March 2014 update

Task/Caesar-cipher/Scala/caesar-cipher-3.scala

@@ -0,0 +1,12 @@
+class Caeser(val key: Int) {
+  @annotation.tailrec
+  private def rotate(p: Int, s: IndexedSeq[Char]): IndexedSeq[Char] = if (p < 0) rotate(s.length + p, s) else s.drop(p) ++ s.take(p)
+
+  val uc = 'A' to 'Z'
+  val lc = 'a' to 'z'
+  val as = uc ++ lc
+  val bs = rotate(key, uc) ++ rotate(key, lc)
+
+  def encode(c: Char) = if (as.contains(c)) bs(as.indexOf(c)) else c
+  def decode(c: Char) = if (bs.contains(c)) as(bs.indexOf(c)) else c
+}