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danieroux 2019-11-28T18:57:37.037200Z
(defn boring-location [a b]
(< (haversine a b) 5))
(defn dedupe-if
([f]
(fn [xf]
(let [prev (volatile! ::none)]
(fn
([] (xf))
([result] (xf result))
([result input]
(let [prior @prev]
(if (and (not= ::none prior) (f prior input))
result
(do
(vreset! prev input)
(xf result input)))))))))
([f coll] (sequence (dedupe-if f) coll)))
(defn remove-boring-locations [locations]
(dedupe-if boring-location locations))locations is a set of GPS coordinates. The intent is to dedupe when an adjacent GPS coordinate is less than 5km’s away.
2019-12-02T14:04:35.038300Z
do you want to recursively dedupe or just one pass?
2019-12-02T14:07:13.038500Z
you can use partitionand mapcat
2019-12-02T14:07:36.038700Z
(def r (range 1 10))
(->> r (partition 2 2)
(mapcat (fn [[a b]] ;;apply haversine here
(if ( < a 5) [a b] [b])))) 2019-12-02T14:08:49.039Z
but if [a b c d] are all close , this will generate [a c] or similar, not [a]
2019-12-03T14:37:52.039200Z
I would name f something more meaningful.
Except this, the function looks right.
2019-12-03T15:33:24.039500Z
I would also rename xf to rf