Count a Sequence – Rich 4Clojure Problem 22 – See: https://github.com/PEZ/rich4clojure

rich4clojure_easy_problem_022.clj

(ns rich4clojure.easy.problem-022
  (:require [hyperfiddle.rcf :refer [tests]]))

;; = Count a Sequence =
;; By 4Clojure user: dbyrne
;; Difficulty: Easy
;; Tags: [seqs core-functions]
;; 
;; Write a function which returns the total number of
;; elements in a sequence.

(def restricted [count])

(def __ :tests-will-fail)

(comment
  
  )

(tests
  (__ '(1 2 3 3 1)) := 5
  (__ "Hello World") := 11
  (__ [[1 2] [3 4] [5 6]]) := 3
  (__ '(13)) := 1
  (__ '(:a :b :c)) := 3)

;; To participate, fork:
;; https://github.com/PEZ/rich4clojure

;; Post your solution below, please!

(fn [s]
    (loop [ss s
           n 0]
      (if (empty? ss)
        n
        (recur (rest ss) (inc n)))))

#(count %)

#(reduce (fn [acc _] (inc acc)) 0 %)

(fn [sq] (last (for [ind (range)
                             :while (get (vec sq) ind)]
                       (inc ind)))))

(defn my-count [coll]
  (let [counter (fn [acc _val]
                  (inc acc))]
    (reduce counter 0 coll)))

(fn [coll] 
    (loop [x coll
           n 0]
      (if-not (seq x)
        n
        (recur (rest x) (+ n 1)))))

  (def __ #(apply + (for [_ %] 1)))