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Finished third koan

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Matt Davidson 2022-11-04 15:11:36 +00:00
parent d6eb655d9b
commit 86f57e71d4
1 changed files with 12 additions and 12 deletions
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24
src/koans/03_lists.clj
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@ -3,43 +3,43 @@
(meditations
"Lists can be expressed by function or a quoted form"
(= '(__ __ __ __ __) (list 1 2 3 4 5))
(= '(1 2 3 4 5) (list 1 2 3 4 5))
"They are Clojure seqs (sequences), so they allow access to the first"
(= __ (first '(1 2 3 4 5)))
(= 1 (first '(1 2 3 4 5)))
"As well as the rest"
(= __ (rest '(1 2 3 4 5)))
(= '(2 3 4 5) (rest '(1 2 3 4 5)))
"Count your blessings"
(= __ (count '(dracula dooku chocula)))
(= 3 (count '(dracula dooku chocula)))
"Before they are gone"
(= __ (count '()))
(= 0 (count '()))
"The rest, when nothing is left, is empty"
(= __ (rest '(100)))
(= () (rest '(100)))
"Construction by adding an element to the front is easy"
(= __ (cons :a '(:b :c :d :e)))
(= '(:a :b :c :d :e) (cons :a '(:b :c :d :e)))
"Conjoining an element to a list isn't hard either"
(= __ (conj '(:a :b :c :d) :e))
(= '(:e :a :b :c :d) (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)))
(= :a (peek '(:a :b :c :d :e)))
"Or the others"
(= __ (pop '(:a :b :c :d :e)))
(= '(:b :c :d :e) (pop '(:a :b :c :d :e)))
"But watch out if you try to pop nothing"
(= __ (try
(= "No dice!" (try
(pop '())
(catch IllegalStateException e
"No dice!")))
"The rest of nothing isn't so strict"
(= __ (try
(= '() (try
(rest '())
(catch IllegalStateException e
"No dice!"))))