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; Copyright (c) Rich Hickey and contributors.
; All rights reserved.
; The use and distribution terms for this software are covered by the
; Eclipse Public License 1.0 (
; which can be found in the file epl-v10.html at the root of this distribution.
; By using this software in any fashion, you are agreeing to be bound by
; the terms of this license.
; You must not remove this notice, or any other, from this software.
(ns alioth.reverse-complement)
(set! *warn-on-reflection* true)
(set! *unchecked-math* true)
(def from "ACBDGHK\nMNSRUTWVYacbdghkmnsrutwvy")
(def compl
"Byte-array based lookup for complement"
(fn [^bytes m [from to]]
(aset m (byte (int from)) (byte (int to)))
(byte-array 256)
(map vector from to)))
(defn revcomp
"Reverse and complement a in range begin (inclusive) - end (exclusive).
Updates in place."
[^bytes a ^long begin ^long end]
(when-not (= (int \>) (aget a begin))
(loop [begin begin
end (dec end)]
(let [bb (aget a begin)
be (aget a end)]
(= 10 bb) (recur (inc begin) end)
(= 10 be) (recur begin (inc end))
(<= begin end) (do
(aset a begin (aget ^bytes compl be))
(aset a end (aget ^bytes compl bb))
(recur (inc begin) (dec end))))))))
(defn with-each-line-rc
"Calls revcomp for each line in buf"
[^bytes buf]
(let [ct (count buf)]
(loop [i 0 j 0]
(if (<= ct j)
(when (> j (inc i))
(revcomp buf i j))
(if (= 10 (aget ^bytes buf j))
(when (> j (inc i))
(revcomp buf i j)
(recur (inc j) (inc j))))
(recur i (inc j)))))))
(defn -main [& args]
(let [buf (byte-array (.available System/in))]
(.read System/in buf)
(with-each-line-rc buf)
(.write System/out buf)))
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