fwf.clj

; In R language there’s a very cool function which allows you to read FWF files w/o a hassle:
; http://stat.ethz.ch/R-manual/R-patched/library/utils/html/read.fwf.html
; Following is a Clojure function to parse a line from a FWF file.

(defn fixed-width-format
    [s widths]
    (->> (reductions (fn [acc n] (+ acc (Math/abs n))) (cons 0 widths))
         (partition 2 1)
         (map (fn [[start end]] (subs s start end)))
         (keep-indexed (fn [idx e] (if (pos? (nth widths idx)) e)))))

(def line "14460   14484              Boston-Quincy, MA Metropolitan Division")
(fixed-width-format line [5 -3 5 -14 39])

; => ("14460" "14484" "Boston-Quincy, MA Metropolitan Division")