compress_js_hofs.rye

; Third set of solutions is inspired by Simon's Clojure solution.
; Clojure function Partition seems like made for this problem,
; so I added it to Ryelang.
; 
; (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")))

; using partition, map and join

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

; using partition and fold

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

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

; assertions

"AAAAABBCCC" .compress-a .assert-equal "5A2B3C"

"AAAABBBCCC" .compress-b .assert-equal "4A3B3C"

"AAAABBCCCC" .compress-c .assert-equal "4A2B4C"