clojure-koans/src/koans/02_lists.clj
Colin Jones 04b3c4a960 Bump koan-engine dependency
Also eliminates some ns forms that we can do without now.

Closes #71
2014-05-02 16:39:13 -05:00

47 lines
1.1 KiB
Clojure

(ns koans.02-lists
(:require [koan-engine.core :refer :all]))
(meditations
"Lists can be expressed by function or a quoted form"
(= '(__ __ __ __ __) (list 1 2 3 4 5))
"They are Clojure seqs (sequences), so they allow access to the first"
(= __ (first '(1 2 3 4 5)))
"As well as the rest"
(= __ (rest '(1 2 3 4 5)))
"Count your blessings"
(= __ (count '(dracula dooku chocula)))
"Before they are gone"
(= __ (count '()))
"The rest, when nothing is left, is empty"
(= __ (rest '(100)))
"Construction by adding an element to the front is easy"
(= __ (cons :a '(:b :c :d :e)))
"Conjoining an element to a list isn't hard either"
(= __ (conj '(:a :b :c :d) :e))
"You can use a list like a stack to get the first element"
(= __ (peek '(:a :b :c :d :e)))
"Or the others"
(= __ (pop '(:a :b :c :d :e)))
"But watch out if you try to pop nothing"
(= __ (try
(pop '())
(catch IllegalStateException e
"No dice!")))
"The rest of nothing isn't so strict"
(= __ (try
(rest '())
(catch IllegalStateException e
"No dice!"))))