Create exercise-rot13Reader.go

exercise-rot13Reader.go

@@ -0,0 +1,36 @@
+import (
+	"io"
+	"os"
+	"strings"
+)
+
+type rot13Reader struct {
+	r io.Reader
+}
+
+// rot13 转换
+func rot13Tr(b byte) byte {
+	switch {
+	case ('A' <= b && b <= 'M') || ('a' <= b && b <= 'm'):
+		b += 13
+	case ('M' < b && b <= 'Z') || ('m' < b && b <= 'z'):
+		b -= 13
+	}
+	return b
+}
+
+func (r13 rot13Reader) Read(bytes []byte) (int, error) {
+	n, err := r13.r.Read(bytes)
+
+	for i := range bytes {
+		bytes[i] = rot13Tr(bytes[i])
+	}
+
+	return n, err
+}
+
+func main() {
+	s := strings.NewReader("Lbh penpxrq gur pbqr!")
+	r := rot13Reader{s}
+	io.Copy(os.Stdout, &r)
+}