clojure.core/unchecked-dec

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Type: function Added: Clojure 1.0 Examples: 2 Runnable: 1

([x])

Returns a number one less than x, a long. Note - uses a primitive operator subject to overflow.

Examples

by boxie on 2010-11-08 ▶

(unchecked-dec 4) 3 (unchecked-dec Integer/MIN_VALUE) 2147483647

by svenschoenung on 2017-02-25 . May have evaluation errors. ▶

;; Illustrates the difference between (dec), (dec') and (unchecked-dec) ;; The "N" suffix denotes a BigInt instance ;; https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/BigInt.java Long/MIN_VALUE ;;=> -9223372036854775808 (dec Long/MIN_VALUE) ;;=> ArithmeticException integer overflow clojure.lang.Numbers.throwIntOverflow (Numbers.java:1501) (dec' Long/MIN_VALUE) ;;=> -9223372036854775809N ;; Notice how the resulting number becomes POSITIVE: (unchecked-dec Long/MIN_VALUE) ;;=> 9223372036854775807

See also

• clojure.core/unchecked-add
• clojure.core/unchecked-dec (1)
• clojure.core/unchecked-inc (1)
• clojure.core/unchecked-negate
• clojure.core/unchecked-divide
• clojure.core/unchecked-subtract
• clojure.core/unchecked-multiply
• clojure.core/unchecked-remainder
• clojure.core/dec
• clojure.core/dec' (1)

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