`clojure.core/hash-ordered-coll`¶

Type: function Added: Clojure 1.6 Examples: 2 Runnable: 0

([coll])

Returns the hash code, consistent with =, for an external ordered collection implementing Iterable. See http://clojure.org/data_structures#hash for full algorithms.

Examples¶

by svenschoenung on 2017-05-24 . May have evaluation errors.

;;;; Clojure's (hash-ordered-coll) produces the same hash code regardless
;;;; of collection type when both of the following two conditions are met:
;;;;   (1) collections contain the same elements
;;;;   (2) collection elements are ordered the same when returned by .iterator()

(hash-ordered-coll [1 2])
;;=> 156247261
(hash-ordered-coll '(1 2))
;;=> 156247261
(hash-ordered-coll (sorted-set 1 2))
;;=> 156247261
(hash-ordered-coll (doto (new java.util.ArrayList) (.add 1) (.add 2)))
;;=> 156247261
(hash-ordered-coll (doto (new java.util.TreeSet) (.add 1) (.add 2)))
;;=> 156247261

(hash-ordered-coll [2 1])
;;=> -1994590503
(hash-ordered-coll '(2 1))
;;=> -1994590503
(hash-ordered-coll (sorted-set-by > 2 1))
;;=> -1994590503
(hash-ordered-coll (doto (new java.util.ArrayList) (.add 2) (.add 1)))
;;=> -1994590503
(hash-ordered-coll (doto (new java.util.TreeSet >) (.add 2) (.add 1)))
;;=> -1994590503

;;;; Notice that this differs from (hash) which 
;;;;   (1) doesn't rely on element order as returned by .iterator()
;;;;   (2) falls back on Java's .hashCode() for non-Clojure collections

(hash [1 2])
;;=> 156247261
(hash '(1 2))
;;=> 156247261
(hash (sorted-set 1 2))
;;=> 460223544
(hash (sorted-set-by > 2 1))
;;=> 460223544
(hash (doto (new java.util.ArrayList) (.add 1) (.add 2)))
;;=> 994
(hash (doto (new java.util.TreeSet) (.add 1) (.add 2)))
;;=> 3

by svenschoenung on 2017-05-24 . May have evaluation errors.

clojure.core/hash-ordered-coll¶

Examples¶

See also¶

`clojure.core/hash-ordered-coll`¶