goland tutorial rot13 reader

ro13.go

package main

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

type rot13Reader struct {
	r io.Reader
}

func (rot *rot13Reader) Read(b []byte) (n int, err error) {
	n, err = rot.r.Read(b)
	
	for i := range b {
		if ( (b[i] >= 'A' && b[i] <= 'M') || (b[i] >= 'a' && b[i] <= 'm') )  {
    		b[i] = b[i]+13 
		} else if ( (b[i] >= 'N' && b[i] <= 'Z') || (b[i] >= 'n' && b[i] <= 'z') ) {
			b[i] = b[i]-13
		}
	}
	return n, err
}

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