As discussed previously in
https://github.com/ztellman/immutable-int-map/pull/1
I note that the existing Seq implementation is not lazy, so i've just implemented a basic reverse iterator around this rather than walking the tree right-first - I was actually fairly surprised core clojure doesn't provide Reversible for ArrayLists already.
Patch taken from
https://github.com/glenjamin/data.int-map/tree/rseq attached, benchmarks below:
user=> (require '[clojure.data.benchmark :refer (entries)]
#_=> '[clojure.data.int-map :as i]
#_=> '[criterium.core :as c])
nil
user=>
user=> (let [m (into (i/int-map) entries)]
#_=> (println "seq")
#_=> (c/quick-bench (dorun (seq m)))
#_=> (println "rseq")
#_=> (c/quick-bench (dorun (rseq m))))
seq
WARNING: Final GC required 8.9263203426305 % of runtime
WARNING: Final GC required 48.03202811726098 % of runtime
Evaluation count : 12 in 6 samples of 2 calls.
Execution time mean : 75.794581 ms
Execution time std-deviation : 421.571821 µs
Execution time lower quantile : 75.476998 ms ( 2.5%)
Execution time upper quantile : 76.483561 ms (97.5%)
Overhead used : 2.127421 ns
Found 1 outliers in 6 samples (16.6667 %)
low-severe 1 (16.6667 %)
Variance from outliers : 13.8889 % Variance is moderately inflated by outliers
rseq
WARNING: Final GC required 54.64906330819225 % of runtime
Evaluation count : 6 in 6 samples of 1 calls.
Execution time mean : 101.840831 ms
Execution time std-deviation : 723.601456 µs
Execution time lower quantile : 100.881998 ms ( 2.5%)
Execution time upper quantile : 102.496873 ms (97.5%)
Overhead used : 2.127421 ns
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