Clojure Destructuring Tutorial and Cheat Sheet

destructuring.md

Vectors

Syntax: [symbol another-symbol] ["value" "another-value"]

(def my-vector [:a :b :c :d])
(def my-nested-vector [:a :b :c :d [:x :y :z]])

(let [[a b c d] my-vector]
  (println a b c d))
;; => :a :b :c :d

(let [[a _ _ d [x y z]] my-nested-vector]
  (println a d x y z))
;; => :a :d :x :y :z

Hashmaps

Syntax: {symbol :key, another-symbol :another-key} {:key "value" :another-key "another-value"}

(def my-hashmap {:a "A" :b "B" :c "C" :d "D"}) (def my-nested-hashmap {:a "A" :b "B" :c "C" :d "D" :q {:x "X" :y "Y" :z "Z"}})

(let [{a :a d :d} my-hashmap] (println a d)) ;; => A D

(let [{a :a b :b {}}])

Default values for when a key is not in the map

Shortcuts

Vectors + Hashmaps + Vectors...

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Compojure