第25回シェル芸勉強会 Q6 -- UTF-16LE

q6.scm

#!r6rs
;; 第25回シェル芸勉強会 Q6 -- UTF-16LE
;; http://qiita.com/nakataSyunsuke/items/339965853684dd11e755
(import (rnrs)
        (rnrs mutable-strings))

(define (transcoded-from-hexstring-port in)
  (define temporary (make-string 4))
  (define (read-cp)
    (let* ((h (get-string-n! in temporary 2 2))
           (l (get-string-n! in temporary 0 2)))
      (if (or (eof-object? h) (eof-object? l))
          (eof-object)
          (string->number temporary 16))))
  (define (read! str start count)
    (define cp)
    (do ((start start (+ start 1))
         (i 0 (+ i 1)))
        ((or (= i count) (begin (set! cp (read-cp)) (eof-object? cp))) i)
      (string-set! str start (integer->char cp))))
  (define (close) (close-port in))
  (make-custom-textual-input-port "hexstring->string" read! #f #f close))

(define (q6 str)
  (get-string-all
   (transcoded-from-hexstring-port (open-string-input-port str))))

(display (q6 "b730a730eb30b8820a00"))