Return to Answer

I used similar logic to the original, but made it simpler using modulus operation:

func (self rot13Reader) Read(p []byte) (n int, err error) {
 n, err = self.r.Read(p)
 for i,v := range p {
 switch {
 case v > 64 && v < 91:
 p[i] = (v - 64 + 13) % 26 + 64
 case v > 96 && v < 123:
 p[i] = (v - 96 + 13) % 26 + 96
 }
 }
 return
}

I used similar logic to the original, but made it simpler using modulus operation:

func (self rot13Reader) Read(p []byte) (n int, err error) {
 n, err = self.r.Read(p)
 for i,v := range p {
 switch {
 case v > 64 && v < 91:
 p[i] = (v - 65 + 13) % 26 + 65
 case v > 96 && v < 123:
 p[i] = (v - 97 + 13) % 26 + 97
 }
 }
 return
}