A Tour of Go: Rot13 Reader

rot13_reader.go

package main

import (
  	"io"
	"os"
	"strings"
	)

type rot13Reader struct {
	r io.Reader
}

func (reader rot13Reader) Read(p []byte) (n int, err error){
	alf := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"	
	n,e := reader.r.Read(p)
	for i,b := range(p) {
		ru := rune(b)
		idx:=strings.IndexRune(alf,ru)
		if idx>0 {
			p[i] = alf[(idx+13)%len(alf)]
		}
	}	
    	return n,e
}

func main() {
	s := strings.NewReader("Lbh penpxrq gur pbqr!")
	r := rot13Reader{s}
	io.Copy(os.Stdout, &r)
}