caesarCipher

$ scala
Welcome to Scala version 2.8.0.final (Java HotSpot(TM) Client VM, Java 1.6.0_16).
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scala> def caesarCipher(text:String, n: Int) = {
     |   val l = (' ' to '~').toList
     |   val ll = (l drop n) ::: (l take n)
     |   text map (l compose ll.zipWithIndex.toMap) mkString
     | }
caesarCipher: (text: String,n: Int)String

scala> caesarCipher("The quick brown fox jumps over the lazy dog", 3)
res0: String = Qeb|nrf`h|_oltk|clu|grjmp|lsbo|qeb|i^wv|ald

scala> caesarCipher("Qeb|nrf`h|_oltk|clu|grjmp|lsbo|qeb|i^wv|ald", (' ' to '~').toList.size-3)
res1: String = The quick brown fox jumps over the lazy dog

scala>