From c556fa9b7cd32fbb0b3a241c6f9ae434f18cb3bb Mon Sep 17 00:00:00 2001
From: Dan Buch <daniel.buch@gmail.com>
Date: Tue, 6 Nov 2012 07:35:11 -0500
Subject: [PATCH] Implementation of rot13 reader

Although I'm sure there's a fancier way to do the lookup table.
Hmmm...
---
 .../exercise-rot13-reader/main.go             | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 gotime/src/meatballhat.com/gotour-artifacts/exercise-rot13-reader/main.go

diff --git a/gotime/src/meatballhat.com/gotour-artifacts/exercise-rot13-reader/main.go b/gotime/src/meatballhat.com/gotour-artifacts/exercise-rot13-reader/main.go
new file mode 100644
index 0000000..0e477a1
--- /dev/null
+++ b/gotime/src/meatballhat.com/gotour-artifacts/exercise-rot13-reader/main.go
@@ -0,0 +1,97 @@
+package main
+
+import (
+    "fmt"
+    "io"
+    "os"
+    "strings"
+)
+
+var lookupTable = map[byte]byte{
+    'A': 'N',
+    'B': 'O',
+    'C': 'P',
+    'D': 'Q',
+    'E': 'R',
+    'F': 'S',
+    'G': 'T',
+    'H': 'U',
+    'I': 'V',
+    'J': 'W',
+    'K': 'X',
+    'L': 'Y',
+    'M': 'Z',
+    'N': 'A',
+    'O': 'B',
+    'P': 'C',
+    'Q': 'D',
+    'R': 'E',
+    'S': 'F',
+    'T': 'G',
+    'U': 'H',
+    'V': 'I',
+    'W': 'J',
+    'X': 'K',
+    'Y': 'L',
+    'Z': 'M',
+    'a': 'n',
+    'b': 'o',
+    'c': 'p',
+    'd': 'q',
+    'e': 'r',
+    'f': 's',
+    'g': 't',
+    'h': 'u',
+    'i': 'v',
+    'j': 'w',
+    'k': 'x',
+    'l': 'y',
+    'm': 'z',
+    'n': 'a',
+    'o': 'b',
+    'p': 'c',
+    'q': 'd',
+    'r': 'e',
+    's': 'f',
+    't': 'g',
+    'u': 'h',
+    'v': 'i',
+    'w': 'j',
+    'x': 'k',
+    'y': 'l',
+    'z': 'm',
+}
+
+type rot13Reader struct {
+    reader io.Reader
+}
+
+func (rot *rot13Reader) Read(p []byte) (i int, err error) {
+    if len(p) == 0 {
+        return 0, nil
+    }
+    buf := make([]byte, len(p))
+    i, err = rot.reader.Read(buf)
+
+    var (
+        b, c byte
+        found bool
+    )
+    for i := range buf {
+        b = buf[i]
+        c, found = lookupTable[b]
+        if found {
+            p[i] = c
+        } else {
+            p[i] = b
+        }
+    }
+    return
+}
+
+func main() {
+    s := strings.NewReader("Lbh penpxrq gur pbqr!")
+    r := rot13Reader{s}
+    io.Copy(os.Stdout, &r)
+    fmt.Println("")
+}