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ato/scratch.clj

Created November 30, 2009 09:57
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scratch.clj
(defn select-indices
"Given a sorted seq of indices return the items in coll at those positions."
([indices coll] (select-indices 0 indices coll))
([start indices coll]
(lazy-seq
(when-let [[i & is] (seq indices)]
(let [xs (drop (- i start) coll)]
(cons (first xs)
(select-indices i is xs)))))))
(select-indices [0 3 3 4] [:a :b :c :d :e :f :g])
;; -> (:a :d :d :e)
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