert-equal "4A2B3C"