random state and words generator

core.clj

(ns honeycomb.core
  (:gen-class)
  (:require [clojure.string :as string]
            [clojure.java.io :as io]))

;; this is basically an iterative approach, which avoids building up lazy sequences. there
;; would be almost no overhead here in terms of memory or objects

(defn -main-simple
  "Prints n random rows from given filenames. All command-line arguments are strings."
  [n-rows & filenames]
  (let [n (Integer/parseInt n-rows)
        ;; the use of memoize here means we won't read a repeated
        ;; filename more than once, so we can just map over the filenames
        datasets (map (memoize #(line-seq (io/reader %))) filenames)]
    (dotimes [_ n]
      (println (string/join "," (map rand-nth datasets)))))

;; this version uses more lazy sequences, which will not consume any extra memory either, but which
;; will be built up as they go

(defn -main-lazy
  "Prints n random rows from given filenames. All command-line arguments are strings."
  [n-rows & filenames]
  (let [n (Integer/parseInt n-rows)
        ;; the use of memoize here means we won't read a repeated
        ;; filename more than once, so we can just map over the filenames
        datasets (map (memoize #(line-seq (io/reader %))) filenames)
        ;; infinite lazy sequence of random data
        rows (repeatedly #(map rand-nth datasets))]
    (doseq [row (take n rows)]
      (println (string/join "," row)))))