Data commit

Task/Caesar-cipher/Fantom/caesar-cipher.fantom

@@ -0,0 +1,52 @@
+class Main
+{
+  static Int shift (Int char, Int key)
+  {
+    newChar := char + key
+    if (char >= 'a' && char <= 'z')
+    {
+      if (newChar - 'a' < 0)   { newChar += 26 }
+      if (newChar - 'a' >= 26) { newChar -= 26 }
+    }
+    else if (char >= 'A' && char <= 'Z')
+    {
+      if (newChar - 'A' < 0)   { newChar += 26 }
+      if (newChar - 'A' >= 26) { newChar -= 26 }
+    }
+    else // not alphabetic, so keep as is
+    {
+      newChar = char
+    }
+    return newChar
+  }
+
+  static Str shiftStr (Str msg, Int key)
+  {
+    res := StrBuf()
+    msg.each { res.addChar (shift(it, key)) }
+    return res.toStr
+  }
+
+  static Str encode (Str msg, Int key)
+  {
+    return shiftStr (msg, key)
+  }
+
+  static Str decode (Str msg, Int key)
+  {
+    return shiftStr (msg, -key)
+  }
+
+  static Void main (Str[] args)
+  {
+    if (args.size == 2)
+    {
+      msg := args[0]
+      key := Int(args[1])
+
+      echo ("$msg with key $key")
+      echo ("Encode: ${encode(msg, key)}")
+      echo ("Decode: ${decode(encode(msg, key), key)}")
+    }
+  }
+}