Indexing Sequences – Rich 4Clojure Problem 157 – See: https://github.com/PEZ/rich4clojure

rich4clojure_easy_problem_157.clj

(ns rich4clojure.easy.problem-157
  (:require [hyperfiddle.rcf :refer [tests]]))

;; = Indexing Sequences =
;; By 4Clojure user: jaycfields
;; Difficulty: Easy
;; Tags: [seqs]
;; 
;; Transform a sequence into a sequence of pairs
;; containing the original elements along with their
;; index.

(def __ :tests-will-fail)

(comment
  
  )

(tests
  (__ [:a :b :c]) := [[:a 0] [:b 1] [:c 2]]
  (__ [0 1 3]) := '((0 0) (1 1) (3 2))
  (__ [[:foo] {:bar :baz}]) := [[[:foo] 0] [{:bar :baz} 1]])

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

;; Post your solution below, please!

(defn pairs* [coll]
  (map (fn [a b] [a b]) coll (range)))

(def __ (fn [seq-in]
          (partition 2 (interleave seq-in (iterate inc 0)))))

Shush as blogscot wrote - range rather than (iterate inc 0) doh!

(def __ (fn [seq-in]
          (partition 2 (interleave seq-in (range)))))

(defn pairs* [coll]
  (map (fn [a b] [a b]) coll (range)))

Shush as blogscot wrote - range rather than (iterate inc 0) doh!

(def __ (fn [seq-in]
          (partition 2 (interleave seq-in (range)))))

(def __ (fn [s]
          (map vector s (range))))

(defn enumerate 
  "Transform a sequence into a sequence of pairs containing 
   the original elements along with their index."
  [coll]
  (map list coll (range)))