clojure-koans/src/koans/20_partition.clj

(ns koans.20-partition
  (:require [koan-engine.core :refer :all]))

(meditations
  "To split a collection you can use the partition function"
  (= '((0 1) (2 3)) (__ 2 (range 4)))

  "But watch out if there are not enough elements to form n sequences"
  (= '(__) (partition 3 [:a :b :c :d :e]))

  "You can use partition-all to also get partitions with less than n elements"
  (= __ (partition-all 3 (range 5)))

  "If you need to, you can start each sequence with an offset"
  (= '((0 1 2) (5 6 7) (10 11 12)) (partition 3 __ (range 13)))

  "Consider padding the last sequence with some default values..."
  (= '((0 1 2) (3 4 5) (6 :hello)) (partition 3 3 [__] (range 7)))

  "... but notice that they will only pad up to the given sequence length"
  (= '((0 1 2) (3 4 5) __) (partition 3 3 [:these :are "my" "words"] (range 7))))