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