clojure.core/bit-shift-left

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Type: function Added: Clojure 1.0 Examples: 2 Runnable: 2

([x n])

Bitwise shift left

Examples

by zmila on 2010-07-28 ▶

(bit-shift-left 1 10) 1024 (bit-shift-left 2r1101 2) ; fill rightmost bits with 0s 52 ;; 52 = 2r110100

by Claj on 2012-04-13 ▶

;;a bogus bit-array implementation (def ba (atom (long 0))) (defn set-ba "sets bit n in long atom ba" [n] (let [number-set (bit-shift-left 1 n) _ (println "number to set: " number-set) new-array (bit-or @ba number-set)] (reset! ba new-array))) (defn get-ba "gets bit n in long atom ba" [n] (not (zero? (bit-and (bit-shift-left 1 n) @ba)))) (comment (set-ba 0) ;; 0 [....0001] (set-ba 3) ;; 2^3 = 8 [....1001] (get-ba 0) ;; (bit-and ba 2^0) = 1 (get-ba 1) ;; (bit-and ba 2^1) = 0 (get-ba 3) ;; (bit-and ba 2^3) = 1 ;;but: (set-ba 65) ;; [....1011] ;;number to set: 2 ;;modulo because long has only 64 bit ;;also note that long always is two-complemented (signed) in java implementation )

See also

• clojure.core/bit-shift-left (2)
• clojure.core/unsigned-bit-shift-right (3)
• clojure.core/bit-shift-right (4)

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