From 60a1cb67a0dd69870ae682a459755b8a79f9b256 Mon Sep 17 00:00:00 2001 From: Evan Mezeske Date: Sun, 20 May 2012 14:23:04 -0700 Subject: [PATCH] Add clojure.core/shuffle and a test. --- src/cljs/cljs/core.cljs | 7 +++++++ test/cljs/cljs/core_test.cljs | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/src/cljs/cljs/core.cljs b/src/cljs/cljs/core.cljs index cb86d9f..888030e 100644 --- a/src/cljs/cljs/core.cljs +++ b/src/cljs/cljs/core.cljs @@ -997,6 +997,13 @@ reduces them without incurring seq initialization" (recur nval (next coll)))) val)))) +(defn shuffle + "Return a random permutation of coll" + [coll] + (let [a (to-array coll)] + (garray/shuffle a) + (vec a))) + (defn reduce "f should be a function of 2 arguments. If val is not supplied, returns the result of applying f to the first 2 items in coll, then diff --git a/test/cljs/cljs/core_test.cljs b/test/cljs/cljs/core_test.cljs index 0f46da3..2ce5fb7 100644 --- a/test/cljs/cljs/core_test.cljs +++ b/test/cljs/cljs/core_test.cljs @@ -626,6 +626,13 @@ (assert (= ["a" [ 1 2] "foo"] (sort-by count ["foo" "a" [1 2]]))) (assert (= ["foo" [1 2] "a"] (sort-by count > ["foo" "a" [1 2]]))) + ;; shuffle + (let [coll [1 2 3 4 5 6 7 8 9 10] + ; while it is technically possible for this test to fail with a false negative, + ; it's _extraordinarily_ unlikely. + shuffles (filter #(not= coll %) (take 100 (iterate shuffle coll)))] + (assert (not (empty? shuffles)))) + ;; js->clj (assert (= {"a" 1, "b" 2} (js->clj (js* "{\"a\":1,\"b\":2}")))) (assert (= {"a" nil} (js->clj (js* "{\"a\":null}")))) -- 1.7.10.2